Small thermostatic electric storage water heater for water supply terminal

Abstract

Disclosed is a thermostatic, electric storage, water heater for a water supply terminal, which mainly consists of a water storage tank (2), a heating pipe (3), a three-way water valve (16), an electrical control three-way water valve (11), a thermostatic water valve (9) for mixing hot and cold water, and a controller (13), wherein a horizontal end of the three-way water valve (16) is connected to a water inlet pipe of a hot water source, and a lower end thereof is connected to a second water inlet (17) of the electrical control three-way water valve (11). A fifth water inlet (4) on a lower end of the electrical control three-way water valve (11) is connected to a tap-water pipe, and a horizontal end thereof is connected to a third water inlet (12) of the thermostatic water valve (9) for mixing hot and cold water. Temperature signals and water flow signals from the heating pipe (3), the three-way water valve (16) and a water flow sensor (14) provided inside the thermostatic water valve (9) for mixing hot and cold water are transmitted to the controller (13). The electric water heater can quickly obtain continuous and stable constant-temperature hot water.

Claims

1. An electric water storage heater for a water supply terminal and in fluid communication with a hot water source inlet pipe and an external water source inlet pipe, the electric water storage heater comprising: a housing; a water storage tank arranged in the housing; a heating pipe disposed in the water storage tank; a three-way water valve arranged in the housing, the three-way water valve including a horizontal terminal connected to the hot water source inlet pipe, a lower terminal connected to the external water source inlet pipe via an electrically controlled three-way water valve, and an upper terminal connected to a fourth water inlet located at a lower portion of the water storage tank; the electrically controlled three-way water valve arranged between the three-way water valve and the thermostatic hot-and-cold water mixing valve, the electrically controlled three-way water valve including a second water inlet connected with the lower terminal, a fifth water inlet connected to the external water source inlet pipe, and a horizontal terminal having a first water outlet; a thermostatic hot-and-cold water mixing valve arranged in the housing, the thermostatic hot-and-cold water mixing valve including a second water outlet, a sixth water inlet, and a third water inlet being connected with the first water outlet; a first temperature sensor arranged in the heating pipe, the first temperature sensor including a signal output terminal; a second temperature sensor arranged in the three-way water valve, the second temperature sensor including a signal output terminal; a water flow sensor arranged in the second water outlet, the water flow sensor including a signal output terminal; a controller arranged in the housing, the controller including three signal input terminals connected to the respective signal output terminals of the first temperature sensor, the second temperature sensor, and the water flow sensor, and including three control signal output terminals respectively connected to a signal input terminal of the heating pipe, a signal input terminal of the electrically controlled three-way water valve, and a signal input terminal of the thermostatic hot-and-cold water mixing valve; and a first water pipe including a lower terminal vertically disposed and connected to the sixth water inlet, and an upper terminal connected to a cavity in an upper portion of the water storage tank.

2. The electric water storage heater according to claim 1, wherein the water storage tank has a volume in a range of 3 L-10 L.

3. The electric water storage heater according to claim 1, wherein the heating pipe has an electric power in the range of 600 w-3 kW.

4. The electric water storage heater according to claim 1, wherein the thermostatic hot-and-cold water mixing valve has a water outlet temperature in the range of 30 C.-55 C.

5. The electric water storage heater according to claim 1, wherein a temperature of hot water from the first water pipe or a temperature of hot water supplied from the hot water source inlet pipe is higher than a preset water outlet temperature of the thermostatic hot-and-cold water mixing valve.

6. The electric water storage heater according to claim 1, wherein when a temperature of water flowing from the hot water source inlet pipe to the three-way water valve is far lower than a preset water outlet temperature, the controller is configured to output a control signal to the electrically controlled three-way water valve that effects closure of the fifth water inlet, and when the temperature of water flowing from the hot water source inlet pipe to the three-way water valve rises to a temperature which is 1 C.-4 C. below the preset water outlet temperature, the controller is configured to output a control signal to the electrically controlled three-way water valve that effects switching and closure of the second water inlet of the electrically controlled three-way water valve, and wherein a switching time between closing the fifth water inlet and closing the second water inlet is in a range of 10 seconds to 60 seconds.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of the structure of the small water storage thermostatic electric water heater for a water supply terminal of the present disclosure.

(2) FIG. 2 is a schematic cross-sectional view of the electrically controlled three-way water valve shown in FIG. 1.

DETAILED DESCRIPTION

(3) The present disclosure is discussed in detail through the following embodiment.

(4) As shown in FIG. 1, there is provided a small water storage electric water heater for a water supply terminal comprising a housing 1, a water storage tank 2, a three-way water valve 16, an electrically controlled three-way water valve 11 and a thermostatic hot-and-cold water mixing valve 9. The water storage tank 2 is internally provided with a heating pipe 3. A first temperature sensor 19 is arranged in the heating pipe 3. An upper terminal of the three-way water valve 16 is connected with a fourth water inlet 6 at the lower portion of the water storage tank 2. A lower terminal of the three-way water valve 16 is connected with a second water inlet 17 of the electrically controlled three-way water valve 11. A horizontal terminal of the three-way water valve 16 is connected with a first water inlet 5 of the hot water source inlet pipe. A second temperature sensor 15 is inside the three-way water valve 16. The lower terminal of the electrically control three-way water valve 11 is connected with the fifth water inlet 4 of, for example, the external water source pipe of the external device. The first water outlet 18 at the horizontal terminal of the electrically controlled three-way water valve 11 is connected to the third water inlet 12 of the thermostatic hot-and-cold water mixing valve 9. The sixth water inlet 8 of the thermostatic hot-and-cold water mixing valve 9 is connected to a lower terminal of the first water inlet 7 which is vertically disposed. An upper terminal of the first water pipe 7 is connected to a cavity in an upper portion of the water storage tank 2. The thermostatic hot-and-cold water mixing valve 9 is provided with a second water outlet 10. A water flow sensor 14 is disposed in the second water outlet 10. A signal output terminal of the first temperature sensor 19, a signal output terminal of the second temperature sensor 15 and a signal output terminal of the water flow sensor 14 are respectively connected with three signal input terminals of the controller 13. Three control signal output terminals of the controller 13 are respectively connected with a signal input terminal of the heating pipe, a signal input terminal of the electrically controlled three-way water valve, and a signal input terminal of the thermostatic hot-and-cold water mixing valve 9.

(5) The panel of the controller 13 is mounted on the surface of the housing 1. The water outlet temperature and the preset water outlet temperature are displayed on the panel. The preset water outlet temperature can be changed by pressing the keys. The preset water outlet temperature of the thermostatic hot-and-cold water mixing valve is set between 30 C. and 55 C. The volume of the water storage tank 2 is within 3 L-10 L. The electric power of the heating pipe 3 is within 600 W-3 KW. The temperature of the hot water flowing out from the first water pipe 7 or the hot water supplied by the hot water source is required to be higher than the preset water outlet temperature of the thermostatic hot-and-cold water mixing valve. When temperature of water flowing from a hot water source to the three-way water valve 16 via the first water inlet 5 is far lower than a preset water outlet temperature, the controller 13 outputs a control signal to the electrically controlled three-way water valve 11, closing the fifth water inlet 4, and when the temperature of water flowing from a hot water source to the three-way water valve 16 rises to a temperature which is 1 C.-4 C. below the preset water outlet temperature, the controller 13 outputs a control signal to the electrically controlled three-way water valve 11, switching to close the second water inlet 17 of the electrically controlled three-way water valve 11. The switching time between closing the fifth water inlet and closing the second water inlet is in the range of 10 s-60 s.

(6) After the electric water heater works is powered on, the heating pipe 3 is energized to heat up, heating the water in the water storage tank 2 to about 75 C.

(7) When the water is used, the controller 13 starts upon the signal output by the water flow sensor 14. The thermostatic hot-and-cold water mixing valve 9 mixes the high temperature water flowing from the high temperature water outlet 7 of the water storage tank 2 with the cold water flowing from the first water inlet 18 of the electrically controlled three-way water valve 11 to be thermostatic hot water with the same temperature as the preset water outlet temperature for flowing from the second water outlet 10. At this time, if the controller 13 detects, from the second temperature sensor 15 of the three-way water valve 16, that the temperature of the water flowing from the first water inlet 5 of the three-way water valve 16 is 2 C. lower than the preset water outlet temperature, the controller 13 instructs the electronic control three-way water valve 11 to close the fifth water inlet 4. A part of the water flowing from the hot water source via the first water inlet 5 of the three-way water valve enters the water storage tank 2 via the fourth water inlet 6, while the other part of the water enters the third water inlet 12 of the hot and cold mixing thermostatic water valve 9 via the three-way water valve 16, the second water inlet 17 of the electrically controlled water valve 11. At this time, the hot water source water flow amount is equal to the thermostatic water outlet amount of the electric water heater. By contrast, if there is no electrically controlled three-way water valve 16, the water flowing from the hot water source enters the water storage tank 2 alone. At this time, small amount of hot water in the water storage tank 2 can be mixed with the unheated water to produce thermostatic hot water with proper temperature. At this time, the hot water flow amount of the hot water source is equal to that of the hot water. The cold water in the heating pipe between the hot water source and the first water inlet 5 increases to several times much due to the small flow amount when replaced by the hot water. That is, the hot water in the water storage tank 2 is replenished by plenty of cold water and the temperature thereof drops dramatically. If there is no electrically controlled three-way water valves as illustrated in this embodiment, the equivalent volume of the water storage tank 2 will be increased many times, so that the first-cold-then-hot phenomenon occurs before the hot water from the hot water source arrives.

(8) When the hot water flow in the hot water source water inlet pipe gradually replaces cold water in the pipe, the temperature of water flowing into the first water inlet 5 of the three-way water valve gradually increases. When the second temperature sensor 15 detects that the water temperature is close to the preset water temperature, the controller 13 instructs the electronically controlled three-way water valve 11 to switch from closing the fifth water inlet 4 to closing the second water inlet 17. The embodiment begins when the difference between the hot water source water inlet temperature and the preset water outlet temperature is 2 C. It takes about 20 s to switch the three-way water valve 11 from totally closing the fifth water inlet to totally closing the second water inlet 17.

(9) One, non-limiting, example of a thermostatic hot-and-cold water mixing valve is taught in Patent Publication No. CN101893114B, titled: A Mixing Adjustment Thermostatic Water Valve With Pressure Balance Device, and is incorporated herein in its entirety. Such thermostatic hot-and-cold water mixing valves may have a good thermostatic effect, and may produce thermostatic hot water with the same temperature as the outlet water within several seconds.

(10) As shown in FIG. 2, the second water inlet 17 and the fifth water inlet 4 of the electrically controlled three-way water valve 11 are respectively provided with one-way valves 11a and 11b to prevent the regulating member 11c from making the water flow back and forth due to the pressure difference between the fifth water inlet 4 and the second water inlet 17, in the procedure of switch of the valve inlet or outlet 11d, 11e closing, causing the water temperature of the third water inlet 12 of the thermostatic hot-and-cold water mixing valve 9 to fluctuate repeatedly. The pressure balance device 11f can make the electronically controlled three-way water valve 11 normally perform closing switching operation and achieve good closing effect when the water pressure difference between the fifth water inlet 4 and the second water inlet 17 is more than 0.5 Mpa.

(11) When the controller 13 receives the water flow signal of the water flow sensor 14, if the water flow signal is smaller than the normal value, the controller 13 sends a heating instruction to the heat pipe 3 in the water storage tank 2, ordering the heating pipe 3 to heat up at once, even if the temperature of the water in the water storage tank 2 has reached 75 C., and ordering the heating pipe 3 to stop heating up when the water temperature in the water storage tank 2 reaches 80 C., thus increasing equivalent volume of the water storage tank 2.

(12) In the condition approaching the hot water supply maximum limit, the volume of the water storage tank 2 is selected as 5 liters, the water temperature in the high temperature water storage tank 2 is selected as 75 C., the total volume of the water inlet pipe is selected as 6 liters, the cold water temperature in the water inlet pipe is selected as 5 C., the preset water outlet temperature is selected as 50 C., the theoretical volume of the 50 C. thermostatic hot water formed by mixing the 75 C. hot water in the water storage tank 2 with the 5 C. cold water flowing from the water inlet pipe is 7.8 liters. And, in further consideration of the volume increase effect brought about by the heating pipe 3 heating up forcibly in the procedure of water inlet pipe emptying, as long as the temperature of the hot water supplied later by the hot water source is above the preset water outlet temperature and the hot water supplied later by the hot water source has enough hot energy, the notable effect that the continuous stable thermostatic hot water can be provided in several seconds is achieved.

(13) While the above disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from its scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiments disclosed, but will include all embodiments falling within the scope of the present disclosure.