The principle is similar to conventional heat pumps. The basis is a small gas engine and an industrial compressor which are connected to a coolant circuit together with an evaporator and a condenser. The unit delivers cold from the evaporator circuit and the heat released from the condenser, engine block and exhaust gases. In case of necessity, the unit can operate in pure heating mode under favourable climatic conditions, it can „take“ the heat from the surroundings (increase of heat output).
The gas engine burns the natural gas, heats itself up, generates exhaust gases and rotates the piston compressor. The combustion engine must, of course, be cooled, the heat can be taken away through the heat exchanger and used for heating or warming the non-potable water (NPW, 90°C). The produced exhaust gases also carry a considerable amount of usable energy. It can be used due to an additional condensing exhaust gas exchanger. The compressor generates, through its activity, different physical conditions at the inlet and outlet of the compressor – the whole compressor circuit is divided into 2 parts through the work of an expansion valve, the condenser side and the evaporator side. In the compressor circuit, the coolant circulates in gaseous or liquid state.
Coefficient of performance = ratio of energy output and input. Further information can be found in the section “Frequently Asked Questions“.
At the compressor displacement, the coolant is forced to condensate by the increase of pressure. Condensation of coolant vapors accompanied by heat release occurs in the condensator. Such heat can subsequently be used for example for heating (low-temperature heat, temperature around 50°C).The expansion valve located in front of the evaporator releases the pressure in the compressor suction circuit and ensures the injection of the coolant into the evaporator in which the coolant evaporates even at a relatively low temperature, thereby removing the heat from the surrounding (cooling the surrounding area). We use this part of the compressor circuit for cooling we take the heat from the places where it is undesirabe or from where it must be “moved” elsewhere.
The designing of the TEDOM Polo 100 gas heat pump was based on years of development, production and operation of CHP units. Due to this fact, the servicing and maintenance of the engine part of a gas heat pump is similar to that of the TEDOM CHP units.
The compressor part in which the coolant circulates, was engineered directly by a producer of heat pumps and its maintenance is not much different from the maintenance of conventional heat pumps.