A gas water heater and a constant temperature control method thereof

Abstract

The application provides a gas water heater and a constant temperature control method thereof. The method comprises determining a restart water inflow Fz, wherein the restart water inflow Fz is less than a water inflow after the water heater is started for the first time; starting a water quantity adjustment mode according to the restart water inflow Fz when the water heater receives a restart signal; obtaining mixed water temperature Wi, a set temperature Wx and a corresponding rated load Lz, and calculating an input load Ls according to the mixed water temperature Wi, the set temperature Wx and the rated load Lz, wherein the input load Ls is greater than the rated load Lz; starting a heating mode according to the input load Ls to heat, so that the outlet water temperature Wx' reaches the set temperature Wx; and closing the water quantity adjustment mode when the outlet water temperature Wx' reaches the set temperature Wx. The method can realize constant temperature water supply, avoid the situation that cold water appears when a user uses water again, and ensure that the water temperature is relatively stable during use.

Description

Technical Field

[0001] This invention relates to the field of home appliance technology, and in particular to a gas water heater and its constant temperature control method. Background Technology

[0002] A gas water heater, also known as a gas water boiler, is a gas appliance that uses gas as fuel and heats water by transferring heat to cold water flowing through a heat exchanger. Gas water heaters are widely used in households due to their advantages such as instant hot water supply, small footprint, and high safety performance.

[0003] During use, if the user temporarily turns off the hot water, the gas water heater will be shut off immediately. After the water is turned off, it stops flowing, and the water remaining in the water heater will have its temperature rise due to the high residual heat of the heat exchanger. When the user turns the hot water back on, the water heater still needs to determine the safety of the operating environment and the system before it can ignite. After successful ignition, it will heat the water to gradually raise the temperature to the set temperature, which takes a certain amount of time. During this process, a large amount of cold water will flow out. Therefore, when the tap is turned on again to turn on the water heater, the water temperature will be hot at first, then cold, and then return to normal. This gives the user an experience of inconsistent water temperature and a poor user experience. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a gas water heater and its constant temperature control method to solve the problem that when the tap is turned on twice in existing gas water heaters, the water temperature will be hot first, then cold, and then return to normal, which will give users an experience of inconsistent water temperature and poor user experience.

[0005] To solve the above-mentioned technical problems, the technical solution used in this invention is as follows:

[0006] The present invention discloses a method for constant temperature control of a gas water heater, comprising the following steps:

[0007] S1: Determine the water inlet flow rate Fz for restarting based on the water flow after the water heater is turned on once, and the water inlet flow rate Fz for restarting is less than the water inlet flow rate after the water heater is turned on once.

[0008] S2: When the water heater receives a restart signal, it activates the water flow adjustment mode according to the restart inlet water flow rate Fz.

[0009] S3: Obtain the mixed water temperature Wi, the set temperature Wx, and the corresponding rated load Lz, and calculate the input load Ls based on the mixed water temperature Wi, the set temperature Wx, and the rated load Lz, wherein the input load Ls is greater than the rated load Lz;

[0010] S4: start heating mode heating according to the input load Ls, so that the outlet water temperature Wx' reaches the set temperature Wx;

[0011] S5: when the outlet water temperature Wx' reaches the set temperature Wx, the water quantity adjustment mode is closed.

[0012] Preferably, in step S1, the first water inflow Fa is determined according to the water flow after the water heater is started for the first time, and then the second water inflow Fz is calculated according to the first water inflow Fa, and the second water inflow Fz is less than the first water inflow Fa.

[0013] Further preferably, the first water inflow Fa is an average value within a preset time t.

[0014] Further preferably, in step S1, the second water inflow Fz = K*Fa; in the formula, K < 1, and is an integer multiple of 0.1.

[0015] Further preferably, in step S1, the second water inflow Fz = K*Fa; the value of K ranges from 0.3 to 0.6, and the larger the first water inflow Fa, the smaller K.

[0016] Preferably, in step S3, the input load Ls = K1*Fz*(Wx-Wi), in the formula, K1 > 1; and / or, in step S4, a preset temperature difference Wn is set, when the outlet water temperature Wx' is equal to the difference W between the set temperature Wx and the preset temperature difference Wn, the heating mode is changed from the input load Ls to running at the rated load Lz, and the difference W is less than the set temperature Wx.

[0017] Preferably, in step S5, when the outlet water temperature with the set temperature Wx lasts for a preset time T, the water quantity adjustment mode is closed.

[0018] Another object of the present application is to provide a gas water heater, which comprises a master control device, a water inflow adjusting device, a water inflow collector and an outlet water temperature collector, the water inflow collector is arranged on the water inflow pipeline of the gas water heater, the outlet water temperature collector is arranged on the outlet water pipeline of the gas water heater, the water inflow adjusting device, the water inflow collector and the outlet water temperature collector are connected with the master control device respectively, the water inflow adjusting device adjusts the water inflow size according to the control instruction of the master control device, and the master control device is used for controlling the operation of the gas water heater according to the above method.

[0019] Preferably, the water inflow adjusting device comprises a stepping motor and an adjusting valve, the stepping motor is in transmission connection with the adjusting valve, and the stepping motor is connected with the master control device.

[0020] Further preferably, the water inflow adjusting device is a water servo mechanism of the gas water heater.

[0021] The gas water heater and the constant temperature control method thereof have the following advantages:

[0022] In the secondary opening, the water inflow Fz of the second start is less than the water inflow after the first start of the water heater, that is, the water inflow Fz of the second start is reduced, so that the amount of cold water is reduced, the temperature Wi of the mixed water after the heat exchange between the cold water and the residual heat of the heat exchanger of the water heater is increased, and the minimum value of the water outlet temperature Wx' after the secondary opening is increased. On the other hand, the input load Ls is greater than the rated load Lz, that is, the input load is increased, so that the heating time of the cold water is reduced, and the heating rate of the hot water is increased. In the secondary opening, the water is heated by the method, the constant temperature water supply is realized, the cold water is avoided in the use of the user, the water temperature is maintained relatively stable in the use of the user, and the user experience is improved. The control logic of the method is simple and reasonable, and the safety is high. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present application are shown by way of illustrative example. Like reference numerals in the drawings denote like elements, and the drawings are not necessarily to scale, with emphasis being placed upon illustrating the principles of the present application.

[0024] Figure 1 A flowchart of a constant temperature control method of a gas water heater provided by an embodiment of the present application is shown in the figure.

[0025] Figure 2 A schematic diagram of a constant temperature control system of a gas water heater provided by an embodiment of the present application is shown in the figure.

[0026] Figure 3 A structure diagram of the stepper motor and the adjusting valve provided by an embodiment of the present application is shown in the figure.

[0027] Figure 4 A water system schematic diagram of a gas water heater provided by an embodiment of the present application is shown in the figure.

[0028] BRIEF DESCRIPTION OF DRAWINGS: main control device 1, water servo mechanism 2, stepper motor 201, adjusting valve 202, water inflow collector 3, water outlet temperature collector 4, water pump 5, water inlet pipeline 6, water outlet pipeline 7, heat exchanger 8. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described in further detail below in combination with the drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it. However, the embodiments are not intended to limit the present application. In the embodiments, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0030] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element and integrated as a whole, or a middle element can exist at the same time. The terms "mount", "one end", "the other end" and the like used in the present application are only for the purpose of illustration.

[0031] The present embodiment provides a constant temperature control method for a gas water heater, as shown in the following steps: Figure 1

[0032] S1: According to the water flow after the first start of the water heater, determine the restart water flow Fz, and the restart water flow Fz is less than the water flow after the first start of the water heater;

[0033] S2: When the water heater receives a restart signal, start the water quantity adjustment mode according to the restart water flow Fz, that is, adjust the water flow to the restart water flow Fz;

[0034] S3: Obtain the mixed water temperature Wi, the set temperature Wx and the corresponding rated load Lz, and calculate the input load Ls according to the mixed water temperature Wi, the set temperature Wx and the rated load Lz, and the input load Ls is greater than the rated load Lz; wherein the mixed water temperature Wi refers to the outlet water temperature of the water mixed by the water temporarily stored in the water heater after the first use and the cold water entering the water heater after the second start;

[0035] S4: Start the heating mode according to the input load Ls to heat, so that the outlet water temperature Wx' reaches the set temperature Wx;

[0036] S5: When the outlet water temperature Wx' reaches the set temperature Wx, the water quantity adjustment mode is closed.

[0037] ​The water flow Fz of the second start is less than the water flow after the first start of the water heater, that is, the water flow Fz of the second start is reduced, so that the amount of cold water is reduced, the temperature of the mixed water after the heat exchange with the heat exchanger 8 is improved, the minimum value of the water outlet temperature Wx' after the second start is improved, the input load Ls is greater than the rated load Lz, that is, the input load is increased, so that the heating rate of the hot water is increased, and the heating time of the cold water is reduced. By heating the water through the scheme during the second start, constant temperature water supply can be realized, the situation of cold water outlet during the second use of the user is avoided, the water temperature is maintained relatively stable during the use of the user, and the user experience is improved. The control logic of the method is simple and reasonable, and the safety is high.

[0038] It should be noted that the "first time" in the embodiment is the first occurrence relative to the "second time" or "second time", and is not the first time or the first time. Similarly, the "second time" or "second time" is the second occurrence relative to the "first time", and is not the second time. The water quantity adjustment mode is the water quantity adjustment for implementing the control method, which needs to be distinguished from other water quantity adjustment controls during the operation of the gas water heater, that is, the water quantity adjustment mode is closed in step S5, which does not mean that all water quantity adjustment controls and operations of the water heater are closed.

[0039] In step S1, the water flow after the first start of the water heater is determined, and then the water flow Fz of the second start is calculated according to the water flow Fz of the second start, and the water flow Fz of the second start is less than the water flow Fz of the first start. By introducing the water flow Fz of the first start, the control mode of step S1 is simplified.

[0040] Further, the water flow Fz of the first start is an average value in a preset time t. Specifically, in step S1, after the first start of the water heater, the water flow is obtained every Ti time period in the preset time t to obtain Fa1, Fa2, Fa3,..., Fan, and the water flow Fz of the first start is (Fa1+Fa2+Fa3+...+Fan) / n. By obtaining data at different time nodes and calculating the average value, the average situation of the water flow during the use of the user can be accurately determined, the deviation of the sampling value caused by the fluctuation of the total water inlet pressure of the user during the use or the opening of other water points can be avoided, the accuracy of the determination of the water flow of the second start is not affected, and the actual use effect is not good. The preset time t can be selected as an integer minute according to the user's bathing time, and the value n can be selected as an integer multiple of one minute according to the user's bathing time.

[0041] The re-starting water inflow Fz = K * Fa; wherein K < 1, and is an integer multiple of 0.1, which is conducive to making the temperature constant more accurate. Too small water inflow is prone to re-starting risk, and experiments have proved that when K > 0.6, the hot water outflow effect is poor, and in another preferred embodiment, the value of K ranges from 0.3 to 0.6, and the greater the water inflow Fa, the smaller the K.

[0042] In step S3, preferably, the input load Ls = K1 * Fz * (Wx - Wi), wherein K1 > 1, the input load Ls calculated by the formula is greater than the required heat load (i.e. rated load Lz), which can ensure that the water temperature is quickly raised, and by introducing the water inflow Fz parameter, the input load Ls can be accurately calculated according to the water inflow during user use, so that the set temperature Wx can be quickly and accurately reached, and the user experience is guaranteed. The calculation formula of the rated load Lz is a prior art, which is not described here.

[0043] In step S4, a preset temperature difference Wn is preferably set, when the water temperature Wx' is equal to the difference W between the set temperature Wx and the preset temperature difference Wn, the heating mode is changed from the input load Ls to the rated load Lz, and the difference W is less than the set temperature Wx, that is, the water temperature Wx' is changed to the rated load Lz before the set temperature Wx is reached, and by recovering to the rated load in advance, the overshoot of the water temperature can be avoided, and the user experience is further guaranteed.

[0044] In step S5, when the water temperature reaches the preset time T at the set temperature Wx, the water quantity adjustment mode is closed, at this time, the water inflow adjustment condition returns to the flow adjustment condition when the water quantity adjustment mode is started in step S1, and by this way, it can be judged whether the water temperature is stable, so as to reasonably confirm the exit time point of the water quantity adjustment mode, and guarantee the user experience during bathing. The preset time T is a fixed value, for example, it can be 8s, 10s, etc.

[0045] The above-mentioned temperature parameters are all in ℃, the flow parameters are all in L / min, and the load parameters are all in Kw.

[0046] Referring to Figure 2 and Figure 4The application discloses a gas water heater, which comprises a master control device 1, a water inflow adjusting device, a water inflow collector 3 and a water outlet temperature collector 4. The water inflow collector 3 and the water inflow adjusting device are arranged on a water inflow pipeline 6 of the gas water heater, and the water outlet temperature collector 4 is arranged on a water outlet pipeline 7 of the gas water heater. The water inflow adjusting device, the water inflow collector 3 and the water outlet temperature collector 4 are connected with the master control device 1 respectively. The water inflow adjusting device adjusts the water inflow according to the control instruction of the master control device 1. The master control device 1 is used for controlling the operation of the gas water heater according to the constant temperature control method.

[0047] Specifically, the gas water heater is provided with the master control device 1, which receives various parameters sent by the devices including the water inflow adjusting device, the water inflow collector 3 and the water outlet temperature collector 4 and processes the parameters correspondingly, so as to realize the operation control of the gas water heater. The water inflow signal of the water inflow Fa is collected and sent by the water inflow collector 3 arranged on the water inflow pipeline 6 of the gas water heater. The water flow signals of the mixed water temperature Wi and the water outlet temperature Wx' are collected and sent by the water outlet temperature collector 4 arranged on the water outlet pipeline 7 of the gas water heater. In the water flow direction, the water inflow adjusting device can be arranged upstream of the water inflow collector 3 or downstream of the water inflow collector 3, and the specific position of the water inflow adjusting device in the water pipeline of the water heater does not have different influences on the use effect.

[0048] The water inflow temperature is the temperature of the water flowing into the water inlet of the water heater without being heated. When the cold water flows in, the water inflow temperature is the temperature of the flowing-in water. When there is no water circulation or the cold water flows in, the water inflow temperature represents the temperature of the water remaining in the water inflow pipeline 6.

[0049] Referring to FIGS. 1, 2 and 3, Figure 3 and Figure 4 As shown in the figures, the water inflow adjusting device is a component of a water servo mechanism 2 of the gas water heater, which comprises a step motor 201 and an adjusting valve 202. The step motor 201 is in transmission connection with the adjusting valve 202, and the step motor 201 is connected with the master control device 1. The water servo mechanism 2 can be arranged at any position in the water pipeline of the water heater, and can be arranged on the water inflow pipeline 6 or the water outlet pipeline 7. After the master control device 1 receives the water heater restart signal, the step motor 201 adjusts the rotating speed and rotating direction according to the control instruction of the master control device 1, so as to drive the adjusting valve 202 to change the size of the passage, thereby realizing the accurate adjustment of the water inflow. The water servo mechanism 2 is the inherent water amount adjusting mechanism of the gas water heater. In the embodiment, the inherent water servo mechanism 2 of the gas water heater is used as the water inflow adjusting device, so that no additional components are needed, and the cost is not increased. Meanwhile, the step motor 201 can realize stepless speed regulation, and the combination of the step motor 201 and the adjusting valve 202 can realize the accurate control of the water inflow, and further realize the accurate control of the water temperature.

[0050] Among them, the water inlet pipeline 6 of the gas water heater can selectively add a water pump 5 to ensure the flow rate of the water flow. The gas water heater of the embodiment can realize constant temperature water outlet, avoid the situation that cold water appears when the user uses water again, ensure that the water temperature is maintained stable during the use of the user, has good user experience, and the cost is controllable, has cost advantage.

[0051] In the present specification, unless specifically defined and limited otherwise, a first feature is "on", "above", or "under" a second feature can mean that the first and second features are directly in contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "over", and "on" the second feature can mean that the first feature is directly above or obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under", and "under" the second feature can mean that the first feature is directly below or obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0052] In the description of the present specification, the description of the terms "preferred embodiment", "further embodiment", "other embodiment", or "specific example" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0053] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method of constant temperature control of a gas water heater, characterized by, The method comprises steps of: S1: determining a water flow Fz for a second start according to a water flow after a first start of the water heater, and the water flow Fz for the second start is less than the water flow after the first start of the water heater; determining a water flow Fa for a first start according to a water flow after a first start of the water heater, and then calculating the water flow Fz for the second start according to the water flow Fa for the first start, wherein the water flow Fz for the second start is less than the water flow Fa for the first start; the water flow Fa for the first start is an average value within a preset time t; the water flow Fz for the second start = K*Fa; the value of K ranges from 0.3 to 0.6, and the greater the water flow Fa for the first start, the smaller K is; S2: starting a water quantity adjustment mode according to the water flow Fz for the second start when the water heater receives a second start signal; S3: obtaining a mixed water temperature Wi, a set temperature Wx and a corresponding rated load Lz, and calculating an input load Ls according to the mixed water temperature Wi, the set temperature Wx and the rated load Lz, wherein the input load Ls is greater than the rated load Lz; the input load Ls = K1*Fz*(Wx-Wi), wherein K1>1; S4: starting a heating mode to heat according to the input load Ls, so that an outlet water temperature Wx' reaches the set temperature Wx; In step S4, a preset temperature difference Wn is set, and when the outlet water temperature Wx' is equal to a difference W between the set temperature Wx and the preset temperature difference Wn, the heating mode is switched from the input load Ls to running at the rated load Lz, and the difference W is less than the set temperature Wx; S5: when the outlet water temperature Wx' reaches the set temperature Wx, the water quantity adjustment mode is closed.

2. The method of claim 1, wherein: In step S5, when the outlet water temperature at the set temperature Wx lasts for a preset time T, the water quantity adjustment mode is closed.

3. A gas water heater characterised by: The method comprises steps of:

4. The gas water heater of claim 3, wherein: The water heater comprises a main control device, a water inflow adjusting device, a water inflow collector and an outlet water temperature collector, the water inflow collector is arranged on a water inflow pipeline of the water heater, the outlet water temperature collector is arranged on an outlet water pipeline of the water heater, the water inflow adjusting device, the water inflow collector and the outlet water temperature collector are connected with the main control device respectively, the water inflow adjusting device adjusts a water inflow size according to a control instruction of the main control device, and the main control device is used for performing operation control of the water heater according to the method in any one of claims 1 to 2.

5. The gas water heater of claim 4, wherein: The water inflow adjusting device comprises a stepping motor and an adjusting valve, the stepping motor is in transmission connection with the adjusting valve, and the stepping motor is connected with the main control device. The water inflow adjusting device is a component of a water servo mechanism of the water heater.

Images