Compressor and the isentropic efficiency of the compressor

Assignment Help Mechanical Engineering

Reference no: EM13717737

A refrigeration unit operating on R-134a is used to maintain a freezer at -15°C. The refrigeration unit operates at a suction pressure of 140kPa and a discharge pressure of 900kPa. The condenser of the refrigeration unit is cooled by a water cooled heat exchanger. Cooling water flows through the condenser heat exchanger at a rate of 50kg/min, entering at a temperature of 20°C and leaving at a temperature of 29°C. It is known that the refrigeration unit can be modelled as an ideal vapour compression cycle for the heat rejection, throttling and heat absorption stages; however the compressor is known to be non-isentropic. The discharge temperature from the compressor is 60°C.

1) Determine the mass flow rate of the refrigerant, assuming a constant specific heat for the cooling water of C water=4.184 kJ/(kg.K).

2) What is the required power input to the compressor and the isentropic efficiency of the compressor?

Reference no: EM13717737

Questions Cloud

Write the half-reactions for electrode : Write the half-reactions for what must have happened at each electrode for the reactions. Indicate what was oxidized and what was reduced.

Determine the rate of heat transfer out of the condenser : An air-conditioner which uses refrigerant R134-a operates on the Carnot refrigeration cycle. Determine the rate of heat transfer (kW) out of the condenser. Determine the power input (kW) to the compressor.

Calculate the volume of hydrogen gas : Calculate the volume of hydrogen gas (26.0oC, 1.50 atm) when 50.00 mL (Density 1.00 g/mL) water is decomposed by an electrical current

Gauge pressure and convert to absolute pressure : A pressure guage reads in tuscaloosa alababama 16 psi. can this pressure be a vacuumed pressure? Why or why not? if you think it can convert it to absolute pressure. If you think it cannot assume that it is a gauge pressure and convert to absolute pr..

Compressor and the isentropic efficiency of the compressor : A refrigeration unit operating on R-134a is used to maintain a freezer at -15°C. The refrigeration unit operates at a suction pressure of 140kPa and a discharge pressure of 900kPa. The condenser of the refrigeration unit is cooled by a water cooled h..

Explain how much energy is required to vaporize : The heat of vaporization of acetone, CH3COCH3, at its boiling point is 29.1 kJ/mol. How much energy is required to vaporize 125.0 g of acetone at its boiling point?

How many kci(aq) are required to react completely : How many mL of .100 M KCI(aq) are required to react completely with 4.325 g of solid Pb(NO3) to form PbCl2?

Describe the initial partial pressure of oxygen : Consider a chamber filled with gaseous N2 (molar mass 28.0 g/mol) and O2 (molar mass 32.0 g/mol) which behave ideally (cv = (3/2)R). The chamber has a volume of 1.00 L and is initially at a temperature T = 25.0 OC ; the total initial pressure of a..

User Account

All Pages