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

Rankine degree represent larger or smaller temperature

Does the Rankine degree represent a larger or smaller temperature unit than the Kelvin degree? Explain. Specified states, the change in temperature between the end states is

Analytical definition of the gradient

This shows that the equation ∇T = (δT/δx)e1→+(δT/δy)e2→ cannot be used as the analytical definition of the gradient because it gives different results in different coordinate

Determine the maximum shear stress at the inner surface

The inner surface of a hollow cylinder is subjected to tangential and axial stresses of 40,000 and 24,000 psi, respectively. Determine the maximum shear stress at the inner

Determine the optimal replacement age of all tires or second

The tires that fail in a period are replaced in the same period. The company is currently considering two options. First, to determine the optimal replacement age (period) o

For the spring-mass-damper system

For the spring-mass-damper system (refer to Ogata Figure 4.1). (i) Find the equations of motion (the differential equation). Assume m = 1, b = 7, and k = 12. 1(ii) Assuming f(

Determine the rated power of the motor

The motor is delivering its rated output power at a speed of 910 rpm. Rotational loss of the motor is 600 watts. Using the approximate equivalent circuit, (a) determine the

What is the difference between initial and residual preload

What is the difference between initial and residual preload? Typically, what percentage of the work we do with a torque wrench ends up as preload in an individual bolt?

Calculate the force required in direct extrusion

Calculate the force required in direct extrusion of 1100-O aluminum from a diameter of 6 in. to 2 in. Assume that the redundant work is 30% of the ideal work of deformation,

Reviews

Write a Review

 
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd