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# Bianca Hopes "The B" Group

PublicÂ·40 members
Frank Pruett

# Experiment 1: Refrigeration and Mechanical Heat Pump Experiment

## Experiment 1: Refrigeration and Mechanical Heat Pump Experiment

In this experiment, students will learn about the principles and applications of refrigeration and mechanical heat pump systems. They will use a thermodynamic cycle simulator to model the performance of a vapor-compression refrigeration system and a mechanical heat pump system under different operating conditions. They will also measure the actual coefficient of performance (COP) of a refrigeration unit and compare it with the theoretical value.

## Experiment1RefrigerationandMechanicalHeatPumpExperimentpdf

The objectives of this experiment are:

• To understand the basic components and operation of a vapor-compression refrigeration system and a mechanical heat pump system.

• To analyze the thermodynamic cycle of a refrigeration system and a heat pump system using a pressure-enthalpy diagram.

• To calculate the theoretical COP of a refrigeration system and a heat pump system using the first law of thermodynamics.

• To measure the actual COP of a refrigeration unit and compare it with the theoretical value.

The equipment used in this experiment are:

• A refrigeration unit with a compressor, a condenser, an expansion valve, and an evaporator.

• A thermodynamic cycle simulator software that can plot pressure-enthalpy diagrams and calculate COP values.

• A digital thermometer, a pressure gauge, and a wattmeter to measure the temperature, pressure, and power input of the refrigeration unit.

The procedure of this experiment are:

• Set up the refrigeration unit and connect it to the power supply.

• Turn on the refrigeration unit and let it run for 10 minutes to reach steady state.

• Measure and record the temperature and pressure at different points of the refrigeration cycle (compressor inlet, compressor outlet, condenser outlet, expansion valve outlet, evaporator outlet).

• Measure and record the power input of the compressor using the wattmeter.

• Use the thermodynamic cycle simulator software to plot the pressure-enthalpy diagram of the refrigeration cycle and calculate the theoretical COP.

• Calculate the actual COP of the refrigeration unit using the measured data and compare it with the theoretical value.

• Repeat steps 2 to 6 for different settings of the expansion valve (high, medium, low) and observe how they affect the performance of the refrigeration system.

• Switch the mode of the refrigeration unit to heat pump mode and repeat steps 2 to 7 for different settings of the expansion valve (high, medium, low) and observe how they affect the performance of the heat pump system.

The expected results and discussion points are:

• The theoretical COP of a refrigeration system is higher than that of a heat pump system for the same operating conditions.

• The actual COP of a refrigeration unit is lower than the theoretical COP due to irreversibilities such as friction, heat loss, pressure drop, etc.

• The COP of a refrigeration system or a heat pump system increases as the expansion valve setting decreases (higher throttling effect).

• The pressure-enthalpy diagram shows that a higher expansion valve setting results in a larger area enclosed by the cycle curve, which means more work input and more heat output.

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