CN110749108A - Combustion power regulating circuit of gas water heater - Google Patents
Combustion power regulating circuit of gas water heater Download PDFInfo
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
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- F24H9/2007—Arrangement or mounting of control or safety devices for water heaters
- F24H9/2035—Arrangement or mounting of control or safety devices for water heaters using fluid fuel
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Abstract
The invention discloses a combustion power regulating circuit of a gas water heater, which comprises a sensitivity detection unit, a proportional value calculation unit and a proportional valve driving unit. The gas water heater comprises a first hot water outlet, a second hot water outlet, a cold water inlet and a gas proportion regulating valve, and a regulating signal is provided to the gas water heater to the proportion value calculating unit by adopting a method of remotely controlling the relative sizes of two paths of hot water flows through a water valve; the sensitivity of controlling the opening degree of the gas proportional regulating valve is realized by a mode that a sensitivity detection unit detects the temperature of inlet cold water and outputs sensitivity control voltage to a proportional value calculation unit; the proportional value calculating unit outputs proportional value control voltage to control the opening of the gas proportional regulating valve. The method does not need a wired or wireless remote controller, and can realize the remote regulation of the combustion power of the gas water heater.
Description
The invention discloses a remote combustion power adjusting device with sensitivity cold water temperature compensation for a gas water heater, which is a divisional application with the original application number of 201610000436.X and the application date of 2016, 1, month and 4.
Technical Field
The invention relates to a control technology of a gas water heater, in particular to a combustion power regulating circuit of the gas water heater.
Background
If the temperature of the gas water heater is not properly set, great inconvenience is brought to people, particularly, when a user takes a shower, the temperature of the gas water heater without a wireless remote control or a remote wire control cannot be adjusted, and the gas water heater is easy to extinguish due to the fact that cold water is added by the water mixing valve. The temperature of the gas water heater is adjusted by adopting wireless remote control, and signals of a remote controller cannot be transmitted to the gas water heater on many occasions due to the limitation of the installation position. When a remote wire control mode is adopted, the special waterproof wired remote controller is high in cost, wires need to be buried in advance, the electronic wired remote controller works in a wet environment such as a bathroom for a long time, and the failure rate of the electronic wired remote controller is high.
Disclosure of Invention
The invention aims to provide a solution for remotely controlling the hot water temperature of a gas water heater, namely, a combustion power regulating circuit of the gas water heater is provided, which comprises:
the gas water heater comprises a gas proportion adjusting valve, a cold water inlet, a first hot water outlet and a second hot water outlet; the combustion power regulating circuit comprises a sensitivity detection unit, a proportional value calculation unit and a proportional valve driving unit; the opening of the gas proportional regulating valve is controlled by the proportional value control voltage output by the proportional value calculating unit, and the sensitivity for regulating the opening of the gas proportional regulating valve is controlled by the sensitivity control voltage output by the sensitivity detecting unit.
The function of the sensitivity detection unit is that when the temperature of the inlet cold water is reduced, the sensitivity control voltage is increased; as the inlet cold water temperature rises, the sensitivity control voltage decreases. The sensitivity detection unit comprises a cold water temperature sensor (907), a first operational amplifier (301), a first resistor (302), a second resistor (303) and a third resistor (304); the cold water temperature sensor (907) is an NTC thermistor; one end of the first resistor (302) is connected to a positive power supply, and the other end of the first resistor is connected with one end of the cold water temperature sensor (907) and the positive input end of the first operational amplifier (301); the other end of the cold water temperature sensor (907) is connected to a common ground; one end of the second resistor (303) is connected to the common ground, and the other end of the second resistor is connected with one end of the third resistor (304) and the negative input end of the first operational amplifier (301); the other end of the third resistor (304) is connected to the output end of the first operational amplifier (301); the output terminal of the first operational amplifier (301) outputs a sensitivity control voltage.
Detecting the outlet hot water flow of the first hot water outlet and converting the outlet hot water flow into first flow voltage for output; detecting the total cold water flow at the inlet of the cold water inlet and converting the total cold water flow into total flow voltage to be output; the proportional value calculating unit comprises a parallel A/D converter, a parallel D/A converter and an oscillator; the periodic pulse output by the oscillator is connected to the starting conversion input end of the parallel A/D converter, and each pulse starts one-time A/D conversion to enable the parallel A/D converter to work in an automatic continuous conversion mode; the parallel D/A converter is in a direct D/A conversion state; the first flow voltage is connected to the analog voltage input end of the parallel A/D converter, and the total flow voltage is connected to the reference voltage input end of the parallel A/D converter; the parallel data input end of the parallel D/A converter is connected to the parallel data output end of the parallel A/D converter; the sensitivity control voltage is connected to the reference voltage input end of the parallel D/A converter; the conversion voltage output end of the parallel D/A converter outputs proportional value control voltage.
The cold water inlet is connected to a heat exchanger of the gas water heater through a cold water pipe; hot water at the outlets of the first hot water outlet and the second hot water outlet comes from the heat exchanger of the gas water heater; the hot water at the outlets of the first hot water outlet and the second hot water outlet is converged and flows out from the same water outlet end after the flow of the hot water is regulated. The total inlet cold water flow of the cold water inlet is equal to the sum of the outlet hot water flows of the first hot water outlet and the second hot water outlet.
The ratio of the first flow voltage to the total flow voltage is changed by adjusting the hot water flow at the outlets of the first hot water outlet and the second hot water outlet. The ratio of the outlet hot water flow of the first hot water outlet to the sum of the outlet hot water flows of the first hot water outlet and the second hot water outlet is changed, namely the ratio of the outlet hot water flow of the first hot water outlet to the total inlet cold water flow is changed, so that the ratio of the first flow voltage to the total flow voltage is changed.
The hot water flow of the first hot water outlet and the second hot water outlet is realized by an outlet hot water flow adjusting device. The hot water flow of the first hot water outlet and the second hot water outlet is adjusted and changed by the water mixing valve; 2 water inlets of the water mixing valve are respectively connected to a first hot water outlet and a second hot water outlet of the gas water heater through water pipes. The hot water flow of the outlets of the first hot water outlet and the second hot water outlet is adjusted and changed by a first adjusting valve and a second adjusting valve respectively; the water inlet of the first regulating valve is connected to a first hot water outlet of the gas water heater through a water pipe, and the water inlet of the second regulating valve is connected to a second hot water outlet of the gas water heater through a water pipe; the water outlets of the first regulating valve and the second regulating valve are communicated to form a water outlet end.
The first flow voltage and the outlet hot water flow of the first hot water outlet are in a direct proportion relation; the total flow voltage and the inlet cold water total flow of the cold water inlet are in a direct proportion relation; the proportional value between the total flow voltage and the inlet cold water total flow of the cold water inlet is equal to the proportional value between the first flow voltage and the outlet hot water flow of the first hot water outlet.
In the proportional value control voltage which is calculated and output according to the ratio between the first flow voltage and the total flow voltage and the sensitivity control voltage, the proportional value control voltage and the ratio are in a direct proportional relation, and the proportional value control voltage and the sensitivity control voltage are in a direct proportional relation.
The proportional valve driving unit has the function of controlling the opening of the gas proportional regulating valve to increase and the combustion power to increase when the proportional value control voltage is increased; when the proportional value control voltage is reduced, the opening degree of the gas proportional control valve is controlled to be reduced, and the combustion power is reduced.
If the first flow rate voltage is U1, the total flow rate voltage is U2, the sensitivity control voltage is U3, and the proportional control voltage is UK, the proportional control voltage UK is expressed by the following formula
And (6) performing calculation.
The combustion power regulating circuit of the gas water heater further comprises a first flow measuring unit, a second flow measuring unit and a flow threshold value switch unit. A first flow sensor is arranged in front of the first hot water outlet and used for detecting the outlet hot water flow of the first hot water outlet; and a second flow sensor and a cold water temperature sensor are arranged behind the cold water inlet and are respectively used for detecting the total inlet cold water flow and the inlet cold water temperature of the cold water inlet. The first flow measuring unit converts the outlet hot water flow of the first hot water outlet detected by the first flow sensor into first flow voltage for output; the second flow measuring unit converts the inlet cold water total flow of the cold water inlet detected by the second flow sensor into a total flow voltage output.
The flow threshold switch unit consists of a flow threshold setting circuit, a comparison driving circuit and a relay gas switch; the flow threshold setting circuit outputs a flow threshold voltage, and the flow threshold is determined by the flow threshold voltage. The flow threshold switching unit functions to: when the total flow voltage is greater than the flow threshold voltage, the total flow of cold water at the inlet is greater than the flow threshold, the relay gas switch is closed, and the gas is switched on; when the total flow voltage is smaller than the flow threshold voltage, the total flow of the inlet cold water is smaller than the flow threshold, the relay gas switch is disconnected, and the gas is turned off. The flow threshold voltage and the flow threshold are in a direct proportional relation; the proportional value between the flow threshold voltage and the flow threshold is equal to the proportional value between the first flow voltage and the outlet hot water flow of the first hot water outlet.
The proportional valve driving unit comprises a proportional valve driving circuit; the gas proportion regulating valve is driven and controlled by a proportion valve driving circuit according to the proportion value control voltage.
The combustion power control device of the gas water heater is composed of the combustion power adjusting circuit of the gas water heater and the outlet hot water flow adjusting device. The control system of the gas water heater consists of a combustion power control device of the gas water heater, a controller, an ignition discharge needle, a flame induction needle, an exhaust fan and an electromagnetic valve; a gas proportion regulating valve in the device is arranged behind an electromagnetic valve in a gas pipeline. Or the control system of the gas water heater consists of a temperature adjusting controller, an ignition discharge needle, a flame induction needle, an exhaust fan, an electromagnetic valve, a gas proportion adjusting valve, a first flow sensor, a second flow sensor and a cold water temperature sensor; the regulating circuit is included in a tempering controller; the adjusting circuit comprises corresponding circuits in a first flow measuring unit, a second flow measuring unit, a sensitivity detecting unit, a proportional value calculating unit, a flow threshold value switching unit and a proportional valve driving unit.
The electromagnetic valve preferably uses a safety stop valve in a fuel gas proportional valve assembly; the gas proportion regulating valve is a gas proportion regulating valve in a gas proportion valve assembly.
The invention has the advantages that the method of controlling the relative magnitude of the flow of two paths of hot water by the water valve is adopted to provide the adjusting signal for the gas water heater, the control of the opening degree of the gas proportional adjusting valve is carried out by the analog operation circuit, the ADC circuit and the DAC circuit, the sensitivity of adjusting the opening degree of the gas proportional adjusting valve is compensated by the temperature of cold water at the inlet of the water heater, and the combustion power is changed; the regulating circuit is simple, the control device is stable and reliable, a wired or wireless remote controller is not needed, and the remote regulation of the hot water temperature of the gas water heater can be realized.
Drawings
FIG. 1 is a schematic block diagram of a combustion power regulating circuit of a gas water heater.
Fig. 2 is a block diagram showing the structure of the flow sensor mounting embodiment 1.
Fig. 3 is a block diagram showing the structure of embodiment 2 of flow sensor mounting.
Fig. 4 shows an embodiment of the first flow measurement unit 100.
Fig. 5 is an embodiment of a sensitivity detection unit 300.
Fig. 6 is an embodiment of the proportional value calculating unit 400.
Fig. 7 is an embodiment of a flow threshold switch unit 500.
Fig. 8 is an embodiment of a proportional valve drive circuit in a proportional valve drive unit 600.
FIG. 9 is a block diagram of a conventional control system for a gas water heater.
Fig. 10 is a block diagram of a gas water heater control system with a temperature remote adjustment function.
Detailed Description
The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.
Fig. 1 shows a schematic block diagram of a combustion power control circuit of a gas water heater, which includes a first flow measuring unit 100, a second flow measuring unit 200, a sensitivity detecting unit 300, a proportional value calculating unit 400, a flow threshold value switching unit 500, and a proportional valve driving unit 600. The cold water temperature measuring unit 300 in fig. 1 is a sensitivity detecting unit 300.
The gas water heater is provided with 1 cold water inlet and 2 hot water outlets, and the cold water inlet and 1 of the hot water outlets are respectively provided with a flow sensor for respectively detecting water flow. The first flow measuring unit 100 measures the outlet hot water flow Q1 of 1 of the hot water outlets, and the second flow measuring unit 200 measures the inlet cold water total flow Q2 of the cold water inlet, and outputs the measured values as a first flow voltage U1 and a total flow voltage U2. The total flow voltage U2 is sent to a flow threshold value switch unit 500 to be compared with a set flow threshold value voltage, and when the total inlet cold water flow Q2 is larger than the set flow threshold value, a relay gas switch is controlled to be closed; and when the total inlet cold water flow Q2 is smaller than a set flow threshold value, the gas switch of the control relay is switched off.
The sensitivity detection unit 300 is provided with an output end of a sensitivity control voltage U3, and after the sensitivity detection unit 300 measures the inlet cold water temperature T, the inlet cold water temperature T is converted into a sensitivity control voltage U3 to be output.
The first flow voltage U1, the total flow voltage U2, and the sensitivity control voltage U3 are sent to the proportional value calculation unit 400, the proportional value calculation unit 400 calculates a ratio between the first flow voltage U1 and the total flow voltage U2, and then calculates a proportional value control voltage UK according to the ratio and the sensitivity control voltage U3; the proportional value control voltage UK is sent to the proportional valve driving unit 600, and the opening degree of the gas proportional control valve is controlled by the UK; when the UK is the minimum value, the opening degree of the gas proportion regulating valve is the minimum; and when the UK is the maximum value, the opening degree of the gas proportion regulating valve is maximum.
The structural block diagram of the installation embodiment 1 of the flow sensor is shown in fig. 2, and the water path system of the device is composed of a heat exchanger 901, a first flow sensor 902, a second flow sensor 903, a cold water temperature sensor 907, a first hot water outlet 904, a second hot water outlet 905, a cold water inlet 906, a cold water pipe 921, a main hot water pipe 922, a first hot water pipe 923, a second hot water pipe 924, a water mixing valve 931, a first connecting water pipe 925, a second connecting water pipe 926, a mixed hot water pipe 927 and a water outlet nozzle 932 outside the gas water heater.
The gas water heater is provided with 1 cold water inlet and 2 hot water outlets, and the cold water pipe 921 is connected between the cold water inlet 906 and the heat exchanger 901; one end of the first hot water pipe 923 is connected to the first hot water outlet 904, and the other end is communicated to the water outlet end of the main hot water pipe 922; one end of the second hot water pipe 924 is connected to the second hot water outlet 905, and the other end is connected to the water outlet end of the main hot water pipe 922; the water inlet end of the main hot water pipe 922 is connected to the heat exchanger 901.
The first flow sensor 902 is arranged in front of the first hot water outlet 904 and is used for detecting the outlet hot water flow Q1 of the first hot water outlet 904; the second flow sensor 903 is arranged behind the cold water inlet 906 and is used for detecting the total inlet cold water flow Q2 of the cold water inlet 906; the cold water temperature sensor 907 is installed behind the cold water inlet 906 and is used for detecting the inlet cold water temperature T of the cold water inlet 906. Specifically, the first flow sensor 902 is installed on the first hot water pipe 923, and the second flow sensor 903 and the cold water temperature sensor 907 are installed on the cold water pipe 921; the second flow sensor 903 may be installed after the cold water temperature sensor 907 as shown in fig. 2, or may be installed before the cold water temperature sensor 907.
2 water inlets of the water mixing valve 931 are connected to the first hot water outlet 904 and the second hot water outlet 905 of the gas water heater through a first connecting water pipe 925 and a second connecting water pipe 926 respectively; the outlet of the mixing valve 931 is connected to the outlet nozzle 932 by a mixing hot water pipe 927. When the mixing valve 931 is a cold water and hot water mixing valve, the first connecting water pipe 925 is connected to a hot water inlet of the mixing valve 931, and the second connecting water pipe 926 is connected to a cold water inlet of the mixing valve 931. The outlet hot water flow rate Q1 of the first hot water outlet 904 and the inlet cold water total flow rate Q2 of the cold water inlet 906 are changed by adjusting the mixing valve 931.
Fig. 3 shows a block diagram of a flow sensor mounting embodiment 2, which is different from embodiment 1 in that a first adjusting valve 933 and a second adjusting valve 934 are used instead of a mixing valve 931; the water inlet of the first adjusting valve 933 is connected to the first hot water outlet 904 of the gas water heater through a first connecting water pipe 925, and the water inlet of the second adjusting valve 934 is connected to the second hot water outlet 905 of the gas water heater through a second connecting water pipe 926. The water outlets of the first adjusting valve 933 and the second adjusting valve 934 are communicated to form a water outlet end which is connected with the mixed hot water pipe 927. The hot water flow at the outlets of the first hot water outlet 904 and the second hot water outlet 905 is changed by adjusting the first adjusting valve 933 and the second adjusting valve 934 respectively; the sum of the outlet hot water flows of the first hot water outlet 904 and the second hot water outlet 905 is equal to the inlet cold water total flow Q2 of the cold water inlet 906.
An embodiment of the first flow measurement unit 100 is shown in fig. 4 and has a first flow voltage output. The first flow sensor 902 is a low cost hall water flow sensor with the sensor output being a pulse frequency proportional to flow. The first flow rate measuring unit 100 is composed of a first flow rate sensor 902 and a frequency-voltage conversion circuit. In the embodiment shown in fig. 4, the frequency-voltage conversion circuit is composed of a monolithic frequency-voltage converter 101, and its peripheral components, i.e., a resistor 102, a resistor 104, a resistor 106, a capacitor 103, and a capacitor 105, where the monolithic frequency-voltage converter 101 is of a type LM2917, and a pin 10 of the LM2917 is a first flow voltage output terminal, and outputs a first flow voltage U1. The frequency-voltage conversion circuit may also adopt other circuits capable of realizing the frequency/voltage conversion function.
The second flow measurement unit 200 is composed of a second flow sensor 903 and a frequency-voltage conversion circuit, the second flow sensor 903 is a low-cost hall water flow sensor, the principle and structure of the frequency-voltage conversion circuit are completely the same as those of the frequency-voltage conversion circuit in the first flow measurement unit 100, and a total flow voltage output end is provided to output a total flow voltage U2.
The first and second flow measurement units 100, 200 may also employ other measurement schemes, such as measuring Q1, Q2 using integrated flow transmitters that directly output U1, U2, respectively.
The first flow measurement unit 100 detects Q1 and outputs U1, U1 and Q1 in a direct proportional relationship
U1＝KQ·Q1；
The second flow measurement unit 200 detects Q2 and outputs U2, U2 and Q2 in a direct proportional relationship
U2＝KQ·Q2；
KQ in the above 2 expressions is a flow measurement coefficient. The first flow measurement unit 100 and the second flow measurement unit 200 have the same flow measurement coefficient.
The sensitivity detection unit 300 is provided with a sensitivity control voltage output end, and converts the measured temperature T of the inlet/outlet cold water into a sensitivity control voltage U3 for output. The lowest value of the inlet cold water temperature is TL, the highest value is TH, and the inlet cold water temperature T is changed in the interval of TL and TH. The functions of the sensitivity detection unit 300 are: when the inlet cold water temperature T is equal to the minimum value TL, the sensitivity control voltage U3 is equal to the maximum value U3 max; when the inlet cold water temperature T is equal to the highest value TH, the sensitivity control voltage U3 is equal to the minimum value U3 min; the sensitivity control voltage U3 decreases with increasing cold water inlet temperature T as the cold water inlet temperature T varies over the interval TL, TH.
The embodiment of the sensitivity detection unit 300 is shown in fig. 5, and comprises a cold water temperature sensor 907, an operational amplifier 301, a resistor 302, a resistor 303 and a resistor 304, wherein the cold water temperature sensor 907 is selected from an NTC thermistor. The operational amplifier 301, the resistor 302, the resistor 303 and the resistor 304 form a temperature/voltage conversion circuit.
Assuming that the resistance of the cold water temperature sensor 907 is RT, and the resistances of the resistor 302, the resistor 303 and the resistor 304 are R2, R3 and R4 respectively in the embodiment shown in fig. 5, there are
Therein
Is a fixed value.
In the embodiment of fig. 5, when the inlet cold water temperature T decreases, RT increases and the sensitivity control voltage U3 increases; as the inlet cold water temperature T rises, RT decreases and the sensitivity control voltage U3 decreases.
The proportional value calculating unit 400 is provided with a first sub-voltage input terminal, a second sub-voltage input terminal, a denominator voltage input terminal, and a proportional value control voltage output terminal. The first molecular voltage input end is connected to the first flow voltage output end and inputs a first flow voltage U1; the denominator voltage input end is connected to the total flow voltage output end and inputs the total flow voltage U2; and the second molecular voltage input end is connected to the sensitivity control voltage output end and inputs a sensitivity control voltage U3. The proportional value calculating unit 400 outputs a proportional value control voltage UK, and an embodiment thereof is shown in fig. 6 and is composed of a parallel a/D converter 401, a parallel D/a converter 402, a 555 time base device 411, a resistor 412, a resistor 413 and a capacitor 414.
The model of the parallel a/D converter 401 is an 8-bit parallel a/D converter ADC 0841. The 555 time base device 411, the resistor 412, the resistor 413 and the capacitor 414 form an oscillator, periodic pulses output by the oscillator are connected to a start conversion input end WR of the parallel A/D converter 401, and each pulse starts an A/D conversion, so that the parallel A/D converter 401 works in an automatic continuous conversion mode.
The analog voltage input negative terminal VIN-, the output enable terminal RD, the chip select terminal CS, the digital ground DGND and the analog ground AGND of the ADC0841 are connected to a common ground, and the power supply terminal VCC of the ADC0841 is connected to the positive power supply + VDD. When the output enable terminal RD of the ADC0841 is inputted with a low level, the data output terminals DB7 DB0 keep outputting valid. When each conversion of the ADC0841 is finished, the result is automatically output from the data output terminals DB7 DB 0.
U1 is connected to the analog voltage input VIN + of ADC0841 and U2 is connected to the reference voltage input VREF of ADC 0841. Let X be the 8-bit digital signal output from the output terminals DB 7-DB 0 of the ADC0841, and the maximum value thereof is 255. Then there is
I.e. the ratio between the two input voltages U1, U2 is
The model of the parallel D/a converter 402 is an 8-bit parallel D/a converter AD 5330. The parallel data input end of the AD5330 is DB 7-DB 0, the reference voltage input end is VREF, and the conversion voltage output end is VOUT.
A buffer switch control end BUF, an output proportion control end GAIN, an input register control end WR, a DAC register control end LDAC, a chip selection end CS and a ground end GND of the AD5330 are connected to a common ground, and a zero clearing end CLR, a low power consumption control end PD and a power supply end VDD of the AD5330 are connected to a positive power supply + VDD. When the input register control end WR of the AD5330 and the DAC register control end LDAC input are in a direct D/A conversion state, and when the conversion delay is not considered, the conversion voltage output end VOUT reflects the data conversion results of the parallel data input ends DB 7-DB 0 in real time.
Parallel data inputs DB 7-DB 0 of the AD5330 are connected to parallel data outputs DB 7-DB 0 of the ADC0841, and the input data is X, and the maximum value is 255. The voltage input to the reference voltage input terminal VREF of the AD5330 is the sensitivity control voltage U3, and the voltage output from the conversion voltage output terminal VOUT is UK, if any
Considering the input-output relationship of AD0841, the proportional value calculating unit 400 follows the equation
The proportional value control voltage UK is calculated according to the ratio between the first flow voltage U1 and the total flow voltage U2, and the sensitivity control voltage U3. U3 is the maximum value of the proportional-value-control-voltage UK, the magnitude of which adjusts the sensitivity of the proportional-value-control-voltage UK. When the temperature T of the inlet cold water is reduced, the sensitivity control voltage U3 is increased, the sensitivity of the proportional value control voltage UK is adjusted to be increased, and the maximum value of the proportional value control voltage UK is increased; when the inlet cold water temperature T rises, the sensitivity control voltage U3 decreases, the sensitivity of the adjustment proportional value control voltage UK decreases, and the maximum value of the proportional value control voltage UK decreases. When the inlet cold water temperature T changes from the highest value TH to the lowest value TL, the sensitivity control voltage U3 changes from the minimum value U3min to the maximum value U3 max. The cold water temperature only plays a compensation role in the adjusting process, so the minimum value U3min of the sensitivity control voltage U3 is selected to be 0.4-1 time of the maximum value U3 max. When U3min equals U3max, the device has no sensitivity cold water temperature compensation function.
The minimum value U3min and the maximum value U3max of the sensitivity control voltage U3 are realized by adjusting the parameters of the elements in the sensitivity detection unit 300.
The sensitivity detection unit 300 may also use a circuit other than the embodiment shown in fig. 5. For example, the cold water temperature sensor 907 may be a PTC thermistor, and in this case, the positions of the cold water temperature sensor 907 and the resistor 302 in the embodiment shown in fig. 5 may be interchanged. In order to adjust the minimum value U3min and the maximum value U3max of the sensitivity control voltage U3 more flexibly and conveniently, a resistor may be connected in parallel to the cold water temperature sensor 907 in the embodiment shown in fig. 5. In addition, when the NTC thermistor or the PTC thermistor is used as the cold water temperature sensor 907, a resistance bridge may be used to measure a resistance value change of the cold water temperature sensor 907 due to a temperature change.
The embodiment shown in fig. 6 is suitable for the situation that the requirement on the calculation speed of the comparative value is not high and the change of the input voltage is relatively gentle. In the invention, U1 and U2 reflect the flow of the water heater, and the change is smooth, so the invention is suitable. The proportional value calculating unit 400 may also use other analog dividers and analog multiplier circuits, for example, an analog divider and an analog multiplier circuit formed by using integrated analog multipliers/dividers such as AD734 and AD534 to calculate UK according to U1, U2 and U3.
The flow rate threshold value switching unit 500 receives the total flow rate voltage U2 as an input, and outputs a switching signal related to the flow rate threshold value QY. Fig. 7 shows an embodiment of the flow threshold value switching unit 500, which is composed of a comparator 501, a resistor 502, a resistor 503, a resistor 504, a transistor 505, a freewheeling diode 506, a relay coil 507, and a relay gas switch 508, and a switching signal related to the flow threshold value QY is the closing and opening of the relay gas switch 508.
In the embodiment shown in fig. 7, the voltage dividing circuit formed by the resistor 502 and the resistor 503 is a flow threshold QY setting circuit, and is provided with a flow threshold voltage output end for outputting a set flow threshold voltage UY; the set flow rate threshold QY can be changed by changing the voltage division ratio between the resistor 502 and the resistor 503. The relationship between the flow threshold voltage UY and the flow threshold value QY is
The comparator 501, the resistor 504, the triode 505, the freewheeling diode 506 and the relay coil 507 constitute a comparison driving circuit of the relay gas switch 508.
When the inlet cold water total flow Q2 is greater than the flow threshold value QY, the total flow voltage U2 is greater than the flow threshold voltage UY, the comparator 501 outputs high level, the triode 505 is conducted, the relay coil 507 is electrified, and the relay gas switch 508 is closed; when the total inlet cold water flow Q2 is less than the flow threshold QY, the relay gas switch 508 is turned off.
The proportional valve driving unit 600 includes a proportional valve driving circuit. The input end of the proportional valve driving circuit is connected to the proportional value control voltage output end, and the opening degree of the fuel gas proportional regulating valve is driven by the proportional valve driving circuit.
An embodiment of the proportional valve driving circuit is shown in fig. 8 and comprises a power operational amplifier 601, a resistor 602, a resistor 603 and a freewheeling diode 604. A freewheeling diode 604 is connected in parallel across the proportional coil 630. The working principle is as follows: the flow of the gas can be changed by changing the opening of the gas proportion adjusting valve, so that the combustion power of the gas water heater is changed, and the temperature of hot water is changed. The method specifically comprises the following steps: when the proportional value control voltage UK is increased, the output voltage UB of the proportional valve driving circuit is increased, the current on the proportional coil 630 is increased, the opening degree of the gas proportional regulating valve is increased, the combustion power of the gas water heater is increased, and the temperature of hot water is increased; when the proportional value control voltage UK is reduced, the output voltage UB of the proportional valve driving circuit is reduced, the current on the proportional coil 630 is reduced, the opening degree of the gas proportional regulating valve is reduced, the combustion power of the gas water heater is reduced, and the temperature of hot water is reduced.
The resistor 602 and the resistor 603 are used for adjusting the range of the output voltage UB of the proportional valve driving circuit, and when the proportional value control voltage UK is equal to the maximum control voltage UM, the maximum control current, i.e., the rated current, flows through the proportional coil 630, so that the opening degree of the gas proportional regulating valve reaches the maximum value.
Other types of drive circuits may be used for the proportional valve drive circuit, such as triode power drive circuits, voltage/PWM conversion and PWM drive circuits, and so forth. The proportional valve drive circuit functions as: when the proportional value control voltage UK increases, the current on the proportional coil 630 is controlled to increase; when the proportional value control voltage UK decreases, the current on the proportional coil 630 is controlled to decrease; when the proportional value control voltage UK is the maximum value UM, the current on the proportional coil 630 is controlled to be the rated current.
The block diagram of the conventional control system of the gas water heater is shown in fig. 9, and the conventional control system comprises a controller 10, a water control switch 11, an ignition discharge needle 12, a flame induction needle 13, an exhaust fan 14 and an electromagnetic valve 15. The working principle is as follows: after a water outlet faucet of the water heater is turned on, the water control switch 11 is turned on, the controller 10 controls the exhaust fan 14 to work by electrifying, and simultaneously controls the ignition discharge needle 12 to ignite by discharging; slightly delaying to control the electromagnetic valve 15 to suck and open the coal gas; the ignition discharge needle 12 keeps igniting for tens of seconds, so that the ignition reliability is ensured; after the discharge is finished, the flame induction needle 13 is used for determining whether the ignition is successful or not, and the controller 10 controls the maintaining electromagnetic valve 15 to suck and open the coal gas when the ignition is successful through the induction of the flame induction needle 13; when the ignition is not successful, the electromagnetic valve 15 is controlled to bounce, the gas is cut off, and the water heater stops heating.
In order to ensure the safe use of the gas water heater, the gas water heater can also comprise a wind pressure switch 16 and a temperature control switch 17 shown in fig. 9. In the use process of the water heater, if the air pressure switch 16 detects that the exhaust fan is not started, or the temperature control switch 17 detects that the fire is too large and the temperature of the outlet water is too high, or the water control switch 11 detects that the water flow is too small, the electromagnetic valve 15 can be bounced to turn off the gas, and safety accidents are avoided.
When the control device of the invention is used in the gas water heater, the control system of the gas water heater consists of the control device and the controller 10, the ignition discharge needle 12, the flame induction needle 13, the exhaust fan 14 and the electromagnetic valve 15 of the system shown in figure 9, or can also selectively comprise a wind pressure switch 16 and a temperature control switch 17. The water control switch 11 in the conventional control system of the gas water heater shown in fig. 9 is replaced by a relay gas switch 508 in the device of the present invention, in which a gas proportional regulating valve is installed in the gas pipeline after the electromagnetic valve 15. Since a gas proportional regulating valve and a safety stop valve are usually included in a conventional gas proportional valve assembly, the electromagnetic valve 15 in the conventional control system of the gas water heater shown in fig. 9 preferably uses the safety stop valve in the gas proportional valve assembly, and the gas proportional regulating valve uses the gas proportional regulating valve in the gas proportional valve assembly.
When the control device of the invention is used for the gas water heater, the controller 10 can use various popular ignition controllers of the gas water heater at present, such as a DKG2 controller, a DKG3 controller, a DHS-B7A controller, a DHS-B7B controller, a HD 7PQA1-CP controller and various other ignition controllers of the gas water heater.
When the control device is used for the gas water heater, the regulating circuit can be combined with the controller 10 to form a new temperature regulating controller. Fig. 10 shows a block diagram of a gas water heater control system with a remote temperature adjustment function, which is composed of a temperature adjustment controller 20, an ignition discharge needle 12, a flame sensing needle 13, an exhaust fan 14, an electromagnetic valve 15, a gas proportional adjustment valve 21, a first flow sensor 902, a second flow sensor 903, and a cold water temperature sensor 907, or optionally includes a wind pressure switch 16 and a temperature control switch 17. The temperature-adjusting controller 20 is composed of a functional circuit in the controller 10 and an adjusting circuit according to the present invention, and the adjusting circuit according to the present invention includes corresponding circuits in the first flow measuring unit 100, the second flow measuring unit 200, the sensitivity detecting unit 300, the proportional value calculating unit 400, the flow threshold value switching unit 500, and the proportional valve driving unit 600. Similarly, the solenoid valve 15 in fig. 10 preferably uses a safety shut-off valve in a gas proportional valve assembly, and the gas proportional control valve 21 uses a gas proportional control valve in the gas proportional valve assembly.
The above description is only an example of the present invention and is not intended to limit the present invention, and various modifications and changes may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.
Claims (10)
1. A combustion power regulating circuit of a gas water heater is characterized in that:
the gas water heater comprises a gas proportion adjusting valve, a cold water inlet, a first hot water outlet and a second hot water outlet; the combustion power regulating circuit comprises a sensitivity detection unit, a proportional value calculation unit and a proportional valve driving unit;
the opening of the gas proportional regulating valve is controlled by the proportional value control voltage output by the proportional value calculating unit, and the sensitivity for regulating the opening of the gas proportional regulating valve is controlled by the sensitivity control voltage output by the sensitivity detecting unit.
2. The combustion power regulating circuit of a gas water heater as claimed in claim 1, wherein:
the sensitivity detection unit comprises a cold water temperature sensor (907), a first operational amplifier (301), a first resistor (302), a second resistor (303) and a third resistor (304); the cold water temperature sensor (907) is an NTC thermistor; one end of the first resistor (302) is connected to a positive power supply, and the other end of the first resistor is connected with one end of the cold water temperature sensor (907) and the positive input end of the first operational amplifier (301); the other end of the cold water temperature sensor (907) is connected to a common ground; one end of the second resistor (303) is connected to the common ground, and the other end of the second resistor is connected with one end of the third resistor (304) and the negative input end of the first operational amplifier (301); the other end of the third resistor (304) is connected to the output end of the first operational amplifier (301); the output terminal of the first operational amplifier (301) outputs a sensitivity control voltage.
3. The combustion power regulating circuit of a gas water heater as claimed in claim 2, wherein:
detecting the outlet hot water flow of the first hot water outlet and converting the outlet hot water flow into first flow voltage for output; detecting the total cold water flow at the inlet of the cold water inlet and converting the total cold water flow into total flow voltage to be output; the proportional value calculating unit comprises a parallel A/D converter, a parallel D/A converter and an oscillator; the periodic pulse output by the oscillator is connected to the starting conversion input end of the parallel A/D converter, and each pulse starts one-time A/D conversion to enable the parallel A/D converter to work in an automatic continuous conversion mode; the parallel D/A converter is in a direct D/A conversion state; the first flow voltage is connected to the analog voltage input end of the parallel A/D converter, and the total flow voltage is connected to the reference voltage input end of the parallel A/D converter; the parallel data input end of the parallel D/A converter is connected to the parallel data output end of the parallel A/D converter; the sensitivity control voltage is connected to the reference voltage input end of the parallel D/A converter; the conversion voltage output end of the parallel D/A converter outputs proportional value control voltage.
4. The combustion power regulating circuit of a gas water heater as set forth in claim 3, wherein:
the total inlet cold water flow of the cold water inlet is equal to the sum of the outlet hot water flows of the first hot water outlet and the second hot water outlet; hot water at the outlets of the first hot water outlet and the second hot water outlet comes from the heat exchanger of the gas water heater; the hot water at the outlets of the first hot water outlet and the second hot water outlet is converged and flows out from the same water outlet end after the flow of the hot water is regulated.
5. The combustion power regulating circuit of a gas water heater as set forth in claim 4, wherein: the ratio of the first flow voltage to the total flow voltage is changed by adjusting the hot water flow at the outlets of the first hot water outlet and the second hot water outlet.
6. The combustion power regulating circuit of a gas water heater as set forth in claim 5, wherein: the hot water flow of the first hot water outlet and the second hot water outlet is adjusted and changed by the water mixing valve; 2 water inlets of the water mixing valve are respectively connected to a first hot water outlet and a second hot water outlet of the gas water heater through water pipes.
7. The combustion power regulating circuit of a gas water heater as set forth in claim 5, wherein:
the hot water flow of the outlets of the first hot water outlet and the second hot water outlet is respectively adjusted and changed by a first adjusting valve and a second adjusting valve; the water inlet of the first regulating valve is connected to a first hot water outlet of the gas water heater through a water pipe, and the water inlet of the second regulating valve is connected to a second hot water outlet of the gas water heater through a water pipe; the water outlets of the first regulating valve and the second regulating valve are communicated to form a water outlet end.
8. The combustion power regulating circuit of a gas water heater as claimed in any one of claims 6 to 7, wherein: the first flow voltage and the outlet hot water flow of the first hot water outlet are in a direct proportion relation; the total flow voltage and the inlet cold water total flow of the cold water inlet are in a direct proportion relation.
9. The combustion power regulating circuit of a gas water heater as set forth in claim 8, wherein: the proportional value control voltage is calculated and outputted according to the ratio between the first flow rate voltage and the total flow rate voltage and the sensitivity control voltage by a method in which the proportional value control voltage and the ratio are in a direct proportional relationship and the proportional value control voltage and the sensitivity control voltage are in a direct proportional relationship.
10. The combustion power regulating circuit of a gas water heater as set forth in claim 8, wherein: the proportional valve driving unit has the function of controlling the opening of the gas proportional regulating valve to increase and the combustion power to increase when the proportional value control voltage is increased; when the proportional value control voltage is reduced, the opening degree of the gas proportional control valve is controlled to be reduced, and the combustion power is reduced.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911049149.8A CN110749108B (en) | 2016-01-04 | 2016-01-04 | Combustion power regulating circuit of gas water heater |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610000436.XA CN105546831B (en) | 2016-01-04 | 2016-01-04 | Gas heater combustion power remote regulating device with sensitivity cold water temperature compensation |
| CN201911049149.8A CN110749108B (en) | 2016-01-04 | 2016-01-04 | Combustion power regulating circuit of gas water heater |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201610000436.XA Division CN105546831B (en) | 2016-01-04 | 2016-01-04 | Gas heater combustion power remote regulating device with sensitivity cold water temperature compensation |
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| CN110749108A true CN110749108A (en) | 2020-02-04 |
| CN110749108B CN110749108B (en) | 2021-04-23 |
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| CN201911049149.8A Expired - Fee Related CN110749108B (en) | 2016-01-04 | 2016-01-04 | Combustion power regulating circuit of gas water heater |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56133529A (en) * | 1980-03-19 | 1981-10-19 | Omron Tateisi Electronics Co | Burning controller |
| CN2418432Y (en) * | 2000-04-10 | 2001-02-07 | 广东万家乐燃气具有限公司 | Controller for water heater |
| CN102022832A (en) * | 2009-09-11 | 2011-04-20 | 海尔集团公司 | Water temperature control device and water temperature control method for gas water heater |
| CN102235754A (en) * | 2010-04-21 | 2011-11-09 | 海尔集团公司 | Constant-temperature water outlet control device and method |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1133446A (en) * | 1995-04-08 | 1996-10-16 | 朱日昭 | Method of regulating fluid flow by closedopen of electromagetic stop valve |
| WO2008070906A1 (en) * | 2006-12-12 | 2008-06-19 | Rheem Australia Pty Limited | A controllable water heater |
| CN104101099A (en) * | 2013-04-15 | 2014-10-15 | 陈山石 | Throttling method for water flow heating device |
| CN104729104B (en) * | 2015-03-06 | 2017-12-19 | 芜湖美的厨卫电器制造有限公司 | The constant-temperature control method of gas heater and gas heater, device |
-
2016
- 2016-01-04 CN CN201610000436.XA patent/CN105546831B/en active Active
- 2016-01-04 CN CN201911049149.8A patent/CN110749108B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56133529A (en) * | 1980-03-19 | 1981-10-19 | Omron Tateisi Electronics Co | Burning controller |
| CN2418432Y (en) * | 2000-04-10 | 2001-02-07 | 广东万家乐燃气具有限公司 | Controller for water heater |
| CN102022832A (en) * | 2009-09-11 | 2011-04-20 | 海尔集团公司 | Water temperature control device and water temperature control method for gas water heater |
| CN102235754A (en) * | 2010-04-21 | 2011-11-09 | 海尔集团公司 | Constant-temperature water outlet control device and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110749108B (en) | 2021-04-23 |
| CN105546831B (en) | 2019-12-06 |
| CN105546831A (en) | 2016-05-04 |
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