2. A freezer with a capacity of 180 kW is needed for a food processing plant. The required cooling will be provided by an ideal vapor-compression refrigeration cycle with its evaporator at 320 kPa and its condenser at 1.4 MPa. If the refrigerant used in the cycle is R-134a, show the cycle on the T-s diagram with respect to saturation lines and determine, a) the mass flow rate of the refrigerant,

2. A freezer with a capacity of 180 kW is needed for a food processing plant. The required cooling will be provided by an ideal vapor-compression refrigeration cycle with its evaporator at 320 kPa and its condenser at 1.4 MPa. If the refrigerant used in the cycle is R-134a, show the cycle on the T-s diagram with respect to saturation lines and determine, a) the mass flow rate of the refrigerant,

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter28: Special Refrigeration Applications

Section: Chapter Questions

Problem 15RQ: Why is two-stage compression popular for extra-low-temperature refrigeration systems?

See similar textbooks

Similar questions

Refrigeration Cycle: A refrigerator operates on the ideal vapor-compression refrigeration cycle and use R-134a as the working fluid. The condenser operates 1.4 MPa and the evaporator at 0.140 MPa. (a) Show the cycle on a T-s diagram, indicating the enthalpies at the end of each process, with respect to saturation lines. For a mass flow rate of 0.100 kg/s, determine (b) the net power input to the compressor, in kW, (c) the heat rejection to the environment, in kW, (d) the heat rejection from the cold refrigerated space to the evaporator, in kW, and (e) the coefficient of performance. use the formula in the picture
1. Consider a steam power plant that operates on a simple ideal Rankine cycle and has a net power output of45 MW. Steam enters the turbine at 7 MPa and 500°C and iscooled in the condenser at a pressure of 10 kPa by runningcooling water from a lake through the tubes of the condenserat a rate of 2000 kg/s. Show the cycle on a T-s diagram withrespect to saturation lines, and determine (a) the thermal efficiency of the cycle, (b) the mass flow rate of the steam, and(c) the temperature rise of the cooling water. Answers:(a) 38.9 percent, (b) 36 kg/s, (c) 8.4°C 2. Consider a 210-MW steam power plant that operateson a simple ideal Rankine cycle. Steam enters the turbine at10 MPa and 500°C and is cooled in the condenser at a pressure of 10 kPa. Show the cycle on a T-s diagram with respectto saturation lines, and determine (a) the quality of the steamat the turbine exit, (b) the thermal efficiency of the cycle,and (c) the mass flow rate of the steam. Answers: (a) 0.793,(b) 40.2 percent, (c) 165…
Refrigerant 134a is used as the working fluid in a refrigerator, and it operates in an ideal vapor compression refrigeration cycle, if the refrigerant enters the evaporator at -4 ° C and enters the condenser at 1200 kPa. If the mass flow of the refrigerant is 180 kg / h, determine a) the Ts and Ph diagrams of the cycle with all the information b) the rate of heat removal from the refrigerated space and the power input to the compressor, and c) the COP Of fridge
: Refrigerant 134a enters a compressor of a vapour compression of a refrigeration cycle at 120Kpa as a saturated vapour and leaves at 900 Kpa and 75oc. The refrigerant leaves the condenser as a saturated liquid. The rate of cooling provided by the system is 18000 Btu/hr. Determine (1) Mass flow rate of R134a (2) The Cop of the cycle (3) Also determine the Cop of the cycle if the expansion valve is replaced by an isentropic turbine. Do you recommend such a replacement for the refrigeration system? (4) Determine the Cop if the evaporator pressure is 160Kpa and otheer values remains the same. (5) Determine the Cop if the condenser pressure is 800 Kpa and other values remain the same.
Consider a water-ammonia binary vapor cycle consisting. In the steam cycle, superheated vapor enters the turbine at 7 MPa, 450C, and saturated liquid exits the condenser at 55C. The heat rejected from the steam cycle is provided to the ammonia cycle, producing saturated vapor at 45C, which enters the ammonia turbine. Saturated liquid leaves the ammonia condenser at 1 MPa. For a net power output of 24 MW from the binary cycle, determine (a) the mass flow rates for the steam and ammonia cycles, respectively, in kg/s, (b) the power output of the steam and ammonia turbines, respectively, in MW. (c) the rate of heat input to the ammonia cycle, in MW, (d) the rate of heat addition to the binary cycle, in MW, and (e) the thermal efficiency of the binary vapor cycle.
Refrigerant 134a enters a refrigerator compressor as superheated vapor at 0.20 MPa and -5 ° C at a rate of 0.7 kg / s, and exits at 1.2 MPa and 70 ° C. The refrigerant is cooled in the condenser to 44 ° C and 1.15 MPa, and is throttled to 0.2 MPa. Neglecting any heat transfer and any pressure drop in the connecting lines between the components, show the cycle on a Ts and Ph diagram with respect to the saturation lines, and determine (a) the rate of heat removal from the refrigerated space and the power input to the compressor, b) the isentropic efficiency of the compressor, and c) the COP of the refrigerator
Refrigerant 134a enters the compressor of a refrigerator as superheated vapor at 0.20 MPa and -5 ° C at a rate of 0.7 kg / s, and exits at 1.2 MPa and 70 ° C. The refrigerant is cooled in the condenser to 44 ° C and 1.15 ° C. MPa, and throttles at 0.2 MPa. Neglecting any heat transfer and any pressure drop in the connecting lines between the components, show the cycle on a Ts diagram with respect to the saturation lines, and determine (a) the rate of heat removal from the refrigerated space and the inlet power to the compressor, b) the isentropic efficiency of the compressor, c) the COP of the refrigerator, d) show the Ts and Ph diagrams with all points
The pressure in the boiler of a steam power plant operating on the ideal Rankine cycle is 1250 psia. The condenser pressue is 2 psia. The mass flow rate of steam through the system is 75 lbm/s and the quality of the steam at the turbine exit is 0.9. Show the cycle on a T-s diagram, and determine (a) the turbine inlet temperature, (b) the rate of heat input in the boiler, and (c) the thermal efficiency of the cycle.
An ideal vapor-compression refrigeration cycle employs refrigerant 134a as the working fluid and operates at a steady state. At the compressor inlet, saturated vapor enters a -20 degrees celcius, and the saturated liquid leaves the condenser at 42 degrees celcius. The mass flow rate of the refrigerant is 0.5 kg/s. Determine: a) The rate of heat rejection from the condenser in kW b) The compressor power in kW c) The coefficient of performance
Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.22 MPa and 27 C at a rate of 0.07 kg/s, and it leaves at 1.2 MPa and 73°C. The refrigerant is cooled in the condenser to 44°C and 1.16 MPa, and t is throttied to 0.21 MPa. Disregarding any heat transfer and pressure drops in the connecting lines between the components, show the cycle on a T-s diagram with respect to saturation lines, and determine (a) the rate of heat removal from the refrigerated space and the power input to the compressor, (b) the isentropic efficiency of the compressor, and (c) the COP of the refrigerator.
Given the ideal compression refrigeration cycle steam with refrigerant 134a as fluid work, as shown, and which operates between the pressure limits of 120 and 800 kPa.Given a rate of heat removal from space refrigerated of 30 kJ/s, determine:a) The mass flow of the refrigerant, in kg/s.b) The minimum necessary power input, in kWc) Show the T-s diagram of the cycle.
A refrigerator uses refrigerant-134a as the working fluid and operates on an ideal vapourcompression refrigeration cycle between 0.12 MPa and 0.7 MPa. The mass flow rate of therefrigerant is 0.05 kg/s. Show the cycle on a T-s diagram with respect to saturation lines.Determine;(a) The rate of heat removal from the refrigerated space and the power input to thecompressor,(b) The rate of heat rejection to the environment, and(c) The coefficient of performance.