Quick heating type heat pump water heater for recovering shower waste heat

[0048] Such as figure 1 As shown, the heat pump water heater has the following parts: valve 1, condenser 2, auxiliary water tank 3, preheater 4, mixing water controller 5, spray device 6, regenerator 7, evaporator 8, compressor 9. Throttle device 10, main water tank 11. The positional connection relationship between them is: the regenerator 7 and the evaporator 8 are installed at the feet of the showerer, the regenerator 7 is on the upper side, and the evaporator 8 is on the lower; the spray device 6 is placed above the showerer’s head and another One end communicates with the water mixing controller 5; the preheater 4 is placed in the auxiliary water tank 3, the condenser 2 is placed in the main water tank 11, the water outlet of the auxiliary water tank 3 is connected with the inlet of the water mixing controller 5, and the auxiliary water tank 3 enters water One end of the valve 1 is connected with the water inlet pipe of the condenser 2; one end of the valve 1 is connected to the tap water, and the other end is connected to the inlet pipe of the main water tank 11 and the inlet pipe of the regenerator 7 through a three-way connection, and the outlet end of the regenerator 7 is connected to the mixed water The controller 5 is connected; the condenser 2, the throttling device 10, the evaporator 8 and the compressor 9 form a closed loop, the outlet of the condenser 2 is connected with the inlet of the throttling device 10, and the outlet of the throttling device 10 is connected to the evaporator 8. The inlet of the evaporator 8 is connected with the inlet of the compressor 9, and the outlet of the compressor 9 is connected with the inlet of the condenser 2.

[0049] The condenser 2 is a refrigerant flow and heat exchange channel, combined with the main water tank to form a liquid-liquid heat exchanger, here is a commercially available fully brazed stainless steel plate heat exchanger;

[0050] The evaporator 8 is a flat plate heat exchanger or a coil type heat exchanger, here is an open lattice plate heat exchanger of Foshan Delta Electric Technology Co., Ltd. (trade name is Bathing Bao);

[0051] The throttle device 10 is a capillary throttle commonly used in air conditioners;

[0052] The compressor 9 is a commercially available piston compressor or a vortex compressor;

[0053] The regenerator 7 is an open lattice plate heat exchanger of Foshan Delta Electric Technology Co., Ltd., here it is the upper heat exchange structure of the TL-07 "Bayubao";

[0054] The preheater 4 is an armored electric heating rod or a silicon nitride heating chip;

[0055] The main water tank 11 is a water flow and heat exchange channel, combined with a condenser to form a liquid-to-liquid heat exchanger, here is a commercially available fully brazed stainless steel plate heat exchanger;

[0056] The auxiliary water tank 3 is a cylindrical stainless steel or enamel container with a volume set to 3L;

[0057] The water mixing controller 5 is a commercially available thermostatic water mixing valve equipped with a temperature difference water flow exchange device (ZL200820204843.3) of Foshan Delta Electric Technology Co., Ltd.;

[0058] The spray device 6 is a commercially available shower head;

[0059] The valve 1 is a commercially available general valve, and a brass ball valve is selected.

[0060] Among them, valve 1 (including tee), main water tank 11, auxiliary water tank 3, water mixing controller 5 and spray device 6 constitute a waterway, called the main waterway; valve 1 (including tee), regenerator 7, The water mixing controller 5 constitutes a water circuit parallel to the main water circuit, called a branch water circuit; the spray device 6, the regenerator 7 (outer surface) and the evaporator 8 (outer surface) constitute an open water circuit, called the outer water circuit; The condenser 2, the throttling device 10, the evaporator 8 and the compressor 9 constitute a closed refrigerant circuit, called a heat pump circuit; the external waterway transfers part of the heat of the shower wastewater to the branch waterway through the regenerator 7; the external waterway through evaporation The heat pump 8 transfers part of the heat of the shower wastewater to the heat pump circuit, and the waste water after heat exchange is directly discharged; the heat pump circuit transfers the heat of the compressor 9 to the main waterway through the condenser 2.

[0061] Among them, the branch waterway is in parallel with the main waterway, and the water temperature of the branch waterway is lower than that of the main waterway. The two are mixed by the water mixing controller 5. The water mixing controller 5 adjusts the mixed water temperature through the flow ratio of the main waterway and the branch waterway, that is, the outlet water. Water temperature.

[0062] Among them, the preheater 4 in the auxiliary water tank 3 is equipped with a built-in temperature control device. The power of the preheater 4 is equivalent to the power of the compressor 9, and the two do not work at the same time. The two can be realized by manual control switches and automatic control devices. When the working status is switched, the spray device can be turned on when the average temperature of the auxiliary water tank 3 is above 45.0°C; the compressor 9 will only start when the spray device 6 discharges water and the water temperature of the auxiliary water tank 3 is lower than the water outlet temperature set by the user. Under other conditions under normal working conditions, the preheater 4 works.

[0063] The mixing water controller 5 can adjust the shower temperature after mixing the water by adjusting the flow of tap water in the regenerator 8.

[0064] The circulation route of the refrigerant is: evaporator 8→compressor 9→condenser 2→throttling device 10→evaporator 8. There are two pipelines for tap water, one is: condenser 2→water tank 3→mixing controller 5→spraying device 6, the other is: regenerator 7→mixing water controller 5→spraying device 6, two The tap water in the pipeline is finally mixed in the water mixing controller 5 for shower spraying, and then the shower waste water passes through the regenerator 7 and the evaporator 8 to recover heat. The two water circuits are connected in parallel. Compared with the series connection, the inlet water temperature of the condenser 2 is increased, the heat exchange temperature difference is reduced, and the heat exchange efficiency of the condenser 2 has a certain beneficial effect. At the same time, the size of the condenser 2 can be reduced to a certain extent, which is beneficial to the miniaturization of the heat pump water heater system.

[0065] When the water heater is used, it must be preheated first. When the temperature of the entire auxiliary water tank 3 is about 60℃, the water heater has been fully preheated and you can start showering. The preheating process takes more than 15 minutes; the preheater 4 is built-in The temperature controller will stop the preheater 4 to preheat when the temperature of the auxiliary water tank is higher than 75°C and wait for the user to take a shower. Taking a preheating power of 3500W, a 2.5L water tank and a water temperature of 15°C as an example, the preheating time is about 2.25 minutes.

[0066] The heat pump does not work for the first 10 seconds after the shower starts, and the hot water for the shower comes from the auxiliary tank. Assuming that the temperature of the water in the auxiliary tank in the shower room is 60℃, 10 seconds after the shower starts, that is, when the heat pump starts, the average of the auxiliary tank 3 The temperature is 50.5°C. During this period, the hot water in the auxiliary water tank 3 can fully meet the shower requirements. After the heat pump is turned on, the average temperature of the auxiliary water tank 3 will gradually decrease until it finally reaches an equilibrium state. When the power of the heat pump compressor 9 is 3500W, the efficiency is 0.8, and the condensate water flow rate is 4.8L/min, the outlet temperature of the auxiliary water tank 3 after equilibrium is 48.3°C. The change trend of the spray flow rate is also gradually decreasing, and will eventually reach an equilibrium state. If the shower temperature is set at 40°C, the spray water flow rate after reaching the equilibrium state is 9.1L/min. Then this state continues until the water stops during the shower.

[0067] After the water is stopped, the heat pump stops immediately, and the preheater 4 is turned on, and the water in the auxiliary water tank 3 is heated as the initial heat source when the heat pump restarts. There is still a 10 second delay when the heat pump restarts. When the water stop time is short, the heating effect of the preheater 4 will not be significant, and it may not be able to provide a sufficient initial heat source for the heat pump to start. Take the worst case as an example, that is, the sprinkler device 6 is started immediately after the water is stopped. The preheater 4 only works for 10 seconds each time. When the heat pump starts again, the temperature of the water in the auxiliary water tank 3 is 42.0°C, which is still sufficient. The shower hot water and meet the requirements of the initial heat source for heat pump startup. However, if the spray device 6 is turned on immediately after the water is stopped again, the outlet water temperature of the auxiliary water tank 3 when the heat pump restarts is 37.5°C, which will not meet the requirements of bathing and providing an initial heat source for the heat pump to start. That is to say, the sprinkler device 6 cannot be restarted immediately after the water is stopped for two consecutive times.

[0068] This situation is also rare, but it should still be considered. The best solution is to monitor the average temperature in the sub-tank 3. If it is necessary to ensure that the outlet water temperature of the auxiliary water tank 3 is above 40°C after spraying in 10s, the average temperature of the auxiliary water tank 3 must be maintained at least 45.0°C or more when the spray is started. Therefore, the average temperature of the auxiliary water tank 3 must be monitored. Through the control function of the control system, the spray device 6 can be turned on only when the average temperature of the auxiliary water tank 3 is above 45.0°C. When this rare situation occurs, the spray device 6 will not be able to discharge water after a certain period of time after the spray device 6 is turned on. However, due to the large power of the preheater, this time is very short and the longest does not exceed 15s. , Will not affect the normal use of users. figure 2 It is a schematic diagram of the control system of the heat pump water heater.