Tankless water heater

Abstract

This invention is including a controller, a waterway and a heat pump circulation loop; the waterway, in the water-flowing direction, successively includes: an inlet, a heating part and an outlet; the heat pump circulation loop successively includes: a compressor, an evaporator, a condenser and a throttle device, wherein the compressor is in control connection with the controller, and the condenser includes a heating condenser and a pressure relief condenser, wherein the heating condenser is in heat conduction contact with the heating part in the waterway and is set in series with the pressure relief condenser in the heat pump circulation loop, besides, a heating condenser valve is set in the branch where the heating condenser lies and a pressure relief condenser valve in that where the pressure relief condenser stands, wherein the heating condenser valve and the pressure relief condenser valve are in control connection with the controller.

What is claimed is: 
     
         1 . A tankless water heater, characterized in that it includes a controller, a waterway, and a heat pump circulation loop; the waterway, in the water-flowing direction, successively includes: an inlet, a heating part and an outlet;
 The heat pump circulation loop successively includes: a compressor, an evaporator, a condenser and a throttle device, wherein the compressor is in control connection with the controller, and the condenser includes a heating condenser and a pressure relief condenser, wherein the heating condenser is in heat conduction contact with the heating part in the waterway and is set in series with the pressure relief condenser in the heat pump circulation loop, besides, a heating condenser valve is set in the branch where the heating condenser lies and a pressure relief condenser valve in that where the pressure relief condenser stands, wherein the heating condenser valve and the pressure relief condenser valve are in control connection with the controller;   The controller is used for controlling the opening and closing of the compressor, the heating condenser valve and the pressure relief condenser valve, specifically, when the water heater supplies hot water, keeping the heating condenser valve open; when requiring the closing of the compressor, judging whether the compressor running time is over the preset time, and if so, close the compressor; if not, close the heating condenser valve and open the pressure relief condenser valve, so as to enable the compressor to run till the preset time before closing it.   
     
     
         2 . The tankless water heater according to  claim 1 , characterized in that the tankless water heater includes a fan, wherein the evaporator and the pressure relief condenser are located in the same air duct formed by the fan. 
     
     
         3 . The tankless water heater according to  claim 1 , characterized in that the evaporator and the pressure relief condenser are in heat conduction connection via radiator. 
     
     
         4 . The tankless water heater according to any one of  claims 1  to  3 , characterized in that:
 the tankless water heater further includes an outflow water temperature sensor, which is connected with the controller and used for measuring the outflow temperature of the water in the waterway; 
 the controller is used to open the pressure relief condenser valve when the water heater supplies hot water and the outflow temperature measured by the outflow water temperature sensor is higher than the set pressure relief temperature. 
 
     
     
         5 . The tankless water heater according to any one of  claims 1  to  3 , characterized in that the heating condenser valve and the pressure relief condenser valve are solenoid valves. 
     
     
         6 . A tankless water heater, characterized in that, including a controller, a waterway and a heat pump circulation loop;
 In the water-flowing direction, the waterway successively includes: an inlet, a heating part and an outlet;   The heat pump circulation loop successively includes: a compressor, an evaporator, a condenser and a throttle device, wherein the compressor is in control connection with the controller, and the condenser includes a heating condenser and a pressure relief condenser, wherein the heating condenser is in heat conduction contact with the heating part in the waterway and is set in series with the pressure relief condenser in the heat pump circulation loop, besides, a heating condenser valve is set in the branch where the heating condenser lies and a pressure relief condenser valve in that where the pressure relief condenser stands, wherein the heating condenser valve and the pressure relief condenser valve are in control connection with the controller;   The controller is used for controlling the opening and closing of the compressor, the heating condenser valve and the pressure relief condenser valve, specifically, when the water heater supplies hot water, keeping the heating condenser valve open; when requiring the closing of the compressor, judging whether the compressor running time is over the preset time, and if so, close the compressor; if not, close the heating condenser valve and open the pressure relief condenser valve, so as to enable the compressor to run till the preset time before closing it.   
     
     
         7 . The tankless water heater according to  claim 6 , characterized in that the tankless water heater includes a fan, wherein the evaporator and the pressure relief condenser are located in the same air duct formed by the fan. 
     
     
         8 . The tankless water heater according to  claim 6 , characterized in that the evaporator and the pressure relief condenser are in heat conduction connection via radiator. 
     
     
         9 . The tankless water heater according to any one of  claims 6  to  8 , characterized in that the tankless water heater further includes an outflow water temperature sensor, which is connected with the controller and used for measuring the outflow temperature of the water in the waterway;
 The controller is used to open the pressure relief condenser valve when the water heater supplies hot water and the outflow temperature measured by the outflow water temperature sensor is higher than the set pressure relief temperature. 
 
     
     
         10 . The tankless water heater according to any one of  claims 6  to  8 , characterized in that the heating condenser valve and the pressure relief condenser valve are solenoid valves.