Product number: R853

The unit may be regarded as a combined heat engine and a refrigerator/heat pump. The system powering the refrigerator/heat pump works on the well-known Rankine cycle (frequently used in steam power plants.) In this cycle the unit takes in heat at a very modest temperature (about 90°C) and rejects heat at the condenser temperature (about 30°C). The work output of this engine is in the form of the kinetic energy of a jet instead of shaft work as is normal with a Rankine cycle.

The refrigerator/heat pump operates on the Vapour Compression Cycle and uses the output of the Rankine Cycle (i.e. the kinetic energy of the jet). It takes in heat at a low temperature in an evaporator and rejects heat at a higher temperature using the same condenser as the engine.

Both the Rankine Power Plant Cycle and the Vapour Compression/Heat Pump Cycle are included in most courses of study for young engineers. The Hilton Vapour Jet Refrigerator/Heat Pump R853 demonstrates practically, the potential of combining these cycles so that a heat pump or refrigerator can be run from a heat output.

Specifications and resources

Panel: High quality GRP.
Steam Generator: Rectangular GRP insulated vessel fitted with 1.5kW immersion heater and containing the refrigerant vapour generator.
Refrigerant Vapour Generator: stainless steel shell, Ø75mm x 200(L) mm, with sight glass and pre-heating coil.
Ejector Nozzle: Convergent-divergent, throat diameter 1.7mm.
Compressor Diffuser: With combining cone, parallel and divergent portions.
Evaporator: Thick walled glass cylinder, incorporating a 500W heater controlled by a variable transformer and a float type expansion valve.
Condenser: Thick walled glass cylinder fitted with water cooling coil. Surface area of coil: 0.1m2.
Feed Pump:
Throttle Valve: Manually adjustable to vary nozzle inlet pressure.
Thermometer: Digital type K, 0.1°C resolution, 12 way selector connected to 9 thermocouples.
Pressure Gauges:
- Two, range 0 to 800 kNm-2 to indicate refrigerant vapour generator and nozzle inlet pressure.
- Two, range – 100 to + 100 kNm-2 to indicate evaporator and condenser pressure.
Flow Meter: Variable area glass tube type. Range 0 to 75g s-1.
Voltmeter and Ammeter: To measure power input to evaporator. Ranges 0 to 250Vand 0 to 3A respectively.
Pressure Relief Valves: Fitted to vapour generator, evaporator and condenser.
High Pressure Cut Out: Fitted to vapour generator and condenser.
Low Water Flow Switch: To switch off power supply if insufficient water flows through the condenser.
Solenoid Valve: To isolate vapour generator from ejector, evaporator and condenser.
High Temperature Cut Out: Fitted to all heater elements.
All circuits are protected by a fuse.