Swedish heat pump project

Press, 14 May 1981, Page 16

Swedish heat pump project

From the Swedish International Press Bureau,

Stockholm

A full-scale project involving the use of exterior air to supply heat and hot water to 55 single-family houses in the city of Ronneby, South Sweden, has demonstrated that oil consumption can be reduced thereby by 60 per cent, reports Volvo Penta, who delivered the 127 KW low-speed diesel engine for the heat pump installation. The system is based on a design by Mr Lars Wahlgren, a Malmo engineer who has developed the two-stage, diesel engine-powered heat pump. Main units in the first stage are fans, an evaporator, a compressor, and a condenser, which operate within a temperature range of between - 20°C and +3O°C. The condenser '

in the first stage is integrated with the evaporator in the second stage, which also incorporates a second compressor and condenser and operates in the +24°C to +6O°C temperature range. The heat from the engine cooling jacket is delivered across the heat exchanger to a buffer tank and then on to the distribution pipes. Another heat exchanger is used to extract the heat from the engine exhaust gases. The system of distribution pipes delivers water at 60°C to the radiators of the individual houses, where the water is cooled to 40°C and is then returned to the heat pump unit. In addition, every house has its

own heat exchanger for supplying other domestic heat demands.

The system can supply the heat demands of the entire district without the need for make-up heat. It is the largest of its type in Sweden, with an output of 500 kW. The experimental plant is operated by the city of Ronneby and is receiving

financial and technical support from the Swedish Council for Building Research and from Studsvik Energy Technology. After evaluating this project, serial production of heating stations for groups of houses is being planned. The stations will be prefabricated, and will be delivered in a flexible container system for local installation.