WATER HEAT SOURCE HEAT PUMP UNIT PIPING SYSTEM

PROBLEM TO BE SOLVED: To provide a water heat source heat pump unit piping system capable of reducing power of a heat source water pump in the state of maintaining functions of respective water heat source heat pump units installed in a plurality of groups.SOLUTION: The system 10A performs a normal operation mode and an energy-saving operation mode depending on a temperature of heat source water. In the normal operation mode, a feed rate of a pump 13 is kept at a normal flow rate; the heat source water fed from the pump 13 flows into feed branch pipes 16a of the groups 18-21 from a feed main 15a; and the heat source water heat-exchanged in units 14a-14d flows into a return main pipe 15b from return branch pipes 16b of the groups 18-21. In the energy-saving operation mode, the heat source water heat-exchanged in the respective units 14a and 14c of the groups 18 and 20 flows into the feed branch pipes 16a of the groups 19 and 21 via bypass pipes 39 and 45, so as to be reused in the units 14b and 14d.