Constant temperature control method of water heater

Abstract

The invention relates to a constant temperature control method of a water heater, which comprises the following steps: S1, when the water heater works, acquiring water inlet flow Fn of a water inlet waterway passage at different time; s2, when the water heater receives a restarting signal, the operation conditions of primary starting and restarting of the water heater are obtained, and if the operation conditions of primary starting and restarting of the water heater meet preset conditions, a water volume adjusting mode is started; s3, immediately closing the second waterway channel; the restarting water inlet flow Fz is compared with a preset threshold value, so that whether a second waterway channel is opened or not is judged; s4, the water inlet temperature Wi, the set temperature Wx and the corresponding rated load Lz are obtained, and the given load Ls is calculated based on the water inlet temperature Wi, the set temperature Wx and the rated load Lz; s5, a heating mode is started for heating according to the given load Lz; and S6, when the outlet water temperature Wx (out) reaches the set temperature Wx, the water volume adjusting mode is closed.

Description

Technical Field

[0001] The invention relates to the technical field of gas water heaters, and in particular to a constant temperature control method for water heaters. Background Art

[0002] When users are using a water heater, hot water is usually not turned on continuously. Generally, after turning on the burner for the first time to use hot water, the user will intermittently turn off the water heater for a short period of time. After a short period of time, the user will turn on the burner again to use hot water. This method of repeatedly turning the water heater on and off in a short period of time will cause the water temperature of the water heater to be extremely unstable, causing the user to experience non-constant water temperature. For this reason, a series of technical improvements on water temperature control have been made to address this situation.

[0003] However, the existing gas water heaters with improved water constant temperature technology still need to be turned off and turned on again after the second time. The conditions such as the use environment safety and system safety are judged. After the judgment is qualified, the ignition is started. After the ignition is qualified, the temperature gradually rises to the set temperature. A large amount of cold water flows out in the middle process, which makes the user feel that the water heater is not constant temperature, and the user experience is poor;

[0004] Some companies also adopt methods such as increasing the gas filling speed during the constant temperature process and increasing the internal circulation. However, the number of water connection interfaces of the internal circulation machine increases, which increases the potential safety hazards of water leakage. At the same time, a built-in circulation pump is required, which increases the cost. Accelerating the gas filling speed during the constant temperature process is likely to cause problems such as cold start resonance in a low temperature environment, reducing the user's comfort.

[0005] Therefore, the current constant temperature technology improvements still cannot solve the problem of unstable water temperature. Summary of the invention

[0006] Based on this, it is necessary to provide a constant temperature control method for a water heater, which can solve the problem of non-constant temperature when the gas water heater is turned on for the second time.

[0007] An embodiment of the present invention provides a constant temperature control method for a water heater, comprising the following steps:

[0008] S1. When the water heater is working, the water inlet flow rate Fn of the water inlet waterway at different times is obtained; wherein the water inlet waterway of the water heater includes a first waterway channel and a second waterway channel;

[0009] S2. After the water adjustment of the water heater is completed, when the water heater receives a restart signal, the operation status of the water heater is obtained. If the operation status of the water heater meets the preset conditions, the water volume adjustment mode is started;

[0010] S3, immediately closing the second water channel so that the restarted water inlet flow Fz is the water inlet flow of the first water channel; comparing the restarted water inlet flow Fz with a preset threshold value to determine whether to open the second water channel;

[0011] S4, obtaining the water inlet temperature Wi, the set temperature Wx and the corresponding rated load Lz, and calculating the given load Ls based on the water inlet temperature Wi, the set temperature Wx and the rated load Lz, wherein the given load Ls is greater than the rated load Lz;

[0012] S5, starting the heating mode according to the given load Lz to make the outlet water temperature Wx(out) reach the set temperature Wx;

[0013] S6: When the outlet water temperature Wx(out) reaches the set temperature Wx, the water volume adjustment mode is turned off.

[0014] Preferably, in step S1, it is confirmed that the reading interval of the water inlet flow is Ti, and a water inlet flow Fx in a time period t is obtained, and the water inlet flow Fx is an average value within a preset time t.

[0015] Preferably, in step S3, the preset threshold is Q+n, and judging whether to open the second water channel according to the restart water inlet flow Fz specifically includes:

[0016] According to whether the water inlet flow Fz after restarting is greater than Q+n, it is determined whether the water stop valve is opened for the second time, where n is an integer multiple of 0.1 and n>0.5.

[0017] Preferably, the water inlet flow rate of the first water channel is F1, and the water inlet flow rate of the second water channel is F2, so that the water inlet flow rate Fx of the water heater's water inlet water channel is the sum of the water inlet flow rate F1 of the first water channel and the water inlet flow rate F2 of the second water channel, Fx=F1+F2.

[0018] Preferably, in step S4, a load Ls is given, Ls=Fz*(Wx-Wi).

[0019] Preferably, in step S5, a preset temperature difference Wn is set. When the water outlet temperature Wx(out) is equal to the difference W between the set temperature Wx and the preset temperature difference Wn, the heating mode is changed from the given load Ls to operating at the rated load Lz, and the difference W is less than the set temperature Wx.

[0020] Preferably, in step S6, when the outlet water temperature remains at the set temperature Wx for a preset time period T, the water volume regulation mode is turned off.

[0021] A gas water heater is also provided, comprising a water inlet flow regulating device, a water inlet flow collector, a temperature collector, and a main control device for controlling the operation of the gas water heater according to any one of claims 1 to 7, wherein the water inlet flow collector is arranged in the water inlet water passage of the gas water heater, the temperature collector is arranged in the water outlet pipe of the gas water heater, the water inlet flow regulating device, the water inlet flow collector and the temperature collector are respectively connected to the main control device, and the water inlet flow regulating device adjusts the water inlet flow according to the control instruction of the main control device. .

[0022] Preferably, the water inlet flow regulating device includes the water channel stop valves arranged at the positions of the first water channel and the second water channel.

[0023] Preferably, the water inlet flow regulating device is a component of a water servo mechanism of the gas water heater.

[0024] The present invention provides a water thermostatic control system for a water heater capable of adjusting the water flow rate upon secondary start-up. When a user uses water for a secondary time, the water flow rate and the amount of cold water are reduced. The cold water is combined with the surplus heat exchanged with the heat exchanger in the early stage to increase the minimum temperature of the secondary use and reduce the amount of cold water. At the same time, the control logic is more reasonable and simpler, and the user's use safety is higher. The water servo structure controls the number of water passages by a water stop valve, and can quickly switch the water volume, thereby realizing precise temperature control. This well solves the problem of non-constant water temperature caused by excessive cold water in the secondary start-up of the current water heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other purposes, features and advantages of the present invention will become more clear by more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals indicate the same parts in all the accompanying drawings, and the accompanying drawings are not deliberately scaled to the actual size, and the focus is on illustrating the main purpose of the present invention.

[0026] Figure 1 is a flow chart of a method according to an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of a water circuit system of a water heater according to a preferred embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of water flow and water temperature control according to an embodiment of the present invention;

[0029] Figure 4 It is a schematic structural diagram of a water inlet waterway and a waterway stop valve according to an embodiment of the present invention;

[0030] Heat exchanger 1; water servo 2; water inlet water channel 3; first water channel 31; second water channel 32; water outlet pipeline 4; water channel stop valve 5; water inlet flow collector 6; temperature collector 7. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0032] As shown in the figure, a constant temperature control method for a water heater includes the following steps:

[0033] S1. When the water heater is working, the water inlet flow rate Fn of the water inlet waterway at different times is obtained; wherein the water inlet waterway of the water heater includes a first waterway channel and a second waterway channel;

[0034] S2. After the water adjustment of the water heater is completed, when the water heater receives a restart signal, the operation status of the water heater is obtained. If the operation status of the water heater meets the preset conditions, the water volume adjustment mode is started;

[0035] S3, immediately closing the second water channel so that the restarted water inlet flow Fz is the water inlet flow of the first water channel; comparing the restarted water inlet flow Fz with a preset threshold value to determine whether to open the second water channel;

[0036] S4, obtaining the water inlet temperature Wi, the set temperature Wx and the corresponding rated load Lz, and calculating the given load Ls based on the water inlet temperature Wi, the set temperature Wx and the rated load Lz, wherein the given load Ls is greater than the rated load Lz;

[0037] S5, starting the heating mode according to the given load Lz to make the outlet water temperature Wx(out) reach the set temperature Wx;

[0038] S6: When the outlet water temperature Wx(out) reaches the set temperature Wx, the water volume adjustment mode is turned off.

[0039] In this embodiment, when the water heater is turned on for the second time, on the one hand, the re-start water inlet flow Fz is less than the water inlet flow after the water heater is turned on once, that is, the re-start water inlet flow Fz is reduced. In this way, the amount of cold water can be reduced, and the mixed water temperature Wi of hot water and cold water after heat exchange with the residual temperature of the heat exchanger 1 can be increased, thereby increasing the minimum value of the outlet water temperature Wx(out) after the second start. On the other hand, the given load Ls is greater than the rated load Lz, that is, the given load is increased. In this way, the hot water temperature rise rate can be accelerated, and the cold water heating time can be reduced. When the water is heated by this scheme during the second start, constant temperature water supply can be achieved, avoiding the situation of cold water when the user uses the water again, ensuring that the water temperature remains relatively stable during the user's use, thereby improving the user experience; and the control logic of the method of the present invention is simple and reasonable, and the use safety is relatively high.

[0040] It should be noted that the "once" in the embodiment means that it occurs before the "second time" or "second time", and does not refer to the first time or the first time. Similarly, the "second time" or "second time" means that it occurs after the "once", and does not refer to the second time. Among them, the water volume adjustment mode is the water volume adjustment performed for the implementation of this control method, which needs to be distinguished from other water volume adjustment controls during the operation of the gas water heater. That is, turning off the water volume adjustment mode in step S6 does not mean turning off all water volume adjustment controls and operations of the water heater.

[0041] According to the water flow conditions after the water heater is turned on once, the first water inlet flow Fa is determined, and the second water channel is immediately closed so that the water inlet flow Fz after restarting is the water inlet flow of the first water channel; the restarted water inlet flow Fz is compared with the preset threshold value to determine whether to open the second water channel. In this way, the restarted water inlet flow Fz is smaller than the first water inlet flow Fa. By introducing the first water inlet flow Fa parameter, the control method of implementing step S1 is simplified.

[0042] Further, the one-time water inflow Fa is the average value within the preset time t. Specifically, in step S1, after the water heater is turned on once, within the preset time t, the water inflow is obtained every Ti time period to obtain Fa1, Fa2, Fa3...Fan. The one-time water inflow Fa = (Fa1+Fa2+Fa3...+Fan) / n. By obtaining data at different time nodes and finding the average value, the average water flow rate during the user's water use can be determined more accurately, which can avoid the user's total water inlet pressure fluctuation during the water use process or the opening of other water use points causing the water flow fluctuation sampling value to deviate and affect the determination of the secondary boiling water flow rate, resulting in inaccurate determination of the secondary boiling water flow rate and poor actual use effect. Among them, the preset time t can be selected in integer minutes according to the user's bathing time, and the value n can be selected in integer multiples of one minute according to the user's bathing time.

[0043] In a preferred embodiment, in step S1, it is confirmed that the reading interval of the water inlet flow is Ti, and a water inlet flow Fx in a time period t is obtained, and the water inlet flow Fx is an average value within the preset time t.

[0044] In a preferred embodiment, in step S3, the preset threshold is Q+n, and judging whether to open the second water channel according to the restart water inlet flow Fz specifically includes:

[0045] According to whether the water inlet flow Fz after restarting is greater than Q+n, it is determined whether the water stop valve is opened for the second time, where n is an integer multiple of 0.1 and n>0.5.

[0046] In a preferred embodiment, the water inlet flow rate of the first water channel is F1, and the water inlet flow rate of the second water channel is F2, so that the water inlet flow rate Fx of the water heater's water inlet water channel is the sum of the water inlet flow rate F1 of the first water channel and the water inlet flow rate F2 of the second water channel, Fx=F1+F2.

[0047] In a preferred embodiment, in step S4, a given load Ls is given, Ls=Fz*(Wx-Wi). The given load Ls calculated by this formula is greater than the rated load Lz; it can ensure that the outlet water temperature is quickly increased, and by introducing the water inlet flow Fz parameter, the given load Ls can be accurately calculated according to the water inlet flow during the user's use, so that the set temperature Wx can be reached quickly and accurately to ensure user experience. Among them, the calculation formula of the rated load Lz is a prior art and will not be repeated here.

[0048] In a preferred embodiment, in step S5, a preset temperature difference Wn is set. When the outlet water temperature Wx(out) is equal to the difference W between the set temperature Wx and the preset temperature difference Wn, the heating mode is switched from the given load Ls to operating at the rated load Lz, and the difference W is less than the set temperature Wx, that is, before the outlet water temperature Wx' reaches the set temperature Wx, heating is switched to the rated load Lz. By restoring to the rated load in advance, overshoot of the outlet water temperature can be avoided, thereby further ensuring the user experience.

[0049] In a preferred embodiment, in step S6, when the outlet water temperature is at the set temperature Wx for a preset time T, the water volume adjustment mode is turned off. At this time, the water inlet flow adjustment is restored to the flow adjustment when it is turned on once in step S1. In this way, it can be judged whether the outlet water temperature is stable, so as to reasonably confirm the exit time point of the water volume adjustment mode and ensure the user's bathing experience. Among them, the preset time T is a fixed value, for example, the value range of T can be any value in 0-10s.

[0050] The units of the temperature parameters mentioned above are all ℃, the units of the flow parameters are all L / min, and the units of the load parameters are all Kw.

[0051] A gas water heater comprises a water inlet flow regulating device, a water inlet flow collector, a temperature collector, and a main control device for controlling the operation of the gas water heater using the control method, wherein the water inlet flow collector is arranged in the water inlet water passage of the gas water heater, the temperature collector is arranged in the water outlet pipe of the gas water heater, the water inlet flow regulating device, the water inlet flow collector and the temperature collector are respectively connected to the main control device, and the water inlet flow regulating device adjusts the water inlet flow according to the control instruction of the main control device.

[0052] Specifically, the gas water heater is provided with a main control device for receiving various parameters sent by the equipment including the water inlet flow regulating device, the water inlet flow collector 6 and the temperature collector 7 and performing corresponding processing to realize the operation control of the gas water heater. Among them, the water flow signal of the water inlet flow Fa is collected and sent by the water inlet flow collector 6 arranged in the water inlet pipeline 6 of the gas water heater, and the water flow signal of the mixed water temperature Wi and the water outlet temperature Wx (out) is collected and sent by the temperature collector 7 arranged in the water outlet pipeline 4 of the gas water heater. In the direction of water flow, the water inlet flow regulating device can be arranged upstream of the water inlet flow collector 6 or downstream of the water inlet flow collector 6, and its specific position in the water circuit of the water heater will not bring different effects on the use effect. The water inlet temperature is the temperature of the water that flows into the water inlet of the water heater but is not heated. When cold water flows in, it is the temperature of the water that flows in. When there is no water circulation or cold water flows in, the water inlet temperature represents the temperature of the water remaining in the current water inlet pipeline 3.

[0053] In a preferred embodiment, the water inlet flow rate regulating device includes the waterway stop valve 5 disposed at the first waterway channel 31 and the second waterway channel 32. The opening and closing of the second waterway channel 32 is controlled by the waterway stop valve 5, so as to quickly control the total water inlet flow rate, thereby quickly and effectively controlling the water temperature and ensuring the temperature of the outlet water is stable. The gas water heater of this embodiment can achieve constant temperature water outlet, avoid the situation of cold water outlet when the user uses water again, ensure that the water temperature remains stable during the user's use, have a good user experience, and the cost is controllable, with cost advantages.

[0054] In a preferred embodiment, the water inlet flow regulating device is a component of the water servo mechanism of the gas water heater. The water servo 2 can be placed at any position in the water circuit of the water heater, and can be set in the water inlet water circuit passage 3 or the water outlet pipe 4; after the main control device receives the water heater restart signal, the water circuit stop valve 5 opens and closes the second water circuit passage 32 according to the control instruction of the main control device to adjust the water inlet flow. The water servo 2 is a water volume regulating mechanism inherent in the gas water heater. In this embodiment, the water servo 2 inherent in the gas water heater is used to act as the water inlet flow regulating device, which will not add additional components and will not lead to an increase in cost. At the same time, the water circuit stop valve 5 can achieve rapid control, thereby achieving precise control of the water temperature.

[0055] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A constant temperature control method for a water heater, characterized in that: The steps include: S1. When the water heater is working, the water inlet flow rate Fn of the water inlet waterway at different times is obtained; wherein the water inlet waterway of the water heater includes a first waterway channel and a second waterway channel; S2. After the water adjustment of the water heater is completed, when the water heater receives a restart signal, the operation status of the water heater is obtained. If the operation status of the water heater meets the preset conditions, the water volume adjustment mode is started; S3, after starting the water adjustment mode, immediately close the second water channel, so that the water inlet flow Fz after restarting is the water inlet flow of the first water channel; compare the restarted water inlet flow Fz with the preset threshold value to determine whether to open the second water channel; S4, obtaining the water inlet temperature Wi, the set temperature Wx and the corresponding rated load Lz, and calculating the given load Ls based on the water inlet temperature Wi, the set temperature Wx and the rated load Lz, wherein the given load Ls is greater than the rated load Lz; S5, starting the heating mode according to the given load Lz to make the outlet water temperature Wx(out) reach the set temperature Wx; S6: When the outlet water temperature Wx(out) reaches the set temperature Wx, the water volume adjustment mode is turned off.

2. The constant temperature control method according to claim 1, characterized in that: In step S1, it is confirmed that the reading interval of the water inlet flow is Ti, and a water inlet flow Fx in a time period t is obtained. The water inlet flow Fx is an average value within a preset time t.

3. The constant temperature control method according to claim 1, characterized in that: In step S3, the preset threshold is Q+n, and judging whether to open the second water channel according to the restart water inlet flow Fz specifically includes: According to whether the water inlet flow Fz is greater than Q+n when the water is restarted again, it is determined whether the water stop valve is opened for the second time, where n is an integer multiple of 0.1, and n>0.

5.

4. The constant temperature control method according to claim 1, characterized in that: The water inlet flow rate of the first water channel is F1, and the water inlet flow rate of the second water channel is F2, so that the water inlet flow rate Fx of the water heater's water inlet water channel is the sum of the water inlet flow rate F1 of the first water channel and the water inlet flow rate F2 of the second water channel, Fx=F1+F2.

5. The constant temperature control method according to claim 1, characterized in that: In step S4, a load Ls is given, Ls=Fz*(Wx-Wi).

6. The constant temperature control method according to claim 5, characterized in that: In step S5, a preset temperature difference Wn is set. When the water outlet temperature Wx(out) is equal to the difference W between the set temperature Wx and the preset temperature difference Wn, the heating mode is changed from the given load Ls to the rated load Lz, and the difference W is less than the set temperature Wx.

7. The constant temperature control method according to claim 1, characterized in that: In step S6, when the outlet water temperature remains at the set temperature Wx for a preset time period T, the water volume adjustment mode is turned off.

8. A gas water heater, characterized in that: It includes a water inlet flow regulating device, a water inlet flow collector, a temperature collector, and a main control device for controlling the operation of a gas water heater according to the method described in any one of claims 1 to 7, wherein the water inlet flow collector is arranged in the water inlet water channel of the gas water heater, the temperature collector is arranged in the water outlet pipe of the gas water heater, the water inlet flow regulating device, the water inlet flow collector and the temperature collector are respectively connected to the main control device, and the water inlet flow regulating device adjusts the water inlet flow according to the control instruction of the main control device.

9. The constant temperature control method according to claim 1, characterized in that: The water inlet flow regulating device includes the waterway stop valves arranged at the first waterway channel and the second waterway channel.

10. The constant temperature control method according to claim 1, characterized in that: The water inlet flow regulating device is a component of the water servo mechanism of the gas water heater.

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