Bench Top Mechanical Heat Pump Trainer .
The air-to-water heat pump trainer consists of a compressor, an evaporator with fan, a thermostatic expansion valve and a coaxial coil heat exchanger as condenser. All components are clearly arranged in the trainer.
The compressed refrigerant vapour condenses in the outer pipe of the condenser and thereby discharges heat to the water in the inner pipe. The liquid refrigerant evaporates at low pressure in the finned tube evaporator and thereby absorbs heat from the ambient air.
The hot water circuit consists of a tank, a pump and the condenser as heater. For a continuous operation the generated heat is dissipated via an external cooling water connection. The cooling water flow rate is set via a valve and measured.
Design and operation of an air-to-water heat pump
Representation of the thermodynamic cycle in the log p-h diagram
Determination of important characteristic variables
Compressor pressure ratio
Ideal coefficient of performance
Real coefficient of performance
Dependence of the real coefficient of performance on the temperature difference (air-to-water)
Operating behavior under load
Capacity: 372W at 7,2/32°C
Coaxial coil heat exchanger (condenser)
Refrigerant content: 0,55L
Water content: 0,3L
Finned tube evaporator
Transfer area: approx. 0,175m2
Max. Flow rate: 1,9m3/h
Max. Head: 1,4m
Hot water tank volume: approx. 4,5L
Filling volume: 1kg
Pressure: 2x -1…15bar
Temperature: 4x 0…100°C, 2x -100…100°C
Flow rate: 0…108L/h (water)
Flow rate: 10…160L/h (cooling water)
Required for operation
230V, 50Hz, 1 phase
230V, 60Hz, 1 phase