CN108019954B - Control method of gas water heater - Google Patents

Abstract

The invention relates to a method for controlling a gas water heater comprising a burner for firing the burnerThe some firearm of fire, the proportional valve, the fan for the main control board of control proportional valve current value, fan rotational speed and firearm switching, and the outlet valve who is connected with the main control board, its characterized in that: the combustion gas secondary pressure detection device is characterized by further comprising a pressure sensor arranged between the proportional valve and the combustion chamber and used for detecting secondary pressure of combustion gas, a storage is arranged in the main control panel, and a comprehensive environment influence factor K for calculating the rotating speed of the fan is stored in the storage_nAnd a comprehensive environmental influence factor K for calculating the opening of the proportional valve_s，K_nAnd K_sAll initial values of (1). Compared with the prior art, the invention has the advantages that: the method provided by the invention can take all factors influencing the environment into the calculation formula of the opening of the proportional valve and the rotating speed of the fan, and continuously memorizes the proportional factor which best meets the current environment, thereby achieving the purposes of quickly stabilizing the water temperature and stabilizing the combustion.

Description

Control method of gas water heater

Technical Field

The invention relates to a control method of a gas water heater.

Background

The actual operation environment of the household gas water heater is different from the laboratory test environment, and the operation environments of different weathers in the same place are completely different. These various environmental factors are significant in the impact on the operating conditions of the gas water heater. Improper conditions can cause unstable and incomplete combustion, excessive carbon monoxide generation, and even risk of combustion flameout, combustion deflagration and the like. The control technology of the gas water heater considers all influencing factors into a calculation formula, and continuously memorizes a scale factor which best meets the current environment so as to achieve the purposes of quickly stabilizing the water temperature and stabilizing the combustion.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art and provides a control method of a gas water heater, which can continuously memorize a scale factor most conforming to the current environment so as to achieve the aims of quickly stabilizing water temperature and stably burning.

The technical scheme adopted by the invention for solving the problems in the prior art is as follows: a control method of a gas water heater, the gas water heater comprising a burner, an igniter for igniting the burner, a proportional valve for controlling the amount of combustion gas entering the combustion chamber, a fan for controlling the amount of air entering the combustion chamber, a main control board for controlling the current value of the proportional valve, the rotation speed of the fan and the opening and closing of the igniter, and a water outlet valve connected to the main control board, the method comprising the steps of: the combustion gas secondary pressure detection device is characterized by further comprising a pressure sensor arranged between the proportional valve and the combustion chamber and used for detecting secondary pressure of combustion gas, a storage is arranged in the main control panel, and a comprehensive environment influence factor K for calculating the rotating speed of the fan is stored in the storage_nAnd a comprehensive environmental influence factor K for calculating the opening of the proportional valve_s，K_nAnd K_sThe initial value of the main control board is 1, and the main control board controls the gas water heater to work through the following steps:

step one, reading K in a memory after a gas water heater is powered on_nAnd K_s；

Step two, judging whether a water outlet valve of the gas water heater is opened or not, if so, executing step three, otherwise, returning to execute step one;

step three, the fan operates for a first set time according to the preset front sweeping wind speed, and then the step four is executed;

step four, the fan operates according to the preset ignition wind speed, and then step five is executed;

opening an igniter for ignition, opening a proportional valve and opening a fan, wherein the rotating speed of the fan is

The opening degree of the proportional valve is

Then executing the step six; wherein n is₀For a predetermined ignition wind speed, p₀As density of combustion gas, q₀Is the heat value of combustion gas, C₁、C₂、C₃Are all experimental measured values, which are factory default values, C_pIs the specific heat capacity of water, M_{Water (W)}Is the water mass flow, t_{Setting up}To set the water temperature, t_{Inflow water}To the temperature of the inlet water, P_{Second pressing}The secondary pressure of the combustion gas detected by the pressure sensor;

step six, adjusting the rotating speed of the fan and the opening of the proportional valve through a PID algorithm according to the set water temperature, and then executing step seven;

step seven, judging whether the water outlet temperature reaches the set water temperature, if not, executing step eight, if so, judging whether the water outlet temperature is stable for more than 10-20 seconds, if not, executing step eight, if so, acquiring the fan rotating speed n 'and the proportional valve opening S' at the current moment, and calculating K through the following formula_s' and K_n’，

Then step eight is executed;

step eight, judging whether a water outlet valve of the gas water heater is closed, if so, executing the step nine, and if not, executing the step five;

step nine, stopping combustion, and closing the proportional valve; the fan runs at the preset post-cleaning wind speed for a second set time and then executes the step ten;

step ten, adding K_nAnd K_sIs updated to K_s' and K_n’；

Eleventh step of judging K_s' and K_sWhether the difference is greater than A, A is within 5% of K_s，10％K_s]If yes, then K is_sIs updated to K_s' post-store to memory save; judgment of K_n' and K_nWhether the difference is greater than B, which belongs to [ 5% K ]_n，10％K_n]If yes, then K is_nIs updated to K_n' post-store to memory save, otherwise not update K_nAnd K_sAnd then returning to the step two.

Compared with the prior art, the invention has the advantages that: the method provided by the invention can take all factors influencing the environment into the calculation formula of the opening of the proportional valve and the rotating speed of the fan, and continuously memorizes the proportional factor which best meets the current environment, thereby achieving the purposes of quickly stabilizing the water temperature and stabilizing the combustion.

Drawings

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

fig. 2 is a flow chart of a control method of the gas water heater in the embodiment of the invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

As shown in FIG. 1, the present invention provides a method for controlling a gas water heater, wherein the gas water heater comprises a burner, an igniter for igniting the burner, a proportional valve for controlling the amount of combustion gas entering the combustion chamber, a fan for controlling the amount of air entering the combustion chamber, a main control board for controlling the current value of the proportional valve, the rotating speed of the fan and the opening and closing of the igniter, a water outlet valve connected with the main control board, and a pressure sensor arranged between the proportional valve and the combustion chamber for detecting the secondary pressure of the combustion gas, as shown in FIG. 1, a memory is arranged in the main control board, and a comprehensive environmental influence factor K for calculating the rotating speed of the fan is stored in the memory_nAnd a comprehensive environmental influence factor K for calculating the opening of the proportional valve_s，K_nAnd K_sIs 1, the main control board controls the gas water heater to work through the following steps, as shown in fig. 2:

step one, reading K in a memory after a gas water heater is powered on_nAnd K_s；

Step two, judging whether a water outlet valve of the gas water heater is opened or not, if so, executing step three, otherwise, returning to execute step one;

step three, the fan operates for a first set time according to the preset front sweeping wind speed, and then the step four is executed;

step four, the fan operates according to the preset ignition wind speed, and then step five is executed;

opening an igniter for ignition, opening a proportional valve and opening a fan, wherein the rotating speed of the fan is

The opening degree of the proportional valve isThen executing the step six; wherein n is₀For a predetermined ignition wind speed, p₀As density of combustion gas, q₀Is the heat value of combustion gas, C₁、C₂、C₃Are all experimental measured values, which are factory default values, C_pIs the specific heat capacity of water, M_{Water (W)}Is the water mass flow, t_{Setting up}To set the water temperature, t_{Inflow water}To the temperature of the inlet water, P_{Second pressing}The secondary pressure of the combustion gas detected by the pressure sensor;

step six, adjusting the rotating speed of the fan and the opening of the proportional valve through a PID algorithm according to the set water temperature, and then executing step seven;

step seven, judging whether the water outlet temperature reaches the set water temperature, if not, executing step eight, if so, judging whether the water outlet temperature is stable for more than 10-20 seconds, if not, executing step eight, if so, acquiring the fan rotating speed n 'and the proportional valve opening S' at the current moment, and calculating K through the following formula_s' and K_n’，

Then step eight is executed;

step eight, judging whether a water outlet valve of the gas water heater is closed, if so, executing the step nine, and if not, executing the step five;

step nine, stopping combustion, and closing the proportional valve; the fan runs at the preset post-cleaning wind speed for a second set time and then executes the step ten;

step ten, adding K_nAnd K_sIs updated to K_s' and K_n’；

Eleventh step of judging K_s' and K_sWhether the difference is greater than A, A is within 5% of K_s，10％K_s]If yes, then K is_sIs updated to K_s' post-store to memory save; judgment of K_n' and K_nWhether the difference is greater than B, which belongs to [ 5% K ]_n，10％K_n]If yes, then K is_nIs updated to K_n' post-store to memory save, otherwise not update K_nAnd K_sAnd then returning to the step two.

Claims (1)

1. A control method of a gas water heater, the gas water heater comprising a burner, an igniter for igniting the burner, a proportional valve for controlling the amount of combustion gas entering the combustion chamber, a fan for controlling the amount of air entering the combustion chamber, a main control board for controlling the current value of the proportional valve, the rotation speed of the fan and the opening and closing of the igniter, and a water outlet valve connected to the main control board, the method comprising the steps of: the combustion gas secondary pressure detection device is characterized by further comprising a pressure sensor arranged between the proportional valve and the combustion chamber and used for detecting secondary pressure of combustion gas, a storage is arranged in the main control panel, and a comprehensive environment influence factor K for calculating the rotating speed of the fan is stored in the storage_nAnd a comprehensive environmental influence factor K for calculating the opening of the proportional valve_s，K_nAnd K_sThe initial value of the main control board is 1, and the main control board controls the gas water heater to work through the following steps:

step one, reading K in a memory after a gas water heater is powered on_nAnd K_s；

Step two, judging whether a water outlet valve of the gas water heater is opened or not, if so, executing step three, otherwise, returning to execute step one;

step three, the fan operates for a first set time according to the preset front sweeping wind speed, and then the step four is executed;

step four, the fan operates according to the preset ignition wind speed, and then step five is executed;

opening an igniter for ignition, opening a proportional valve and opening a fan, wherein the rotating speed of the fan is

The opening degree of the proportional valve isThen executing the step six; wherein n is₀For a predetermined ignition wind speed, p₀As density of combustion gas, q₀Is the heat value of combustion gas, C₁、C₂、C₃Are all experimental measured values, which are factory default values, C_pIs the specific heat capacity of water, M_{Water (W)}Is the water mass flow, t_{Setting up}To set the water temperature, t_{Inflow water}To the temperature of the inlet water, P_{Second pressing}The secondary pressure of the combustion gas detected by the pressure sensor;

step six, adjusting the rotating speed of the fan and the opening of the proportional valve through a PID algorithm according to the set water temperature, and then executing step seven;

step seven, judging whether the water outlet temperature reaches the set water temperature, if not, executing step eight, if so, judging whether the water outlet temperature is stable for more than 10-20 seconds, if not, executing step eight, if so, acquiring the fan rotating speed n 'and the proportional valve opening S' at the current moment, and calculating K through the following formula_s' and K_n’，

Then is re-executedStep eight;

step eight, judging whether a water outlet valve of the gas water heater is closed, if so, executing the step nine, and if not, executing the step five;

step nine, stopping combustion, and closing the proportional valve; the fan runs at the preset post-cleaning wind speed for a second set time and then executes the step ten;

step ten, adding K_nAnd K_sIs updated to K_s' and K_n’；

Eleventh step of judging K_s' and K_sWhether the difference is greater than A, A is within 5% of K_s，10％K_s]If yes, then K is_sIs updated to K_s' post-store to memory save; judgment of K_n' and K_nWhether the difference is greater than B, which belongs to [ 5% K ]_n，10％K_n]If yes, then K is_nIs updated to K_n' post-store to memory save, otherwise not update K_nAnd K_sAnd then returning to the step two.

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