Water circulating working medium type heat-pump water heater

The invention relates to the field of water circulating working medium type heat-pump water heaters. The water circulating working medium type heat-pump water heater comprises a vertical water heater box body, a heat collector, a heat preserving water tank, a first heat exchanger, a second heat exchanger and a heat pump; the heat collector is connected with the second heat exchanger to form a circulating channel; a heat pump evaporator is positioned in the second heat exchanger; a heat pump condenser is positioned in the first heat exchanger; the heat preserving water tank communicates with the first heat exchanger to form another circulating channel; the water tank is mounted in the middle of the water heater box body; the heat pump is mounted at the bottom part of the water heater box body; the first heat exchanger and the second heat exchanger are annularly arranged at the outside of the heat preserving water tank and fixed on the water heater box body; the first heat exchanger and the second heat exchanger are sleeve type heat exchangers; the heat pump evaporator is used as a shell pass of the first heat exchanger, and the heat collector is connected with a tube pass of the first heat exchanger; the heat pump condenser is used as the shell pass of the second heat exchanger, and the heat preserving water tank is connected with the tube pass of the second heat exchanger.