Solar Energy Fundamentals and Applications

Series of lectures

By

Prof. M. A. Hassab

Picture of sun by NASA

Solar Thermal Application

a. Low-temperature applications (below100oC), such as solar drying, hot water supplies, swimming Pool heating, etc.

b. Medium-temperature applications (about 150oC),

such as refrigeration, industrial process heat, etc.

c. High-temperature applications (above 200 oC),such as electricity generation.

Low Temperature Thermal Applications

• Solar hot water and Solar space heating and

cooling

• systems may be classified as:

• Passive system – operates without mechanical

devices

• Active system- uses pumps or fan

Thermosyphone Principle-Solar Heater

I- Low Temperature Thermal Applications

Residential Solar DHW with an demand backup

Simple pool heat system design

• • Construction

• – No glazing or insulation

• – Typically UV stabilized plastic/polymer construction

• • Characteristic

• – High wetted area to compensate for poor heat transfer of

• polymer material

• – Large Surface area to account for large load

• – Designed for high flow rate

• • Applications

• – Seasonal pool heating systems

• – Temperature ~ ambient +/- 10 degrees

Unglazed Collectors

CPC Evacuated Tube Solar Thermal Collectors

Solar powered single-effect air-conditioning system

II- Medium-temperature applications

Largest Solar Thermal Electric Power Station, Mojave Desert, California

III- High-temperature Thermal applications

Thermodynamic cycles can be divided into two general

categories: power cycles, and refrigeration cycles

The devices or systems used to produce a net power output are

often called engines, and the thermodynamic cycles they

operate on are called power cycles.

The devices or systems used to produce a refrigeration effect are

called refrigerators, air conditioners, or heat pumps, and the

cycles they operate on are called refrigeration cycles.

Thermodynamic cycles can be categorized yet another way:

closed and open cycles. In closed cycles, the working fluid is

returned to the initial state at the end of the cycle and is

recirculated. In open cycles, the working fluid is renewed at the

end of each cycle instead of being recirculated.

The Solar Energy Conversion System

The Flat Plate Collector

Low-temperature Thermal applications

Actual Useful Heat Gain, Qu

Performance of Flat-Plate Collectors

Collector Heat Removal Factor C

Collector Heat Removal Factor

performance test data for a wide range of solar collectors.

(Tfi –Ta), oF