JPS6237614A - Supplied hot water temp. control method of gas hot water supplier and gas supplied amount control device - Google Patents

Abstract

PURPOSE:To rapidly converge supplied hot water temp. to the set value by controlling a throttle at a gas supply pipe path in such a manner that a measured value of supplied hot water temp. is compared with the set value and then the pressure target value of gas supplied to a burner before a nozzle is calculated to make gas supply pressure to the target value. CONSTITUTION:When supplied hot water temp. is varied by change of flow amount etc. of hot water supplied from a hot water supply hole 4, its temp. is found out by a hot water temp. detector 7 and a detected value is put in a control device 8 of a gas hot water supplier and the gas target value before a nozzle is calculated from the detected value of temp. settled by a hot water temp. setting device 9. After the target value is compared with the pressure before the nozzle fond out by a pressure detector 34 of a gas supplied amount control device 11, a calculated control signal is put into a pulse motor 22 as a pulse signal. An output shaft 23 rotates by the angle in proportion to the pulse signal and thereby, a rotating plate 19 rotates on a fixed plate 17 and width of a groove 20 facing an opening 18 is changed and the gas pressure before the nozzle is controlled to coincide with the target value calculated by the gas hot water supplier control device 3.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention provides a method for controlling the hot water outlet temperature of a gas water heater, which makes it possible to suppress variations in the hot water outlet temperature with respect to a set value, and a method used to implement the method. This invention relates to a gas supply amount control device.

Conventional gas water heaters are equipped with a temperature control device to keep the hot water output temperature constant, but the conventional temperature control device is The hot water temperature is detected by the temperature sensor b installed in the hot water temperature sensor b, and this detected value is fed back and input to the comparison circuit d of the main control unit C, and the temperature is calculated by comparing it with the set temperature input from the hot water temperature setting unit f. The control signal is amplified into an operating current by an amplifier e, and the operating current is supplied to a drive unit i of a comparison valve installed in a gas supply pipe g to control the opening degree of the throttle hole. Automatic control was used to maintain the outlet temperature near the set temperature by controlling the flow rate of gas supplied to the boiler.

Problems to be Solved by the Invention However, with such conventional hot water tap temperature control devices, when the hot water tap temperature changes due to fluctuations in the amount of hot water used or the temperature of cold water supplied to the heat exchanger, The temperature is detected and the gas supply flow rate is controlled so that the temperature approaches the set temperature.

Proportional valves generally have hysteresis in their operation, and there is a difference in the opening in the direction of expanding and decreasing the opening even if the control current is the same, and there is also variation in the operating characteristics. It was difficult to control the proportional valve to an appropriate opening. For this reason, while comparing the actual value of the outlet hot water temperature with the set value, the opening degree of the proportional valve was repeatedly controlled to roughly expand or contract, gradually approaching the set value. From the time the temperature changes until the outlet temperature changes, the amount of heat generated changes due to changes in the gas supply flow rate, and the temperature of the outlet changes as the temperature of the wood pipe or smoke pipe changes and the amount of heat transfer changes. Since there is a long delay time, repeating the rough control described above has the drawback that it takes a long time for the outlet temperature to converge to the set value. Since the supply flow rate itself is not controlled as a target value, the gas supply flow rate is not grasped as a control value.

For this reason, the flow rate of combustion air supplied to the burner was controlled in proportion to the control current supplied to the proportional valve, but as mentioned above, the opening degree of the proportional valve is not always accurate to the control current. Since it is not proportional to , it is difficult to always maintain the ratio of the flow rate of gas supplied to the burner and combustion air at a predetermined value, and there is a drawback that the thermal firing efficiency cannot be made sufficiently high.

Means for Solving the Problems As a means for solving the above-mentioned problems, the hot water outlet temperature control device method of the present invention compares the measured value of the hot water outlet temperature with a set value and controls the nozzle of the gas supplied to the burner. A configuration is adopted in which a target value of the front pressure is calculated, the target value is compared with an actual value of the gas nozzle front pressure, and the opening degree of the throttle hole provided in the gas supply pipe is controlled based on the comparison value, and , the gas supply amount control device of the present invention includes a proportional valve that changes the opening degree of the throttle hole in response to a control signal in the gas supply line to the burner, and the proportional valve controls the amount of gas supplied to the burner. The control device is equipped with a control device that inputs the target value and actual measured value of the nozzle front pressure of the gas and outputs the control signal to the proportional valve.

Effects and Effects The hot water outlet temperature control method of the present invention calculates a target value of the pressure in front of the nozzle of gas supplied to the burner by comparing the measured value of the hot water outlet temperature with a set value, and determines that the gas supply pressure is equal to the target value. Since the opening degree of the throttle hole in the gas supply pipe is controlled so that the gas nozzle pressure itself is controlled as a target value and kept at an appropriate value, the tapping temperature can be It quickly converges to the set value, and the amount of combustion air supplied to the burner can be accurately controlled in proportion to the gas pressure in front of the nozzle, making it possible to improve the thermal sintering efficiency.

In addition, the gas supply amount control device of the present invention can quickly match the nozzle pressure of the proportional valve to the target value and maintain it at that value, so the gas supply amount can be controlled regardless of hysteresis or variations in operating characteristics. Accurate control can be performed in response to signals, and the invention of the hot water tap temperature control method described above can be carried out reliably.

EXAMPLE Hereinafter, an example of the present invention will be explained based on FIGS. 1 to 3.

In the figure, 1 indicates that a burner 5 equipped with a gas jet nozzle (not shown) is arranged below a water pipe 2 that is bent between a water intake 3 and a hot water supply port 4, and a blower 6 is arranged below it. The hot water temperature detected by the hot water temperature detection device 7 installed near the hot water supply port 4 of the water pipe 2 is input to the control device 8 of the gas water heater as an electric signal, and the hot water temperature is set. A target value of the gas nozzle pressure is calculated by comparing it with the set temperature inputted from the device 9, and the calculated value is applied to the gas supply amount control device 11 interposed in the gas supply pipe line 10 connected to the nozzle. ) is input to the control device 26. In the gas supply amount control device 11, a proportional valve 16 is attached to the outlet 15 side of the main body 12, which has a gas passage 13 extending from an inlet 14 to an outlet 15. As shown in FIG. 2, a rotary plate 19 in which a circumferential groove 20 whose groove width gradually decreases is formed is disposed in close contact with the upper surface of the fixed plate 17 having an opening 18 facing the center of the fixed plate 17. As the fixed drive shaft 21 rotates and slides on the fixed plate 17, the width of the groove 20 corresponding to the opening 18 changes continuously, and the opening 18 is fully opened in proportion to the rotation angle of the drive shaft 21. The rotating plate 19 connects the gear 25 fixed to the drive shaft 21 to the pinion 24 fixed to the output shaft 23 of the pulse motor 22 fixed to the upper surface of the main body 1°2. By engaging with each other, the pulse motor 22 rotates the drive shaft 21 by an angle proportional to the number of pulse signals output from the control device 26 fixed to the upper surface of the pulse motor 22. It is designed to let you do so. As shown in FIG. 3, this control device 26 consists of a comparison section 27 and an amplification section 28, and includes a gas nozzle front pressure detected by a pressure detection device 34 installed near the outlet 15 of the gas flow path 13. is the electric signal and the comparison section 2
7 and calculated by comparing it with the target value of the gas nozzle front pressure input from the gas water heater control device 8 is amplified by the amplifier 28 and input to the pulse motor 22. Further, the control signal is amplified by an amplifier 33 and inputted to a servo motor 32 that adjusts the opening degree of a damper 31 provided at the intake port 3o of the blower 6. Note that the gas supply amount control device 1
An electromagnetic opening/closing valve 35 is installed on the inlet 14 side of the main body 12, and the valve body 37 is operated and opened by the excitation of the solenoid 3G, forming a unit with the gas supply amount control device 11.

Next, the operation of this embodiment will be explained.

Due to changes in the flow rate of hot water flowing out from the hot water supply port 4, etc.
゛When the hot water temperature changes, the temperature is detected by the hot water temperature detection device 7, inputted into the control device 8 of the gas water heater, and compared with the set temperature set by the hot water temperature setting device 9 to determine the gas nozzle front pressure. The target value is calculated, and the target value is the gas supply amount control device! The control signal is compared with the gas nozzle front pressure detected by the pressure detection device 34 of 1111, and the calculated control signal is amplified by the amplifier 28 and inputted to the pulse motor 22 as a pulse signal, and its output shaft 23 is converted into a pulse signal. The rotating plate 19 rotates on the fixed plate 17 and the width of the groove 20 corresponding to the opening 18 changes, and the pressure in front of the gas nozzle is calculated by the control system [8] of the gas water heater. As a result, the flow rate of the gas supplied to the burner 5 changes and the calorific value changes, and the temperature of the water flowing out from the hot water supply port 4 of the water pipe 2 changes to the hot water temperature setting device i. ! 9 The set temperature is reached. On the other hand, the control signal output from the comparator 27 of the control device 26 of the gas supply amount control device 11 is amplified by the amplifier 33 and sent to the servo motor 32 that adjusts the opening degree of the damper 31 provided at the inlet 30 of the blower 6. This input controls the opening degree of the damper 31, and a flow rate of combustion air proportional to the gas flow rate supplied to the burner 5 is supplied to the burner 5, so that complete combustion is always performed at the correct air-fuel ratio. It will be done.

In this embodiment, the proportional valve 16 of the gas supply amount control device 11 changes the width of the groove 2° corresponding to the opening 18 by sliding and rotating the rotary plate 17 on the fixed plate 19, so that the width of the groove 2° corresponding to the opening 18 is changed. Since a structure in which the opening degree can be changed is used, the opening 18 can be completely sealed by the rotary plate 19. Therefore, conventionally, it was necessary to arrange two on-off valves in series for safety reasons. Instead of the existing structure, it is only necessary to provide l electromagnetic on-off valves 35, which has the advantage of being downsized.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of one embodiment of the present invention, and FIG.
Figure A-A is an enlarged cross-sectional view, Figure 3 is its block diagram, Figure 4 is its block diagram.
The figure is a block diagram of a conventional hot water temperature control device for a gas water heater. l: Main body of gas water heater 2: Water pipe 3: Water intake 4: Hot water inlet 5: Burner 6: Air blower 7: Hot water temperature detection device 8
: Gas water heater control system! ! 9: Water temperature setting device! ! 10
: Gas supply pipe line 11: Gas supply amount control device! 1
6: Proportional valve 22: Pulse motor 26: Control device for gas supply amount control device 27: Comparison section 29: Amplification section 32
: Servo motor 34: Gas nozzle front pressure detection device Applicant: CKD Controls Co., Ltd. Agent
Patent Attorney Hirotomi Noguchi 2nd time

Claims (1)

[Claims] 1. Compare the actual measured value of the outlet temperature with a set value to calculate the target value of the nozzle front pressure of the gas supplied to the burner, and compare the target value with the actual measured value of the gas nozzle front pressure. A method for controlling the hot water outlet temperature of a gas water heater, characterized in that the opening degree of a throttle hole provided in a gas supply pipe is controlled based on the comparison value. A proportional valve whose opening degree of the throttle hole changes correspondingly is provided, and the target value and actual measured value of the nozzle front pressure of the gas supplied to the burner are inputted to the proportional valve, and the control signal is sent to the proportional valve. A gas supply amount control device for a gas water heater, characterized by being equipped with a control device that outputs