HEAT-PUMP HOT WATER APPARATUS

摘要

In conventional heat-pump hot water apparatuses, a circulation pipeline forming a boil-up circulating path has different length depending on a distance between a hot water storage tank and a water-cooling medium heat exchanger, and the number of bending parts is different depending on a route of the pipeline. Consequently, a method for controlling the circulating flow rate using the rotation speed of a circulation pump has a problem of uncontrollability to the target circulating flow rate because of variation in the pump flow rate corresponding to the rotation speed of the pump depending on a pressure loss of the boil-up circulating path. If control is performed by directly measuring the circulating flow rate within the circulating path using a flow sensor, control to the desirable circulating flow rate is possible, although the component count is increased due to use of the flow sensor, or malfunction of the flow sensor takes place due to foreign particles clogged in the sensor or any other problems. The heat-pump hot water apparatus corrects the output of the circulation pump such that the circulating water flow rate is controlled to the setting value when the flow rate is different from the setting value due to resistance caused by the length or the number of the bending parts of the circulating path between the hot water storage tank and a water-cooling medium heat exchanger.