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LOG SHEET Name: MUTHUKUMAR SWATHY Group: Date: GP18 Results and
Discussion Tabulation and Calculations 1. Tabulate your results
under the following headings in Table 1: 2. Calculate the rates of
heat removal from the evaporator Q L and heat delivered to the
condenser Q H at different water flow rates and then determine
their coefficients of performance of air refrigerator (COPR) and
heat pump (COPH) at different cooling water msflow rates. 3. Using
the data obtained in Table 1 and the calculated values from step
(2), plot the graphs below and discuss. (i) Heat delivered Q H (kW)
to the condenser and compressor load W C (kW) against condenser
water mass flow rate (kg/s). (ii) Heat delivered Q H (kW) to the
condenser and COPH versus condenser water mass flow rate (kg/s). 4.
Based on the data obtained for the maximum and minimum cooling
water flow rates, plot the vapour compression cycle on P-H diagram
(Fig. 5) and compare with those based on ideal cycles. Discuss the
results obtained.
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1. unit 1 2 3 4 Condenser water mass flow rate, mw Kg/s x 10^-3
20 30 40 50 Compressor electrical power input, WC 590 540 520 500
Absolute pressure of condenser, PH 1451 1201 1101 1001 Absolute
pressure of evaporator, PL 346 321 321 301 HFC134a temperature at
compressor inlet, T1 22.3 22.5 22.4 21.8 HFC134a temperature at
compressor outlet, T2
102.6 99.0 96.4 88.1 HFC134a temperature of condensed liquid,
T3
54.6 47.7 44.1 40.4 HFC134a temperature at expansion valve
outlet, T4
10.4 8.5 7.0 5.0 Compressor cooling water inlet temperature, T5
30.3 30.9 31.3 30.5 Compressor cooling water outlet temperature, T6
30.8 31.2 31.4 30.6 Condenser water outlet temperature, T7 50.8
43.7 40.1 37.2 Refrigerant mass flow rate, m 7.5 6.9 6.5 6.3 Heat
delivered to condenser, QH 1672 1567.5 1454.64 1379.4 Heat removal
from 937.5 862.5 812.5 787.5
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evaporator, QL Compressor waste heat, Qcmp 41.8 37.62 16.72 20.9
Total heat delivered, QT 1713.8 1605.1 1471.3 1399.9 Performance of
air refrigerator COPR 1.588 1.597 1.562 1.575 Performance of heat
pump COPH 2.833 2.90 2.79 2.75 Performance of heat pump COPH-T -
2.90 2.97 2.82 2.79 2. The values of QH , QL , COPR , COPH at
different cooling water flow rates are calculated and entered in
the table above. 3. (i) QH , Wc Versus condenser water mass flow
rate
Y axis : series 1 QH , Series 2 WC X axis : mw
1672 1567.5 1454.5 1379.4
590 540 520 500
0 200 400 600 800 1000
1200 1400 1600 1800
0 10 20 30 40 50 60 heat d
elivered
QH ,Com
pressor
load
Wc
condenser water mass Plow rate
Series1 Series2 Linear (Series1) Linear (Series2)
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(ii) QH, COPH versus condenser water mass flow rate
Y axis : series 1 QH , Series 2 COPH X axis : mw
1672 1567.5 1454.5 1379.4
2.833 2.9 2.79 2.75 0 200 400 600 800 1000
1200 1400 1600 1800
0 10 20 30 40 50 60
heat delivered
QH, COPH
condenser water mass Plow rate
Series1 Series2 Linear (Series1) Linear (Series2)
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4. Vapor compression cycle on P-H diagram : A difference between
the real cycle and the ideal is that temperature at which
evaporation takes place is lower than the temperature of the cold
region so heat transfer can take place. Similarly the temperature
of the heat rejection must be higher than the hot region
temperature to bring about heat transfer in the condenser.
