Texts: As part of the cooling system of a bioreactor, 100 kg/h of refrigerant 134A is evaporated in a heat exchanger. Before the exchanger, the refrigerant is throttled from 0.925 MPa and 25°C down to 0.16 MPa, in a throttling valve. The valve outlet is evaporated by a stream of R-1270 refrigerant (pure propylene), which enters the shell of the exchanger at a rate of 520 kg/h, 35°C and 0.3 MPa, and cools down to 18°C at the outlet.
Consider R-1270 as an ideal gas of variable Cp with temperature.
1) The amount of heat transferred by the water.
2) The temperature of the stream.
3) The amount of refrigerant 134A evaporated.
4) The heat exchanger pressure.
P = 360 kPa
n134A = 100 kg/h
T1 = 25°C
P1 = 0.925 MPa
T2 = 18°C
P2 = 0.16 MPa
nR-1270 = 520 kg/h
T3 = 35°C
P3 = 0.3 MPa