buletinul institutului politehnic din iaşi - Universitatea Tehnică ...

74 Ion Zabet and Graţiela-Maria Ţârlea
Nr.
Test
Table 1
Results of the test without vapour injection
Set points Experimental results without injection
P su ΔT SI Pex ΔT sub π t ex;cp
M cd
& cp W& Φcd Φ0 COPheat
bar K bar K C kg/s kW kW kW
1 2 5 17 2 8.50 111.00 0.044 5.32 10.60 5.78 1.99
2 2 6 20 2 10.00 95.18 0.053 6.22 26.69 6.79 3.94
3 3 9 12 3 4.00 115.00 0.096 5.31 12.20 17.61 1.96
4 4 5 12 2 3.00 73.97 0.100 5.38 30.20 18.10 4.22
5 5 3 14 2 2.80 121.20 0.131 6.38 12.41 23.21 1.72
6 5 5 17 3 3.40 75.00 0.149 7.15 22.28 23.11 4.18
7 6 11 19 4 3.17 109.70 0.171 8.17 28.79 27.03 2.86
Nr.
Test
Table 1 (continued)
Results of the test without vapour injection
Set points Experimental results
without injection
P su ΔT SI Pex ΔT sub π COP cool ε s ε v
bar K bar K
1 2 5 17 2 8.50 1.09 0.65 0.76
2 2 6 20 2 10.00 2.96 0.71 0.78
3 3 9 12 3 4.00 1.09 0.66 0.87
4 4 5 12 2 3.00 3.23 0.71 0.86
5 5 3 14 2 2.80 0.91 0.63 0.86
6 5 5 17 3 3.40 3.33 0.69 0.86
7 6 11 19 4 3.17 1.96 0.72 0.86
In Fig. 9 is presented the compressor power ( W ), the cooling capacity
&
(Φ0) and the coefficient of performance (COP) versus the injection ratio (INJR).
As can be seen from Fig. 9 (Zabet, 2011) the cooling capacity has a slight
increase for injection ratio up to 9%.
After this level, the cooling capacity decreases. In the same time with
cooling capacity increases, the compressor power increases in a similar
proportion which gives a quite constant coefficient of performance in the final.
cp