8/18/2019 Assignment 1 Group 1

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Department: Mechanical Engineering Date: February/March 2016

Course: Renewable Energy Marks: 10

Course Code: ME 247 Time: 30 mints

Group: 1 Prof. Adel. Nasser

Question 1:

A flat plate solar collector with an area of 4.1 m2 is tested by the ASHRAE method with beam radiation nearly

normal to the plane of the collector and the following data have been recorded.

Q u MJ/hr Ic W/m2  Tin⁰C Tout⁰C Tamb⁰C ṁ kg/sec

9.05 864 43 49 10 0.0306

8.00 930 65 73 10 0.0314

5.18 730 54 57 10 0.0300

2.88 650 86 90 10 0.0326

1.98 894 93 99 10 0.0333

i.  Consider the mean collector temperature is the mean between inlet and outlet temperatures. Find out

graphically the constants for such a flat plate collector then find the efficiency for the same flat plate

collector when the solar radiation is 600 W/m2, the collector temperature is 27⁰C and the ambient

temperature is 20⁰C. 

Question 2:

A flat plate solar collector of area 3 m2 has been tested and the following results are recorded.

Ic W/m2  ṁ kg/sec Tin⁰C Tout⁰C Tamb⁰C Tcollector ⁰C

661 0.0864 16 20 12 18

894 0.01644 85 91 10 86

Find out either graphically or analytically the ατ and Ul for this collector

Question 3:

A flat plate solar collector is used to generate electric power. The incident radiation is 600 W/m2, The overal

heat transfer coefficient is 4 W/m2.K, The collector efficiency equals 0.7, The mass flow rate of water through

the collector is 0.0008 kg/m2

.sec, The effective transmitivity ατ is 0.8, The ambient temperature is 20⁰C andThe collector area is 50,000 m

2.

Assuming that the efficiency of heat engine is one-third that of the Carnot engine working between the

ambient temperature and the collector outlet temperature. If the collector temperature equals the mean

between inlet and outlet temperatures estimate the power generated.