CN112682789B - Gas water heater - Google Patents

Abstract

The invention discloses a gas-fired water heater, comprising a burner, a first heat exchanger, a second heat exchanger and a pipeline system. The burner is formed with a heat exchange chamber, and the first heat exchanger is arranged in the heat exchange chamber and is used for connecting with the heat exchanger. The flue gas generated by the combustion of the burner is exchanged for heat, the second heat exchanger is arranged on the outer wall of the burner, and the pipeline system is connected with the first heat exchanger and the second heat exchanger for supplying the first heat exchanger and the second heat exchanger Two heat exchangers provide inlet and outlet water. In the technical solution disclosed in the present invention, the first heat exchanger exchanges heat with the flue gas generated by the combustion of the burner to realize the preparation of hot water, and the second heat exchanger exchanges heat with the outer wall of the burner to realize the heat exchange between the outer wall of the burner and the outer wall of the burner. It can prevent the outer wall of the burner from forming a heat storage body, reduce the risk of damage to the electronic components of the gas water heater due to excessive temperature, and prolong the service life of the gas water heater.

Description

gas water heater

This application claims the priority of the Chinese patent application filed on October 17, 2019, with the application number of 201910992986.8, and the application name is "Burner and Gas Water Heater", which is hereby incorporated by reference in its entirety.

technical field

The invention relates to the technical field of gas water heaters, in particular to a gas water heater.

Background technique

Gas water heaters usually have a combustion chamber in which the gas is burned to generate heat radiation, causing the wall of the combustion chamber to form a regenerator. The heat on the wall of the combustion chamber is conducted to other components of the gas water heater, resulting in an increase in the internal temperature of the gas water heater and affecting the service life of the electronic components in the water heater.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to propose a gas water heater which can reduce the temperature of the outer wall of the gas water heater and prolong the service life of the water heater.

In order to achieve the above purpose, the present invention proposes a gas water heater, which includes:

The burner is formed with a heat exchange chamber and a combustion chamber;

a first heat exchanger, which is arranged in the heat exchange chamber and is used for heat exchange with the flue gas generated by the combustion of the burner;

a second heat exchanger provided on the outer wall of the burner; and,

A pipeline system, connected with the first heat exchanger and the second heat exchanger, is used to provide water intake and drainage for the first heat exchanger and the second heat exchanger.

In one embodiment, the combustion chamber is communicated with the heat exchange chamber through a flue gas channel, so that the flue gas generated by the combustion of the combustion chamber flows through the heat exchange chamber through the flue gas channel, and the The outer wall of the burner constitutes the chamber wall of the combustion chamber; or,

The heat exchange chamber includes the combustion chamber, and the outer wall of the burner constitutes a chamber wall of the combustion chamber.

In an embodiment, the second heat exchanger is a coil wound around the outer wall of the burner; or,

The second heat exchanger is a water cooling wall disposed inside the outer wall of the burner.

In an embodiment, the pipeline system includes a water inlet pipeline and a water outlet pipeline, the water inlet ends of the first heat exchanger and the second heat exchanger are respectively connected to the water inlet pipeline, and the The water outlet ends of the first heat exchanger and the second heat exchanger are respectively communicated with the water outlet pipeline;

The water inlet pipeline is provided with a flow valve for adjusting the water flow in the first heat exchanger and the second heat exchanger;

The gas water heater further includes a control device, the control device is electrically connected with the flow valve, and the control device is used to control the opening degree of the flow valve, so as to control the first heat exchanger and the The water flow in the second heat exchanger regulates the outlet water temperature in the water outlet pipeline.

In one embodiment, the water inlet pipeline includes a first connecting section for communicating with an external water circuit, a second connecting section communicating with the second heat exchanger, and a second connecting section communicating with the first heat exchanger. The third connecting section, the first connecting section, the second connecting section and the third connecting section are connected with each other, wherein the flow valve is provided on the second connecting section, or the second connecting section The flow valve is respectively provided on the segment and the third connecting segment.

In one embodiment, the control device is used to:

When the startup state of the gas-fired water heater is a cold startup, controlling the opening of the flow valve to control the water flow in the second heat exchanger to be zero or less than a preset first flow value;

When the water outlet temperature value in the water outlet pipeline rises to the target temperature value, the opening of the flow valve is controlled to control the water flow rate in the second heat exchanger to increase to a preset second flow rate value ;

Alternatively, the control device is used to:

When the startup state of the gas-fired water heater is a cold startup, the opening of the flow valve is controlled to control the water flow in the second heat exchanger to be zero or less than a preset time period first flow value;

The water flow rate in the second heat exchanger is controlled to increase to a preset second flow rate value after the preset time period.

In one embodiment, the control device is used to:

When the startup state of the gas water heater is halfway startup, controlling the opening of the flow valve to control the water flow in the second heat exchanger to be greater than a preset third flow value;

When the water outlet temperature value in the water outlet pipeline drops to the target temperature value, the opening of the flow valve is controlled to control the water flow rate in the second heat exchanger to decrease to a preset fourth flow rate value ;

Alternatively, the control device is used to:

When the startup state of the gas water heater is halfway startup, the opening of the flow valve is controlled to control the water flow in the second heat exchanger to be greater than a preset third flow value within a preset time period ;

The water flow in the second heat exchanger is controlled to decrease to a preset fourth flow value after the preset time period.

In one embodiment, the control device is used to:

Obtain the water outlet temperature value in the water outlet pipeline, and control the opening of the flow valve according to the outlet water temperature value to adjust the water flow in the first heat exchanger and the second heat exchanger, So that the water outlet temperature value in the water outlet pipeline is within the target temperature range.

In one embodiment, the control device is used to:

obtaining the water outlet temperature value of the water outlet pipeline;

When the outlet water temperature value is less than the minimum value of the target temperature interval, the flow valve is controlled so that the water flow in the second heat exchanger is reduced, and the water in the first heat exchanger increased flow;

When the outlet water temperature value is greater than the maximum value of the target temperature interval, the flow valve is controlled to increase the water flow in the second heat exchanger and the water in the first heat exchanger Flow decreases.

In one embodiment, the control device is used to:

obtaining the temperature value of the water outlet end of the second heat exchanger;

When the temperature value of the water outlet end of the second heat exchanger is greater than the target temperature value, the flow valve is controlled to increase the water flow in the second heat exchanger.

In one embodiment, the flow valve is a flow proportional valve.

In one embodiment, the burner includes:

a preheating device for preheating gas and/or air to a preset target temperature and then delivering it to the combustion chamber; and,

The gas component is used for injecting gas into the combustion chamber.

In one embodiment, the preheating device is an electric heating device, a gas heating device or a heat accumulator heating device.

In one embodiment, the preheating device is a gas heating device, and the burner further has an air intake chamber and a primary combustion chamber, and the air intake chamber, the primary combustion chamber and the combustion chamber are sequentially communicated with each other. ;

The gas heating device includes:

a premixer for connecting and premixing gas and air, and providing the mixed gas to the primary combustion chamber; and,

a preheating burner, the preheating burner has a mixed gas distribution chamber, the air inlet of the mixed gas distribution chamber is communicated with the premixer, and the air outlet of the mixed gas distribution chamber is connected with the primary combustion chamber The preheating burner is used for igniting the mixed gas discharged from the mixed gas distribution chamber to the primary combustion chamber, so that the air in the primary combustion chamber is heated to the target temperature.

The present invention also provides a control method for a gas water heater, the gas water heater includes a burner formed with a heat exchange chamber, a first heat exchange device disposed in the heat exchange chamber and used for exchanging heat with flue gas generated by combustion of the burner a heat exchanger, a second heat exchanger provided on the outer wall of the burner, and connected to the first heat exchanger and the second heat exchanger for exchanging heat for the first heat exchanger and the second heat exchanger The pipe system provides a water inlet and drainage pipe system, the pipe system includes a water outlet pipe, and the water outlet ends of the first heat exchanger and the second heat exchanger are respectively communicated with the water outlet pipe; the Control methods for gas water heaters include:

When the startup state of the gas-fired water heater is a cold startup, controlling the pipeline system to adjust the water flow in the second heat exchanger to be zero or less than a preset first flow value;

When the water outlet temperature value in the water outlet pipeline rises to the target temperature value, controlling the pipeline system to adjust the water flow rate in the second heat exchanger to increase to a preset second flow rate value;

or,

When the startup state of the gas-fired water heater is a cold startup, the pipeline system is controlled to adjust the water flow in the second heat exchanger to be zero or less than a preset first flow value within a preset time period ;

After the preset time period, the piping system is controlled to adjust the water flow rate in the second heat exchanger to increase to a preset second flow rate value.

In one embodiment, the control method for the gas water heater further includes:

When the startup state of the gas-fired water heater is halfway startup, controlling the pipeline system to adjust the water flow in the second heat exchanger to be greater than a preset third flow value;

When the water outlet temperature value in the water outlet pipeline drops to a target temperature value, controlling the pipeline system to adjust the water flow rate in the second heat exchanger to reduce to a preset fourth flow rate value;

or,

When the startup state of the gas-fired water heater is halfway startup, controlling the pipeline system to adjust the water flow in the second heat exchanger to be greater than a preset third flow value within a preset time period;

After the preset time period, the piping system is controlled to adjust the water flow rate in the second heat exchanger to decrease to a preset fourth flow rate value.

In one embodiment, the control method for the gas water heater further includes:

Obtain the water outlet temperature value of the water outlet pipeline;

When the outlet water temperature value is less than the minimum value of the target temperature interval, control the pipeline system to adjust the water flow in the first heat exchanger and the second heat exchanger, so that the second heat exchange The water flow in the heat exchanger decreases, and the water flow in the first heat exchanger increases;

When the outlet water temperature value is greater than the maximum value of the target temperature interval, control the pipeline system to adjust the water flow in the first heat exchanger and the second heat exchanger, so that the second heat exchanger The water flow in the heat exchanger increases and the water flow in the first heat exchanger decreases.

In one embodiment, the control method for the gas water heater further includes:

obtaining the temperature value of the water outlet end of the second heat exchanger;

When the temperature value of the water outlet end of the second heat exchanger is greater than the target temperature value, the pipeline system is controlled to adjust the water flow in the second heat exchanger, so that the water flow in the second heat exchanger is increased water flow.

In the technical scheme of the present invention, the first heat exchanger exchanges heat with the flue gas generated by the combustion of the burner to realize the preparation of hot water, and the second heat exchanger exchanges heat with the outer wall of the burner to cool the outer wall of the burner. Avoid the formation of a heat storage body on the outer wall of the burner, reduce the risk of damage to the electronic components of the gas water heater due to excessive temperature, and prolong the service life of the gas water heater.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an embodiment of a gas water heater provided by the present invention;

2 is a schematic structural diagram of another embodiment of the gas water heater provided by the present invention;

3 is a schematic flowchart of an embodiment of a control method for a gas water heater according to the present invention;

4 is a schematic flowchart of another embodiment of a control method for a gas water heater according to the present invention;

FIG. 5 is a schematic flowchart of another embodiment of a control method for a gas water heater according to the present invention;

FIG. 6 is a schematic flow chart of yet another embodiment of a control method for a gas water heater according to the present invention;

7 is a schematic flowchart of an embodiment of a control method for a gas water heater according to the present invention;

FIG. 8 is a schematic flowchart of another embodiment of the control method for the gas water heater according to the present invention.

Description of reference numbers:

label name label name 100 burner 303 third link 101 heat exchange chamber 400 outlet pipe 102 combustion chamber 500 flow valve 200 second heat exchanger 600 Inlet fan 300 Inlet pipeline 700 Gas proportional valve 301 first link 801 Inlet connector 302 second link 802 Outlet connector

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) involved in the embodiments of the present invention, the directional indications are only used to explain a certain posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for the purpose of description, and should not be construed as indicating or implying Its relative importance or implicitly indicates the number of technical features indicated. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the meaning of "and/or" in the whole text includes three parallel schemes. Taking "A and/or B" as an example, it includes scheme A, scheme B, or scheme satisfying both of A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist. , is not within the scope of protection required by the present invention.

Existing gas-fired water heaters usually have a combustion chamber 102 . When the gas-fired water heater is in operation, gas burns in the combustion chamber 102 to generate heat radiation, causing the wall of the combustion chamber 102 to form a regenerator. The heat on the wall of the combustion chamber 102 is conducted to other components of the gas water heater, resulting in an increase in the internal temperature of the gas water heater and affecting the service life of the electronic devices in the water heater.

To this end, the present invention proposes a gas water heater, please refer to FIG. 1 and FIG. 2, the gas water heater includes a burner 100, a first heat exchanger, a second heat exchanger 200 and a piping system, the burner 100 is formed with a heat exchange Chamber 101, the first heat exchanger is installed in the heat exchange chamber 101 for heat exchange with the flue gas generated by the combustion of the burner 100, the second heat exchanger 200 is installed on the outer wall of the burner 100, and the piping system is connected with the first heat exchanger 101. The heat exchanger is connected to the second heat exchanger 200 for providing inlet water and drainage to the first heat exchanger and the second heat exchanger 200 .

In this embodiment, the second heat exchanger 200 may be arranged in the entire area on the outer wall of the burner 100, or may be arranged in a partial area of the outer wall of the burner 100, for example, only corresponding to the outer wall of the combustion chamber 102 in the burner 100, In order to effectively cool while reducing the amount of material. The pipeline system is connected with the first heat exchanger and the second heat exchanger 200, and is used to provide water intake and drainage for the first heat exchanger and the second heat exchanger 200, which can be the first heat exchanger and the second heat exchanger The heat exchanger 200 has separate water inlet pipeline 300 and water outlet pipeline 400 respectively, or the first heat exchanger and the second heat exchanger 200 share the water inlet pipeline 300 and the water outlet pipeline 400, as long as the first heat exchange can be realized The second heat exchanger 200 can cool the outer wall of the burner 100 to prepare hot water.

In the technical solution disclosed in the present invention, when the gas water heater is in operation, the first heat exchanger exchanges heat with the flue gas generated by the combustion of the burner 100 to realize the preparation of hot water. The heat exchange of the outer wall plays the role of cooling the outer wall of the burner 100. In this way, the outer wall of the burner 100 is prevented from forming a heat accumulator, and the outer wall of the burner 100 is reduced to conduct heat to other components of the gas water heater. Risk of component damage, thereby extending the life of the gas water heater.

The second heat exchanger 200 may work at the same time as the burner 100, or may continue to work for a period of time when the burner 100 suspends combustion. Specifically, it can be set as required. In one embodiment, the second heat exchanger 200 and the burner 100 work at the same time. After the burner 100 stops burning, the water in the second heat exchanger 200 no longer flows. The function of heat storage and heat preservation of the burner 100 prevents the temperature in the burner 100 from dropping rapidly, so that the burner 100 can prepare hot water more quickly when the burner 100 is started again. In another embodiment, after the burner 100 stops burning, the second heat exchanger 200 continues to work for a period of time, which is beneficial for the burner 100 to cool down faster, and is beneficial to protect the electronic devices in the gas water heater and prevent the electronic devices from damaged by high temperature.

The burner 100 has a combustion chamber 102. In one embodiment, please refer to FIG. 1 and FIG. 2. The combustion chamber 102 is separated from the heat exchange chamber 101 and communicated with the heat exchange chamber 101 through a flue gas channel, so as to make combustion The flue gas generated by the combustion of the chamber 102 flows through the heat exchange chamber 101 through the flue gas channel, and the outer wall of the burner 100 constitutes the chamber wall of the combustion chamber 102 . In another embodiment, the heat exchange chamber 101 includes a combustion chamber 102 , and the outer wall of the burner 100 constitutes a chamber wall of the combustion chamber 102 . It can be understood that the combustion chamber 102 and the heat exchange chamber 101 share a cavity, and it can also be understood that a part of the area in the heat exchange chamber 101 constitutes the combustion chamber 102 , that is, a part of the area in which the combustion occurs in the heat exchange chamber 101 . In the above embodiment, the second heat exchanger 200 is arranged on the outer wall of the burner 100, that is, the chamber wall of the combustion chamber 102, so as to absorb the heat radiated by the combustion in the combustion chamber 102, so as to cool the outer wall of the gas water heater. effect.

The first heat exchanger is arranged in the heat exchange chamber 101 and may be a common partition heat exchanger, for example, it may include a water pipe arranged in a flue, or a smoke pipe arranged in a water tank. The second heat exchanger 200 is arranged around the outer wall of the burner 100 . For example, in the present embodiment, please refer to FIGS. 1 and 2 , the second heat exchanger 200 includes a disk that is arranged around the outer wall of the burner 100 . The pipe can also be a water cooling wall provided on the inner side of the outer wall of the burner 100, so as to absorb the heat radiated by the combustion in the combustion chamber 102, and play the role of cooling the outer wall of the gas water heater.

In this embodiment, please refer to FIG. 1 and FIG. 2 , the pipeline system includes a water inlet pipeline 300 and a water outlet pipeline 400 , and the water inlet ends of the first heat exchanger and the second heat exchanger 200 are respectively connected to the water inlet pipeline 300 . The water outlet ends of the first heat exchanger and the second heat exchanger 200 are respectively communicated with the water outlet pipeline 400, and the water inlet pipeline 300 is provided with a flow valve 500 for adjusting the first heat exchanger and the second heat exchanger 200. The gas water heater also includes a control device, the control device is electrically connected to the flow valve 500, and the control device is used to control the opening of the flow valve 500, so as to pass the control device in the first heat exchanger and the second heat exchanger 200. The water flow rate adjusts the outlet water temperature in the outlet pipe 400.

In this embodiment, the water inlet pipe 300 is connected to the external water circuit that provides the water source through the water inlet joint 801, and the water outlet pipe 400 is connected to the user's water end through the water outlet joint 802, such as faucets and showers. The two heat exchangers 200 share the water inlet pipeline 300 and the water outlet pipeline 400, so that the cooling water that has undergone heat exchange in the second heat exchanger 200 can be utilized to supply water to the water end, thereby improving energy utilization. In addition, the control device can control the opening degree of the flow valve 500 to adjust the outlet water temperature in the water outlet pipeline 400 by controlling the water flow rates in the first heat exchanger and the second heat exchanger 200 . In this embodiment, the outlet water temperature in the water outlet pipe 400 indicates the temperature of the water pipe 400 after the hot water in the first heat exchanger and the second heat exchanger 200 are evenly mixed. Specifically, in the measurement, it can be the water outlet pipe The temperature of the water outlet of the road 400. Those skilled in the art can understand that the water outlet temperature should be as close as possible to the target temperature value. Specifically, the target temperature value can be the water outlet temperature set by the user, that is, the outlet water temperature of the shower, faucet, etc. The cold water is then connected to mix with the hot water in the water outlet pipeline 400 . The target temperature value may also be higher than the temperature of the water end set by the user, and the water end needs to be mixed with cold water and hot water in the water outlet pipeline 400 to reach the water end temperature set by the user. At this time, the target temperature value is determined according to the proportion of cold water mixed at the water end and the temperature of the water end set by the user.

Specifically, those skilled in the art can understand that the first heat exchanger directly exchanges heat with the flue gas generated by the combustion of the burner 100, and the second heat exchanger 200 is arranged on the outer wall of the burner 100 to absorb and burn, which should be conducted to the combustion. Compared with the excess heat in the outer wall of the heat exchanger 100, the first heat exchanger has a higher heat exchange efficiency and a faster heating speed for the water flow than the second heat exchanger 200. Therefore, when the water flow rate in the water inlet pipe 300 is constant and the temperature of the outlet water in the water outlet pipe 400 needs to be increased, it is necessary to increase the water flow rate in the first heat exchanger and decrease the water flow rate in the second heat exchanger 200 flow. Conversely, when the temperature of the outlet water in the outlet water pipeline 400 needs to be lowered, the water flow rate in the first heat exchanger can be reduced, and the water flow rate in the second heat exchanger 200 can be increased. In this way, by controlling the water flow in the first heat exchanger and the second heat exchanger 200 , the outlet water temperature in the water outlet pipeline 400 can be adjusted as required.

On the basis of the previous embodiment, the specific structure of the water inlet pipeline 300 is not limited, as long as the water flow in the first heat exchanger and the second heat exchanger 200 can be adjusted. Referring to FIG. 1 , in this embodiment, the water inlet pipeline 300 includes a first connection section 301 for communicating with the external water circuit, a second connection section 302 for communicating with the second heat exchanger 200 , and a first heat exchange section 302 . The third connecting section 303 communicated with each other, the first connecting section 301 , the second connecting section 302 and the third connecting section 303 communicate with each other, wherein the second connecting section 302 is provided with a flow valve 500 . In this way, by controlling the flow valve 500, the water flow in the second heat exchanger 200 can be increased or decreased, and when the water pressure at the water inlet end in the water inlet pipeline 300 is constant, the water in the first heat exchanger The flow will change inversely proportional to the water flow in the second heat exchanger 200: when the water flow in the second heat exchanger 200 increases, the water flow in the first heat exchanger decreases; When the water flow rate decreases, the water flow rate in the first heat exchanger increases correspondingly. In this way, by controlling the flow valve 500 and simultaneously controlling the water flow in the first heat exchanger, the outlet water temperature in the water outlet pipeline 400 is adjusted.

In another embodiment, please refer to FIG. 2 , the second connecting section 302 and the third connecting section 303 are respectively provided with flow valves 500 . In this way, the two flow valves 500 cooperate to adjust the water flow, so that the water flow in the first heat exchanger and the second heat exchanger 200 can be controlled more quickly and accurately, so as to adjust the outlet water temperature in the water outlet pipeline 400 .

On the basis of the above two embodiments, the flow valve 500 is preferably a flow proportional valve, so that the water flow and water pressure in the first heat exchanger and the second heat exchanger 200 can be controlled more accurately.

The starting state of the gas water heater includes cold start and halfway start. When the gas water heater is started in a cold state, it takes a long time since the last time the gas water heater stopped working. However, when the gas water heater is started halfway, the time since the last time the gas water heater stopped working is short, and the water temperature in the first heat exchanger in the gas water heater rises rapidly because the water flow is suspended and the temperature in the heat exchange chamber 101 has not yet dropped. May be significantly higher than the target temperature value. In order to improve the user's comfort in using the gas water heater, the water outlet temperature in the water outlet pipeline 400 should be as close to the target temperature value as possible.

There are various ways for the control device to judge the start-up state of the water heater. In one embodiment, the real-time temperature in the combustion chamber 102, the heat exchange chamber or the first heat exchanger can be detected before the gas water heater is started. When the real-time temperature is lower than a preset temperature limit, it can be considered that the gas water heater is far away The last burning time is long, the temperature of the outlet water in the outlet pipe 400 will not be too high, and the gas water heater is started in a cold state. When the real-time temperature is higher than the preset temperature limit, it can be considered that the temperature in the gas water heater is still high due to the influence of the previous combustion, and the phenomenon of reconciliation overshoot may occur, resulting in the high outlet water temperature in the water outlet pipeline 400. The gas water heater is started halfway. In another embodiment, a timer may also be set in the control device to calculate the time from this start to the last time the gas water heater stopped working. When the time is lower than a preset time limit, it is determined that the gas water heater is in the middle of the process. On the contrary, when the time is greater than the preset time limit, it is judged that the gas water heater is started in a cold state. In this way, the start-up state of the gas water heater is determined in a simple manner, and according to the start-up state, by controlling the opening of the flow valve 500, the flow of water flowing through the first heat exchanger and the second heat exchanger 200 is adjusted to adjust The outlet water temperature in the outlet water pipeline 400 is as close to the target temperature value as possible.

Specifically, when the gas water heater is started in a cold state, since it takes a certain time for the gas water heater to start combustion, there is a certain amount of water in the water inlet pipeline 300, the gas water heater and the water outlet pipeline 400. After the gas water heater is started, it often takes a certain amount of time. It takes time to make the water outlet temperature in the water outlet pipeline 400 reach the target temperature value, and the user often needs to wait for a period of time before the hot water can be used. In order to reduce the user's waiting time, the gas water heater provided by the present invention also makes the following improvements.

In one embodiment, the control device is used to:

When the startup state of the gas-fired water heater is a cold startup, the opening of the flow valve 500 is controlled to control the water flow in the second heat exchanger 200 to be zero or less than a preset first flow value;

When the water outlet temperature value in the water outlet pipeline 400 rises to the target temperature value, the opening of the flow valve 500 is controlled to control the water flow rate in the second heat exchanger 200 to increase to a preset second flow rate value.

In this embodiment, at the initial stage of the gas water heater startup, the second heat exchanger 200 does not work temporarily or only allows a small flow of water to pass through, and the water in the water outlet pipeline 400 is mainly produced by the first heat exchanger with high heat exchange efficiency. Provided, so that the outlet water temperature reaches the target temperature value as soon as possible and shortens the time for users to wait for hot water. When the water outlet temperature value in the water outlet pipeline 400 rises to the target temperature value, the water flow rate in the second heat exchanger 200 is increased to the second flow rate value required for normal operation, so that the gas water heater is in the process of preparing hot water. At the same time, the second heat exchanger 200 functions to reduce the temperature of the outer wall of the burner 100 to protect the gas water heater, and to reduce the heat dissipated by radiation to the outer wall of the burner 100 to improve energy utilization.

In another embodiment, the control device is used to:

When the startup state of the gas water heater is cold startup, the opening of the flow valve 500 is controlled to control the water flow in the second heat exchanger 200 to be zero or less than the preset first flow value within a preset time period ;

The water flow rate in the second heat exchanger 200 is controlled to increase to a preset second flow rate value after a preset time period.

In this embodiment, at the initial stage of the gas water heater startup, the second heat exchanger 200 does not work temporarily or only allows a small flow of water to pass through, and the water in the water outlet pipeline 400 is mainly produced by the first heat exchanger with high heat exchange efficiency. Provided, so that the outlet water temperature reaches the target temperature value as soon as possible. After a preset period of time, the water flow in the second heat exchanger 200 is increased to a second flow value required for normal operation, so that while the gas water heater is preparing hot water, the second heat exchanger 200 starts To reduce the temperature of the outer wall of the burner 100, to protect the gas water heater, and to reduce the heat dissipated by radiation to the outer wall of the burner 100, so as to improve the energy utilization rate. Compared with the previous embodiment, the control device controls the opening of the flow valve 500 according to the preset time, and no additional temperature sensor is required to control the opening of the flow valve 500, which makes the gas water heater simpler in structure and lower in cost.

When the gas water heater is started halfway, the time since the last stop of the gas water heater is short, and the water temperature in the first heat exchanger in the gas water heater is too high. At this time, if the gas water heater starts again, it will start halfway, and the water outlet pipeline 400 The outlet water temperature will be much higher than the target temperature, resulting in the high temperature of the water end, affecting the user experience. In order to prevent the water outlet temperature from being too high at the water end, or the temperature at the outlet end being hot and cold, and to improve the user experience, the gas water heater provided by the present invention also makes the following improvements:

In one embodiment, the control device is used to:

When the startup state of the gas water heater is halfway startup, the opening of the flow valve 500 is controlled to control the water flow in the second heat exchanger 200 to be greater than a preset third flow value;

When the water outlet temperature value in the water outlet pipeline 400 drops to the target temperature value, the opening of the flow valve 500 is controlled to control the water flow rate in the second heat exchanger 200 to decrease to a preset fourth flow rate value.

In this embodiment, at the initial stage of the gas water heater being started halfway, the water flow rate in the second heat exchanger 200 is greater than the preset third flow rate value, and the water flow rate from the second heat exchanger 200 in the water outlet pipeline 400 is relatively The first heat exchanger is increased, so that the relatively low water temperature in the second heat exchanger 200 is used to neutralize the excessively high water temperature in the first heat exchanger, so that the outlet water temperature at the outlet end is closer to the target temperature value, preventing the outlet water at the water end. The temperature is too high, affecting the user's use. When the outlet water temperature value in the outlet water pipeline 400 drops to the target temperature value, the opening degree of the flow valve 500 is controlled to control the water flow rate in the second heat exchanger 200 to decrease to when the second heat exchanger 200 is working normally The desired fourth flow value. When the gas water heater prepares hot water, the second heat exchanger 200 plays the role of lowering the temperature of the outer wall of the burner 100, so as to protect the gas water heater and reduce the heat lost by radiation to the outer wall of the burner 100, so as to improve the energy utilization rate .

In another embodiment, the control device is used to:

When the startup state of the gas water heater is halfway startup, the opening of the flow valve 500 is controlled to control the water flow in the second heat exchanger 200 to be greater than a preset third flow value within a preset time period;

The water flow rate in the second heat exchanger 200 is controlled to decrease to a preset fourth flow rate value after a preset time period.

In this embodiment, at the initial stage of the gas water heater being started halfway, the water flow rate in the second heat exchanger 200 is greater than the preset third flow rate value, and the water flow rate from the second heat exchanger 200 in the water outlet pipeline 400 is relatively The first heat exchanger is increased, so that the relatively low water temperature in the second heat exchanger 200 is used to neutralize the excessively high water temperature in the first heat exchanger, so that the outlet water temperature at the outlet end is closer to the target temperature value, preventing the outlet water at the water end. The temperature is too high, affecting the user's use. After a preset period of time, the opening of the flow valve 500 is controlled to control the water flow in the second heat exchanger 200 to decrease to a fourth flow value required when the second heat exchanger 200 works normally. When the gas water heater prepares hot water, the second heat exchanger 200 plays the role of lowering the temperature of the outer wall of the burner 100, so as to protect the gas water heater and reduce the heat lost by radiation to the outer wall of the burner 100, so as to improve the energy utilization rate . Compared with the previous embodiment, the control device controls the opening of the flow valve 500 according to the preset time, and no additional temperature sensor is required to control the opening of the flow valve 500, which makes the gas water heater simpler in structure and lower in cost.

During the working process of the gas water heater, affected by factors such as water pressure and power of the gas water heater, the temperature of the water flow in the first heat exchanger may be unstable. In order to provide a more stable outlet water temperature and improve the user experience, this implementation The gas water heater provided by the example also makes the following improvements.

In one embodiment, the control device is used to:

Obtain the outlet water temperature value in the outlet water pipeline 400, and control the opening of the flow valve 500 according to the outlet water temperature value, so as to adjust the water flow in the first heat exchanger and the second heat exchanger 200, so that in the outlet water pipeline 400 The outlet water temperature value is in the target temperature range.

It is clear to those skilled in the art that due to the difference in heat exchange efficiency between the first heat exchanger and the second heat exchanger 200, the temperature of the water flow in the first heat exchanger is higher, while the temperature of the water flow in the second heat exchanger 200 is lower , in this way, the opening of the flow valve 500 can be controlled by the control device to adjust the water flow in the first heat exchanger and the second heat exchanger 200 , so as to adjust the first heat exchanger and the second heat exchanger in the water outlet pipeline 400 The ratio of the hot water flowing through the heat exchanger 200 is used to control the outlet water temperature of the water outlet pipeline 400. Preferably, the outlet water temperature is maintained within the target temperature range, so that the outflow water temperature at the water end is more constant and the user experience is improved. .

Specifically, in the following manner, the control device is used for:

Obtain the outlet water temperature value of the outlet pipe 400;

When the outlet water temperature value is less than the minimum value of the target temperature interval, the flow valve 500 is controlled so that the water flow rate in the second heat exchanger 200 decreases and the water flow rate in the first heat exchanger increases;

When the outlet water temperature value is greater than the maximum value of the target temperature range, the flow valve 500 is controlled to increase the water flow rate in the second heat exchanger 200 and decrease the water flow rate in the first heat exchanger.

In this embodiment, the target temperature interval is determined according to the target temperature value, preferably a range of about a few degrees above and below the target temperature value, for example, it may be five degrees above and below the target temperature value. In this control method, the temperature value of the outlet water in the outlet pipe 400 is monitored in real time, and the ratio of the flow rate of water flowing through the first heat exchanger and the second heat exchanger 200 is adjusted in real time through the outlet water temperature value, so as to realize the control of the outlet water pipe 400. The closed-loop adjustment of the temperature value of the middle outlet water keeps the outlet water temperature of the outlet water pipeline 400 within the target temperature range, achieving the effect of constant temperature water outlet, and improving the user experience.

The temperature of the water flow in the second heat exchanger 200 is usually lower than that of the first heat exchanger, but under some special conditions, such as the water flow in the second heat exchanger 200 is too small, the water flow in the second heat exchanger 200 may occur. When the temperature is higher than the target temperature value, the second heat exchanger 200 will not be able to play a very good cooling role, and it will not be able to cooperate with the first heat exchanger to adjust the water outlet temperature in the water outlet pipeline 400 to be Therefore, in this embodiment, the control device is used to:

Obtain the temperature value of the water outlet end of the second heat exchanger 200;

When the water outlet temperature value of the second heat exchanger 200 is greater than the target temperature value, the flow valve 500 is controlled to increase the water flow rate in the second heat exchanger 200 .

In this embodiment, the water flow rate in the second heat exchanger 200 is adjusted according to the temperature value of the water outlet end of the second heat exchanger 200. When the temperature value of the water outlet end in the second heat exchanger 200 is higher than the target temperature value , the water flow in the second heat exchanger 200 is controlled to increase, thereby reducing the temperature of the water flow in the second heat exchanger 200 . Therefore, the temperature value of the water outlet end of the second heat exchanger 200 is always lower than the target temperature value, so that the second heat exchanger 200 can always play a good cooling effect, and can cooperate with the first heat exchanger to realize the constant temperature water outlet. Effect.

The above-mentioned embodiments can be applied to ordinary gas-fired water heaters, and in this embodiment, the above-mentioned embodiments are applied to high-temperature air-fired water heaters.

High temperature air combustion is called "mild and deep hypoxic dilution combustion", or soft combustion for short, and it is a new type of combustion. The main characteristics of this combustion are: the chemical reaction mainly occurs in a high temperature and low oxygen environment, the temperature of the reactant is higher than its auto-ignition temperature, and the maximum temperature rise during the combustion process is lower than its auto-ignition temperature, and the oxygen volume fraction is diluted by combustion products to extremely high levels. Low concentrations, usually 3% to 5%. Compared with conventional combustion, in this combustion state, the pyrolysis of the fuel is suppressed, the flame thickness becomes thicker, and the flame front disappears, so that the temperature of the entire furnace is very uniform during this combustion, and pollutants NOx and CO are emitted. drastically reduced.

In this embodiment, high-temperature air combustion occurs in the combustion chamber 102 of the gas water heater. Compared with ordinary gas water heaters, the overall temperature of the combustion chamber 102 is higher, so more heat is radiated to the chamber wall of the combustion chamber 102. The outer wall is more likely to form a heat storage body. Therefore, the second heat exchanger 200 is arranged on the outer wall of the burner 100 to absorb the heat radiated from the combustion chamber 102 to the outer periphery, which can well prevent the outer wall of the gas water heater from forming a regenerator and protect the electronic components. At the same time, the inside of the combustion chamber 102 can be kept warm, which helps to maintain a high temperature environment required for high temperature air combustion, and is conducive to maintaining a stable temperature required for high temperature air combustion.

However, certain conditions are required to achieve high temperature air combustion: it is necessary to ensure that the oxygen concentration at any position in the furnace is lower than a certain value, generally lower than 5% to 10%, and the temperature is higher than the autoignition point of the fuel. This is achieved by relying on the strong internal circulation of the N2 and CO2 rich exhaust gases in the furnace at high temperature to dilute the reactants.

Specifically, in this embodiment, the burner 100 includes a preheating device and a gas component. The preheating device is used for preheating gas and/or air to a preset target temperature and then delivering it to the combustion chamber 102 , and the gas component is used for injecting gas into the combustion chamber 102 . In this embodiment, the preheating device is used to preheat the gas and/or air delivered to the combustion chamber 102, so that the temperature in the combustion chamber 102 reaches the temperature required for high temperature air combustion. The gas component is used to inject gas into the combustion chamber 102, so that an entrainment effect is formed in the combustion chamber, so that a jet combustion zone and a flue gas recirculation zone are formed in the combustion chamber 102, and part of the high-temperature flue gas (rich in N2 and CO2) is formed. Exhaust gas) is strongly circulated in the combustion zone, and then the injected gas and air are fully diluted to form a lower oxygen concentration, reducing the combustion reaction speed, and the circulating high-temperature flue gas can maintain a higher temperature in the combustion zone, ensuring that the temperature is higher than The self-ignition point of the fuel, to achieve self-ignition, after which no ignition is required. In this way, high temperature air combustion is achieved.

It should be noted that in this embodiment, the high-temperature flue gas is entrained and diluted by preheating the air at a high temperature and cooperating with a high-speed jet, so that the fuel gas and the air in the combustion chamber 102 are evenly mixed, so that the oxygen concentration in the combustion chamber 102 is also balanced and lower than A certain value, so that not only the gas can be fully burned during combustion, which reduces the emission of pollutants, but also the combustion chamber 102 will burn evenly, and there will be no problem of excessive local combustion and noise. In addition, the high-speed jet entrainment also realizes the recirculation of the high-temperature flue gas, so that the temperature of the combustion chamber 102 can be kept higher than the auto-ignition point of the fuel, and the combustion can be maintained as long as the gas is continuously fed. The heat after combustion can be exchanged with the heat exchanger of the gas water heater to achieve hot water production.

It should also be noted that the target temperature of the high-temperature preheating air should not be too low, and should not be lower than 600 degrees Celsius as much as possible. Generally, it is controlled at 600 to 1200 degrees Celsius to ensure that when the high-temperature gas contacts the gas in the combustion chamber 102, a better automatic temperature is achieved. Combustion, no longer requires ignition to ignite. Among them, to achieve the target temperature can be achieved by controlling the heating time, controlling the ratio of gas and air, and maintaining heat. The injection speed of gas and/or air is usually pre-determined and set through experiments, and basically does not change after that. Therefore, the oxygen concentration in the combustion chamber 102 can be realized by controlling the real-time intake air volume, that is, controlling the gas and/or air flow rate. The realization of the air intake ratio, based on this theoretical basis, is not difficult to realize the control of the oxygen concentration of the combustion chamber 102 , and will not be repeated here. The size of the oxygen concentration in the combustion chamber 102 can be controlled according to the size of the combustion chamber 102 and the speed of the control injection.

In one embodiment, the above-mentioned gas component is implemented in the following manner. The gas component includes a gas pipeline, a gas proportional valve 700 and a gas injection port, and the gas pipeline is used to connect to the user's gas pipeline to obtain a gas source and a gas ratio. The valve 700 is arranged on the gas pipeline, and the gas injection port is arranged in the combustion chamber 102 and communicated with the gas pipeline. It can be understood that the injection speed of the gas component is usually pre-determined and set through experiments, and will not change after that. Therefore, the oxygen concentration in the combustion chamber 102 can be realized by controlling the intake air volume, that is, controlling the gas and intake air. Proportional implementation. In this way, this embodiment satisfies the conditions of high temperature air combustion: high temperature preheated air and high-speed jets are used to entrain high-temperature flue gas and dilute and ignite the air jets, so that the oxygen concentration is lower than a certain value and the temperature is higher than the autoignition point of the fuel. The heat after combustion is sent to the first heat exchanger for heat exchange, so as to realize the production of hot water.

The preheating device may have various forms. In some embodiments, the gas water heater realizes the preheating of air and/or gas through auxiliary heating. Specifically, in one embodiment, the preheating device is an electric heating device. Specifically, referring to FIG. 1 and FIG. 2 , the air intake fan 600 can be used to inhale the external air, and electric heating elements such as electric heating wires and electric heating tubes can be used to heat the air in a relatively closed space. Hot air equipment, of course, in order to ensure that the heating temperature is high enough, several groups of elements can be set for heating. In this way, the air can be heated to the target temperature by the electric heating device to achieve high temperature preheating of the air.

In another embodiment, a gas heating device or a regenerator heating device. Specifically, the regenerator can be a honeycomb ceramic structure. During the operation of the gas water heater, the regenerator stores the heat generated in the combustion, and the air intake fan 600 is used to inhale the outside air and transport it through the regenerator. into the combustion chamber 102 to achieve high temperature preheated air.

On the basis of the above two embodiments, the burner 100 further includes an ignition assembly, which is arranged in the combustion chamber 102 and is used for igniting the gas in the combustion chamber 102 to realize high temperature air combustion. In this embodiment, when the high-temperature air heated by the preheating device and reaching the target temperature is passed into the combustion chamber 102, the gas proportional valve 700 can be controlled to open, and gas is introduced into the combustion chamber 102. At this time, the ignition assembly is controlled to perform ignition Action, the gas can be ignited, and after ignition, the ignition action is stopped to save energy. It should be noted that this embodiment has the advantages of small size, simple structure, and easy implementation, and can be easily implemented in a gas water heater without increasing costs.

In this embodiment, however, the preheating of the air is realized by means of two-stage combustion.

Specifically, an air intake chamber and a primary combustion chamber 102 are also formed in the casing, and the air intake chamber, the primary combustion chamber 102 and the combustion chamber 102 are communicated in sequence. The preheating device is a gas heating device, and the gas heating device includes a premixer and a preheating burner 100. The premixer is used to connect gas and air through a gas pipeline and perform premixing, and feed it to the primary combustion chamber. To provide mixed gas, the preheating burner 100 has a mixed gas distribution chamber, the air inlet of the mixed gas distribution chamber is communicated with the premixer, and the air outlet of the mixed gas distribution chamber is communicated with the primary combustion chamber 102, and the preheating burner 100 is used for The mixed gas discharged from the mixed gas distribution chamber into the primary combustion chamber 102 is ignited so that the air in the primary combustion chamber 102 is heated to a target temperature. In one embodiment, the preheat combustor 100 may be a fully premixed combustor.

In this embodiment, the air intake chamber is used to supply the external air to the combustion chamber 102 relatively uniformly, and the premixer delivers the mixed gas to the mixed gas distribution chamber of full premixed combustion, and then enters the primary combustion chamber 102, where the premixed gas is delivered by the premixer. The thermal burner 100 is ignited to combust the air-fuel mixture to heat the air in the primary combustion chamber 102 to form high-temperature flue gas. It can be understood that, by controlling the heating temperature, the air in the primary combustion chamber 102 can be heated to the target temperature, thus achieving high temperature preheating of the air. After the high-temperature preheated high-temperature gas is sent into the combustion chamber 102, the gas component is controlled to inject gas, the gas is combined with the high-temperature gas, and the high-temperature gas ignites the gas to realize the formation of high-temperature air combustion in the combustion chamber 102. Since the gas is injected through the gas component, An entrainment effect will be formed in the combustion chamber 102, so that a jet combustion area and a flue gas recirculation area will be formed in the combustion chamber 102, so that part of the flue gas will be strongly circulated in the combustion chamber 102, and then the injected gas and air will be fully diluted to form The lower oxygen concentration reduces the combustion reaction speed, and maintains a relatively high temperature in the combustion chamber 102 to ensure that the temperature is higher than the self-ignition point of the fuel to achieve self-ignition. In this way, this embodiment satisfies the conditions of high temperature air combustion: high temperature preheated air and high-speed jets are used to entrain high-temperature flue gas and dilute and ignite the air jets, so that the oxygen concentration is lower than a certain value and the temperature is higher than the autoignition point of the fuel. The heat after combustion can be exchanged with the heat exchanger of the gas water heater to achieve hot water production.

With reference to the embodiment of the burner 100 above, the working principle of the gas water heater in this embodiment is described:

The gas water heater is started, the air and gas mixed by the premixer in a certain proportion are supplied to the preheating burner 100, the ignition device is ignited, and combustion starts in the primary combustion chamber 102, and the air inlet fan 600 corresponding to the air entering the chamber also acts to suck into the combustion chamber. The required air, the cold air and the high-temperature flue gas generated by the combustion of the preheating burner 100 are stirred and mixed in multiple mixing zones to form high-temperature flue gas. When the required temperature is reached, the gas proportional valve 700 provides gas to the gas pipeline, and the gas required for high-temperature air combustion is injected from the gas injection port connected to the gas pipeline into the combustion chamber 102 to combine with the high-temperature gas, and the high-temperature gas ignites the gas to achieve High-temperature air combustion is formed in the combustion chamber 102. Due to the injection of gas through the gas injection port, an entrainment effect will be formed in the combustion chamber 102, so that a jet combustion area and a flue gas recirculation area are formed in the combustion chamber 102, so that part of the flue gas is in the combustion chamber 102. The combustion chamber 102 is strongly circulated, and then the injected fuel gas and air are fully diluted to form a lower oxygen concentration, reduce the combustion reaction speed, and maintain a relatively high temperature of the combustion chamber 102 to ensure that the temperature is higher than the self-ignition point of the fuel to achieve spontaneous combustion . In this way, this embodiment satisfies the conditions of high temperature air combustion: high temperature preheated air and high-speed jets are used to entrain high-temperature flue gas and dilute and ignite the air jets, so that the oxygen concentration is lower than a certain value and the temperature is higher than the autoignition point of the fuel. The heat after combustion can be exchanged with the heat exchanger of the gas water heater and then discharged to the outside to achieve hot water production. It can be understood that, since the MILD combustion method is adopted in the gas water heater provided in this embodiment, the gas water heater can effectively reduce the emission of CO and NOx and reduce the noise of the gas water heater.

In addition, the present invention also provides a control method for a gas water heater. The method can be implemented based on the structure of the gas water heater described above, or can be implemented based on a structure based on the same principle, which is not limited. For the convenience of understanding, the structure of the gas water heater in this embodiment is described: the gas water heater includes a burner 100 formed with a heat exchange chamber 101 , and a flue gas disposed in the heat exchange chamber 101 and used for combustion with the burner 100 to generate flue gas. The first heat exchanger for heat exchange, the second heat exchanger 200 provided on the outer wall of the burner 100, and the first heat exchanger and the second heat exchanger 200 are connected and used to supply the first heat exchanger and the second heat exchanger The heat exchanger 200 provides a water inlet and drainage pipeline system, the pipeline system includes a water outlet pipeline 400, and the water outlet ends of the first heat exchanger and the second heat exchanger 200 are respectively communicated with the water outlet pipeline 400.

It is clear to those skilled in the art that due to the difference in heat exchange efficiency between the first heat exchanger and the second heat exchanger 200, the temperature of the water flow in the first heat exchanger is higher, while the temperature of the water flow in the second heat exchanger 200 is lower , in this way, the opening of the flow valve 500 can be controlled by the control device to adjust the water flow in the first heat exchanger and the second heat exchanger 200 , so as to adjust the first heat exchanger and the second heat exchanger in the water outlet pipeline 400 The ratio of the hot water flowing through the heat exchanger 200 is used to control the outlet water temperature of the water outlet pipeline 400 . In this embodiment, the outlet water temperature in the water outlet pipe 400 indicates the temperature of the water pipe 400 after the hot water in the first heat exchanger and the second heat exchanger 200 are evenly mixed. Specifically, in the measurement, it can be the water outlet pipe The temperature of the water outlet of the road 400. Those skilled in the art can understand that the water outlet temperature should be as close as possible to the target temperature value. Specifically, the target temperature value can be the water outlet temperature set by the user, that is, the outlet water temperature of the shower, faucet, etc. The cold water is then connected to mix with the hot water in the water outlet pipeline 400 . The target temperature value may also be higher than the temperature of the water end set by the user, and the water end needs to be mixed with cold water and hot water in the water outlet pipeline 400 to reach the water end temperature set by the user. At this time, the target temperature value is determined according to the proportion of cold water mixed at the water end and the temperature of the water end set by the user.

In this embodiment, the structure of the pipeline system is not limited. Specifically, the pipeline system has a flow control function, which can adjust the water flow in the first heat exchanger and the second heat exchanger 200. Set flow valve 500 and flow proportional valve to realize.

Referring to Figure 3, the control method of the gas water heater includes:

S10: when the startup state of the gas water heater is a cold startup, the control pipeline system adjusts the water flow in the second heat exchanger 200 to be zero or less than a preset first flow value;

In this step, when the gas water heater is started in a cold state, it is a long time since the last time the gas water heater stopped working. In this way, there will be no situation where the temperature of the outlet water in the outlet pipe 400 is higher than the target temperature value due to the excessively high temperature of the water in the first heat exchanger.

S11: When the water outlet temperature value in the water outlet pipeline 400 rises to the target temperature value, the control pipeline system adjusts the water flow rate in the second heat exchanger 200 to increase to a preset second flow rate value.

In this step, the second flow value refers to the water flow required for the cooling effect of the second heat exchanger 200 when the burner 100 is working, and the second flow value can be set according to the burning intensity of the burner 100 as required. Certainly. It can be understood that the second flow rate value should be greater than the first flow rate value.

When the gas water heater is started in a cold state, since it takes a certain time for the gas water heater to start and burn, there is a certain amount of water in the water inlet pipe 300, the gas water heater and the water outlet pipe 400. After the gas water heater is started, it often takes a certain amount of time to When the temperature of the outlet water in the outlet pipe 400 reaches the target temperature value, the user often needs to wait for a period of time before the hot water can be used.

In this embodiment, at the initial stage of the gas water heater startup, the second heat exchanger 200 does not work temporarily or only allows a small flow of water to pass through, and the water in the water outlet pipeline 400 is mainly produced by the first heat exchanger with high heat exchange efficiency. Provided, so that the outlet water temperature reaches the target temperature value as soon as possible, reducing the user's waiting time. When the water outlet temperature value in the water outlet pipeline 400 rises to the target temperature value, the water flow rate in the second heat exchanger 200 is increased to the second flow rate value required for normal operation, so that the gas water heater is in the process of preparing hot water. At the same time, the second heat exchanger 200 functions to reduce the temperature of the outer wall of the burner 100 to protect the gas water heater, and to reduce the heat dissipated by radiation to the outer wall of the burner 100 to improve energy utilization.

In another embodiment, referring to FIG. 4 , the control method includes:

S20: when the startup state of the gas water heater is cold startup, the control pipeline system adjusts the water flow in the second heat exchanger 200 to be zero or less than a preset first flow value within a preset time period;

S21: After a preset time period, the control pipeline system adjusts the water flow rate in the second heat exchanger 200 to increase to a preset second flow rate value.

In this step, the preset time period is generally determined according to the time required to restore the room temperature after the gas water heater stops burning.

In this embodiment, at the initial stage of the gas water heater startup, the second heat exchanger 200 does not work temporarily or only allows a small flow of water to pass through, and the water in the water outlet pipeline 400 is mainly produced by the first heat exchanger with high heat exchange efficiency. Provided, so that the outlet water temperature reaches the target temperature value as soon as possible. After a preset period of time, the water flow in the second heat exchanger 200 is increased to a second flow value required for normal operation, so that while the gas water heater is preparing hot water, the second heat exchanger 200 starts To reduce the temperature of the outer wall of the burner 100, to protect the gas water heater, and to reduce the heat dissipated by radiation to the outer wall of the burner 100, so as to improve the energy utilization rate. Compared with the previous embodiment, the control device controls the opening of the flow valve 500 according to the preset time, and no additional temperature sensor is required to control the opening of the flow valve 500, which makes the gas water heater simpler in structure and lower in cost.

In another embodiment, referring to FIG. 5 , the control method includes:

S30: when the startup state of the gas-fired water heater is halfway startup, control the pipeline system to adjust the water flow rate in the second heat exchanger 200 to be greater than a preset third flow rate value;

In this step, when the gas water heater is started halfway, the time since the last time the gas water heater stopped working is short, and the water temperature in the first heat exchanger in the gas water heater is due to the suspension of water flow and the temperature in the heat exchange chamber 101 has not yet dropped. Raised rapidly, possibly well above the target temperature value. This will lead to the phenomenon of reconciliation overshoot, that is, the temperature value of the outlet water in the outlet pipe 400 is too high, resulting in the water temperature at the water end being too hot, and the outlet water being hot and cold, which affects the user experience.

S31: When the outlet water temperature value in the water outlet pipeline 400 drops to the target temperature value, the control pipeline system adjusts the water flow rate in the second heat exchanger 200 to decrease to a preset fourth flow rate value.

In this step, the fourth flow value refers to the water flow required for the cooling effect of the second heat exchanger 200 when the burner 100 is working, and the fourth flow value can be set according to the burning intensity of the burner 100 as required. Certainly. It can be understood that the fourth flow value should be smaller than the third flow value.

When the gas water heater is started halfway, the time since the last stop of the gas water heater is short, and the water temperature in the first heat exchanger of the gas water heater is too high. The outlet water temperature will be much higher than the target temperature, resulting in an excessively high temperature at the water end, affecting the user experience.

For this reason, in this embodiment, in the initial stage of the gas water heater halfway startup, the water flow rate in the second heat exchanger 200 is greater than the preset third flow rate value, and the water in the water outlet pipeline 400 from the second heat exchanger 200 Compared with the first heat exchanger, the flow rate is increased, so that the relatively low water temperature in the second heat exchanger 200 is used to neutralize the excessively high water temperature in the first heat exchanger, so that the outlet water temperature at the outlet end is closer to the target temperature value, preventing The temperature of the water at the water end is too high, which affects the user's use. When the outlet water temperature value in the outlet water pipeline 400 drops to the target temperature value, the opening degree of the flow valve 500 is controlled to control the water flow rate in the second heat exchanger 200 to decrease to when the second heat exchanger 200 is working normally The desired fourth flow value. When the gas water heater prepares hot water, the second heat exchanger 200 plays the role of lowering the temperature of the outer wall of the burner 100, so as to protect the gas water heater and reduce the heat lost by radiation to the outer wall of the burner 100, so as to improve the energy utilization rate .

In another embodiment, please refer to FIG. 6 , the control method includes:

S40: when the startup state of the gas water heater is halfway startup, control the pipeline system to adjust the water flow in the second heat exchanger 200 to be greater than a preset third flow value within a preset time period;

S41: After a preset time period, the control pipeline system adjusts the water flow in the second heat exchanger 200 to decrease to a preset fourth flow value.

In this embodiment, at the initial stage of the gas water heater being started halfway, the water flow rate in the second heat exchanger 200 is greater than the preset third flow rate value, and the water flow rate from the second heat exchanger 200 in the water outlet pipeline 400 is relatively The first heat exchanger is increased, so that the relatively low water temperature in the second heat exchanger 200 is used to neutralize the excessively high water temperature in the first heat exchanger, so that the outlet water temperature at the outlet end is closer to the target temperature value, preventing the outlet water at the water end. The temperature is too high, affecting the user's use. After a preset period of time, the opening of the flow valve 500 is controlled to control the water flow in the second heat exchanger 200 to decrease to a fourth flow value required when the second heat exchanger 200 works normally. When the gas water heater prepares hot water, the second heat exchanger 200 plays the role of lowering the temperature of the outer wall of the burner 100, so as to protect the gas water heater and reduce the heat lost by radiation to the outer wall of the burner 100, so as to improve the energy utilization rate . Compared with the previous embodiment, the control device controls the opening of the flow valve 500 according to the preset time, and no additional temperature sensor is required to control the opening of the flow valve 500, which makes the gas water heater simpler in structure and lower in cost.

In another embodiment, referring to FIG. 7 , the control method includes:

S50: Obtain the water outlet temperature value of the water outlet pipeline 400;

S51: When the outlet water temperature value is less than the minimum value of the target temperature range, control the pipeline system to adjust the water flow in the first heat exchanger and the second heat exchanger 200, so that the water flow in the second heat exchanger 200 decreases small, and the water flow in the first heat exchanger increases;

S52: When the outlet water temperature value is greater than the maximum value of the target temperature range, control the pipeline system to adjust the water flow in the first heat exchanger and the second heat exchanger 200 to increase the water flow in the second heat exchanger 200 large, the water flow in the first heat exchanger decreases.

In this embodiment, the target temperature interval is determined according to the target temperature value, preferably a range of about a few degrees above and below the target temperature value, for example, it may be five degrees above and below the target temperature value. In this control method, the temperature value of the outlet water in the outlet pipe 400 is monitored in real time, and the ratio of the flow rate of water flowing through the first heat exchanger and the second heat exchanger 200 is adjusted in real time through the outlet water temperature value, so as to realize the control of the outlet water pipe 400. The closed-loop adjustment of the temperature value of the middle outlet water keeps the outlet water temperature of the outlet water pipeline 400 within the target temperature range, achieving the effect of constant temperature water outlet, and improving the user experience.

In another embodiment, referring to FIG. 8 , the control method includes:

S60: Obtain the temperature value of the water outlet end of the second heat exchanger 200;

S61: When the temperature value of the water outlet of the second heat exchanger 200 is greater than the target temperature value, control the pipeline system to adjust the water flow in the second heat exchanger 200 to increase the water flow in the second heat exchanger 200 .

In this embodiment, the water flow rate in the second heat exchanger 200 is adjusted according to the temperature value of the water outlet end of the second heat exchanger 200. When the temperature value of the water outlet end in the second heat exchanger 200 is higher than the target temperature value , the water flow in the second heat exchanger 200 is controlled to increase, and the temperature of the water flow in the second heat exchanger 200 is decreased. Therefore, the temperature value of the water outlet end of the second heat exchanger 200 is always lower than the target temperature value, so that the second heat exchanger 200 can always play a good cooling effect, and can cooperate with the first heat exchanger to realize the constant temperature water outlet. Effect.

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the inventive concept of the present invention, the equivalent structure transformation made by the contents of the description and drawings of the present invention, or directly/indirectly applied to other All relevant technical fields are included in the scope of patent protection of the present invention.

Claims (14)

1. A gas-fired water heater, wherein the gas-fired water heater comprises: The burner is formed with a heat exchange chamber and a combustion chamber; a first heat exchanger, which is arranged in the heat exchange chamber and is used for heat exchange with the flue gas generated by the combustion of the burner; a second heat exchanger provided on the outer wall of the burner; and, a piping system, connected to the first heat exchanger and the second heat exchanger, for providing water intake and drainage to the first heat exchanger and the second heat exchanger, the piping system includes Water inlet pipeline and water outlet pipeline, the water inlet ends of the first heat exchanger and the second heat exchanger are respectively connected with the water inlet pipeline, the first heat exchanger and the second heat exchange The water outlet ends of the heat exchanger are respectively communicated with the water outlet pipeline, and the water inlet pipeline is provided with a flow valve for adjusting the water flow in the first heat exchanger and the second heat exchanger; The gas water heater further includes a control device, the control device is electrically connected with the flow valve, and the control device is used to control the opening degree of the flow valve, so as to control the first heat exchanger and the The water flow in the second heat exchanger adjusts the outlet water temperature in the outlet pipe; The water inlet pipeline includes a first connecting section for communicating with an external water circuit, a second connecting section for communicating with the second heat exchanger, and a third connecting section for communicating with the first heat exchanger, so The first connecting section, the second connecting section and the third connecting section are communicated with each other, wherein the flow valve is provided on the second connecting section, or the second connecting section and the third connecting section are connected with each other. The flow valve is respectively provided on the connecting section; The control device is used for: When the startup state of the gas-fired water heater is a cold startup, controlling the opening of the flow valve to control the water flow in the second heat exchanger to be zero or less than a preset first flow value; When the water outlet temperature value in the water outlet pipeline rises to the target temperature value, the opening of the flow valve is controlled to control the water flow rate in the second heat exchanger to increase to a preset second flow rate value ; Alternatively, the control device is used to: When the startup state of the gas-fired water heater is a cold startup, the opening of the flow valve is controlled to control the water flow in the second heat exchanger to be zero or less than a preset time period first flow value; controlling the water flow in the second heat exchanger to increase to a preset second flow value after the preset time period; Alternatively, the control device is used to: When the startup state of the gas water heater is halfway startup, controlling the opening of the flow valve to control the water flow in the second heat exchanger to be greater than a preset third flow value; When the water outlet temperature value in the water outlet pipeline drops to the target temperature value, the opening of the flow valve is controlled to control the water flow rate in the second heat exchanger to decrease to a preset fourth flow rate value ; Alternatively, the control device is used to: When the startup state of the gas water heater is halfway startup, the opening of the flow valve is controlled to control the water flow in the second heat exchanger to be greater than a preset third flow value within a preset time period ; The water flow in the second heat exchanger is controlled to decrease to a preset fourth flow value after the preset time period. 2 . The gas water heater according to claim 1 , wherein the combustion chamber is communicated with the heat exchange chamber through a flue gas passage, so that the flue gas generated by the combustion of the combustion chamber passes through the flue gas passage. 3 . flowing through the heat exchange chamber, the outer wall of the burner constitutes the chamber wall of the combustion chamber; or, The heat exchange chamber includes the combustion chamber, and the outer wall of the burner constitutes a chamber wall of the combustion chamber. 3. The gas water heater according to claim 1, wherein the second heat exchanger is a coil arranged around the outer wall of the burner; or, The second heat exchanger is a water cooling wall disposed inside the outer wall of the burner. 4. The gas water heater according to claim 1, wherein the control device is used for: Obtain the water outlet temperature value in the water outlet pipeline, and control the opening of the flow valve according to the outlet water temperature value to adjust the water flow in the first heat exchanger and the second heat exchanger, So that the water outlet temperature value in the water outlet pipeline is within the target temperature range. 5. The gas water heater according to claim 4, wherein the control device is used for: obtaining the water outlet temperature value of the water outlet pipeline; When the outlet water temperature value is less than the minimum value of the target temperature interval, the flow valve is controlled so that the water flow in the second heat exchanger is reduced, and the water in the first heat exchanger increased flow; When the outlet water temperature value is greater than the maximum value of the target temperature interval, the flow valve is controlled so that the water flow in the second heat exchanger increases, and the water in the first heat exchanger increases. Flow decreases. 6. The gas water heater according to claim 1, wherein the control device is used for: obtaining the temperature value of the water outlet end of the second heat exchanger; When the temperature value of the water outlet end of the second heat exchanger is greater than the target temperature value, the flow valve is controlled to increase the water flow in the second heat exchanger. 7. The gas water heater according to any one of claims 1 to 6, wherein the flow valve is a flow proportional valve. 8. The gas water heater according to any one of claims 1 to 6, wherein the burner comprises: a preheating device for preheating gas and/or air to a preset target temperature and then delivering it to the combustion chamber; and, The gas component is used for injecting gas into the combustion chamber. 9 . The gas water heater according to claim 8 , wherein the preheating device is an electric heating device, a gas heating device or a heat storage body heating device. 10 . 10. The gas water heater according to claim 9, wherein the preheating device is a gas heating device, the burner further has an air intake chamber and a primary combustion chamber, the air intake chamber, the The primary combustion chamber is communicated with the combustion chamber in sequence; The gas heating device includes: a premixer for connecting and premixing gas and air, and providing the mixed gas to the primary combustion chamber; and, a preheating burner, the preheating burner has a mixed gas distribution chamber, the air inlet of the mixed gas distribution chamber is communicated with the premixer, and the air outlet of the mixed gas distribution chamber is connected with the primary combustion chamber In communication, the preheating burner is used for igniting the mixed gas discharged from the mixed gas distribution chamber into the primary combustion chamber, so that the air in the primary combustion chamber is heated to the target temperature. 11. A control method for a gas-fired water heater, the gas-fired water heater comprising a burner formed with a heat exchange chamber, a first heat exchanger disposed in the heat exchange chamber and used for exchanging heat with flue gas generated by combustion of the burner a heat exchanger, a second heat exchanger provided on the outer wall of the burner, and connected to the first heat exchanger and the second heat exchanger for providing the first heat exchanger and the second heat exchanger A pipeline system for water intake and drainage, the pipeline system includes a water outlet pipeline, and the water outlet ends of the first heat exchanger and the second heat exchanger are respectively connected to the water outlet pipeline; it is characterized in that, The control method of the gas water heater includes: When the startup state of the gas-fired water heater is a cold startup, controlling the pipeline system to adjust the water flow in the second heat exchanger to be zero or less than a preset first flow value; When the water outlet temperature value in the water outlet pipeline rises to the target temperature value, controlling the pipeline system to adjust the water flow rate in the second heat exchanger to increase to a preset second flow rate value; or, When the startup state of the gas-fired water heater is a cold startup, the pipeline system is controlled to adjust the water flow in the second heat exchanger to be zero or less than a preset first flow value within a preset time period ; After the preset time period, the piping system is controlled to adjust the water flow rate in the second heat exchanger to increase to a preset second flow rate value. 12. The control method for a gas water heater according to claim 11, wherein the control method for the gas water heater further comprises: When the startup state of the gas-fired water heater is halfway startup, controlling the pipeline system to adjust the water flow in the second heat exchanger to be greater than a preset third flow value; When the water outlet temperature value in the water outlet pipeline drops to a target temperature value, controlling the pipeline system to adjust the water flow rate in the second heat exchanger to reduce to a preset fourth flow rate value; or, When the startup state of the gas-fired water heater is halfway startup, controlling the pipeline system to adjust the water flow in the second heat exchanger to be greater than a preset third flow value within a preset time period; After the preset time period, the piping system is controlled to adjust the water flow rate in the second heat exchanger to decrease to a preset fourth flow rate value. 13. The control method for a gas water heater according to claim 11 or 12, wherein the control method for the gas water heater further comprises: Obtain the water outlet temperature value of the water outlet pipeline; When the outlet water temperature value is less than the minimum value of the target temperature interval, control the pipeline system to adjust the water flow in the first heat exchanger and the second heat exchanger, so that the second heat exchange The water flow in the heat exchanger decreases, and the water flow in the first heat exchanger increases; When the outlet water temperature value is greater than the maximum value of the target temperature interval, control the pipeline system to adjust the water flow in the first heat exchanger and the second heat exchanger, so that the second heat exchanger The water flow in the heat exchanger increases and the water flow in the first heat exchanger decreases. 14. The control method for a gas water heater according to claim 13, wherein the control method for the gas water heater further comprises: obtaining the temperature value of the water outlet end of the second heat exchanger; When the temperature value of the water outlet end of the second heat exchanger is greater than the target temperature value, the pipeline system is controlled to adjust the water flow in the second heat exchanger, so that the water flow in the second heat exchanger is increased water flow.

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