Experimental and Theoretical Analysis of Thermal Losses in A Flat Plate Solar Heater with Multi Risers and Headers


Mahmmod A. Muhammed Al-Saiydee*


Electromechanical Engineering Department – Engineering technical college in Maysan – Southern Technical University – Iraq

Corresponding Author Email: mahmmodaziz@stu.edu.iq

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Experimental and theoretical calculations are made to a flat plate solar heater which is manufactured from vertical copper pipes (called risers) and two horizontal copper pipes (called headers) through which distilled water passes. The risers and headers are bonded to a 1 m2 square galvanized steel plate and mounted inside a wooden case equipped with thermal insulation and double glass covers. Two flow rates are applied 100 L/hr & 200 L/hr and the water enters the solar heater is preheated using a solar preheater so that no conventional energy is used to raise the temperature of water. The heat gain and efficiency are calculated experimentally but the top heat losses are calculated experimentally and theoretically. Accordingly, the error was calculated according to the discrepancy between the experimental and theoretical data. The results show that the maximum heat gain, outlet temperature and efficiency occurred at flow rate of 100 L/hr. The maximum heat gain obtained is 920 W/m2, maximum outlet temperature is 73⁰C and maximum efficiency of 82%. Both values occurred at 100 L/hr and at the first run hour. The reason is the maximum thermal equilibrium the solar heater reached before the experiment was run. The overall error between experimental and theoretical data is mostly laid below 20% except at the first and last hours because the theoretical calculation was based on the temperature of absorbing plate while the experimental calculations are based on inlet and outlet temperatures.