Automatic adjustment method for gas water heater

Abstract

The present invention relates to an automatic adjustment method for a gas water heater. During the operation of the gas water heater, the theoretical proportional valve current Ic and the actual proportional valve current I of the current combustion stage s of the gas water heater are calculated, and the deviation coefficient Asj of I relative to Ic is calculated, where I=AsjIc; j is a natural number; when the deviation value |1-Asj|≥B, Asj is recorded, where B is a preset deviation threshold, 0<B<1; when the situation of |1-Asj|≥B continuously appears and satisfies the preset abnormal working condition, it is judged that the situation is caused by gas source parameter difference and / or component aging, and at this time, the calculation parameter of the theoretical proportional valve current Ic is corrected to C in the control system. The automatic adjustment method for the gas water heater can effectively discover abnormal working conditions that cannot be solved, such as gas source parameter difference and component aging, thereby avoiding repeated adjustment of the gas water heater due to abnormal working conditions, thereby improving the adjustment speed of the constant temperature of the outlet water.

Description

Technical Field

[0001] The invention relates to an automatic regulating method for a gas water heater. Background Art

[0002] With household instantaneous gas water heaters, the amount of gas input is controlled by controlling the opening of the proportional valve, thereby controlling the output yield. The gas pressure (i.e., primary pressure) in the gas pipeline entering the gas water heater is usually around 2kPa. After the gas passes through the main valve, the gas pressure can be limited to a certain range through the proportional valve, thereby ensuring the accuracy of the gas pressure at the rear end of the proportional valve, and coordinating the control of the proportional valve to achieve the purpose of fast and accurate temperature control. However, as time goes by, the components will gradually age, or some kind of failure will occur, such as blockage of the gas valve, pipeline or fire grate, or the gas pressure or quality will change. The output yield that can be achieved by the proportional valve opening set by the system will deviate from the normal value, and the water outlet temperature will also deviate from the set temperature, affecting the user's constant temperature experience.

[0003] At present, the main method used in the industry is to add a gas pressure sensor, which directly detects the gas pressure and controls the working components such as the gas proportional valve, fan and water valve according to the pressure, so as to adapt them to different gas pressure conditions. On the one hand, this solution will increase the cost of the product. On the other hand, there is no scientific and effective way to control the impact of component aging, changes in gas quality and structural component failure. In addition, the accuracy of constant temperature control is not easy to grasp when the gas pressure is used as the basis for judgment, which increases the difficulty of development. In addition, the gas source parameters of different users are different, and a fixed single gas pressure determination method cannot achieve accurate calibration of the yield. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an automatic adjustment method for the gas water heater that can effectively detect abnormal operating conditions that cannot be solved such as differences in gas source parameters and aging of components, thereby avoiding repeated adjustments of the gas water heater due to abnormal operating conditions, thereby improving the adjustment speed of the constant temperature of the water outlet.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: an automatic adjustment method for a gas water heater, characterized in that: during the operation of the gas water heater, the theoretical proportional valve current Ic and the actual proportional valve current I of the current combustion stage s of the gas water heater are calculated, and the deviation coefficient Asj of I relative to Ic is calculated, where I=AsjIc; j is a natural number;

[0006] When the deviation value |1-Asj|≥B, Asj is recorded, where B is the preset deviation threshold, 0<B<1;

[0007] When the situation of |1-Asj|≥B continues to occur and meets the preset abnormal operating conditions, it is judged that the situation is caused by differences in gas source parameters and / or component aging. At this time, the calculation parameter of the theoretical proportional valve current Ic is corrected to C in the control system, and the recorded Asj is cleared at the same time.

[0008] In order to accurately adjust the stability deviation, C is the average value of each Asj that satisfies the condition |1-Asj|≥B.

[0009] For convenient operation, the preset judgment conditions of abnormal working conditions are as follows: the number of positive deviations D of Asj relative to 1 is counted, the number of reverse deviations E of Asj relative to 1 is counted, one of D and E reaches the preset number threshold M, and the larger number of D and E is more than X times the smaller number, X>1;

[0010] When C is obtained by calculation, D and E are cleared.

[0011] Preferably, X≥2.

[0012] In order to improve the speed of detecting abnormal situations, when B≤|1-Asj|<2B, the count of Asj in the deviation direction relative to 1 is increased by 1; when |1-Asj|≥2B, the count of Asj in the deviation direction relative to 1 is increased by 2.

[0013] Preferably, B=15%.

[0014] As an improvement, the following steps are included

[0015] Initialize the relationship between the proportional valve current and the yield of each combustion section I i =F i (O);

[0016] When the gas water heater is turned on, the current target yield value O0 is calculated according to the target temperature T0, and then the working combustion stage s of the gas water heater is determined according to O0, s∈i; the corresponding theoretical proportional valve current Ic=F is calculated according to O0 and s s (O0);

[0017] As the gas water heater works, the output rate Ot is adjusted according to the difference between the actual outlet water temperature T and the target temperature T0, and then the actual proportional valve current I=F is adjusted according to Ot. s (Ot);

[0018] After C is calculated, the relationship between the proportional valve current and the yield of each combustion section is corrected to I i =CF i (O).

[0019] Compared with the prior art, the advantages of the present invention are: the automatic adjustment method of the gas water heater in the present invention can detect stability abnormalities such as aging of equipment in the user's home and gas source parameter deviation without performing pressure detection, and then systematically adjust the working parameters to improve adaptability to abnormal situations, and also avoid the need to adjust the gas water heater according to these situations every time it is working, thereby improving the working stability of the gas water heater and improving the constant temperature of the output water. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Flow chart of the automatic adjustment method of the gas water heater in the embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to the accompanying drawings.

[0022] Usually, when a water heater burns, there are different combustion stages. For example, the combustion stages of a gas water heater can be divided into one, two, and three stages. Different stages correspond to different numbers of working fire bars, and the corresponding gas water heaters have different yields, but there are overlapping intervals between adjacent combustion stages. The yield is the product of the inlet and outlet water temperature difference and the water flow rate. For this reason, the corresponding relationship is different in different working stages. The yield O of each combustion stage has a certain range. Using i to represent the number of combustion stages, the yield range of each combustion stage of the gas water heater is [O imin ,O imax ],O imin represents the minimum yield value of the i-th combustion stage, O imax Indicates the maximum yield value of the i-th combustion stage. As the combustion stage increases, the minimum and maximum yields corresponding to the combustion stage increase accordingly. i The relationship between the yield O i =F i (O). For a gas water heater with three combustion stages, the corresponding relationship formulas for the first, second and third combustion stages are respectively: 1 =F 1 (O), I 2 =F 2 (O), I 3 =F 3 (O).

[0023] Under normal circumstances, each combustion stage of the water heater has a default yield parameter. When the required yield is within a certain range, the proportional valve current value corresponding to the target yield in that stage will be calculated based on the corresponding relationship and output to achieve the required yield. However, when the equipment is aging, the smoke pipe or valve body is blocked, or the gas parameters change, the proportional valve current value calculated according to the above method will deviate from the normal value, which will directly manifest as a high or low water outlet temperature, affecting the user experience.

[0024] like Figure 1 As shown, in order to solve this problem, the automatic adjustment method of the gas water heater in this embodiment includes the following steps.

[0025] S1, initialize the proportional valve current I of each combustion section i The relationship between the yield O i =F i (O).

[0026] S2. When the gas water heater is turned on, the current target yield value O0 is calculated according to the target temperature T0. When calculating the target yield value O0, the temperature sensor at the water inlet of the gas water heater can be used to obtain the water inlet temperature, and the water flow sensor can be used to obtain the water flow.

[0027] S3. Determine the working combustion stage s of the gas water heater according to O0, s∈i; the method for determining the working combustion stage s of the gas water heater can be determined by various methods in the prior art.

[0028] S4. Calculate the corresponding theoretical proportional valve current Ic=F according to O0 and s. s (O0), the operating current of the gas water heater regulating proportional valve is Ic.

[0029] S5. As the gas water heater works, the output rate Ot is calculated and adjusted according to the difference between the actual outlet water temperature T and the target temperature T0. The actual outlet water temperature can be detected and obtained by using the temperature sensor set at the outlet. Then the actual proportional valve current I=F is calculated and adjusted according to Ot. s (Ot).

[0030] S6. Calculate the deviation coefficient Asj of I relative to Ic, I=AsjIc; j is a natural number, and j is convenient for recording the deviation coefficient Asj.

[0031] S6. After Asj is obtained, the deviation value |1-Asj| of Asj relative to 1 is calculated. When the deviation value |1-Asj|≥B, Asj is recorded, where B is a preset deviation threshold, 0<B<1, and the value of B can be set as needed. In this embodiment, B=15%.

[0032] In order to more accurately count the deviation of I relative to Ic, Asj is recorded according to the different deviation directions of Asj relative to 1. At the same time, in this embodiment, the number of positive deviations D of Asj relative to 1 is counted, and the number of reverse deviations E of Asj relative to 1 is counted. If the number of positive deviations D and the number of reverse deviations E of Asj relative to 1 are not much different, it is the normal regulation of the proportional valve current in the gas water heater. When the number of positive deviations D and the number of reverse deviations E of Asj relative to 1 are greatly different, it is considered to be caused by the abnormal working condition of the gas water heater itself.

[0033] Therefore, in this embodiment, the abnormal working condition is preset as follows: one of D and E reaches a preset number threshold M, and the larger number of D and E is more than X times the smaller number, X>1. Preferably, X≥2. In this embodiment, M=4, X=2.

[0034] In order to make the current deviation larger, it is more likely to be considered as caused by abnormal working conditions. Therefore, in this embodiment, when B≤|1-Asj|<2B, the count of Asj relative to the deviation direction of 1 is increased by 1, and when |1-Asj|≥2B, the count of Asj relative to the deviation direction of 1 is increased by 2.

[0035] S7. During the continuous use of the gas water heater, the aforementioned S3 to S6 are performed. When the situation of |1-Asj|≥B continues to occur and satisfies the preset abnormal working condition, it is determined that the situation is caused by the difference in gas source parameters and / or aging of components. At this time, the calculation parameter of the theoretical proportional valve current Ic is corrected in the control system to C. In this embodiment, C is the average value of each Asj that satisfies the condition of |1-Asj|≥B.

[0036] S8. After C is calculated, the relationship between the current and yield of each combustion section proportional valve is corrected to I i =CF i (O), clear the recorded Asj and clear D and E at the same time.

[0037] In this way, the formula calculation parameters in the working process of the gas water heater can be directly modified from the system perspective. On the basis of not conducting pressure detection, it can realize the detection of stability abnormalities such as aging of equipment in the user's home and deviation of gas source parameters, and then systematically adjust the working parameters to improve the adaptability to abnormal situations. It also avoids the need to adjust these situations every time the gas water heater is working, thereby improving the working stability of the gas water heater and improving the constant temperature of the output water.

[0038] After an automatic adjustment, the system will include the value of the correction parameter C in the calculation formula of the proportional valve current, and continuously update and iterate it during the subsequent combustion process to continuously adapt to changes in the system and external conditions, achieve adaptive control, improve constant temperature performance, and reduce the maintenance rate of the gas water heater.

Claims

1. An automatic adjustment method for a gas water heater, characterized in that: The following steps are included Initialize the proportional valve current I of each combustion section i The relationship between the yield O i =F i (O); When the gas water heater is turned on, the current target yield value O0 is calculated according to the target temperature T0, and then the working combustion stage s of the gas water heater is determined according to O0, s∈i; the corresponding theoretical proportional valve current Ic=F is calculated according to O0 and s s (O0); As the gas water heater works, the output rate Ot is adjusted according to the difference between the actual outlet water temperature T and the target temperature T0, and then the actual proportional valve current I= F is adjusted according to Ot. s (Ot); During the operation of the gas water heater, the theoretical proportional valve current Ic and the actual proportional valve current I of the current combustion stage s of the gas water heater are calculated, and the deviation coefficient Asj of I relative to Ic is calculated, where I=Asj*Ic; j is a natural number; When the deviation value |1-Asj|≥B, Asj is recorded, where B is the preset deviation threshold, 0<B<1; When the situation of |1-Asj|≥B continues to occur and meets the preset abnormal working condition, it is judged that the situation is caused by the difference in gas source parameters and / or component aging. At this time, the calculation parameter of the theoretical proportional valve current Ic is corrected to C in the control system, and the recorded Asj is cleared at the same time; After C is calculated, the relationship between the proportional valve current and the yield of each combustion section is corrected to I i =CF i (O).

2. The automatic adjustment method for a gas water heater according to claim 1, characterized in that: C is the average value of each Asj that satisfies the condition |1-Asj|≥B.

3. The automatic adjustment method of a gas water heater according to claim 1, characterized in that: The preset judgment conditions of abnormal working conditions are as follows: the number of positive deviations D of Asj relative to 1 is counted, and the number of reverse deviations E of Asj relative to 1 is counted, one of D and E reaches the preset number threshold M, and the larger number of D and E is more than X times the smaller number, X>1; When C is obtained by calculation, D and E are cleared.

4. The automatic adjustment method of a gas water heater according to claim 3, characterized in that: X≥2。 5. The automatic adjustment method for a gas water heater according to claim 3, characterized in that: When B≤|1-Asj|<2B, the count of Asj in the deviation direction relative to 1 is increased by 1; when |1-Asj|≥2B, the count of Asj in the deviation direction relative to 1 is increased by 2.

6. The automatic adjustment method for a gas water heater according to any one of claims 1 to 5, characterized in that: B=15%。

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