Gas water heater and wind pressure protection method and minimum load protection method thereof

Abstract

The invention discloses a gas water heater and a wind pressure protection method and a minimum load protection method thereof, the gas water heater comprises a water heater main body, a pressure detection assembly and a control device, and the water heater main body is provided with a ventilation channel; the pressure detection assembly comprises a first pressure detection piece and a second pressure detection piece, the measuring range of the first pressure detection piece is smaller than that of the second pressure detection piece, and the precision of the first pressure detection piece is larger than that of the second pressure detection piece; and the control device is electrically connected with the first pressure detection piece and the second pressure detection piece, and the control device is used for determining the corresponding pressure detection piece according to a pressure change signal of the ventilation channel and controlling the water heater body according to a pressure detection signal detected by the determined pressure detection piece. According to the technical scheme, the pressure detection assembly can be matched with different pressure detection pieces, so that the accuracy of wind pressure detection in the gas water heater is improved, and the environment adaptation capacity of the gas water heater is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas water heaters, and in particular to a gas water heater and a wind pressure protection method and a minimum load protection method thereof. Background Art

[0002] The existing fully premixed gas water heater reads the wind pressure on the air inlet pipe and transmits the signal to the wind pressure switch. When the wind pressure sensor's closing value is reached, the circuit is disconnected for wind pressure protection; when the wind pressure sensor's starting value is restored, it is reopened. Since the air inlet pipe is far away from the fan, the wind pressure value is easily affected by the sealing of the air inlet pipe, and the obtained wind pressure value is unstable. Secondly, the wind pressure switch can only set a starting value and a closing value, and can only provide wind pressure protection for a certain load point, but not for the full load section. Summary of the invention

[0003] The main purpose of the present invention is to provide a gas water heater, aiming to improve the accuracy of wind pressure detection in the gas water heater.

[0004] In order to achieve the above-mentioned object, the present invention provides a gas water heater, which comprises:

[0005] The water heater body has a ventilation passage;

[0006] A pressure detection assembly, comprising a first pressure detection member and a second pressure detection member, wherein the measuring range of the first pressure detection member is smaller than the measuring range of the second pressure detection member, and the accuracy of the first pressure detection member is greater than the accuracy of the second detection member; the first pressure detection member and the second pressure detection member are respectively used to detect the pressure of the ventilation channel; and

[0007] A control device is electrically connected to the first pressure detection component and the second pressure detection component respectively, and is used to determine the corresponding pressure detection component according to the pressure change signal of the ventilation channel, and control the water heater body according to the pressure detection signal detected by the determined pressure detection component.

[0008] In one embodiment, the measuring range of the first pressure detection component is a, and the value range of a satisfies: a1≤a≤a2; the measuring range of the second pressure detection component is b, and the value range of b satisfies: b1≤a≤b2, b1 <a2;

[0009] The pressure change signal is that the pressure in the ventilation channel increases from b1 to a2, and the control device controls the water heater body according to the pressure detection signal detected by the first pressure detection element;

[0010] When the pressure change signal is that the pressure in the ventilation passage decreases from a2 to b1, the control device controls the water heater main body according to the pressure detection signal detected by the second pressure detection component.

[0011] In one embodiment, the value range of a satisfies: 0 < a ≤ 200 Pa, and the value range of b satisfies: 150 < b ≤ 1000 Pa.

[0012] In one embodiment, the gas water heater includes:

[0013] A blower, provided in the water heater main body; and

[0014] A premixer, provided in the water heater main body, the premixer having a premixing chamber and an air inlet, a gas inlet, and a premixed gas outlet communicating with the premixing chamber, the premixed gas outlet communicating with the air inlet side of the blower; the pressure detection assembly is used to detect the pressures at the air inlet and the premixed gas outlet, and output detection signals.

[0015] In one embodiment, the first pressure detection component and the second pressure detection component are arranged in parallel.

[0016] In one embodiment, the first pressure detection component / second pressure detection component has a positive pressure chamber and a first pressure taking port communicating with the positive pressure chamber, a negative pressure chamber and a second pressure taking port communicating with the negative pressure chamber;

[0017] The first pressure taking port communicates with the air inlet / the premixed gas outlet; the second pressure taking port communicates with the external air;

[0018] Alternatively, the second pressure taking port communicates with the air inlet / the premixed gas outlet; the first pressure taking port communicates with the external air.

[0019] The present invention also provides a wind pressure protection method for a gas water heater. The wind pressure protection method is applied to the gas water heater described in any of the foregoing embodiments. The gas water heater further includes a blower and a premixer provided in a ventilation passage; the premixer has a premixing chamber and an air inlet, a gas inlet, and a premixed gas outlet communicating with the premixing chamber, the premixed gas outlet communicating with the air inlet side of the blower; the pressure detection assembly is used to detect the pressures at the air inlet and the premixed gas outlet, and output pressure detection signals; the wind pressure protection method includes the following steps:

[0020] Obtain the wind pressure FP at the air inlet detected by the pressure detection assembly, and obtain the secondary gas pressure SP at the premixed gas outlet detected by the pressure detection assembly;

[0021] When the wind pressure FP exceeds the first preset pressure range, output a wind pressure fault alarm signal;

[0022] When the gas secondary pressure SP exceeds the second preset pressure range, a secondary pressure fault alarm signal is output;

[0023] When the wind pressure FP exceeds the first preset pressure range and the gas secondary pressure SP exceeds the second preset pressure range, a wind pressure protection fault signal is output.

[0024] The present invention also proposes a minimum load protection method for a gas water heater, which is applied to the gas water heater described in any of the above embodiments, wherein the gas water heater further comprises a fan and a premixer arranged in the ventilation channel; the premixer comprises a premixing chamber and an air inlet, a gas inlet and a premixed gas outlet connected to the premixing chamber, and the premixed gas outlet is connected to the air inlet side of the fan; the pressure detection component is used to detect the pressure at the air inlet and the premixed gas outlet, and output a pressure detection signal; the minimum load protection method comprises the following steps:

[0025] Obtaining the wind pressure FP at the air inlet detected by the pressure detection component, and obtaining the gas secondary pressure SP at the premixed gas outlet detected by the pressure detection component;

[0026] When the control device does not receive an instruction to adjust the fan speed and an instruction to adjust the gas proportional valve opening, and the wind pressure FP and the gas secondary pressure SP continue to decrease; the fan speed n is increased so that the gas secondary pressure SP reaches a preset gas secondary pressure SP0 and the wind pressure FP reaches a preset wind pressure FP0;

[0027] Among them, SP0 is the secondary pressure of gas when the gas water heater is burning normally when the external wind speed is 0, and FP0 is the wind pressure when the gas water heater is burning normally when the external wind speed is 0.

[0028] In one embodiment, when the fan speed n reaches a first preset speed, the fan speed n is stopped from being increased.

[0029] In one embodiment, after stopping increasing the speed n of the fan, the method further includes the following steps:

[0030] When the wind pressure FP exceeds the first preset pressure range, a wind pressure fault alarm signal is output;

[0031] When the gas secondary pressure SP exceeds the second preset pressure range, a secondary pressure fault alarm signal is output;

[0032] When the wind pressure FP exceeds the first preset pressure range and the gas secondary pressure SP exceeds the second preset pressure range, a wind pressure protection fault signal is output, and flameout protection is performed on the gas water heater.

[0033] The technical solution of the present invention provides a pressure detection component, which has at least two pressure detection components with different ranges and different accuracies, and improves the accuracy of wind pressure detection in the gas water heater by adapting different pressure detection components, thereby improving the ability of the gas water heater to adapt to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0035] Figure 1 It is a structural schematic diagram of an embodiment of a gas water heater of the present invention;

[0036] Figure 2 It is a structural schematic diagram of an embodiment of a pressure detection component;

[0037] Figure 3 It is a structural schematic diagram of an embodiment of a premixer;

[0038] Figure 4 for Figure 3 Sectional view;

[0039] Figure 5 for Figure 3 A side view of

[0040] Figure 6 for Figure 3 Another side view of;

[0041] Figure 7 The relationship curve between wind pressure and fan speed obtained by fitting a gas water heater of a certain model of the present invention;

[0042] Figure 8 The relationship curve between the secondary pressure of gas and the speed of the fan obtained by fitting a gas water heater of a certain model of the present invention;

[0043] Fig. 9 A curve showing the relationship between heat output and fan speed obtained by fitting a gas water heater of a certain model of the present invention;

[0044] Fig.10 This is a curve showing the relationship between heat load and fan speed obtained by fitting a gas water heater of a certain model of the present invention.

[0045] Description of Figure Numbers:

[0046] Label name Label name 10 Gas water heater 200 Pressure detection components 100 Water heater body 210 The first pressure detection piece 110 case 220 Second pressure detection piece 120 Heat Exchanger 300 Controls 130 Gas Proportional Valve 500 Premixer 140 Burner 501 Air Inlet 150 Water Proportional Valve 502 Gas Inlet 400 Fan 503 Premixed gas outlet

[0047] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0050] 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 descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0051] The existing fully premixed gas water heater reads the wind pressure on the air inlet pipe and transmits the signal to the wind pressure switch. When the wind pressure sensor's closing value is reached, the circuit is disconnected for wind pressure protection; when the wind pressure sensor's starting value is restored, it is reopened. Since the air inlet pipe is far away from the fan, the wind pressure value is easily affected by the sealing of the air inlet pipe, and the obtained wind pressure value is unstable. Furthermore, the wind pressure switch can only set a starting value and a closing value, and can only provide wind pressure protection for a certain load point, but not for the full load section.

[0052] In order to solve the above technical problems, some fully premixed gas water heaters (wall-mounted boilers) use high-precision wind pressure sensors. Such high-precision wind pressure sensors are generally used in precision instruments such as medical machinery and have high requirements for a dust-free environment. However, the air of the fully premixed gas water heater (wall-mounted boiler) is generally taken from the outdoors through a pipe, and the dust in the air will enter the gas water heater and even enter the wind pressure sensor through the air inlet pipe. The above-mentioned high-precision wind pressure sensor consists of a central heating element and two adjacent thin-film temperature sensors, and has a small inner cavity. When dusty air enters, on the one hand, it will block the inner cavity, and on the other hand, it will be adsorbed onto the thin-film temperature sensor, resulting in a decrease in its sensitivity, making the measured wind pressure value inaccurate and causing false alarms.

[0053] Based on this, the present invention proposes a gas water heater.

[0054] In the embodiment of the present invention, Figures 1 to 10 As shown, the gas water heater 10 includes a water heater body 100, a pressure detection component 200 and a control device 300, the water heater body 100 has a ventilation channel; the pressure detection component 200 includes a first pressure detection component 210 and a second pressure detection component 220, the measuring range of the first pressure detection component 210 is smaller than the measuring range of the second pressure detection component 220, and the accuracy of the first pressure detection component 210 is greater than the accuracy of the second detection component; the first pressure detection component 210 and the second pressure detection component 220 are respectively used to detect the pressure of the ventilation channel; the control device 300 is electrically connected to the first pressure detection component 210 and the second pressure detection component 220, respectively, and the control device 300 is used to determine the corresponding pressure detection component according to the pressure change signal of the ventilation channel, and control the water heater body 100 according to the pressure detection signal detected by the determined pressure detection component.

[0055] The technical solution of the present invention provides a pressure detection component 200, which has at least two pressure detection components with different ranges and different accuracies, and improves the accuracy of wind pressure detection in the gas water heater 10 by adapting different pressure detection components, thereby improving the ability of the gas water heater 10 to adapt to the environment.

[0056] The gas water heater 10 of the present invention can be a water heater for showering, or a gas wall-mounted boiler that can be used for both hot water and heating. Figure 1 , Figure 1The schematic diagram of the structure of an embodiment of a gas water heater 10 involved in the embodiment of the present invention. The gas water heater 10 includes a housing 110, and a fan 400, a heat exchanger 120, a gas proportional valve 130, a water proportional valve 150, a control device 300, a burner 140, a combustion chamber, an air inlet pipe and a smoke exhaust pipe arranged in the housing 110. The burner 140 is arranged between the fan 400 and the smoke exhaust pipe, the heat exchanger 120 is arranged between the burner 140 and the smoke exhaust pipe, and the combustion chamber is arranged between the burner 140 and the smoke exhaust pipe. The gas pipeline is used to transport gas to the burner 140, and the fan 400 is used to transport air to the burner 140. The gas proportional valve 130 is arranged on the gas pipeline and is used to cut off, connect and adjust the gas in the gas pipeline. The burner 140 is provided with a plurality of injection ports, through which the fan 400 and the gas pipeline deliver air and gas to the burner 140, and then the burner 140 injects the gas mixed with the air and gas into the combustion chamber for combustion, and finally exchanges heat with the combustion chamber through the heat exchanger 120 to heat the water in the water pipe. The water proportional valve 150 is provided on the water system to control the water intake of the water system. The smoke exhaust pipe is used to discharge the smoke exhausted from the combustion in the combustion chamber to the outside.

[0057] The control system of the gas water heater 10 may include a system control unit, a gas control unit, a fan 400 control unit, a pressure detection unit and a water flow detection unit. Among them, the system control unit is a core control unit, which is mainly used to analyze the operating state of the gas water heater 10 and control the operation of each component in the gas water heater 10. The gas control unit is mainly used to control the supply of gas. For example, the gas control unit can be connected to the gas proportional valve 130, and the gas control unit can receive the set output value sent by the system control unit, and then control the gas proportional valve 130 to open to the corresponding opening according to the set output value, and adjust the amount of gas delivered to the burner 140. The fan 400 control unit is mainly used to control the opening and speed of the fan 400. The fan 400 control unit can receive the set output value sent by the system control unit, and then control the fan 400 to run at the corresponding speed according to the set output value. The pressure detection unit is mainly used to detect the pressure state in the gas water heater 10, which can be composed of a wind pressure sensor. The water flow detection unit is mainly used to detect the water inlet and outlet of the gas water heater 10, which can be composed of a flow sensor. The system control unit receives the detection signals fed back by the pressure detection unit and the water flow detection unit, analyzes the operating status of the gas water heater 10 according to the detection signals, and executes the corresponding control process.

[0058] In a preferred embodiment, in order to improve the accuracy of the data detected by the pressure detection assembly 200, the measuring range of the first pressure detector 210 is a, and the value range of a satisfies: a1 ≤ a ≤ a2; the measuring range of the second pressure detector 220 is b, and the value range of b satisfies: b1 ≤ a ≤ b2, b1 < a2; the pressure change signal is that the pressure in the ventilation passage increases from b1 to a2, and the control device 300 controls the water heater main body 100 according to the pressure detection signal detected by the first pressure detector 210; when the pressure change signal is that the pressure in the ventilation passage decreases from a2 to b1, the control device 300 controls the water heater main body 100 according to the pressure detection signal detected by the second pressure detector 220. Thus, the present invention selects data of different measuring ranges and different precision pressure detectors under different working conditions, thereby further improving the accuracy of the data detected by the pressure detection assembly 200, and further improving the accuracy of the air pressure protection control. Exemplarily, the value range of a satisfies: 0 < a ≤ 200 Pa, and the value range of b satisfies: 150 < b ≤ 1000 Pa.

[0059] In another preferred embodiment, the gas water heater 10 includes a blower 400 and a premixer 500. In order to avoid the influence of the air inlet pipe's airtightness on the results detected by the pressure detection assembly 200, the blower 400 is arranged on the water heater main body 100; the premixer 500 is arranged on the water heater main body 100. The premixer 500 has a premixing chamber and an air inlet 501, a gas inlet 502, and a premixed gas outlet 503 that communicate with the premixing chamber. The premixed gas outlet 503 communicates with the air inlet side of the blower 400; the pressure detection assembly 200 is used to detect the pressure at the air inlet 501 and output a detection signal. Thus, by detecting the pressure at the air inlet 501 of the premixer 500 by the pressure detection assembly 200 as the air pressure of the gas water heater 10, the influence of the air inlet pipe's airtightness on the results detected by the pressure detection assembly 200 is avoided.

[0060] In this embodiment, the premixer 500 has an air inlet 501, a gas inlet 502, a premixed gas outlet 503, a premixing chamber, and an air chamber and a gas chamber connected to the premixing chamber. The air inlet 501 is connected to the air chamber, the gas inlet 502 is connected to the gas chamber, the premixed gas outlet 503 is connected to the premixing chamber, and the premixed gas outlet 503 is connected to the air inlet side of the fan 400. In this way, when the gas water heater 10 is working, the fan 400 rotates to form a negative pressure, and the air enters the ventilation channel from the air inlet seat, then enters the air chamber of the premixer 500 through the air inlet pipe, and then enters the mixing chamber of the premixer 500 to perform the first premixing with the gas, and then enters the fan 400, and completes the second premixing of air and gas in the fan chamber of the fan 400 itself.

[0061] Furthermore, the first pressure detection component 210 and the second pressure detection component 220 are arranged in parallel.

[0062] In one embodiment, the first pressure detecting component 210 / the second pressure detecting component 220 has a positive pressure chamber and a first pressure port connected to the positive pressure chamber, and a negative pressure chamber and a second pressure port connected to the negative pressure chamber; the first pressure port is connected to the air inlet 501 / the premixed gas outlet 503; the second pressure port is connected to the external air; or, the second pressure port is connected to the air inlet 501 / the premixed gas outlet 503; the first pressure port is connected to the external air.

[0063] In the present embodiment, the first pressure detection member 210 / the second pressure detection member 220 is a wind pressure sensor, and the first pressure detection member 210 / the second pressure detection member 220 both have a positive pressure chamber, a negative pressure chamber and two pressure taking nozzles, one for taking positive pressure and the other for taking negative pressure. When the pressure to be measured is negative pressure, one end of the positive pressure taking nozzle is connected to the atmosphere, and the other end is connected to the positive pressure chamber, and one end of the negative pressure taking nozzle is connected to the ventilation channel to be measured, and the other end is connected to the negative pressure chamber. The air flow pressure enters the positive pressure chamber of the wind pressure sensor through the positive pressure taking nozzle; the pressure of the ventilation channel to be measured enters the negative pressure chamber of the wind pressure sensor through the negative pressure taking nozzle. When the pressure to be measured is positive pressure, the connection method is the opposite.

[0064] In this embodiment, there is an isolation diaphragm between the positive pressure chamber and the negative pressure chamber of the pressure detection component, and the pressure on both sides is transmitted to the two sides of the measuring diaphragm through the isolation diaphragm and the filling liquid in the element. The measuring diaphragm and the electrodes on the insulating sheets on both sides each form a capacitor. When the pressures on both sides are inconsistent, the pressure difference will cause the measuring diaphragm to displace, and the displacement is proportional to the pressure difference. The displacement makes the capacitance on both sides of the diaphragm unequal, and through the oscillation and demodulation links, it is converted into a frequency signal proportional to the pressure, and then transmitted to the controller for processing. For air with trace dust, after entering the pressure chamber and being adsorbed into the wall or the isolation diaphragm, it will not affect the pressure difference value, that is, it will not affect the pressure detection value. Therefore, the wind pressure sensor can adapt to the use environment of the gas water heater 10.

[0065] In an exemplary embodiment, see Figure 2 , the first pressure detection component 210 / the second pressure detection component 220 is a wind pressure sensor, and the pressure detection assembly 200 is composed of two wind pressure sensors, three silicone tubes and a three-way pipe. Among them, the range of the pressure detection component corresponding to the second pressure detection component 220 is 0-200Pa, and the accuracy is ±1Pa, and the range of the pressure detection component corresponding to the second pressure detection component 220 is 150-1000Pa, and the accuracy is ±3%; in this embodiment, the gas water heater 10 takes negative pressure, the negative pressure ports of the two pressure detection components are connected to the silicone tube, and the positive pressure ports are connected to the atmosphere. The two silicone tubes are then connected to the two interfaces of the three-way pipe, and the third interface of the three-way pipe is connected to the pressure nozzle on the premixer 500 through another silicone tube. That is, the first pressure detection component 210 and the second pressure detection component 220 are connected in parallel, and both can detect wind pressure. The wind pressure detection program is set as follows:

[0066] When the wind pressure is between 0 and 150 Pa, the pressure data detected by the first pressure detection element 210 is selected. Since the accuracy of the first pressure detection element 210 is ±1 Pa, it can detect slight wind pressure changes and is more suitable for the pressure detection requirements under this working condition.

[0067] When the wind pressure is between 200-1000 Pa, the pressure data detected by the second pressure detection element 220 is selected. Since the wind pressure changes greatly at this stage, the accuracy of the second pressure detection element 220 is ±3%, which is more suitable for the pressure detection requirements under this working condition.

[0068] When the wind pressure is between 150 and 200 Pa, two situations need to be considered: if the wind pressure is gradually increasing, the pressure data detected by the first pressure detection member 210 is selected. If the wind pressure is gradually decreasing, the pressure data detected by the second pressure detection member 220 is selected. This arrangement enables the control device 300 to obtain more accurate wind pressure detection data, thereby more accurately controlling the water heater body 100.

[0069] The present invention further proposes a wind pressure protection method for a gas water heater 10, which is applied to the gas water heater 10 described in any of the aforementioned embodiments, wherein the gas water heater 10 further comprises a fan 400 and a premixer 500 arranged in the ventilation channel; the premixer 500 comprises a premixing chamber and an air inlet 501, a gas inlet 502 and a premixed gas outlet 503 connected to the premixing chamber, and the premixed gas outlet 503 is connected to the air inlet side of the fan 400; the pressure detection component 200 is used to detect the pressure at the air inlet 501 and the premixed gas outlet 503, and output a pressure detection signal; the wind pressure protection method comprises the following steps:

[0070] Obtaining the wind pressure FP at the air inlet 501 detected by the pressure detection component 200, and obtaining the gas secondary pressure SP at the premixed gas outlet 503 detected by the pressure detection component 200;

[0071] When the wind pressure FP exceeds the first preset pressure range, a wind pressure fault alarm signal is output;

[0072] When the gas secondary pressure SP exceeds the second preset pressure range, a secondary pressure fault alarm signal is output;

[0073] When the wind pressure FP exceeds the first preset pressure range and the gas secondary pressure SP exceeds the second preset pressure range, a wind pressure protection fault signal is output.

[0074] The wind pressure protection method provided by the technical solution of the present invention can avoid false alarms caused by abnormality of a certain value through feedback control of both the wind pressure FP and the gas secondary pressure SP.

[0075] In this embodiment, during the design phase of the gas water heater 10, basic data of different heat loads W (or heat output Q) and the speed n of the fan 400 are collected from multiple prototypes, and the curves of the two are fitted, and through linear regression, the corresponding relationship between the two is obtained, W=f1(n), or Q=f2(n). The inlet water temperature sensor, the inlet water flow sensor, and the outlet water temperature sensor read the inlet water temperature T0, the water flow q, and the outlet water temperature Tt, respectively. The controller calculates the heat output according to Q=q*(Tt-T0), and then calculates the heat load according to the thermal efficiency η.

[0076] As the rotational speed n of the blower 400 increases, the secondary gas pressure SP and the air pressure FP will also increase accordingly. Therefore, there is a one-to-one correspondence between the rotational speed of the blower 400 and the secondary pressure, and there is also a one-to-one correspondence between the rotational speed of the blower 400 and the air pressure. During design, first collect the basic data of the rotational speed n of the blower 400, the secondary pressure SP, and the air pressure FP of multiple prototypes, fit the curves of the two, and through linear regression, obtain the corresponding relationships between the two: SP = f(n), FP = g(n). There is a one-to-one correspondence among the heat load W, the heat output Q, the rotational speed n of the blower 400, the secondary pressure SP, and the air pressure FP. Therefore, the basic data (W, Q, n, SP, FP) can be collected through multiple water heaters. For details, please refer to Figures 7 to 10 .

[0077] When the water heater is operating, the controller calculates the heat output Q based on the inlet water temperature T0, the water flow rate q, and the outlet water temperature T, and quickly determines the rotational speed n of the blower 400 according to the basic data of (W, Q, n, SF, FP) and Q = f2(n). Then, based on the rotational speed n of the blower 400, the secondary gas pressure SP and FP can be quickly determined.

[0078] After obtaining the corresponding relationships SP = f(n) and FP = g(n) between the secondary gas pressure SP, the air pressure FP, and the rotational speed n of the blower 400, according to the conditions such as the water seal protection, the flue pipe blockage protection, and the blowing protection of the fully premixed gas water heater 10, use multiple water heaters to collect the basic data to obtain the upper limit value SP = fmax(n) and the lower limit value SP = fmin(n) of the secondary gas pressure SP, as well as the upper limit value FP = gmax(n) and the lower limit value FP = gmin(n) of the air pressure FP. For each rotational speed n of the blower 400 determined by the heat output, the corresponding secondary pressure SP and air pressure FP should satisfy fmin(n) < SP < fmax(n), gmin(n) < FP < gmax(n). Since in the normal operating state, the rotational speed n of the blower 400 determines the secondary pressure SP and the air pressure FP. Therefore, when the secondary pressure SP and the air pressure FP change, their information is transmitted to the controller, enabling it to make corresponding judgments and protect or give safety prompts to the gas water heater 10.

[0079] Among them, the first preset pressure range refers to all the pressure values between the upper limit value FP = gmax(n) and the lower limit value FP = gmin(n) of the air pressure FP, and the second preset pressure range refers to the upper limit value SP = fmax(n) and the lower limit value SP = fmin(n) of the secondary gas pressure SP.

[0080] It can be understood that there is usually a display device on the housing 110 of the gas water heater 10. As mentioned above, the comparison of the secondary gas pressure SP and the air pressure FP is carried out in the control device 300, and the fault type is displayed on the display.

[0081] For example, gmin(n) can be set as the wind pressure protection value. When the smoke pipe is blocked, the wind pressure FP corresponding to the speed n of the fan 400 of the gas water heater 10 decreases. When it drops below the wind pressure protection value gmin(n) corresponding to the speed, the control device 300 outputs a signal to close the gas proportional valve 130, the gas water heater 10 stops running, and a wind pressure fault is reported on the display. This can protect the gas water heater 10 from burning normally and avoid generating excess exhaust gas during combustion. It can also prevent the water seal from being blown open and prevent smoke from being discharged into the room through the water seal.

[0082] When the wind speed increases, the wind pressure FP corresponding to the speed n of the fan 400 of the gas water heater 10 decreases. When it drops below the wind pressure protection value gmin(n) corresponding to the speed, the control device 300 outputs a signal to close the gas proportional valve 130, the gas water heater 10 stops running, and reports a wind pressure fault on the display. This can protect the gas water heater 10 from burning normally, avoid the generation of excess exhaust gas by burning, and also prevent the water seal from being blown open, and prevent the smoke from being discharged into the room through the water seal.

[0083] When the water seal is blocked, the wind pressure FP corresponding to the speed n of the fan 400 of the gas water heater 10 decreases. When it drops below the wind pressure protection value gmin(n) corresponding to the speed, the control device 300 outputs a signal to close the gas proportional valve 130, the gas water heater 10 stops running, and reports a wind pressure fault on the display. This can protect the gas water heater 10 from burning normally and avoid generating excess exhaust gas during combustion.

[0084] The wind pressure protection of water seal, blockage and blowing will be carried out when any wind pressure reaches the wind pressure protection condition.

[0085] The gas water heater 10 can output different amounts of hot water according to different water consumption requirements of users. In order to save gas resources, different amounts of water are heated to the user's target water temperature and the corresponding heat loads are different. When the gas water heater 10 can provide the minimum load water, the fan speed n is very small at the minimum load state, so the secondary pressure SP and wind pressure FP are also very small. At this time, when the external wind speed is high, it is easy to blow out the flame.

[0086] Based on this, in order to improve the wind resistance of the gas water heater 10, the present invention also provides a minimum load protection method for the gas water heater 10, and the minimum load protection method is applied to the gas water heater 10 described in any of the aforementioned embodiments, and the gas water heater 10 also includes a fan 400 and a premixer 500 arranged in the ventilation channel; the premixer 500 has a premixing chamber and an air inlet 501, a gas inlet 502 and a premixed gas outlet 503 connected to the premixing chamber, and the premixed gas outlet 503 is connected to the air inlet side of the fan 400; the pressure detection component 200 is used to detect the pressure at the air inlet 501 and the premixed gas outlet 503, and output a pressure detection signal; the minimum load protection method includes the following steps:

[0087] Obtaining the wind pressure FP at the air inlet 501 detected by the pressure detection component 200, and obtaining the gas secondary pressure SP at the premixed gas outlet 503 detected by the pressure detection component 200;

[0088] When the control device 300 does not receive an instruction to adjust the speed of the fan 400 and does not receive an instruction to adjust the opening of the gas proportional valve 130, and the wind pressure FP and the gas secondary pressure SP continue to decrease; the speed n of the fan 400 is increased to make the gas secondary pressure SP reach the preset gas secondary pressure SP0 and the wind pressure FP reach the preset wind pressure FP0;

[0089] Among them, SP0 is the secondary pressure of gas when the gas water heater 10 is burning normally when the external wind speed is 0, and FP0 is the wind pressure when the gas water heater 10 is burning normally when the external wind speed is 0.

[0090] In this embodiment, when the control device 300 does not receive an instruction to adjust the speed of the fan 400 and does not receive an instruction to adjust the opening of the gas proportional valve 130, and the wind pressure FP and the gas secondary pressure SP continue to decrease; one of the use scenarios can be understood as that since the air of the gas water heater 10 (wall-mounted boiler) is generally taken from the outdoors through a pipeline, the external wind speed will have an impact on the gas water heater 10, which is usually reflected in that when the wind speed of the outside wind increases, the gas water heater 10 (wall-mounted boiler) itself does not have an instruction to adjust the speed of the fan 400 and adjust the opening of the gas proportional valve 130, and the wind pressure FP and the gas secondary pressure SP will also continue to decrease. The continuous decrease here can be determined according to the preset, and the wind pressure FP and the gas secondary pressure SP can be under pressure for 5 seconds to 30 seconds. In this way, this embodiment improves the wind resistance of the gas water heater 10 by adjusting the wind speed of the fan.

[0091] Furthermore, when the speed n of the fan 400 reaches the first preset speed, the speed n of the fan 400 is stopped from being increased. The first preset speed is also data obtained through experiments during the design stage of the gas water heater 10, that is, the external wind speed increases to a level where the gas secondary pressure SP and the wind pressure FP cannot reach the preset gas secondary pressure SP0 and wind pressure FP0 even if the speed n of the fan 400 is increased. For example, when the external wind speed increases suddenly or increases too much, the speed n of the fan 400 cannot be increased in time or exceeds the range of the speed n of the fan 400.

[0092] Furthermore, after stopping increasing the speed n of the fan 400, the following steps are also included:

[0093] When the wind pressure FP exceeds the first preset pressure range, a wind pressure fault alarm signal is output;

[0094] When the gas secondary pressure SP exceeds the second preset pressure range, a secondary pressure fault alarm signal is output;

[0095] When the wind pressure FP exceeds the first preset pressure range and the gas secondary pressure SP exceeds the second preset pressure range, a wind pressure protection fault signal is output, and flameout protection is performed on the gas water heater 10 .

[0096] When the gas water heater 10 is burning in the small load section, if the external wind speed is 0, the secondary pressure of the gas water heater 10 during normal combustion is SP0, and the wind pressure is FP0, and the combustion state is optimal at this time.

[0097] This embodiment can be understood as follows: when the external wind speed increases, the secondary pressure SP of the fuel gas and the wind pressure FP during combustion in the small load stage will decrease. Once the gas secondary pressure SP and the wind pressure FP decrease, the control device 300 analyzes and processes, and increases the speed n of the fan 400 of the gas water heater 10, so that the gas secondary pressure SP and the wind pressure FP are restored to the preset gas secondary pressure SP0 and wind pressure FP0, so as to maintain normal combustion and make the gas water heater 10 (wall-mounted boiler) have a certain wind resistance performance; if the external wind speed increases to the extent that even if the fan 400 speed n is increased, the gas secondary pressure SP and the wind pressure FP cannot reach the preset gas secondary pressure SP0 and wind pressure FP0, such as when the external wind speed increases suddenly or the external wind speed increases too much, the fan 400 speed n cannot be increased in time or exceeds the range of the fan 400 speed n, when the gas secondary pressure SP drops to the minimum gas secondary pressure SPmin or the wind pressure FP drops to the minimum wind pressure FPmin, the fan 400 speed n is no longer increased until the wind pressure FP drops to a level lower than the wind pressure protection value gmin(n) corresponding to the fan 400 speed n, the gas proportional valve 130 is closed, the gas water heater 10 stops running, and a wind pressure fault is reported.

[0098] It should be noted that Figure 1 The structure shown in the figure does not constitute a limitation on the control device of the gas water heater, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently. The system control unit may include a processor and a memory, and the memory may include an operating system, a network communication module, a user interface module, and a control program of the gas water heater. The system control unit may call the control program of the gas water heater stored in the memory through the processor, and execute the control method of the gas water heater provided in the embodiment of the present invention.

[0099] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product is stored in a storage medium (such as a read-only memory image (ROM) / random access memory (RAM), a disk, or an optical disk), including a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0100] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A gas water heater, characterized in that: Comprising: A water heater main body having a ventilation passage; A pressure detection assembly including a first pressure detection element and a second pressure detection element, where the range of the first pressure detection element is less than that of the second pressure detection element, and the accuracy of the first pressure detection element is greater than that of the second detection element; The first pressure detection element and the second pressure detection element are respectively used to detect the pressure of the ventilation passage; And A control device electrically connected to the first pressure detection element and the second pressure detection element respectively. The control device is used to determine the corresponding pressure detection element according to the pressure change signal of the ventilation passage, and control the water heater main body according to the pressure detection signal detected by the determined pressure detection element.

2. The gas water heater according to claim 1, characterized in that: The range of the first pressure detection element is a, and the value range of a satisfies: a1 ≤ a ≤ a2; the range of the second pressure detection element is b, and the value range of b satisfies: b1 ≤ a ≤ b2, b1 < a2; The pressure change signal is that the pressure in the ventilation passage increases from b1 to a2, and the control device controls the water heater main body according to the pressure detection signal detected by the first pressure detection element; The pressure change signal is that when the pressure in the ventilation passage decreases from a2 to b1, the control device controls the water heater main body according to the pressure detection signal detected by the second pressure detection element.

3. The gas water heater according to claim 2, characterized in that: The value range of a satisfies: 0 < a ≤ 200 Pa, and the value range of b satisfies: 150 < b ≤ 1000 Pa.

4. The gas water heater according to claim 2, characterized in that: The gas water heater includes: A blower provided in the water heater main body; and A premixer provided in the water heater main body. The premixer has a premixing chamber and an air inlet, a gas inlet, and a premixed gas outlet communicating with the premixing chamber. The premixed gas outlet is communicated with the air inlet side of the blower; the pressure detection assembly is used to detect the pressures at the air inlet and the premixed gas outlet, and output detection signals.

5. The gas water heater according to claim 1, characterized in that: The first pressure detection element and the second pressure detection element are arranged in parallel.

6. The gas water heater according to claim 5, characterized in that: The first pressure detection element / second pressure detection element has a positive pressure chamber and a first pressure taking port communicating with the positive pressure chamber, a negative pressure chamber and a second pressure taking port communicating with the negative pressure chamber; The first pressure taking port communicates with the air inlet / the premixed gas outlet; the second pressure taking port communicates with the external air; Or, the second pressure taking port communicates with the air inlet / the premixed gas outlet; the first pressure taking port communicates with the external air.

7. A wind pressure protection method for a gas water heater, the wind pressure protection method being applied to the gas water heater according to any one of claims 1 to 6, characterized in that: The gas water heater further includes a blower and a premixer provided in the ventilation passage; the premixer has a premixing chamber and an air inlet, a gas inlet, and a premixed gas outlet communicating with the premixing chamber. The premixed gas outlet is communicated with the air inlet side of the blower; the pressure detection assembly is used to detect the pressures at the air inlet and the premixed gas outlet, and output pressure detection signals; the air pressure protection method includes the following steps: Obtain the air pressure FP at the air inlet detected by the pressure detection assembly, and obtain the secondary gas pressure SP at the premixed gas outlet detected by the pressure detection assembly; When the air pressure FP exceeds the first preset pressure range, output an air pressure fault alarm signal; When the gas secondary pressure SP exceeds the second preset pressure range, a secondary pressure fault alarm signal is output; When the wind pressure FP exceeds the first preset pressure range and the gas secondary pressure SP exceeds the second preset pressure range, a wind pressure protection fault signal is output.

8. A minimum load protection method for a gas water heater, the minimum load protection method being applied to the gas water heater according to any one of claims 1 to 6, characterized in that: The gas water heater further comprises a fan and a premixer arranged in the ventilation channel; the premixer comprises a premixing chamber and an air inlet, a gas inlet and a premixed gas outlet communicated with the premixing chamber, and the premixed gas outlet is communicated with the air inlet side of the fan; the pressure detection component is used to detect the pressure at the air inlet and the premixed gas outlet, and output a pressure detection signal; the minimum load protection method comprises the following steps: Obtaining the wind pressure FP at the air inlet detected by the pressure detection component, and obtaining the gas secondary pressure SP at the premixed gas outlet detected by the pressure detection component; When the control device does not receive an instruction to adjust the fan speed and an instruction to adjust the gas proportional valve opening, and the wind pressure FP and the gas secondary pressure SP continue to decrease; the fan speed n is increased so that the gas secondary pressure SP reaches a preset gas secondary pressure SP0 and the wind pressure FP reaches a preset wind pressure FP0; Among them, SP0 is the secondary pressure of gas when the gas water heater is burning normally when the external wind speed is 0, and FP0 is the wind pressure when the gas water heater is burning normally when the external wind speed is 0.

9. The minimum load protection method for a gas water heater according to claim 8, characterized in that: When the fan speed n reaches a first preset speed, the fan speed n is stopped from being increased.

10. The minimum load protection method for a gas water heater according to claim 9, characterized in that: After stopping increasing the speed n of the fan, the following steps are also included: When the wind pressure FP exceeds the first preset pressure range, a wind pressure fault alarm signal is output; When the gas secondary pressure SP exceeds the second preset pressure range, a secondary pressure fault alarm signal is output; When the wind pressure FP exceeds the first preset pressure range and the gas secondary pressure SP exceeds the second preset pressure range, a wind pressure protection fault signal is output, and flameout protection is performed on the gas water heater.

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