Vibrationsdämpning av värmepump
Thermia Värme AB is one of the market leading manufactures of heat pumps. In order tomaintain this position, the company wants to improve the vibration characteristics of theirproducts. The aim of this thesis is to develop product design changes that lead to a reductionof vibrations in the heat pump Thermia Diplomat 8.The main cause for vibrations in the system is flow pulsation and mechanical forces inducedby the scroll compressor. Vibration is transmitted through the compressor piping and receivedby the heat exchangers, from where it is further transmitted to the connection points for theradiator and heat source circuits.A number of design changes in order to improve the vibration characteristics have beenevaluated through calculations and practical experiments. The changes have included thecompressor and heat exchanger mountings, the compressor suction and discharge line pipingand also pulsation dampening.The results of the experiments show that the vibration levels in the connections for the heatingand brine circuits can be decreased strikingly through changes in suction and discharge linepiping. Further improvements concerning the vibration levels in both the heating and brineconnections and the framework of the heat pump are achieved through detaching the heatexchanger mountings from the compressor mounting plate.Furthermore, a number of proposals to additional improvements of the system have beenlightly described. These suggestions include modification of the heating and brine circuitpiping. Significant improvements are considered to be achieved through using the big massinertia of the hot water tank as an isolating element for the piping connections. Also areplacement of copper tubes that have unwanted natural frequencies with shorter pipe lengthsor flexible hoses would decrease the vibration transmission.