Principle

Pressures and temperatures in the circulation of the heat electrical compression heat pump are measured as a function of time when it is operated as a water-water heat pump. The energy taken up and released is calculated from the heating and cooling of the two water baths. When it is operated as an air-water heat pump, the coefficient of performance at different vaporiser temperatures is determined.

Benefits

• Different operating modes possible
• For both demonstration and student experiments
• Simple set-up

Tasks

1. Water heat pump: To measure pressure and temperature in the circuit and in the water reservoirs on the condenser side and the vaporiser side alternately. To calculate energy taken up and released, also the volume concentration in the circuit and the volumetric efficiency of the compressor.
2. Air-water heat pump: To measure vaporiser temperature and water bath temperature on the condenser side under different operating conditions on the vaporiser side,

• with stream of cold air,
• with stream of hot air,
• without blower.

If a power meter is available, the electric power consumed by the compressor can be determined with it and the coefficient of performance calculated.

Learning objectives

• Refrigerator
• Compressor
• Restrictor valve
• Cycle
• Vaporization
• Condensation
• Vapour pressure
• Vaporisation enthalpy