PRESSURE, MPa 1 0.8 0.6 0.4 0.2 0.1 0.08 0.06 0.04 0.02 0.01 -200 0 2 20 20 10 R-717 ammonia Reference state 2000kg -1.00K) for saturated liquid 0864 Licensed for single user. 2013 ASHRAE, Inc. -200 ° 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 40 40 40 0.40- 0.80 Properties computed with NST REFPROP version 7.0 09 120- 1.60 03- 4.00- T-20°C- 400- 350 08: 120- 100 60- 300 250 200 1404 120 100 160 100+ 100 kg/m³ 88 60 20 40 88 30 10 85 20 8866 15. 4 10 8.0 2 6.0 4.0 1 3.0 0.8 2.0 0.6 1.5 888888 0.4 1.0 0.80 0.2 0.60 20 0.40 IN 0.1 0.30 0.08 0.20 0.06 8.40 kg K) 0.15 0.04 0.10 0.000 0.060 0.02 200 400 600 800 1000 1200 1400 1600 1800 2000 ENTHALPY, kJ/kg 2200 0.01 2400 Based on formulation of Tiner Roth et al (1993) 5.2 An ammonia refrigerating plant is working at an evaporating temperature of-30°C and a condensing temperature of 37°C. There is no subcooling of the liquid refrigerant, and the vapour is in the dry-saturated condition at the inlets to the compressors. The capacity is 150 kW refrigeration. Estimate the power consumption (i) when one-stage is used, (ii) when two-stage compression with flash intercooling is used, and (iii) when two-stage compression with flash chamber and liquid subcooler is used. Assume suitable intermediate pressure. Explain why it is not advisable to use multistage compression to produce refrigeration temperatures of the order of, say, - 90°C.