CN111426051A - A gas water heater with a flow limiting device and a control method thereof - Google Patents

Abstract

The present invention discloses a gas water heater with a flow limiting device and a control method thereof, comprising a controller, a heat exchanger, a water inlet pipe and a water outlet pipe, wherein two ends of the heat exchanger are respectively connected to the water inlet pipe and the water outlet pipe, a mixing water pipe is connected between the water inlet pipe and the water outlet pipe, a flow limiting device is arranged on the water inlet pipe, and the flow limiting device is located at the rear end of the connection between the mixing water pipe and the water inlet pipe, the flow limiting device comprises a flow limiting valve body, a flow limiting water inlet and a flow limiting water outlet are respectively arranged at two ends of the flow limiting valve body, a parallel main water path and a bypass water path are arranged in the flow limiting valve body, a main path solenoid valve is arranged on the flow limiting valve body for conducting or cutting off the main water path, and the main path solenoid valve is electrically connected to the controller, which can accelerate the heating of hot water, shorten the waiting time for hot water, and reduce water waste.

Description

A gas water heater with a flow limiting device and a control method thereof

technical field

The invention relates to the technical field of water heaters, in particular to a gas water heater with a flow limiting device and a control method thereof.

Background technique

In the related art, when the user opens the hot water faucet for the first time, the tap water flows into the gas water heater. At this time, the water flow sensing device of the main water circuit of the gas water heater detects that there is water flow, and then opens the gas valve to ventilate and ignite to heat the tap water. The difference between the preset temperature and the outlet water temperature controls the opening of the gas valve, so that the outlet water temperature gradually reaches the preset temperature of the gas water heater and achieves constant temperature hot water output. The time interval from monitoring the passing of water to the ignition of the gas water heater is at least 2 seconds. It still takes about 20 seconds from the ignition until the outlet water temperature reaches the preset temperature. In addition, it takes a certain amount of time for the hot water to flow through the hot water pipe to the hot water faucet. , the time depends on the length of the pipe and the flow rate of the water; it can be seen that, after opening the hot water faucet, the ordinary constant temperature gas water heater will flow out a period of cold water and then the hot water. It usually takes more than 30 seconds from opening the hot water faucet to the flow of comfortable hot water, and the user needs to The hot water cannot be used until the cold water is finished, which will cause a large amount of tap water to be wasted in vain. Especially in winter, due to the low temperature of tap water and high water temperature demanded by users, the heating time of gas water heaters is prolonged, and the time for users to wait for hot water to be produced is correspondingly prolonged, which makes users vulnerable to cold and wastes more tap water.

In addition, when the ordinary gas water heater turns off the water in the middle of the user's bath, the heat exchange fins still transfer the waste heat to the stored water in the heat exchanger after the gas water heater is turned off, and form a section of high temperature water. Generally speaking, the greater the firepower before the flame is turned off, the higher the temperature of the stored water will rise. When using an ordinary gas water heater, the water is turned off and restarted in the middle. After the hot water faucet runs out of the hot water stored in the hot water pipe section, it then flows out of the high-temperature storage water in the heat exchanger, and then flows out of a section of low-temperature tap water that will not be heated in the future, and the water temperature suddenly rises. dip phenomenon.

It can be seen that ordinary gas water heaters have the following defects: the first startup of hot water is slow, and too much cold water needs to be released; the water is turned off and restarted in the middle, the temperature of the water is too high, and the heat and cold are sudden, which affects the safety of bathing and wastes water resources.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the problems existing in the related art at least to a certain extent. Therefore, the present invention proposes a gas-fired water heater with a current limiting device, which can speed up the heating of hot water and shorten the waiting time for hot water. Reduce water waste.

The above purpose is achieved through the following technical solutions:

A gas-fired water heater with a flow limiting device, comprising a controller, a heat exchanger, a water inlet pipe and a water outlet pipe, the two ends of the heat exchanger are respectively connected with the water inlet pipe and the water outlet pipe, and the water inlet pipe and the water outlet pipe are respectively connected to A water mixing pipe is connected between the water outlet pipes, and a flow limiting device is arranged on the water inlet pipe. The current limiting device is located at the rear end of the connection between the mixing water pipe and the water inlet pipe. A flow valve body, a limited flow inlet and a limited flow outlet are respectively provided at both ends of the flow limiting valve body, and a parallel main water channel and a bypass water channel are arranged in the flow limiting valve body, and the two ends of the main water channel are respectively connected with The flow-limiting water inlet is communicated with the flow-limiting water port, the two ends of the bypass water path are respectively communicated with the flow-limiting water inlet and the flow-limiting water port, and a main-circuit solenoid is arranged on the flow-limiting valve body. The valve is used to conduct or cut off the main water circuit, and the main circuit solenoid valve is electrically connected to the controller.

In some embodiments, the limited flow of the main waterway is greater than the limited flow of the bypass waterway.

In some embodiments, a steady flow valve core is provided in the bypass water path, and the current limiting value of the steady flow valve core is greater than the start-up water flow rate of the gas water heater.

In some embodiments, the pipe diameter of the water mixing pipe is 3 to 5 mm, and the pipe diameter of the water inlet pipe is 10 to 16 mm.

In some embodiments, a water flow detection device is provided on the water inlet pipe, the water flow detection device is located at the front end of the connection between the mixing pipe and the water inlet pipe, and an outlet water temperature detection device is provided on the water outlet pipe , the outlet water temperature detection device is located at the rear end of the connection between the mixing pipe and the water outlet pipe, and the controller is electrically connected to the water flow detection device and the outlet water temperature detection device respectively.

In some embodiments, a burner, a gas control valve and an operation display are also included, wherein the gas control valve is communicated with the intake end of the burner, and the controller is respectively connected with the gas control valve, the Operate the electrical connection of the monitor.

In some embodiments, the controller controls the gas control valve to work so that the outlet water temperature of the gas water heater reaches a preset temperature, wherein the temperature control time during which the controller controls the gas control valve to work is calculated and obtained according to the following formula :

t=(t _max −t _min )×(T _preset− T _{preset min} )/(T _{preset max} −T _{preset min} )+t _min ;

Among them, t _max is the maximum program temperature control time, t _min is the minimum program temperature control time, T _preset is the user preset temperature, T _{preset max} is the maximum preset temperature of the program, and T _{preset min} is the minimum preset temperature of the program .

In addition, the present invention provides a control method of a gas water heater with a flow limiting device, which can speed up the heating of hot water, shorten the waiting time for hot water, and improve the comfort of bathing.

The above purpose is achieved through the following technical solutions:

A control method for a gas water heater with a flow limiting device, applied to the gas water heater as described above, the control method includes the following steps:

Determine whether the measured water flow is greater than the startup water flow;

If the measured water flow is greater than the startup water flow, control the gas water heater to turn on the ignition and enter the shower working mode;

Control the main circuit solenoid valve to cut off the main water circuit, and adjust the opening of the gas control valve to control the outlet water temperature;

After reaching the first program temperature control time, determine whether the outlet water temperature is greater than the preset temperature;

If the outlet water temperature is greater than the preset temperature, the solenoid valve of the main circuit is controlled to conduct the main water circuit, and the opening of the gas control valve is adjusted to control the outlet water temperature.

In some embodiments, it also includes the following steps:

After reaching the second program temperature control time, determine whether the water temperature is lower than the preset temperature;

If the outlet water temperature is lower than the preset temperature, control the main circuit solenoid valve to cut off the main water circuit, and adjust the opening of the gas control valve to control the outlet water temperature;

If the outlet water temperature is greater than the preset temperature, judge whether the measured water flow is less than the shutdown water flow. If the actual measured water flow is greater than the shutdown water flow, continue to control the outlet water temperature with the opening of the gas control valve. If the measured water flow is smaller than the shutdown water flow, control the Turn off the gas water heater to exit the shower working mode, and control the main circuit solenoid valve to cut off the main water circuit.

In some embodiments, after reaching the first program temperature control time, the step of judging whether the outlet water temperature is greater than the preset temperature includes:

If the outlet water temperature is lower than the preset temperature, judge whether the measured water flow is smaller than the shutdown water flow. If the measured water flow is greater than the shutdown water flow, continue to control the outlet water temperature with the opening of the gas control valve. If the measured water flow is smaller than the shutdown water flow, control the Turn off the gas water heater to exit the shower working mode, and control the main circuit solenoid valve to cut off the main water circuit.

Compared with the prior art, the present invention at least includes the following beneficial effects:

1. The gas water heater with the current limiting device of the present invention can speed up the heating of hot water, shorten the waiting time of hot water, and reduce water waste;

2. The control method of the gas water heater with the current limiting device of the present invention can speed up the heating of the hot water, shorten the waiting time of the hot water, and improve the comfort of bathing.

Description of drawings

1 is a schematic structural diagram of a gas water heater in a small water gear state in an embodiment;

2 is a schematic structural diagram of the gas-fired water heater in a state of large water gear in the embodiment;

Fig. 3 is the structural representation of the current limiting device in the embodiment;

4 is a schematic flowchart of a control method in an embodiment;

Fig. 5 is the change curve diagram of the water flow rate at startup of the gas water heater in the embodiment;

Fig. 6 is the change curve diagram of the water temperature change of the gas-fired water heater at the first startup of the embodiment;

Fig. 7 is the change curve diagram of water outlet temperature when the gas water heater is turned off halfway and restarted in the embodiment;

FIG. 8 is a graph showing the program temperature control time and the preset temperature of the gas water heater in the embodiment.

Detailed ways

The following examples illustrate the present invention, but the present invention is not limited by these examples. Modifications to the specific embodiments of the present invention or equivalent replacement of some technical features without departing from the spirit of the solution of the present invention shall all be included in the scope of the technical solution claimed in the present invention.

Embodiment 1: As shown in Figures 1 to 8, this embodiment provides a gas water heater with a flow limiting device, including a controller 1, a heat exchanger 2, a water inlet pipe 3, a water outlet pipe 4, a burner 9, a gas The control valve 10 and the operation display 11, the two ends of the heat exchanger 2 are respectively connected with the water inlet pipe 3 and the water outlet pipe 4, the water inlet end of the water inlet pipe 3 is provided with a water inlet joint, and the water outlet end of the water outlet pipe 4 is provided with a water outlet joint , the heat exchanger 2 is used to absorb the heat of the high-temperature flue gas and heat the tap water, and the gas control valve 10 is communicated with the intake end of the burner 9. Specifically, the gas control valve 10 is installed on the gas supply passage inside the gas water heater, It can control the on-off of the gas and the opening of the gas to meet the constant temperature demand of the hot water. The operation display 11 is provided with a temperature setting key for setting the preset temperature. The water pipe 5 forms a parallel water circuit with the main water circuit flowing through the interior of the heat exchanger 2. A flow limiting device 6 is arranged on the water inlet pipe 3 to control the water flow of the water inlet pipe 3. The flow limiting device 6 is located in the mixing pipe 5 and the water inlet pipe 3. At the rear end of the connection, the flow limiting device 6 includes a flow limiting valve body 601, and a flow limiting water inlet 602 and a limiting flow outlet 603 are respectively provided at both ends of the flow limiting valve body 601. The waterway 604 and the bypass waterway 605, the limited flow of the main waterway 604 is greater than the limited flow of the bypass waterway 605, the two ends of the main waterway 604 are respectively connected with the limited flow inlet 602 and the limited outlet 603, and the two ends of the bypass waterway 605 are respectively connected with The restricting water inlet 602 and the restricting outflow port 603 are in communication, and a main circuit solenoid valve 606 is provided on the current restricting valve body 601 to conduct or cut off the main water circuit 604, and the main circuit electromagnetic valve 606 is electrically connected with the controller 1, wherein When the main circuit solenoid valve 606 is open, the water flow rate of the flow limiting device 6 is relatively large. When the main circuit solenoid valve 606 is closed, the tap water flows through the bypass water path 605 to reduce the water flow rate of the flow limiting device 6 . A water flow detection device 7 is provided on the water inlet pipe 3. The water flow detection device 7 is located at the front end of the connection between the water mixing pipe 5 and the water inlet pipe 3. The water flow detection device 7 can monitor the flow of water flowing through the gas water heater in real time. The outlet water temperature detection device 8 is provided, and the outlet water temperature detection device 8 is located at the rear end of the connection between the mixing pipe 5 and the outlet pipe 4. The controller 1 is respectively connected with the water flow detection device 7, the outlet water temperature detection device 8, the gas control valve 10 and the operation display. 11 Electrical connection.

The gas water heater with the current limiting device in this embodiment can speed up the heating of hot water, shorten the waiting time for hot water, and reduce water waste.

Specifically, the gas water heater of this embodiment can overcome the shortcomings of the prior art, and automatically limit the water flow after the gas water heater is turned on, so as to speed up the heating of hot water, shorten the waiting time for hot water, and effectively prevent the water temperature from rising suddenly after the water is turned off and restarted in the middle. Plunge, improve bathing comfort, reduce water waste, suitable for domestic hot water supply gas instant water heater and dual-purpose furnace.

In this embodiment, a steady flow valve core 607 is provided in the bypass water path 605, and the current limiting value of the steady flow valve core 607 is greater than the start-up water flow rate of the gas water heater. The water flow through the bypass water channel 605 can be more stable by the provision of the steady flow valve core 607, and the phenomenon of the water flow being suddenly large and small can be reduced. When the main circuit solenoid valve 606 is closed, the tap water flows through the steady flow valve core 607 of the bypass water circuit 605 to reduce the flow rate of the water passing through the flow limiting device 6 . The current limiting value of the steady flow valve core 607 in this embodiment is generally 3-6L/min, which is higher than the startup water flow of the gas water heater, which is generally 2.5L/min.

Preferably, the pipe diameter of the water mixing pipe 5 is 3 to 5 mm, and the pipe diameter of the water inlet pipe 3 is 10 to 16 mm, so that when the gas water heater is started, the diversion ratio of the water mixing pipe 5 reaches an appropriate ratio. Preferably, the diversion ratio less than 15%.

As shown in FIG. 1 and FIG. 2 , in this embodiment, by controlling the switch of the main circuit solenoid valve 606 of the current limiting device 6 , the switch between the large and small water levels can be realized. As shown in FIG. 1 , the gas water heater of this embodiment is at the low water level, the main circuit solenoid valve 606 of the current limiting device 6 is closed, and after the hot water tap is turned on, the tap water enters the gas water heater and flows through the water flow detection device 7, and then diverts the flow through the inlet The water pipe 3 and the mixing pipe 5 are then reassembled to flow through the outlet water temperature detection device 8 and the outlet joint, and finally flow to the hot water faucet; The maximum flow rate of the small water gear of the gas water heater in this embodiment is the sum of the current limiting value of the steady flow valve core 607 and the flow rate of the mixing pipe 5, generally 5-8L/min. As shown in FIG. 2 , the gas water heater of this embodiment is in the high-water position, and the main circuit solenoid valve 606 of the current limiting device 6 is opened. After the hot water tap is opened, the water flow of the water inlet pipe 3 is not stabilized by the current limiting device 6 . If the flow valve core 607 is limited, the maximum water flow rate of the large water gear of the gas water heater in this embodiment is the maximum design flow rate of the gas water heater, such as 16L/min.

As shown in Figure 4, the control principle of the gas water heater of this embodiment is as follows:

(1) When the gas water heater is in the shower standby mode, close the main circuit solenoid valve 606 of the current limiting device 6, and in addition, the gas water heater is in the low water gear. At this time, open the hot water faucet, the tap water enters the gas water heater and flows through the water flow detection device 7, and then diverts through the water inlet pipe 3 and the water mixing pipe 5. The water flow of the water inlet pipe 3 is restricted by the limited flow device 6. When the water flow detection device 7 measures the When the water flow is greater than the program startup flow, the program startup flow is generally 2.5L/min, then the controller 1 opens the gas control valve 10, the gas water heater is turned on and ignited, and switches to the shower operation mode.

(2) After the gas water heater is turned on and ignited, the controller 1 automatically adjusts the gas opening of the gas control valve 10 according to the difference between the outlet water temperature monitored in real time by the outlet water temperature detection device 8 and the preset temperature of the operation display 11, and changes the combustion power. Make the outlet water temperature of the gas water heater close to the preset temperature. Since the gas water heater is in the low water gear during the startup phase, the water flow rate is small, which makes the heating speed of the hot water of the gas water heater faster.

(3) The gas water heater is in the stage of starting up and heating up. The controller 1 adjusts the opening of the gas control valve 10 to control the temperature. After the programmed temperature control time is reached, if the water temperature detected by the outlet water temperature detection device 8 is still lower than the preset temperature of the operation display 11 temperature, the working state of the low water gear is maintained, and the main circuit solenoid valve 606 is still not opened. The program temperature control time is a fixed value or is set by the parameter setting mode of the controller 1. In this embodiment, the program temperature control time is generally 5-15s.

(4) The gas water heater is in the stage of starting up and heating up. The controller 1 adjusts the opening of the gas control valve 10 to control the temperature. After the programmed temperature control time is reached, when the water temperature detection device 8 detects that the water temperature reaches the preset temperature of the operation display 11 , then the controller 1 opens the main circuit solenoid valve 606 of the current limiting device 6, switches to the high water gear, increases the hot water flow, synchronously adjusts the opening of the gas control valve 10 and the combustion power, controls the outlet water temperature according to the preset temperature, and restores the Large flow of water and achieve fast constant temperature.

(5) The gas water heater is in the shower working mode of the high water gear. The controller 1 adjusts the opening of the gas control valve 10 to control the temperature. After the programmed temperature control time is reached, if the outlet water temperature is still lower than the preset temperature of the operation display 11, At this time, the water temperature is too low, then close the main circuit solenoid valve 606 of the current limiting device 6, switch to the low water gear, and increase the outlet water temperature.

(6) The gas water heater is in the shower working mode of the low water gear. The controller 1 adjusts the opening of the gas control valve 10 to control the temperature. After the programmed temperature control time is reached, if the outlet water temperature is still higher than the preset temperature of the operation display 11, At this time, the water temperature is too high, so open the main circuit solenoid valve 606 of the current limiting device 6, switch to the high water gear, and reduce the outlet water temperature.

(7) When the gas water heater is in the shower working mode, when the water flow detection device 7 detects that the water flow is less than the programmed shutdown flow, the programmed shutdown flow of the gas hot water is generally 2.0L/min, then the controller 1 closes the gas control valve 10 , switch off the flame and switch back to the shower standby mode, and close the main circuit solenoid valve 606 of the current limiting device 6 to return to the low water gear.

As shown in FIGS. 5 and 6 , the gas water heater of this embodiment is in the low water gear during the startup and heating stage, the water flow rate is small, the heating speed of hot water is fast, and the waiting time for hot water is shortened. By restricting the flow of water when the gas water heater is turned on, the hot water can be quickly produced, and at the same time, too much cold water can be avoided.

As shown in FIG. 7 , when the gas water heater of this embodiment is in the shower working mode, the water is turned off in the middle, the gas water heater is turned off, the main circuit solenoid valve 606 of the current limiting device 6 is closed, and the water is switched to the low water level. After the gas water heater is turned off, the heat exchanger 2 still transfers the waste heat to the water stored in the water inlet pipe 3, thereby forming a section of high temperature water. After the user reopens the hot water faucet, the tap water enters the gas water heater and flows through the water inlet pipe 3 and the mixing pipe 5. The high-temperature storage water in the water inlet pipe 3 and the cold water in the mixing pipe 5 converge and flow out from the outlet joint. The cold water supplemented by the mixing pipe 5 reduces the outlet water temperature. Effectively suppress the temperature rise of water cut off. The gas water heater of this embodiment is in the low water stage during the startup phase, the water flow rate limiting device 6 of the water inlet pipe 3 is restricted, and the flow rate of the high temperature storage water is reduced, the proportion of cold water diversion in the mixing pipe 5 is increased, and after neutralization and mixing The outlet water temperature is lower, and the temperature rise of the water stop is further reduced. In the startup phase of the gas water heater in this embodiment, the water flow rate of the water inlet pipe 3 is reduced, and the temperature of the cold water flowing into the water inlet pipe 3 is faster, which can restrain the temperature drop of the hot water in the latter part of the water outlet. As shown in FIG. 7 , the gas water heater of this embodiment can effectively suppress the problem of sudden rise and fall of water temperature caused by shutting off the water and restarting in the middle, reducing the fluctuation of water temperature, and improving the experience of hot water bathing.

As shown in FIG. 4 , when the gas water heater of the present embodiment switches between large and small water gears during the startup heating phase and the shower working mode, by setting the program temperature control time, the failure of switching back and forth between large and small water gears caused by abnormal water temperature can be avoided.

As shown in FIG. 8 , the program temperature control time t of the gas water heater in this embodiment has a proportional linear relationship with the preset temperature T _preset of the operation display 11 . The higher the specific preset temperature T _preset is, the longer the program temperature control time is. Follow the lengthening to adapt to different bath water temperature needs. If the _preset temperature T is higher than the _preset temperature, the heat exchanger 2 stores more heat when the water is turned off in the middle, and the high-temperature water in the first stage will take a long time to flow out after restarting. It affects the judgment of the controller 1 program, so it needs to match a longer program temperature control time.

The program minimum preset temperature T _{preset min} is generally 35°C, the minimum program temperature control time t _min is generally 5s, the program maximum preset temperature T _{preset max} is generally 60°C, and the maximum program temperature control time t _max is generally 15s; The program minimum preheating temperature T _{preset min} , the program maximum preset temperature T _{preset max} , the minimum program temperature control time t _min and the maximum program temperature control time t _max are all fixed values or can be set by the parameter setting method of the controller 1 . Certainly.

Specifically, the controller 1 controls the operation of the gas control valve 10 to make the outlet water temperature of the gas water heater reach the preset temperature, wherein the temperature control time during which the controller 1 controls the operation of the gas control valve 10 is calculated and obtained according to the following formula:

t=(t _max −t _min )×(T _preset− T _{preset min} )/(T _{preset max} −T _{preset min} )+t _min ;

Among them, t _max is the maximum program temperature control time, t _min is the minimum program temperature control time, T _preset is the user preset temperature, T _{preset max} is the maximum preset temperature of the program, and T _{preset min} is the minimum preset temperature of the program .

Embodiment 2: As shown in FIGS. 1 to 8 , this embodiment provides a control method for a gas water heater with a flow limiting device, which is applied to the gas water heater as described in Embodiment 1. The control method includes the following steps:

Determine whether the measured water flow is greater than the startup water flow;

If the measured water flow rate is greater than the startup water flow rate, control the gas water heater to turn on and ignite to enter the shower working mode, and specifically control the gas control valve 10 to open to make the gas water heater start to ignite and enter the shower working mode;

Control the main circuit solenoid valve 606 to cut off the main water circuit 604 so that the gas water heater is at the low water level, and adjust the opening degree of the gas control valve 10 to control the outlet water temperature;

After reaching the first program temperature control time, determine whether the outlet water temperature is greater than the preset temperature;

If the outlet water temperature is greater than the preset temperature, the main circuit solenoid valve 606 is controlled to conduct the main water circuit 604 to switch the gas water heater to the high water level, and the opening degree of the gas control valve 10 is adjusted to control the outlet water temperature.

The control method of this embodiment can speed up the heating of hot water, shorten the waiting time for hot water, and improve the comfort of bathing.

Further, it also includes the following steps:

After reaching the second program temperature control time, determine whether the water temperature is lower than the preset temperature;

If the outlet water temperature is less than the preset temperature, the main circuit solenoid valve 606 is controlled to cut off the main water circuit 604 to switch the gas water heater to the low water gear, and the opening of the gas control valve is adjusted to control the outlet water temperature;

If the outlet water temperature is greater than the preset temperature, judge whether the measured water flow is less than the shutdown water flow. If the actual measured water flow is greater than the shutdown water flow, continue to control the outlet water temperature with the opening of the gas control valve. If the measured water flow is smaller than the shutdown water flow, control the Turn off the gas water heater to exit the shower working mode, that is, close the gas control valve 10 to turn off the gas water heater to exit the shower working mode, and control the main circuit solenoid valve 606 to cut off the main water circuit 604 so that the gas water heater enters the shower standby mode. At this time, the gas water heater is at the low water level, and the flow of tap water is limited by the flow limiting device 6 .

Further, after reaching the first program temperature control time, the step of judging whether the temperature of the outlet water is greater than the preset temperature includes:

If the outlet water temperature is lower than the preset temperature, judge whether the measured water flow is smaller than the shutdown water flow. If the actual measured water flow is greater than the shutdown water flow, continue to control the outlet water temperature by 10 degrees of opening of the gas control valve. If the measured water flow is smaller than the shutdown water flow, then Control the gas water heater to shut down and turn off the shower to exit the shower working mode, that is, close the gas control valve 10 to turn off the gas water heater to exit the shower working mode, and control the main circuit solenoid valve 606 to cut off the main water circuit 604 so that the gas water heater enters the shower standby mode. At this time, the gas water heater is at the low water level, and the flow of tap water is limited by the flow limiting device 6 .

The foregoing are merely some of the embodiments of the present invention. For those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention.

Claims (10)

1. A gas water heater with a flow limiting device, comprising a controller (1), a heat exchanger (2), a water inlet pipe (3) and a water outlet pipe (4), the two ends of the heat exchanger (2) are respectively connected to the The water inlet pipe (3) and the water outlet pipe (4) are connected, and it is characterized in that a mixing pipe (5) is connected between the water inlet pipe (3) and the water outlet pipe (4). A flow limiting device (6) is arranged on the water inlet pipe (3), the flow limiting device (6) is located at the rear end of the connection between the mixing pipe (5) and the water inlet pipe (3), and the flow limiting device ( 6) Including a flow restricting valve body (601), a flow restricting water inlet (602) and a restricting outflow water port (603) are respectively provided at both ends of the flow restricting valve body (601), and the flow restricting valve body (601) A main waterway (604) and a bypass waterway (605) are arranged in parallel, and the two ends of the main waterway (604) are respectively connected with the restricting water inlet (602) and the restricting water outlet (603), so Both ends of the bypass water path (605) are respectively communicated with the restricting water inlet (602) and the restricting water outlet (603), and a main circuit solenoid valve (606) is provided on the restricting valve body (601). ) is used to conduct or cut off the main water circuit (604), and the main circuit solenoid valve (606) is electrically connected to the controller (1). 2. A gas water heater with a flow limiting device according to claim 1, wherein the limiting flow of the main water path (604) is greater than the limiting flow of the bypass water path (605). 3. A gas water heater with a flow limiting device according to claim 2, characterized in that, a flow-stabilizing valve core (607) is provided in the bypass waterway (605), and the flow-stabilizing valve core ( 607) The current limiting value is greater than the start-up water flow of the gas water heater. 4. A gas water heater with a flow limiting device according to claim 1, wherein the pipe diameter of the water mixing pipe (5) is 3 to 5 mm, and the pipe diameter of the water inlet pipe (3) is 10 mm. to 16mm. 5. A gas water heater with a flow limiting device according to claim 1, 2, 3 or 4, characterized in that a water flow detection device (7) is provided on the water inlet pipe (3), and the water flow The detection device (7) is located at the front end of the connection between the water mixing pipe (5) and the water inlet pipe (3). The device (8) is located at the rear end of the connection between the water mixing pipe (5) and the water outlet pipe (4), and the controller (1) is respectively connected with the water flow detection device (7) and the outlet water temperature detection device (8) Electrical connection. 6. A gas water heater with a flow restricting device according to claim 1, 2, 3 or 4, characterized in that, further comprising a burner (9), a gas control valve (10) and an operation display (11) , wherein the gas control valve (10) is communicated with the intake end of the burner (9), and the controller (1) is electrically connected to the gas control valve (10) and the operation display (11) respectively. sexual connection. 7 . The gas water heater with a flow limiting device according to claim 6 , wherein the controller ( 1 ) controls the gas control valve ( 10 ) to work so that the outlet water temperature of the gas water heater reaches a preset temperature. 8 . temperature, wherein the temperature control time during which the controller (1) controls the operation of the gas control valve (10) is calculated and obtained according to the following formula: t=(t _max −t _min )×(T _preset− T _{preset min} )/(T _{preset max} −T _{preset min} )+t _min ; Among them, t _max is the maximum program temperature control time, t _min is the minimum program temperature control time, T _preset is the user preset temperature, T _{preset max} is the maximum preset temperature of the program, and T _{preset min} is the minimum preset temperature of the program . 8. A control method for a gas water heater with a flow limiting device, wherein, when applied to the gas water heater according to any one of claims 1 to 7, the control method comprises the following steps: Determine whether the measured water flow is greater than the startup water flow; If the measured water flow is greater than the startup water flow, control the gas water heater to turn on the ignition and enter the shower working mode; Control the main circuit solenoid valve to cut off the main water circuit, and adjust the opening of the gas control valve to control the outlet water temperature; After reaching the first program temperature control time, determine whether the outlet water temperature is greater than the preset temperature; If the outlet water temperature is greater than the preset temperature, the solenoid valve of the main circuit is controlled to conduct the main water circuit, and the opening of the gas control valve is adjusted to control the outlet water temperature. 9. The method for controlling a gas water heater with a flow limiting device according to claim 8, further comprising the steps of: After reaching the second program temperature control time, determine whether the water temperature is lower than the preset temperature; If the outlet water temperature is lower than the preset temperature, control the main circuit solenoid valve to cut off the main water circuit, and adjust the opening of the gas control valve to control the outlet water temperature; If the outlet water temperature is greater than the preset temperature, judge whether the measured water flow is less than the shutdown water flow. If the actual measured water flow is greater than the shutdown water flow, continue to control the outlet water temperature with the opening of the gas control valve. If the measured water flow is smaller than the shutdown water flow, control the Turn off the gas water heater to exit the shower working mode, and control the main circuit solenoid valve to cut off the main water circuit. 10 . The method for controlling a gas water heater with a flow limiting device according to claim 8 , wherein, after reaching the first program temperature control time, the step of judging whether the outlet water temperature is greater than the preset temperature comprises: 10 . If the outlet water temperature is lower than the preset temperature, judge whether the measured water flow is smaller than the shutdown water flow. If the measured water flow is greater than the shutdown water flow, continue to control the outlet water temperature with the opening of the gas control valve. If the measured water flow is smaller than the shutdown water flow, control the Turn off the gas water heater to exit the shower working mode, and control the main circuit solenoid valve to cut off the main water circuit.

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