[Engineering Thermodynamics]Please finish the answer with a diagram for reference to me (if needed). Show the answer step by step and clear to see. If you need to answer with words, please type directly. (to avoid cant see clear by handwriting)Thank you. P.S. Use the online software http://www.peacesoftware.de/einigewerte/r134a_e.html or property table and p-h diagram for R134a where necessary. Q.4 (25 marks)A 1200 kW water-cooled chiller has a centrifugal compressor with refrigerant R134a as theworking fluid. The compressor runs at 9600 rev/min and has a slip factor of 0.95 and an overallisentropic efficiency of 90%. The impeller tip speed is not to exceed 160m/s. The evaporatingand condensing temperatures are 2°C and 40°C respectively. Assuming that there is nosuperheating and sub-cooling,a)sketch the refrigration cycle on a P-h diagram (please indicate the pressures and specificenthalpies of all points in the cycle);(7 marks)b)determine the mass flow rate of the refrigerant R134a;(4 marks)c)determine the coefficient of performance of the chilled water plant; and discuss thepossible measures to uplift the plant COP.(6 marks)determine the number of stages and the impeller tip diameters, assuming that all stagesd)would share same work input and each stage compression would have the same impellertip diameter.(6 marks)e)Please also comment how the slip factor can affect the energy performance of thecentrifugal compressor.(2 marks)Use the online software http://www.peacesoftware.de/einigewerte/r134a_e.html or propertytable and p-h diagram for R134a where necessary.(2 marks)

Answered: Image /qna-images/answer/2dccf6b6-bf29-4c8b-9886-d9981283f5e7.jpg

A 1200 kW water-cooled chiller has a centrifugal compressor with refrigerant R134a as the working fluid. The compressor runs at 9600 rev/min and has a slip factor of 0.95 and an overall isentropic efficiency of 90%. The impeller tip speed is not to exceed 160m/s. The evaporating and condensing temperatures are 2°C and 40°C respectively. Assuming that there is no superheating and sub-cooling, а) sketch the refrigration cycle on a P-h diagram (please indicate the pressures and specific enthalpies of all points in the cycle); (7 marks) b) determine the mass flow rate of the refrigerant R134a; (4 marks) determine the coefficient of performance of the chilled water plant; and discuss the c) possible measures to uplift the plant COP. (6 marks)

A 1200 kW water-cooled chiller has a centrifugal compressor with refrigerant R134a as the working fluid. The compressor runs at 9600 rev/min and has a slip factor of 0.95 and an overall isentropic efficiency of 90%. The impeller tip speed is not to exceed 160m/s. The evaporating and condensing temperatures are 2°C and 40°C respectively. Assuming that there is no superheating and sub-cooling, а) sketch the refrigration cycle on a P-h diagram (please indicate the pressures and specific enthalpies of all points in the cycle); (7 marks) b) determine the mass flow rate of the refrigerant R134a; (4 marks) determine the coefficient of performance of the chilled water plant; and discuss the c) possible measures to uplift the plant COP. (6 marks)

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

Chapter45: Domestic Refrigerators And Freezers

Section: Chapter Questions

Problem 20RQ: Welded ______sealed compressors are normally used in household refrigerators.

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