nbl_a12114 fire water design

2

TABLE OF CONTENTS

1 INTRODUCTION .................................................................................................................3 2 SUMMARY AND CONCLUSIONS ....................................................................................3 3 MEASUREMENT PROGRAMME.....................................................................................4 4 MEASUREMENT TECHNIQUES AND UNCERTAINTY .............................................7

4.1 k-factor ..........................................................................................................................7 4.2 Area distribution...............................................................................................................8 4.3 Droplet sizes and velocities............................................................................................10 4.4 Droplet size terminology................................................................................................18 4.5 Droplet velocity..............................................................................................................18

5 CALCULATION OF DROPLET TRAJECTORIES ......................................................19 6 RESULTS .........................................................................................................................22

6.1 k-factor for the nozzles...................................................................................................22 6.2 Exit velocity ...................................................................................................................23 6.3 Droplet sizes measured by two institutes .......................................................................25 6.4 Individual nozzle characteristics ....................................................................................29

6.4.1 Nozzle HV K26...............................................................................................29 6.4.2 Nozzle HVK44................................................................................................37 6.4.3 Nozzle MVK18 ...............................................................................................45 6.4.4 Nozzle MVK41 ...............................................................................................49 6.4.5 Nozzle MVK59 ...............................................................................................54 6.4.6 Nozzle MVK80 ...............................................................................................56

7 EVALUATION ....................................................................................................................61 7.1 Measurement techniques ................................................................................................61 7.2 Differences between nozzles ..........................................................................................62

8 REFERENCES.....................................................................................................................65 9 APPENDIX A.1 NOZZLE HVK26 - 2,6 bar.....................................................................66 10 APPENDIX A.2 NOZZLE HVK 26 5,3 bar ...................................................................93 11 APPENDIX A.3 NOZZLE HVK44 4,9 bar ..................................................................119 12 APPENDIX A.4 NOZZLE MVK18 -2,6 BAR................................................................143 13 APPENDIX A.5 NOZZLE MVK80 -2,1 BAR.................................................................150 14 APPENDIX B: Drawing of ADD apparatus....................................................................158

3

1 INTRODUCTION Deluge nozzles have traditionally been characterised by the spray pattern and the exit velocity, and flow characteristics have been described by the k-factor. Design has been carried out to fulfil the requirements of area coverage, in most cases an application density over a certain area. Little information is available on the droplet sizes and the distribution of droplets in sprays, and when one wants to calculate the behaviour of water droplets in a fire zone or in the vicinity of a fire, the droplet size distribution is really important. In this report, several techniques and approaches to obtain the real droplet size and velocity distribution is used. At present, no single technique presents all the important features, but a combination of two techniques makes it possible to make a good estimate of flow-field, droplet sizes and velocities within a water spray.

2 SUMMARY AND CONCLUSIONS A comprehensive measurement programme to characterise sprays of water from deluge nozzles have been carried out. No method is available to measure all characteristics in one single operation. SINTEF has developed a method to quantify water application during fire, an Actual Delivered Density apparatus, (ADD apparatus). k-factor measurements (relation between nozzle pressure and water flow) have been carried out by different test set-up, including a standardised method. Two different laboratories (TelTek, Porsgrunn, Norway and IdF, Magdeburg, Germany) have been engaged to characterise droplet sizes and velocities. The measurement of k-factor shows minor variations between different laboratories and the manufacturers nominal k-factors are within the acceptance criteria of such measurements. The water application density is in one set of experiments measured by a special apparatus developed by SINTEF (ADD apparatus). The measurement technique allows measurement of Actual Delivered Density of water even during fire conditions, and is useful for research purpose. Used in an open space without any fire, some water is displaced by the airflow above the fixed surface, which leads to a discrepancy of maximum 20% between measured supply and collected water. This discrepancy is normal for this type of technique. Droplet size, velocity and area distribution for 5 deluge nozzles at different pressure have been examined. Two types of Laser Doppler and Phase Doppler anemometry have been used. The examined nozzles have been used in earlier medium-to-large-scale fire tests. The nozzle characteristics are used as input in simulation of the interaction of water droplet and fire development. The used measurement technique for droplet sizes gives a picture of deluge nozzles that produces a large amount of very small water droplets, in contrast to what is earlier reported. The reason for this discrepancy may be the better resolution of the measurement technique, but the presented results may also indicate uncertainties connected to the same technique.

4

3 MEASUREMENT PROGRAMME In the tests carried out to quantify the effect of deluge systems, two main types of nozzles have been used. These are High Velocity (HV) and Medium Velocity (MV) nozzles. The tested HV nozzles produce the water spray by break-up of the flow at the edge of the nozzle orifice, after creating a rotation inside the nozzle body. The MV nozzles are equipped with deflectors that break up the water stream from the orifice. The nozzles used in the former fire tests carried out by SINTEF /1, 2/ has been tested at two different laboratories for droplet characterisation. The two laboratories are Teltek, (Porsgrunn, Norway) /3/ and IdF Institut der Feuerwehr Sachsen-Anhalt, (Magdeburg, Germany) /4/. Water flow characteristics and area distribution have been measured by SINTEF. Table 1 shows the tested nozzles and under which conditions they have been tested. Table 1. Nozzle identification and test programme for droplet characterisation. SINTEF fire tests IdF droplet characterization Teltek droplet characterization

Nozzle id Pressure [bar] Nozzle id Pressure [bar]HV K26 2,6 5,3HV K44 2,4 3,5 4,9 5 8 N7 2,4 5 8MV K18 2,6MV K41 1,9 2,6 N1 2 7MV K59MV K80 2,1 2,5

Figure 1. The High-velocity nozzles HV K44 and HV K26 used in the tests.

5

Figure 2. The High-velocity nozzle HV K44 dismantled.

6

Figure 3. The Medium-velocity nozzles MV K18, MV K41, MV K59 and MV K80 used in the

tests. Table 2. Specifications of the nozzles used in the SINTEF tests.

SINTEF fire tests GW Sprinkler identification Bore diameter Spray angle Operating pressureNozzle id [mm] max minHV K26 Fyrhed type C 8 80-90 5 2,8HV K44 Fyrhed type D 10 60 6 2,8MV K18 Thermospray 6,3 ~60 3,5 1,4MV K41 Thermospray 8,5 90 3,5 1,4MV K59 Thermospray 11 ~120 3,5 1,4MV K80 Thermospray 12,4 ~135 3,5 1,4

7

4 MEASUREMENT TECHNIQUES AND UNCERTAINTY The characterisation of water spray nozzles is normally done by the correlation between flow rate and pressure (k-factor) and application density (litres/m2 min). In some cases, measurement of the area distribution of water is also carried out. However, when the interaction between water droplets and a fire plume is to be simulated by mathematical models, more information is needed. Ultimately, the volume distribution of droplets is what is needed to quantify the action of water in relation to fire. Figure 4 shows different aspects of a water spray used to characterise water distribution. The top two aspects are normally what are presented by nozzle manufacturers. k-factor Spray angle

Area distribution

Droplet velocitydistribution

Droplet sizedistribution

Volume distribution

Spacing

k-factor Spray angle

Area distribution

Droplet velocitydistribution

Droplet sizedistribution

Volume distribution

Spacing Figure 4. Different aspects of water sprays used to characterise water distribution. An overview of measurement techniques and an assessment of uncertainty connected to the different methods of characterisation are presented in this chapter.

4.1 k-factor The nozzle manufacturers characterise the nozzles by the k-factor. The correlation of flow through the nozzle and the pressure drop is characterised by the equation

pkQ =

The k in the equation is called the k-factor for nozzle, and has a dimension [litre/min bar1/2]. It represents the loss factor in hydraulic calculations, and for low flow velocities, the factor is quite insensitive to pressure differences. This holds for the type of nozzles used in normal deluge systems. The set-up for the measurements is described by ISO 6182-1:1993(E) /5/, which includes piping arrangement, measurement programme and presentation of measured data. The results of a k-factor measurement series then include a presentation of the variation of k-factor with pressure.

8

Measurement of k-factor has been carried out by IdF, Teltek and SINTEF. Only the SINTEF measurements were done according to a set-up like the ISO standard. Only single pressure measurements have been carried out. A sketch of this set-up is shown in Figure 5. Measurement uncertainty for the set-up at SINTEF is calculated to 0,6% for single point k-factor measurement.

4.2 Area distribution In the tests carried out during the first phase of the Deluge project /1/, different nozzles at different spacing and elevations were used to obtain a pre-described water application density. However, neither the application density nor the area distribution was available from manufacturers. A special apparatus for characterisation of area distribution of water from spray nozzles was designed and constructed by SINTEF. The apparatus consists of 10 concentric circular sectors with equal surface area. The apparatus is divided in two by a wall, making it possible to measure unsymmetrical distribution. The water supply through the nozzle is also measured by a flow meter and a pressure tap. The k-factors of the nozzles were measured with a setup similar to ISO 6182-1:1993(E). The principle of the ADD apparatus is to collect all the water of a spray at a surface area. The apparatus is water cooled and is constructed to be used in conjunction with a fire source, and to be able to measure the loss of water between the spray nozzle and the collector In the present tests the ADD apparatus is used to characterise area distribution of single nozzles, when no fire interacts with the spray and there is no loss due to evaporation of water. A check on the accuracy of measurements is then possible by comparing the flow measured at the nozzle and at the ADD apparatus. In practise, some loss of water occurs when a spray nozzle is mounted above the collector. Some droplets flow outside the outskirts of the tray and some of the water leaves as very small airborne droplets. The nozzles differ in spray angle, so the height between the nozzle and the collector was varied to match the spray pattern. The height is denoted H in Figure 5.

Figure 5. Measurements set-up for the area distribution of water from deluge nozzles. The

piping and pressure measurement of the k-factor measurements is indicated at the top left in the sketch.

9

Figure 6. The ADD apparatus for measurement of the area distribution of water from deluge

nozzles. Each segment of the collecting area has equal surface area. Tests were carried out with the different nozzles and pressures as described in Table1 and the water flow rate and pressure was measured in a set-up as indicated in Figure 5. Collection of water at a horizontal surface is a challenge, and the fraction of water that is lost during the measurement period is shown in Figure 7. The difference between applied and collected water is shown in percentage of applied water. It seems that for similar nozzles, the loss fraction is increasing with increasing pressure. This is coincident with a larger fraction of smaller droplets and higher exit velocity of the droplets.

ADD-apparatus measurements

0102030405060708090

100

26 26 44 44 44 18 41 41 59 80 80

2,6 5,2 2,7 4,9 7,8 2,6 1,9 2,6 2,5 2,1 2,5

Lost

wat

er [%

]

Figure 7. Lost water during ADD tests. The first number below each bar is the k-factor of

the nozzle, the second number is the pressure (bar).

10

4.3 Droplet sizes and velocities The droplets sizes measurement technique has developed over the last decennium, from different types of photographic methods to the laser Phase Doppler technique. The first presentations of droplet size distributions were based on a sampling technique where a glass plate covered with Glycerine was passed through a spray and then photographed. This technique certainly presented a photograph that might be studied and analysed, but it is thought that this sampling actually changed the droplet size distribution. The smaller droplets tended to agglomerate and hence disappear in the distribution. It is also believed that the larger droplets may have gone through the same process and formed larger droplets at the collection plate than in the spray. Later photographic techniques are based on high-speed film of droplets in a spray. One method based on automatic image analysis was recently published at the Third International Symposium on Water Mist, /6/. The advantage of this is that calibration with well-known mono-disperse particles is possible. The disadvantage is a problem with the illumination of a certain area of the spray and a time-consuming picture analysis connected to the early versions of the technique. The use of high-frequency light (stroboscope technique) has made it possible to analyse the velocity of droplets as well as the size distribution, but it has been a problem to define a precise plane that is illuminated. Laser light has reduced these problems, and auto-analysis of video pictures has also reduced the time consumption. The photographic techniques have its main limitation in the range of droplet sizes to be detected, as the resolution of the photographic film and especially TV screens is limited. In actual sprays the diameter variation may vary from less than 50 m up to several millimetres, which imposes a challenge to available systems. A laser-based photographic technique called Particle Image Velocimetry (PIV) measures the velocity vector of particles in a flow-field. This technique was checked out but discarded in this test programme, since the photographic resolution to be used for particle size measurement was too limited. The present most used technique to measure droplet size and droplet velocity of sprays is the Phase Doppler Anemometry, an extension of the Laser Doppler Anemometry. This technique is widely used to characterise droplet size distributions, but has its limitations and practical problems, /7/. Since the tested sprays have different spray angles, it was decided to carry out droplet characterisation at a fixed distance from the orifice. In all the tests at IdF and at Teltek, the distance was 1 m below the orifice. Figure 8 illustrates the problem that will occur if the data from the droplet size measurements is to be extrapolated to a new level. An assumption of droplet trajectory has to be made. The simplest form of extrapolation is to assume straight lines from the orifice to the new level, through the positions of the droplet measurements. This leaves out the gravity influence on the droplets. The further away this extrapolation is used, the larger error occurs.

11

Droplet size measurement

Actual Delivered Density Apparatus

Figure 8. Illustration of the principle of extrapolation of droplet size measurements to a different position.

The Phase Doppler Anemometry exhibits a new type of measurement technique, as it is based on the refraction of a laser beam inside a droplet. In this technique, droplets passing through a probe volume formed by the intersection of two laser beams scatter light which is imaged by a collection onto a pair of detectors. The droplets act as a lens which magnifies the fringe pattern formed by the intersecting laser beams. The detectors measure the magnified fringe spacing as a temporal phase shift, which is linearly dependent on droplet size. The strength of the system is that it is totally non-intrusive and the number of characterised droplets inside the probe volume is limited of measurement time only. If the measurement time is increased, the number of droplets may become statistically reliable. The uncertainty lies in the software; since some received signals from on burst is discarded because it does not fulfil the criteria of a signal from a recognisable droplet. The signal that is counted as a recognised droplet has to be in a range that is expected from a spherical droplet inside the probe volume. A number of signals are discarded because the software can not discriminate if it is a small droplet inside the probe volume or it is a large droplet in the outskirts of the volume. A droplet that is non-spherical may also be discarded. In the reports from IdF two sets of measurements are presented, one by the originally counted droplets and one Probe Volume Corrected (PVC) value. The in-built software of the measurement apparatus is not available for a user, and it is not possible to quantify the uncertainty of the total measurement technique. The test setup with the crossing laser beams as installed in the laboratory of IdF is shown in Figure 9.

12

Figure 9. Phase-Doppler Anemometry used for droplet size and velocity measurements in the

IdF laboratories, Magdeburg, Germany.

The droplet velocity is measured at the same position as the droplet sizes. Only the vertical component of the velocity is measured. At distances away from the nozzle opening this velocity component is more and more equal to the total velocity, as gravity forces the droplet into vertical direction. The data from the IdF measurements were presented in tables, as shown in Table 3 and 4. Table 3 gives the Original data, Table 4 gives the corrected PVC-data. The tables give information of: Nr: the test number at IdF, the coordinates of the measurement (x,y) in cm, d10, d20, d30,d32 which are the mean diameters (see Chapter 4.4 for explanation), v10 which is the mean vertical velocity, v_std which is the standard deviation of the mean velocity, vfd which is a Volume Flux Density, Rate which is the number of measured droplets, Zeit which is the time of measurement and finally, Druck which is the pressure (bar).

13

Even if the tables give numbers for volume flux density, number of droplets and time of measurement, no meaningful correlation is found when these numbers are presented. The reason for this is not fully explained, but the fact that not all droplets are measured explains the lack of correlation between droplet number, time of measurement and flow rate. If one should expect that the measurements would give an application density or a total flow rate, the technique should assure that all droplets within a certain are were measured. Table 3. The format of data tables as obtained from the IdF tests. The example is valid for

nozzle HV K26, with the original data. Tabelle: PDA-Messergebnisse (Originaldaten) fr die Dse HVK26 Nr. x y d10 d20 d30 d32 v10 v_std vfd Rate Zeit Druck90 0 0 103.3 132.7 167.4 266.3 6.6 1.9 0.019 111 219 2.6 91 10 0 150.7 178.7 209.6 288.5 4.0 2.0 0.023 63 124 2.6 92 20 0 185.6 210.4 234.7 292.0 3.2 1.7 0.026 48 113 2.6 93 30 0 226.5 251.0 272.3 320.7 3.0 1.6 0.019 23 98 2.6 94 40 0 281.5 302.5 320.5 359.6 3.1 1.6 0.018 12 90 2.6 95 50 0 286.4 306.4 323.7 361.1 3.0 1.6 0.019 10 88 2.6 96 60 0 281.4 304.2 324.6 369.5 3.2 1.7 0.011 7 91 2.6 97 -10 0 129.3 158.0 192.0 283.7 3.9 2.6 0.006 22 109 2.6 98 -20 0 159.8 181.0 204.2 259.9 3.1 1.5 0.009 23 91 2.6 99 -30 0 191.2 213.2 235.5 287.5 3.0 1.6 0.010 17 123 2.6 100 -40 0 230.2 251.7 272.4 319.0 3.0 1.5 0.010 12 97 2.6 102 -50 0 264.3 287.6 307.2 350.3 3.2 1.6 0.009 8 95 2.6 103 -60 0 184.9 221.5 253.0 330.0 2.1 1.2 0.010 16 98 2.6 104 0 0 110.9 142.3 179.3 284.6 6.6 1.9 0.018 85 116 2.6 105 0 10 119.7 154.6 194.0 305.6 6.9 2.1 0.018 65 100 2.6 106 0 20 120.3 156.1 194.5 301.9 7.4 2.1 0.017 66 94 2.6 107 0 30 156.5 191.2 225.6 314.0 5.3 2.1 0.026 63 97 2.6 108 0 40 226.9 260.2 288.7 355.4 4.7 2.3 0.031 35 92 2.6 109 0 50 286.8 313.9 336.8 387.6 4.2 2.0 0.020 13 90 2.6 110 0 60 329.1 350.8 368.7 407.3 3.5 1.5 0.010 5 102 2.6 111 0 -10 106.6 141.8 180.7 293.1 7.7 1.9 0.015 69 96 2.6 112 0 -20 136.7 168.8 204.6 300.7 6.4 2.1 0.017 51 94 2.6 113 0 -30 189.6 221.1 250.9 322.8 5.2 2.3 0.022 38 87 2.6 114 0 -40 236.7 266.8 293.7 355.9 4.6 2.2 0.019 19 90 2.6 115 0 -50 303.7 330.3 353.2 403.8 4.2 1.9 0.013 7 90 2.6 116 0 -60 359.4 375.9 390.2 420.7 3.8 1.7 0.006 2 74 2.6 117 0 0 104.3 132.3 163.5 250.0 10.0 2.9 0.032 204 114 5.3 118 10 0 128.7 158.7 191.0 276.7 6.1 2.9 0.041 157 113 5.3 119 20 0 142.0 167.3 193.5 258.9 4.6 2.4 0.037 134 89 5.3 120 30 0 175.7 199.2 221.3 273.4 3.9 2.2 0.039 89 101 5.3 121 40 0 219.7 240.0 259.7 304.3 3.6 2.1 0.032 37 96 5.3 122 50 0 256.5 275.0 291.9 328.9 3.5 2.0 0.025 19 176 5.3 123 60 0 292.9 308.4 321.9 350.7 3.4 1.7 0.016 8 87 5.3 124 -10 0 113.0 134.2 160.4 229.0 5.1 2.1 0.021 133 106 5.3 125 -20 0 136.8 154.3 173.8 220.7 4.3 1.7 0.022 105 75 5.3 126 -30 0 166.3 187.0 207.9 256.8 4.3 2.0 0.028 75 93 5.3

14

127 -40 0 210.2 231.7 251.0 294.5 3.8 2.1 0.038 47 89 5.3 128 -50 0 254.7 274.7 292.1 330.3 3.7 2.0 0.023 20 89 5.3 129 -60 0 160.3 195.1 227.6 310.0 2.2 1.5 0.016 33 90 5.3 130 0 10 124.7 154.3 185.9 269.9 9.7 3.5 0.031 130 92 5.3 131 0 20 124.4 154.8 187.6 275.4 8.3 3.4 0.035 145 92 5.3 132 0 30 161.1 189.5 218.4 290.1 7.4 3.2 0.040 99 94 5.3 133 0 40 223.8 251.1 277.0 336.9 6.1 2.9 0.048 53 92 5.3 135 0 60 338.3 357.1 373.5 408.6 4.3 2.1 0.010 5 93 5.3 136 0 50 294.4 317.3 337.0 380.0 4.9 2.3 0.030 19 93 5.3 137 0 -10 121.6 154.8 191.0 290.8 12.6 3.2 0.025 98 98 5.3 138 0 -20 128.2 158.5 189.4 270.6 8.8 3.1 0.032 127 91 5.3 139 0 -30 174.7 206.3 236.2 309.5 6.6 3.2 0.049 100 92 5.3 140 0 -40 248.6 279.5 305.3 364.5 5.4 2.7 0.034 32 77 5.3 141 0 -50 308.3 326.9 342.9 377.3 5.0 2.1 0.012 7 70 5.3 142 0 -60 335.9 358.5 376.8 416.5 4.3 2.3 0.004 2 74 5.3

Table 4. The format of data tables as obtained from the IdF tests. The example is valid for

nozzle HV K26, with the PVC values. Tabelle: PDA-Messergebnisse (PVC-Werte) fr die Dse HVK26 Nr. x y d10 d20 d30 d32 v10 v_std vfd Rate Zeit Druck90 0 0 68.4 88.7 117.1 204.1 6.6 1.9 0.028 111 219 2.6 91 10 0 103.4 126.9 154.6 229.7 4.0 2.0 0.036 63 124 2.6 92 20 0 129.7 154.4 179.5 242.7 3.2 1.7 0.045 48 113 2.6 93 30 0 157.8 188.9 216.3 283.7 3.0 1.6 0.031 23 98 2.6 94 40 0 208.0 239.4 265.2 325.2 3.1 1.6 0.029 12 90 2.6 95 50 0 222.0 243.9 262.6 304.2 3.0 1.6 0.045 10 88 2.6 96 60 0 208.8 240.3 267.1 330.2 3.2 1.7 0.017 7 91 2.6 97 -10 0 90.7 107.5 132.5 201.2 3.9 2.6 0.010 22 109 2.6 98 -20 0 120.3 135.1 152.8 195.5 3.1 1.5 0.019 23 91 2.6 99 -30 0 141.8 162.0 183.0 233.7 3.0 1.6 0.020 17 123 2.6 100 -40 0 169.9 197.0 221.5 280.2 3.0 1.5 0.017 12 97 2.6 102 -50 0 193.2 229.3 257.5 324.9 3.2 1.6 0.013 8 95 2.6 103 -60 0 119.8 158.7 195.3 295.7 2.1 1.2 0.013 16 98 2.6 104 0 0 74.8 96.9 127.6 221.4 6.6 1.9 0.025 85 116 2.6 105 0 10 78.6 102.4 135.3 236.5 6.9 2.1 0.025 65 100 2.6 106 0 20 79.4 106.7 141.4 248.2 7.4 2.1 0.023 66 94 2.6 107 0 30 105.2 138.5 173.6 273.0 5.3 2.1 0.035 63 97 2.6 108 0 40 157.4 198.7 234.3 325.6 4.7 2.3 0.041 35 92 2.6 109 0 50 211.3 251.5 283.4 360.0 4.2 2.0 0.027 13 90 2.6 110 0 60 264.5 301.8 328.5 389.0 3.5 1.5 0.013 5 102 2.6 111 0 -10 68.3 91.2 123.7 227.3 7.7 1.9 0.021 69 96 2.6 112 0 -20 92.0 115.7 146.4 234.8 6.4 2.1 0.025 51 94 2.6 113 0 -30 129.7 164.1 197.3 285.2 5.2 2.3 0.031 38 87 2.6 114 0 -40 168.8 206.8 239.9 323.0 4.6 2.2 0.026 19 90 2.6 115 0 -50 224.1 264.6 296.8 373.6 4.2 1.9 0.018 7 90 2.6 116 0 -60 305.0 333.2 354.5 401.2 3.8 1.7 0.009 2 74 2.6

15

117 0 0 70.0 90.8 118.0 199.4 10.0 2.9 0.047 204 114 5.3 118 10 0 84.7 108.8 138.2 222.8 6.1 2.9 0.061 157 113 5.3 119 20 0 96.6 120.3 146.2 215.9 4.6 2.4 0.058 134 89 5.3 120 30 0 121.2 147.4 172.4 236.0 3.9 2.2 0.063 89 101 5.3 121 40 0 170.3 187.6 204.6 243.3 3.6 2.1 0.082 37 96 5.3 122 50 0 203.3 220.4 236.2 271.1 3.5 2.0 0.067 19 176 5.3 123 60 0 240.4 255.4 268.6 297.0 3.4 1.7 0.049 8 87 5.3 124 -10 0 81.9 96.8 116.9 170.6 5.1 2.1 0.038 133 106 5.3 125 -20 0 102.2 117.4 134.6 177.1 4.3 1.7 0.044 105 75 5.3 126 -30 0 119.6 139.7 160.6 212.4 4.3 2.0 0.052 75 93 5.3 127 -40 0 163.8 181.5 197.8 234.8 3.8 2.1 0.115 47 89 5.3 128 -50 0 188.6 214.9 237.8 291.1 3.7 2.0 0.041 20 89 5.3 129 -60 0 101.0 128.8 160.8 250.6 2.2 1.5 0.024 33 90 5.3 130 0 10 83.5 106.5 135.1 217.3 9.7 3.5 0.046 130 92 5.3 131 0 20 83.0 106.2 135.5 220.6 8.3 3.4 0.052 145 92 5.3 132 0 30 112.3 138.0 166.6 243.0 7.4 3.2 0.060 99 94 5.3 133 0 40 156.8 186.2 215.2 287.6 6.1 2.9 0.075 53 92 5.3 135 0 60 277.8 310.3 334.2 387.6 4.3 2.1 0.014 5 93 5.3 136 0 50 226.4 261.8 289.6 354.2 4.9 2.3 0.042 19 93 5.3 137 0 -10 80.5 104.4 135.9 230.3 12.6 3.2 0.036 98 98 5.3 138 0 -20 83.9 108.6 137.9 222.4 8.8 3.1 0.047 127 91 5.3 139 0 -30 117.6 150.1 182.6 270.4 6.6 3.2 0.069 100 92 5.3 140 0 -40 177.8 219.4 253.3 337.7 5.4 2.7 0.045 32 77 5.3 141 0 -50 255.7 285.3 307.7 357.9 5.0 2.1 0.016 7 70 5.3 142 0 -60 253.3 293.4 321.7 386.6 4.3 2.3 0.006 2 74 5.3

The measured data from each test run was captured and saved by special routine defined by SINTEF. An example of the data is shown in Table 5. Only original data were captured this way, which means that numbers are as detected during the test. No Probe Volume Correction was applied during the measurement time. This correction was done after the test run, with no possibility of capturing the total amount of data. The data in Table 5 makes it possible to present the full detailed graphs of droplet size distribution needed for simulation. Accumulated volume diameter, which is the basis for calculation of the Median Volume Diameter, is also shown in Figure 10.

16

Table 5 . The format of data tables as specified by SINTEF. The example is valid for nozzle

HV K26 with original data. Only data for the first position (test 90, position x=0, y=0 and the first four data points at position (in cm) x=10, y=0, is shown.

PDA-Messergebnisse(Originaldaten), Hufigkeiten mit Klasseneinteilung

Nozzle Test No

x y Class No

Lower cliameter

[micrometer]

Upper class diameter

[micrometer]

Number of droplets

HVK26 90 0 0 1 0 20 0 HVK26 90 0 0 2 20 40 3489 HVK26 90 0 0 3 40 60 4499 HVK26 90 0 0 4 60 80 4211 HVK26 90 0 0 5 80 100 3358 HVK26 90 0 0 6 100 120 2522 HVK26 90 0 0 7 120 140 1725 HVK26 90 0 0 8 140 160 1051 HVK26 90 0 0 9 160 180 672 HVK26 90 0 0 10 180 200 499 HVK26 90 0 0 11 200 220 349 HVK26 90 0 0 12 220 240 309 HVK26 90 0 0 13 240 260 258 HVK26 90 0 0 14 260 280 203 HVK26 90 0 0 15 280 300 159 HVK26 90 0 0 16 300 320 164 HVK26 90 0 0 17 320 340 126 HVK26 90 0 0 18 340 360 121 HVK26 90 0 0 19 360 380 134 HVK26 90 0 0 20 380 400 81 HVK26 90 0 0 21 400 420 90 HVK26 90 0 0 22 420 440 62 HVK26 90 0 0 23 440 460 65 HVK26 90 0 0 24 460 480 48 HVK26 90 0 0 25 480 500 41 HVK26 90 0 0 26 500 520 27 HVK26 90 0 0 27 520 540 18 HVK26 90 0 0 28 540 560 14 HVK26 90 0 0 29 560 580 6 HVK26 90 0 0 30 580 600 12 HVK26 90 0 0 31 600 620 12 HVK26 90 0 0 32 620 640 8 HVK26 90 0 0 33 640 660 1 HVK26 90 0 0 34 660 680 2 HVK26 90 0 0 35 680 700 0 HVK26 90 0 0 36 700 720 5 HVK26 90 0 0 37 720 740 1 HVK26 90 0 0 38 740 760 1 HVK26 90 0 0 39 760 780 0 HVK26 91 10 0 1 0 20 0 HVK26 91 10 0 2 20 40 381 HVK26 91 10 0 3 40 60 593 HVK26 91 10 0 4 60 80 674

17

Volume mean diameter for position 167Volume median diameter for position 358

X= 0 Y= 0

HVK 26 2,6 bar 90

0

5

10

15

20

20 80 140 200 260 320 380 440 500 560 620 680 740 0 0 0 0 0 0 0

Upper class diameter [micrometer]

Frac

tion

num

ber [

%]

HVK 26 2,6 bar 90

01234567

20 80 140 200 260 320 380 440 500 560 620 680 740 0 0 0 0 0 0 0


Frac

tion

volu

me

[%]

HVK 26 2,6 bar 90

0102030405060708090

100

0 100 200 300 400 500 600 700 800 900

Mean class diameter

Acc

umul

ated

vol

ume

[%]

Figure 10. Example of the full detailed droplet size distribution at one single position (x=0,

y=0) of nozzle HVK26, 2,6 bar. The graphs are based on original data from IdF. All detailed information of droplet distribution is presented in Appendixes to this report, and is available as Excel spreadsheets by SINTEF.

18

4.4 Droplet size terminology From the droplet size distribution, the linear (arithmetic) mean diameter, the surface area mean diameter and the volume mean diameter are calculated, respectively by:

N is the number of measured droplets. In the characterisation of water spray properties, the volume mean diameter is frequently used. As a measure of a water spray, the volume median diameter, which represents a diameter of which half of the mass or volume of the spray, has a diameter that is smaller than that diameter, is frequently used.

4.5 Droplet velocity Droplet velocities are also available as Excel spreadsheets, and an example of such measurements is shown in Figure 11. One can see that the velocities close to the centre show some dependency of exit pressure, but further away from the centre, the velocities are more similar. One anomaly is the high velocity measured at the outskirts of the spray, with a velocity well above the maximum velocity at the centre. No explanation exists for such anomaly, but they occur for all nozzles.

Velocities of HVK26

02468

101214

0 100 200 300 400 500 600 700

Distance from centre [mm]

m/s

2,6 5,3Pressure [bar]

Figure 11. Example of vertical velocities measured at various distances from the spray centre, for nozzle HVK26, 2,6 and 5,3 bar.

19

5 CALCULATION OF DROPLET TRAJECTORIES The equation of droplet velocity in a gravity field is governed by the drag force and the gravity term. This is shown in the equation :

gmVVVVACdt

dV m dgdgdgdd

dd += )(2

1 where md : mass of droplet Vd : velocity of droplet dt : time increment Cd : drag coefficient Ad : projected area of droplet g : density of gas Vg : velocity of gas g : acceleration of gravity g : dynamic viscosity of gas The drag coefficient can be expressed by the Reynolds number as shown in the equation:

)Re15.01(Re24 687,0+=d

C

g

dgdg DVV

=Re

Calculations have been carried out for droplets leaving an orifice vertically downwards, to illustrate the time before terminal velocity is reached. This is shown for 25 and 10 m/s in Figure 12 and 13, respectively.

20

Droplet velocity vs time

0

5

10

15

20

25

30

0 0,1 0,2 0,3 0,4 0,5 0,6

Time [s]

Dro

plet

vel

ocity

,dow

nwar

ds[m

/s]

2503005007009001100

Diameter (micrometer)

Figure 12. Velocity of droplets with different diameter as a function of time. The exit velocity

vertically downwards is 25 m/s. One can see that the velocity is reduced significantly within fractions of a second. The smallest droplets looses their initial velocity almost immediately. Figure 14 shows the travel distance of droplets of different diameters when drag and gravity works. A droplet of 1100 m (1,1 mm) travels about 4 m within the first second, and a smaller droplet, with diameter 200 m travels less than 1 m within the first second. To quantify the density of water in a specified volume, one has to consider the supply of droplets, the different travel patterns and time and finally the droplets that are hitting surfaces, either the floor, walls or other objects. The flow inside a volume, either induced by ventilation, wind or a fire, or induced by the spray nozzles themselves introduces more complex travel patterns than gravity-driven transport only, and this also have to be considered.

21

Droplet velocity vs time

0

2

4

6

8

10

12

0 0,2 0,4 0,6 0,8 1 1,2 1,4

Time [s]

Dro

plet

vel

ocity

,dow

nwar

ds[m

/s]

1502002503005007009001100


Figure 13. Velocity of droplets with different diameter as a function of time. The exit velocity

vertically downwards is 10 m/s.

Travel distance of droplet

0,00

2,00

4,00

6,00

8,00

10,00

0 0,5 1 1,5 2 2,5 3

Time [sec]

m

2002503005007009001100

Exit velocity vertically downwards m/s10


Figure 14. Travel distance of droplets with different diameter as a function of time. The exit

velocity vertically downwards is 10 m/s.

22

6 RESULTS

6.1 k-factor for the nozzles The tested nozzles delivered by NORFASS were all well within the acceptance criterion recommended in the standard for characterisation of such nozzles /5/. This is shown in Figure 15, where the red line shows the match exactly for the nominal k-factor given by the manufacturer, and the two different markers represent tests carried out by SINTEF and IdF, respectively. One single measurement carried out by TelTek is also included, for nozzle HV K44.

0

20

40

60

80

100

0 20 40 60 80 1

Nominal k-factor

Mea

sure

d k-

fact

or

00

SINTEF measurements Manufactureres k-factor IdF measurements Tel-Tek measurement

Figure15. Measured k-factors [litre/min bar1/2] for the nozzles .

23

6.2 Exit velocity The nozzles used in the SINTEF tests were denoted Medium or High velocity nozzles. Figure 16 shows the calculated exit velocities based on average velocity at the orifice, not measured values. The velocities are calculated at the minimum and maximum recommended operating pressure.

0

5

10

15

20

25

0 20 40 60 80 100

k-factor

Exit

velo

city

[m/s

]

HV minHV maxMV minMV max

Figure 16. Calculated exit velocities for the nozzles at minimum and maximum recommended pressure.

No significant difference in exit velocity from the nozzle orifice seems to exist between the High-and Medium-velocity nozzles. However, the main difference is the construction of the nozzles. The Medium-velocity nozzles have a deflector plate that spreads the water and lowers the velocity in downwards direction, and the droplet will tend to fall freely shortly after leaving the nozzle. Table 6. Velocity distribution 1 m below nozzle MVK41, measured by TelTek.

24

Table 7. Velocity distribution 1 m below nozzle HVK44, measured by TelTek.

Table 6 and 7 show the measured droplet velocity 1 m below the nozzles MVK41 and HVK44, respectively. The High-velocity nozzle exhibits velocities above 5 m/s and above 25 m/s at maximum, with 8 bar pressure and near the centre. Higher pressure leads to higher velocities. The Medium-velocity nozzle exhibits velocities in the order of 1-2 m/s, with some maximum velocities of about 6 m/s at the outskirts of the spray.

25

6.3 Droplet sizes measured by two institutes

Figure 17. Mean diameter profile as measured by TelTek, for nozzle HVK44 at 2,4 bar.

HVK44 pvc

0

100

200

300

400

500

-600 -450 -300 -150 0 150 300 450 600

d30pvc d20pvc d10pvc

Figure 18. Mean diameter profile as measured by IdF, for nozzle HVK44 at 2,4 bar ,pvc-values.

HVK44 ori

0

100

200

300

400

500

-600 -450 -300 -150 0 150 300 450 600

d10ori d20ori d30ori

Figure 19. Mean diameter profile as measured by IdF, for nozzle HVK44 at 2,4 bar, ori-values.

26

Comparison of the measurements of the same parameters at two different institutes shows both similarities and differences. Figures 17-19 show mean diameter profiles for the nozzle HVK44 at 2,4 bar pressure. We first look at volume mean diameters variation with distance from centre. The TelTek measurement shows diameters less than 150 m at the centre, as the two measurement from IdF shows about 200 m and 300 m, pvc- and ori-values, respectively. At a distance 400-500 mm from the centre, the TelTek measurements are somewhat unsymmetrical, with diameters of 400 m on one side, and 300 m at the other side. The IdF measurements show diameters from about 350 to 450 m with the pvc-values, and from about 400 to 500 m with the ori-values. For this case, the pvc-values of IdF seem more similar to the TelTek values.

Figure 20. Mean diameter profile as measured by TelTek, for nozzle HVK44 at 5 bar.

HVK44 pvc

0

100

200

300

400

500

-600 -450 -300 -150 0 150 300 450 600

d30pvc d20pvc d10pvc

Figure 21. Mean diameter profile as measured by IdF, for nozzle HVK44 at 5 bar, pvc-values.

27

HVK44 ori

0

100

200

300

400

500

-600 -450 -300 -150 0 150 300 450 600

d10ori d20ori d30ori

Figure 22. Mean diameter profile as measured by IdF, for nozzle HVK44 at 5 bar, ori-values. Figures 20-22 show mean diameter profiles for the nozzle HVK44 at 5 bar pressure. We again first look at volume mean diameters variation with distance from centre .The TelTek measurement shows diameters larger than 300 m at the centre, as the two measurement from IdF shows about 200 m and 300 m, pvc- and ori-values, respectively. At a distance 400-500 mm from the centre, the TelTek measurements again are somewhat unsymmetrical, with diameters of 450 m on one side, and 300 m at the other side. The IdF measurements show diameters from about 250 to 350 m with the pvc-values, and from about 300 to 400 m with the ori-values. For this case, the total shape and numbers of the ori-values of IdF seem more similar to the TelTek values. The TelTek measurements are given in detail in Tables 8 10. Table 8. Mean and Median, Max and Minimum diameters measured by TelTek, nozzle

HVK44, at 2,6 bar pressure.

28

Table 9. Mean and Median, Max and Minimum diameters measured by TelTek, nozzle

HVK44, at 5 bar pressure.

Table 10. Mean and Median, Max and Minimum diameters measured by TelTek, nozzle

HVK44, at 7,8 bar pressure.

29

6.4 Individual nozzle characteristics

6.4.1 Nozzle HV K26

Figure 23. Nozzle HV K26.

Figure 24. Spray pattern of HV K26 at 2,6 bar.

The nominal spray angle of this nozzle is 80 - 90.

30

Figure 25. Spray pattern of HV K26 at 5,3 bar.

6.4.1.1 Application density HV K26

1,87

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

475 670 820 950 1060 1160 1255 1340 1425 1500Distance from centre [mm]

Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average

HV K26 Height m Pressure bar2,6

Figure 26. Measured application density by ADD apparatus for nozzle HVK26, height

1,87 m, 2,6 bar.

31

1,87

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0

18,0

20,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average


Figure27. Measured application density by ADD apparatus for nozzle HV K26, height

1,87 m, 5,3 bar.

Variance of application density

0

5

10

15

20

0 250 500 750 1000 1250 1500Distance from centre [mm]

Appl

icat

ion

dens

ity [l

/m2

min

]

2,6 bar5,3 bar

HV K26 m height1,87

Figure28. Measured application density by ADD apparatus for nozzle HV K26.

32

HVK26 1 m height

0

2

4

6

8

10

12

0 100 200 300 400 500 600


Vel

ocity

[m/s

]

2,6 bar5,3 bar

Figure29. Measured average droplet velocity by PDA for nozzle HV K26.

6.4.1.2 Nozzle HV K26 : Droplet size distribution

Figure 30. Droplet size distribution of nozzle HV K26 at 2,6 bar. The values of the droplet

sizes represent the D10 pvc diameter (Number of droplets). The diameter (d) is in micrometer, the coordinates (x,y) in cm. Measurements with PDA-technique by IdF.

33

Figure 31. Droplet size distribution of nozzle HV K26 at 5,3 bar. The values of the droplet

sizes represent the D10 pvc diameter (Number of droplets). The diameter (d) is in micrometer, the coordinates (x,y) in cm. Measurements with PDA-technique by IdF.

HVK26 - 2,6 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000

Droplet diameter [micrometer]

Num

ber f

ract

ion

0100200300400500600

Distancefrom centre

[mm]

Figure 32. Droplet size distribution of nozzle HV K26 at 2,6 bar. The graph presents the

number fraction of the droplet sizes at different distances from the centre of the spray. Measurements with PDA-technique by IdF, original data without correction (ori-data).

34

HVK26 - 2,6 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500600

Distancefrom centre

[mm]


volume fraction of the droplet sizes at different distances from the centre of the spray. Measurements with PDA-technique by IdF, original data without correction (ori-data).

HVK26 - 5,3 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

0100200300400500600

Distancefrom centre

[mm]



35

HVK26 - 5,3 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500600

Distancefrom centre

[mm]



36


X= -40 Y= 0

HVK 26 2,6 bar 100

02468

101214

20 80 140 200 260 320 380 440 500 560 620 680 740 0 0 0 0 0 0 0


Frac

tion

num

ber [

%]

HVK 26 2,6 bar 100

012345678

20 80 140 200 260 320 380 440 500 560 620 680 740 0 0 0 0 0 0 0


Frac

tion

volu

me

[%]

HVK 26 2,6 bar 100

0102030405060708090

100

0 100 200 300 400 500 600 700 800 900

Mean class diameter

Acc

umul

ated

vol

ume

[%]

Figure 36 Example of individual position measured droplet size distribution of nozzle HVK 26

at 2,6 bar. The graph presents the volume fraction of the droplet sizes at one single distance from the centre of the spray, denoted position 100. x =-4 0, y = 0 means distance from centre in two directions, in (cm). Measurements with PDA-technique by IdF, original data without correction (ori-data).

37

6.4.2 Nozzle HVK44

Figure 37. Nozzle HV K44.

Figure 38. Spray pattern of HV K44 at 2,7 bar pressure, 3,6 m height.

38

Figure 39. Spray pattern of HV K44 at 7,8 bar pressure, 5,7 m height.

39

6.4.2.1 Application density HV K44

3,6

0,0

5,0

10,0

15,0

20,0

25,0

30,0

35,0

40,0

45,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average


8,0Average application density l/m2 min

Figure 40. Measured application density by ADD apparatus for nozzle HV K44, height 3,6 m,

2,7 bar.

3,6

0,0

5,0

10,0

15,0

20,0

25,0

30,0

35,0

40,0

45,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average


10,0Average application density l/m2 min

Figure 41. Measured application density by ADD apparatus for nozzle HV K44, height 3,6 m,

4,9 bar.

40

5,7

0,0

5,0

10,0

15,0

20,0

25,0

30,0

35,0

40,0

45,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average


Figure 42. Measured application density by ADD apparatus for nozzle HV K44, height 5,7 m, 7,8 bar.


0

10

20

30

40

50


Appl

icat

ion

dens

ity [l

/m2

min

]

2,7 bar4,9 bar7,8 bar

HV K44 m height3,6 - 5,7

Figure43. Measured application density by ADD apparatus for nozzle HV K44.

41

HVK44

0

5

10

15

20

25

30

35

0 100 200 300 400 500 600


Velo

city

[m/s

]


N7 - HV K44

05

101520253035

-450 -300 -150 0 150 300 450

Radial position [mm]

Mea

n ve

loci

ty [m

/s]

N7 2,4 barN7 5 barN7 8 bar

Figure44. Measured average droplet velocity for nozzle HV K44. The graph to the left is

measured by by PDA tecnique, by IdF, and the graph to the left is measured by LD technique by TelTelk.

6.4.2.2 Droplet size distribution HVK44

HVK44 - 2,7 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

0100200300400500

Distancefrom centre

[mm]



42

HVK44 - 2,7 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500

Distancefrom centre

[mm]



HVK44 - 4,9 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

0100200300400500

Distancefrom centre

[mm]



43

HVK44 - 4,9 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500

Distancefrom centre

[mm]



HVK44 - 7,8 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

0100200300400500

Distancefrom centre

[mm]

Figure 49. Droplet size distribution of nozzle HV K44 at 7,8 bar. The graph presents the number fraction of the droplet sizes at different distances from the centre of the spray. Measurements with PDA-technique by IdF, original data without correction (ori-data).

44

HVK44 - 7,8 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500

Distancefrom centre

[mm]



45

6.4.3 Nozzle MVK18

Figure 51. Nozzle MV K18.

Figure 52. Spray pattern of nozzle MVK18 at 2,6 bar pressure.

46

6.4.3.1 Application density MV K18

1,02

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average

MV K18 Height m Pressure bar2,6

Figure 53. Measured application density by ADD apparatus for nozzle MV K18, height 1,02 m, 2,6 bar.


01234567


Appl

icat

ion

dens

ity [l

/m2

min

]

2,6 bar

MV K18

Figure54. Measured application density by ADD apparatus for nozzle MV K18.

47

MV K18

0

2

4

6

8

10

12

0 200 400 600 800 1000 1200


m/s 2,6 bar

Figure 55. Measured mean droplet velocity at different distances from centre, for nozzle MV K18, at height 1 m. Measured by PDA technique by IdF.

48

6.4.3.2 Droplet size distribution MV K18

MVK18 - 2,6 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

100300500700900

Distancefrom centre

[mm]

Figure 56. Droplet size distribution of nozzle MV K18 at 2,6 bar. The graph presents the


MVK18 - 2,6 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

100300500700900

Distancefrom centre

[mm]



49

6.4.4 Nozzle MVK41


Figure 59. Spray pattern of MV K41 at 2,6 bar pressure.

50


1,87

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

10,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average



1,87

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

10,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average



51


012345678


Appl

icat

ion

dens

ity [l

/m2

min

]

1,9 bar2,6 bar

MV K41

Figure 62. Measured application density by ADD apparatus for nozzle MV K41, at height 1,87 m.

N1 - MV K41

05

101520253035

-800 -600 -400 -200 0 200 400 600 800


Mea

n ve

loci

ty [m

/s]

N1 2 barN1 7 bar

Figure 63. Measured velocity profile for nozzle MV K41, with LD technique, by TelTek.

52


MVK41 - 1,9 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

100300500700900

Distancefrom centre

[mm]



MVK41 - 1,9 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

100300500700900

Distancefrom centre

[mm]



53

MVK41 - 2,6bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

0100300500700900

Distancefrom centre

[mm]



MVK41 - 2,6bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100300500700900

Distancefrom centre

[mm]



54

6.4.5 Nozzle MVK59


Figure 69. Spray pattern of MVK59 at 2,5 bar pressure

55


1,27

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average


Figure 70. Measured application density by ADD apparatus for nozzle MV K59, height

1,27 m and at pressure 2,5 bar.


02468

101214


Appl

icat

ion

dens

ity [l

/m2

min

]

2,5 bar

MV K59 m height1,27

Figure 71. Measured application density by ADD apparatus for nozzle MV K59.

Droplet size measurements are not carried out for this nozzle.

56

6.4.6 Nozzle MVK80


Figure73. Spray pattern of nozzle MV K80 at 2,1 bar pressure.

57


1,1

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0

18,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average


Figure 74. Measured application density by ADD apparatus for nozzle MV K80, height 1,1 m and at pressure 2,1 bar.

1,1

0,0

5,0

10,0

15,0

20,0

25,0

30,0


Wat

er a

pplic

atio

n [li

tre/

m2

min

]

A B Average


Figure 75. Measured application density by ADD apparatus for nozzle MV K80, height 1,1 m

and at pressure 2,5 bar.

58


0

5

10

15

20


Appl

icat

ion

dens

ity [l

/m2

min

]

2,1 bar2,5 bar

MV K80

Figure 76. Measured application density by ADD apparatus for nozzle MV K80, at height

1,1 m.

MV K80

0

2

4

6

8

10

12

0 200 400 600 800 1000 1200

Distance from centre (mm)

Mea

n ve

loci

ty (m

/s)

2,1 bar2,5 bar

Figure 77. Measured mean droplet velocity at different distances from centre, for nozzle MV

K80, at height 1 m. Measured by PDA technique by IdF.

59


MVK80 - 2,1 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

100300500700900

Distancefrom centre

[mm]



MVK80 - 2,1 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

100300500700900

Distancefrom centre

[mm]



60

MVK80 - 2,5bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Num

ber f

ract

ion

0100300500700900

Distancefrom centre

[mm]



MVK80 - 2,5bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100300500700900

Distancefrom centre

[mm]



61

7 EVALUATION The evaluation of the measurement of spray characteristics is divided into two parts. The first part evaluates the different measurement techniques, as the second part covers the differences of the tested nozzles.

7.1 Measurement techniques Since none of the existing techniques for characterisation of sprays contain a full scheme to quantify both applied density and droplet sizes and velocities, it is still necessary to carry out two different tests to fully characterise what is needed. The tests of k-factor of the nozzles are carried out both by SINTTEF NBL and by TelTek, for some of the nozzles. The k-factor ids the correlation of water flow rate as a function of nozzle pressure. The measurement set-up at SINTEF NBL is according to the ISO standard 6182-1, /5/. The measured k-factor for the tested nozzles is in accordance with the minimum requirements of the ISO standard. Deviations in measurement technique and test set-up may introduce errors in such measurements, and it is recommended to use the ISO method. The ADD-apparatus constructed by SINTF NBL and used in the characterisation of area density distribution has some features which is favourable to use in single nozzle characterisation. The problem of collecting small droplets that follow air flow reduces the accuracy of such measurements, and a fraction of 20-40% is lost. However, this problem is seen with all types of measurements that collect water at floor level, since air flow is directed away from the collectors when a fixed barrier is reached. In measurements where all water is collected, the inaccuracy is related to the distribution. The measurement of droplet characteristics is based on Laser Doppler and Phase Doppler anemometry. This type of measurement is fully automatic, and a software package from the manufacturer transfers the measured signals to droplet sizes and velocities. The measurements converge to a fixed distribution when a sufficiently large number of droplets have been identified. The calculation procedure influences the resulting droplet size distribution. For the IdF measurement equipment, the original measured data was captured by the computer and kept for later analysis, as a special arrangement for this project. The data were continuously processed and stored as so-called pvc-values (probe volume correction). To be able to compare and utilise droplet size measurements, it is of great importance to use the correct denotations of measured values. For instance, the mean diameter is different from median diameter, and it is a great difference between number based, surface area based and volume based distributions. The most common and recommended characteristic is the Median Volume Diameter, MVD, which is the cumulative volume median diameter. Two different laboratories have measured similar nozzles, and some discrepancies are seen in the measured data. With one High-velocity nozzle HV K44, the measured MVD at different locations from the spray centre. The TelTek measurement shows diameters larger than 300 m at the centre, as the two measurements from IdF shows about 200 m and 300 m, pvc- and ori-values, respectively.

62

At a distance 400-500 mm from the centre, the TelTek measurements again are somewhat unsymmetrical, with diameters of 450 m on one side, and 300 m at the other side. The IdF measurements show diameters from about 250 to 350 m with the pvc-values, and from about 300 to 400 m with the ori-values. For this case, the total shape and numbers of the ori-values of IdF seem more similar to the TelTek values. The characterisation of droplet sizes seems to be sensitive to location of the probes, and probably also to the algorithm use to judge the goodness of each single burst. A burst is the electrical signal connected to the detection of one single droplet, and the algorithm decides if the burst represent a real droplet or not. Droplets deviating from spherical may give signals that make the algorithm vote the droplet out, and if there are many droplets of this type, the presented size distribution may be unrealistic. Imaging techniques may treat this differently.

7.2 Differences between nozzles Figure 82 shows a comparison between high-velocity and medium-velocity nozzles, with regard to distribution of droplet sizes at different distances from the spray centre. The main impression is that the MV-nozzles show a larger variation of droplet sizes along the diameter, with a surplus of smaller droplets in the central part of the spray, and larger droplets further away from the centre. Apart from that, the same droplet sizes are present in both medium- and high-velocity nozzles.

High-velocity nozzles Medium-velocity nozzles

HVK26 - 2,6 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500600

Distancefrom centre

[mm]

MVK18 - 2,6 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

100300500700900

Distancefrom centre

[mm]

HVK44 - 2,7 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500

Distancefrom centre

[mm]

MVK41 - 2,6bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100300500700900

Distancefrom centre

[mm]

HVK26 - 5,3 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500600

Distancefrom centre

[mm]

MVK41 - 1,9 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

100300500700900

Distancefrom centre

[mm]

63

HVK44 - 4,9 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500

Distancefrom centre

[mm]

MVK80 - 2,1 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

100300500700900

Distancefrom centre

[mm]

HVK44 - 7,8 bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100200300400500

Distancefrom centre

[mm]

MVK80 - 2,5bar

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 200 400 600 800 1000


Volu

me

frac

tion

0100300500700900

Distancefrom centre

[mm]

Figure 82. A collection of volume fractions of droplets of different sizes measured at different

distances from the spray centre, with varied nozzle pressure. High-velocity nozzles are shown in the left column, as medium-velocity nozzles are shown in the right-hand column.

Figure 83 shows mean droplet velocities measured for the different nozzles, as a function of distance from spray centre. These velocities are measured 1 m below the nozzle, and one can clearly see the difference between the high- and the medium-velocity nozzles.


HVK26 1 m height

0

2

4

6

8

10

12

0 100 200 300 400 500 600


Vel

ocity

[m/s

]

2,6 bar5,3 bar

MV K18

0

2

4

6

8

10

12

0 200 400 600 800 1000 1200


m/s 2,6 bar

# MV K80

0

2

4

6

8

10

12

0 200 400 600 800 1000 1200

Distance from centre (mm)

Mea

n ve

loci

ty (m

/s)

2,1 bar2,5 bar

64

N7 - HV K44

05

101520253035

-450 -300 -150 0 150 300 450


Mea

n ve

loci

ty [m

/s]

N7 2,4 barN7 5 barN7 8 bar

N1 - MV K41

05

101520253035

-800 -600 -400 -200 0 200 400 600 800


Mea

n ve

loci

ty [m

/s]

N1 2 barN1 7 bar

Figure 83. Droplet velocities measured at different distances from the spray centre, with

varied nozzle pressure. High-velocity nozzles are shown in the left column, as medium-velocity nozzles are shown in the right-hand column.



0

5

10

15

20


Appl

icat

ion

dens

ity [l

/m2

min

]

2,6 bar5,3 bar

HV K26 m height1,87


012345678


App

licat

ion

dens

ity [l

/m2

min

]

1,9 bar2,6 bar

MV K41


0

10

20

30

40

50


App

licat

ion

dens

ity [l

/m2

min

]


HV K44 m height3,6 - 5,7


0

5

10

15

20


Appl

icat

ion

dens

ity [l

/m2

min

]

2,1 bar2,5 bar

MV K80

Figure 84. Water application density measured at different distances from the spray centre,

with varied nozzle pressure. High-velocity nozzles are shown in the left column, as medium-velocity nozzles are shown in the right-hand column.

Figure 84 shows water application densities measured for the different nozzles, as a function of distance from spray centre. The high-velocity nozzles have a higher application density at the centre, and the density increases there as pressure is increased. It has to be noted that the nozzles are tested for higher pressures than design pressure, as shown in Chapter 3. The medium-velocity nozzles show a more uniform application density over the cover area, even with higher density at a distance away from the centre.

65

8 REFERENCES 1. Are W. Brandt, Kristen Opstad and Ragnar Wighus: Documentation of active fire fighting

systems as a fire safety design parameter - Tests with different deluge nozzles in 3 m diameter rig. SINTEF report STF22 F99845, Trondheim 2000-01-10.

2. Kristen Opstad, Ragnar Wighus and Are Brandt: Documentation of active fire fighting

systems as a fire safety design parameter - Tests in large-scale 3350m3 SINTEF report NBL10 F01104, Trondheim 2001-11-08.

3. Vidar Mathiesen and Britt Halvorsen: Laser Measurements of Droplet Size and Velocity.

Tel-Tek report number 510390-1, Porsgrunn, September 2000. 4. H. Starke, F. Wienecke: Bestimmen der Tropfenverteilung fr Wassernebeldsen (Typen

HV und MV). Institut der Feuerwehr , Sachsen-Anhalt (IdF LSA), Heyrothsberge, Germany, 2002.

5. ISO 6182-1, First Edition, 1993-07-01. Fire protection Automatic sprinkler systems

Part 1: Requirements and test methods for sprinklers. Reference Number: ISO 6182-1:1993(E).

6. Tsai, R.F., Lee, C.K., Liang, B.C.: The Use of a Visual System to Quantify Geometric

characteristics of Sprays. The 3rd International Water Mist Conference, Madrid, Spain, September 2003. International Water Mist Association. IWMA, http://www.iwma.de/

7. P.A.Starkey, D.G. Talley and W.D. Bacalao: Phase Doppler Measurements in Dense

Sprays, ILASS-Americas 98 Sacramento, CA 17-20 May 1998. 8. ASTM E 799-92: Standard Practice for Determining Data Criteria and Processing for

Liquid Drop Size Analysis,

66

9 APPENDIX A.1 NOZZLE HVK26 - 2,6 bar DROPLET SIZE DISTRIBUTION FOR NOZZLES ORIGINALLY MEASURED DATA BY PDA at IdF, reduced and presented by SINTEF

67


HVK26 2,6 bar x=0 y=0 (90)

0

5

10

15

20

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=0 y=0 (90)

01234567

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=0 y=0 (90)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

68


HVK26 2,6 bar x=10 y=0 (91)

02468

101214

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=10 y=0 (91)

0

1

2

3

4

5

6

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=10 y=0 (91)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

69


HVK26 2,6 bar x=20 y=0 (92)

02468

101214

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=20 y=0 (92)

01234567

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=20 y=0 (92)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

70


HVK26 2,6 bar x=30 y=0 (93)

0

2

4

6

8

10

12

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=30 y=0 (93)

012345678

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=30 y=0 (93)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

71


HVK26 2,6 bar x=40 y=0 (94)

0

2

4

6

8

10

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=40 y=0 (94)

0123456789

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=40 y=0 (94)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

72


HVK26 2,6 bar x=50 y=0 (95)

0

2

4

6

8

10

12

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=50 y=0 (95)

0123456789

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=50 y=0 (95)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

73


HVK26 2,6 bar x=60 y=0 (96)

0

2

4

6

8

10

12

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=60 y=0 (96)

012345678

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=60 y=0 (96)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

74


HVK26 2,6 bar x=-10 y=0 (97)

0

5

10

15

20

25

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=-10 y=0 (97)

01234567

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=-10 y=0 (97)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

75


HVK26 2,6 bar x=-20 y=0 (98)

0

5

10

15

20

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=-20 y=0 (98)

01234567

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=-20 y=0 (98)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

76


HVK26 2,6 bar x=-30 y=0 (99)

02468

10121416

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=-30 y=0 (99)

01234567

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=-30 y=0 (99)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

77


HVK26 2,6 bar x=-40 y=0 (100)

0

2

4

6

8

10

12

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=-40 y=0 (100)

0

1

2

3

4

5

6

20 80 140 200 260 320 380 440 500 560 620 680 740 800


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=-40 y=0 (100)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

78


HVK26 2,6 bar x=-50 y=0 (102)

0

2

4

6

8

10

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=-50 y=0 (102)

0

2

4

6

8

10

20 80 140 200 260 320 380 440 500 560 620 680 740 800


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=-50 y=0 (102)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

79


HVK26 2,6 bar x=-60 y=0 (103)

0

2

4

6

8

10

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=-60 y=0 (103)

0

2

4

6

8

10

20 80 140 200 260 320 380 440 500 560 620 680 740 800


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=-60 y=0 (103)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

80


HVK26 2,6 bar x=0 y=0 (104)

0

5

10

15

20

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=0 y=0 (104)

01234567

20 80 140 200 260 320 380 440 500 560 620 680 740 800


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=0 y=0 (104)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 740


Acc

umul

ated

vol

ume

[%]

81


HVK26 2,6 bar x=0 y=10 (105)

0

5

10

15

20

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

num

ber [

%]

HVK26 2,6 bar x=0 y=10 (105)

012345678

20 80 140 200 260 320 380 440 500 560 620 680 740


Frac

tion

volu

me

[%]

HVK26 2,6 bar x=0 y=10 (105)

0102030405060708090

100

20 80 140 200 260 320 380 440 500 560 620 680 7

nbl_a12114 fire water design

Documents