Q6/ A single compressor system using 134a has a three evaporators of 5, 15 and 20 tons capacities. All evaporators operating at the same temperature of 0 °C. The condenser pressure is 12 bar and the refrigerant exit of the condenser as a sub cool at 40 °C. The discharge from the evaporator is dry saturated vapour *: and the compression is assumed to be isentropic. The cop is

Q6/ A single compressor system using 134a has a three evaporators of 5, 15 and 20 tons capacities. All evaporators operating at the same temperature of 0 °C. The condenser pressure is 12 bar and the refrigerant exit of the condenser as a sub cool at 40 °C. The discharge from the evaporator is dry saturated vapour *: and the compression is assumed to be isentropic. The cop is

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.

See similar textbooks

Similar questions

Four methods for controlling head pressure in an air-cooled condenser are ______, ______, _______, and
Condensers in these refrigerators are all_______cooled.
A cooling system capacity Fifteen ton refrigeration, operating at 150 kPa in the evaporator, while in the condenser is 950 kPa. If refrigerant R-134a is in saturated conditions, calculate the power theoretical required to operate compressor. Power Compressor...kW.
3.) An ammonia compressor operates at evaporator pressure of 316.02 kPa and a condenser pressure of 1557 kPa. A twin-cylinder compressor with bore to stroke ratio of 0.85 is to used at 1200 rpm. The actual volumetric efficiency is 92% and compression and mechanical efficiency is 78% and 80% respectively. For a cooling capacity of 25 TR, (a) the sketch the p-h diagram labeling the evaporating and condensing temperature and pressures (b) define the all properties of ammonia taken from saturation table. Determine (c) the quantity of cooling water in the condenser in kg/min if the increase in temperature is 8°C, (d) the bore and stroke expressed in cm and (e) the size of the driving motor in hp. Given: h2 = h at 1557 kPa and s2 = s1 1695 kJ/kg
Provide the complete solution and diagram. A two stage compressor with an ideal intercooler receives 0.5 kg/s of argon at 120 kPa and 300 K and discharges it at 4500 kPa. Calculate the intercooler pressure in psi. A. 734.85 kPa C. 106.61 psiB. 820.25 psi D. 120.47 ps
7. In a refrigeration plant ammonia enters the expansion valve as a liquid at 32°C and leaves the evaporator as a dry saturated vapour. The pressure limits are 158.8kPa and 1389kPa. The compression may be assumed to be isentropic. The single acting compressor of 130mm bore, 150mm stroke, and 90% mechanical efficiency runs at a rotational speed of 240rpm. Calculate: (a). refrigerant volumetric flowrate (b). cooling load (c). power input to the compressor
Solve using P-h chart with a clear handwriting
Present step by step solution. If EB in to be used, start in System Under Study, then, Fluid Under Study, and draw BED.
(a) What would be the necessary bore and stroke of a single acting four- cylinder, 350 rpm ammonia compressor working on simple saturation cycle between 35°C condenser and -15°C evaporator temperatures and developing 15 tons refrigeration. Given for the compressor: Ratio of stroke to bore = 1 Volumetric efficiency = 0.7 (b) If the index of compression is 1.15, find the error introduced in calculat- ing the work of compression by assuming the process to be isentropic. Also, find the heat rejected to the compressor-jacket cooling water.
A vapour absorption refrigeration system works with a generator temperature of 87⁰C, absorber temperature of 37⁰C and evaporator temperature of -13⁰C. (a) Obtain the COP of the system. (b) If the evaporator temperature falls to -18⁰C, what should be the generator temperature so that the system operates with the same COP?
11. 30 tonnes of ice from and at 0°C is produced in a day of 24 hours by an ammonia refrigerator. The temperature range in the compressor is from 298 K to 258 K. The vapour is dry saturated at the end of compression and expansion valve is used. Assume a co-efficient of performance of 60% of the theoretical and calculate the power in kW required to drive the compressor. Latent heat of ice is 334.72 kJ/kg. Enthalpy Entropy of liquid Entropy of vapour kJ/kg Тетр. K kJ/ kg kJ/ kg K Liquid Vapour 298 100.04 1319.22 0.3473 4.4852 258 -54.56 1304.99 - 2.1338 5.0585 [Ans. 21.59 kW]
An air cooled refrigerant condenser (similar to the ones used for home air conditioners) is shown, The system condenses 0.1 kg/sec of 60 C R134A refrigerant. Air temperature rises by 5 C passing over the coils. Calculate the mass flow rate of air pushed through the condenser.