Abstract
This is a basic study on utilizing the urban waste heat of low level temperature to district heating and cooling systems of Sapporo City. Firstly, we estimated the energy demand used for the domestic sector of Sapporo and its spacial distribution, both which are to be fundamental materials for the study. The total energy demand and total heat demand per annual were 40×10^3TJ and 30×10^3TJ, respectively. We also evaluated the existing urban waste heat and its distribution in the city, and the total amounts to 11×10^3TJ per annual. As for the low level temperature waste heat, through the evaluation, it has been seen that because of low quality the directutilization such as snow melting is to be planned in the first place in the case of Sapporo. A method of assessment is required for the low level temperature waste heat. Then, some performance indices have been produced. They show advantages of the heat pump utilizing the low level waste heat as heat source, against the air source heat pump, in view of energy conservation. Being examined on characteristics and applied to the existing sewage waste heat, these indices have been confirmed to have very usefulness. Lastly, we have indicated a procedure to judge whether to utilize low level waste heat through a simulation on an area where a district heating is assumed possible, to which the indices are actually applied.
