Heat pump heating and hot-water system

A heat pump heating and hot-water system comprising:

• a heat pump for heating a heating medium;
• one or a plurality of heating medium pumps for pumping the heating medium;
• a water heating heat exchanger for heating water by heat exchange between the heating medium and the water;
• an indoor heating heat exchanger for warming a room by the heating medium;
• a flow path switch configured to switch a destination of the heating medium between the water heating heat exchanger and the indoor heating heat exchanger;
• a heating medium piping for connecting the heating medium pump(s), the water heating heat exchanger, the indoor heating heat exchanger, and the flow path switch;
• a hot-water storage tank;
• one or a plurality of water pumps for pumping the water;
• a water piping for connecting the hot-water storage tank, the water pump(s), and the water heating heat exchanger, the water piping includes a piping circuit allowing the water taken out of the hot-water storage tank to go through the water heating heat exchanger and to return to the hot-water storage tank;
• a heat pump controller for controlling the heat pump;
• a pump controller for controlling the heating medium pump(s) and the water pump(s);
• a temperature sensor configured to detect a temperature of the heating medium flowing into the water heating heat exchanger;
• a temperature sensor configured to detect a temperature of the heating medium flowing out of the water heating heat exchanger;
• a temperature sensor configured to detect a temperature of the water flowing into the water heating heat exchanger;
• and
• a temperature sensor configured to detect a temperature of the water flowing out of the water heating heat exchanger, wherein
• the pump controller is configured to control a rotational speed of the heating medium pump(s), while the water is heated by the heat exchange between the heating medium and the water in the water heating heat exchanger, and maintain a difference between the detected temperature of the heating medium flowing into the water heating heat exchanger and the detected temperature of the heating medium flowing out of the water heating heat exchanger is smaller than or equal to a difference between the detected temperature of the water flowing out of the water heating heat exchanger and the detected temperature of the water flowing into the water heating heat exchanger.

A heat pump heating and hot-water system comprising:

• a heat pump for heating a heating medium;
• one or a plurality of heating medium pumps for pumping the heating medium;
• a water heating heat exchanger for heating water by heat exchange between the heating medium and the water;
• an indoor heating heat exchanger for warming a room by the heating medium;
• a flow path switch configured to switch a destination of the heating medium between the water heating heat exchanger and the indoor heating heat exchanger;
• a heating medium piping for connecting the heating medium pump(s), the water heating heat exchanger, the indoor heating heat exchanger, and the flow path switch;
• a hot-water storage tank;
• one or a plurality of water pumps for pumping the water;
• a water piping for connecting the hot-water storage tank, the water pump(s), and the water heating heat exchanger, the water piping includes a piping circuit allowing the water taken out of the hot-water storage tank to go through the water heating heat exchanger and to return to the hot-water storage tank;
• a heat pump controller for controlling the heat pump;
• a pump controller for controlling the heating medium pump(s) and the water pump(s),
• a temperature sensor configured to detect a temperature of the heating medium flowing into the water heating heat exchanger;
• and
• a temperature sensor configured to detect a temperature of the heating medium flowing out of the water heating heat exchanger,
• the pump controller comprising:
• a data storage table configured to store a pump characteristic curve of the water pump(s);
• a calculator configured to calculate a volumetric flow rate of the heating medium based on the detected temperature of the heating medium flowing into the water heating heat exchanger, the detected temperature of the heating medium flowing out of the water heating heat exchanger, and a heating power of the heat pump;
• and
• the calculator configured to calculate a volumetric flow rate of the water based on the pump characteristic curve of the water pump(s) and a rotational speed of the water pump(s),
• the pump controller being configured to control a rotational speed of the heating medium pump(s) and maintain the calculated volumetric flow rate of the heating medium pumped to the water heating heat exchanger by the heating medium pump(s) higher than or equal to the calculated volumetric flow rate of the water pumped to the water heating heat exchanger by the water pump(s).