JPS60245947A - Hot-water supply control device - Google Patents

Abstract

PURPOSE:To prevent the delayed detection of temperature and improve the safety of the device by controlling a bypass control valve, provided in the detour of a heat exchanger, in accordance with the signal of a delivered hot-water temperature setter. CONSTITUTION:A bypass path 10, detouring the heat exchanger 8 heated by a heating unit 27, is provided with the bypass control valve 9 and a heating controller 26, controlling the heating amount of the heating unit 27 by an output signal operated in a hot-water supply controller 30 based on the difference of signals of the delivered hot-water temperature setter 29 and a delivered hot-water temperature detector 13, while the opening degree of the bypass control valve 9 is controlled in accordance with the signal of the delivered hot-water temperature setter 29 to change the ratio of water supplying amount between the heat exchanger 8 and the bypass path 10. Thus, the flow amounts of water of the heat exchanger for a hot-water supplying device and the bypass path are controlled and whereby the pressure loss of water supplying circuit may be reduced and the temperature of hot-water may be stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to water flow control for instantaneous water heaters.

Conventional Structure and Problems It is known that an instantaneous hot water heater uses a system that detects the temperature of hot water and controls the amount of heating. Also, as a known technology, there is a bypass water circuit system that has a bypass path that bypasses a heat exchanger for the purpose of reducing water pressure loss, etc., and supplies hot water by mixing it with hot water heated by the heat exchanger. . There are two types of bypass water circuit systems: a fixed bypass ratio type that maintains a constant ratio of bypass water volume to the total water supply volume, and a variable bypass ratio type that increases the ratio of bypass water volume as the total water supply volume increases. When used in the above-mentioned hot water supply temperature control type water heater, there are the following problems. In other words, the fixed bypass ratio type had the disadvantage that if the bypass ratio was increased, boiling would occur in the heat exchanger if the outlet temperature was set high, and if the bypass ratio was decreased, there would be no effect of reducing pressure loss.

In addition, the above-mentioned inconvenience does not occur with the bypass ratio variable type, but
If the total amount of water supplied changes, the bypass ratio also changes, so there is a drawback that the hot water temperature will fluctuate transiently in response to sudden changes in the total amount of water supplied due to sudden opening and closing of the faucet by the user or sudden changes in water supply pressure. there were.

OBJECTS OF THE INVENTION The present invention controls the flow rate of water between a heat exchanger of a water heater and its bypass passage, thereby reducing pressure loss in a water supply circuit and stabilizing the temperature of hot water.

Structure of the Invention In order to achieve this object, the present invention includes a heat exchanger heated by a heating device, a bypass path that bypasses this heat exchanger, a bypass control valve provided in this bypass path, and a hot water outlet. A temperature setting device, a hot water temperature detector, a hot water supply controller that calculates a deviation signal between the hot water temperature setting device and the hot water temperature detector, and a heating device that controls the heating amount of the heating device using the output signal from the hot water supply controller. The control device controls the opening degree of the bypass control valve in accordance with the signal from the outlet hot water temperature setting device, and changes the ratio of water supply amount between the heat exchanger and the bypass path in accordance with the outlet hot water temperature.

DESCRIPTION OF EMBODIMENTS An embodiment in which the present invention is applied to a gas instantaneous water heater will be described.

In FIG. 1, 1 is a water flow controller, water flows in from an inlet channel 2, passes through a water flow detector 3, enters a large mouth valve chamber 4, and passes through a gap between a main control valve 5 and a main control hole 6. and flows into the outlet valve chamber 7. Water flows in two directions from the outlet valve chamber 7, one flowing into the heat exchanger 8, and the other flowing from the bypass control valve 9 to the bypass path 1o, where it joins the outlet pipe 11 of the heat exchanger 8. The mixing section 12 has a hot water temperature detector 1a. The water amount detector 3 includes an impeller 14 whose rotation speed changes depending on the size of the water flow, and a rotation detection element 1 that detects the rotation speed of the impeller.
It consists of 5. Reference numeral 16 denotes a water flow control drive device, which consists of a motor 17 and a speed reducer 1B, a link mechanism 19, and a valve rod 20.
The main control valve 5 is driven via the main control valve 5. 21 is a return spring. The bypass control valve 9 has a bypass control hole 9a, and a bypass valve drive device 24 consisting of a motor 22 and a speed reducer 23.
is rotated by the pump to control the amount of water in the bypass passage 1o.

The amount of gas is controlled by a heating controller 26 from a gas supply path 25, and is combusted by a heating device 27 to heat the heat exchanger 8. 28 is an inlet water temperature detector such as a thermistor;
Reference numeral 9 denotes a hot water temperature setting device composed of a variable resistor and the like. 30 is a hot water supply controller consisting of a microprocessor, etc., which inputs signals from a water flow rate detector 3, a hot water outlet temperature detector 13, an incoming water temperature detector 28, and a hot water outlet temperature setting device 29, performs arithmetic processing, and then controls the water flow rate. Signals are output to the drive device 16, bypass valve drive device 24, and heating controller 26.

Next, the operation will be explained. In FIG. 1, when the power is turned on, a signal from the hot water outlet temperature setting device 29 is read, and the bypass valve driving device 24 is activated in accordance with the hot water outlet humidity setting to rotate the bypass control valve 9. After that, when the user opens the faucet and water starts flowing, the signal from the water amount detector 3 is read, and fuel is supplied to the heating device 27 and combustion begins.The fuel is heated by the heat exchanger 8. The temperature of the mixed hot water and the water that has passed through the bypass control valve 9 is detected by the hot water temperature sensor 13, and the heating controller 26 is driven by this signal and the signal from the hot water temperature setting device to control the heating amount of the heating device 27. Adjust.

Further, the water amount control drive device 16 is driven by the signal from the water amount detector 3, and the total water supply amount is controlled.

Next, the control operation will be explained in more detail with reference to FIG.

When the power is turned on and the user sets the hot water temperature, the signal from the hot water temperature setting device 29 is read into the hot water supply controller 30, and is calculated by the bypass calculation section 30a inside the hot water supply controller 30, and the signal is set at the hot water temperature setting by the hot water supply controller 30. Bypass valve drive device 2 according to
4 is driven, and the bypass control valve 9 is rotated by a predetermined angle. When the outlet temperature of the outlet hot water temperature setting device 29 is set to the maximum, the bypass control hole 9 rotates to the almost fully open position.
When the setting of the outlet temperature is lowered, the bypass control valve 9 gradually opens, and when it is set to the lowest setting, it becomes almost fully open. Figure 3 (,
) shows the relationship between the outlet hot water temperature setting and the bypass control valve opening when the bypass valve is fully open, and (b) shows the relationship between the ratio of the bypass water amount to the total water supply amount. As shown in Fig. 3(b), when the hot water temperature setting is high, the proportion of bypass water is small and most of the total water supply passes through the heat exchanger 8, so boiling occurs near the outlet of the heat exchanger 8. As the hot water outlet temperature setting becomes lower, the ratio of the amount of bypass water increases, and by bypassing the heat exchanger 8 which has a high pressure loss, a large amount of water can be supplied even when the water supply pressure is low.

Further, the water amount setting calculating section 30b of the hot water supply controller 30 calculates the signal difference between the hot water temperature setting device 29 and the incoming water temperature detector 28 and the heating capacity of the heating device 27, and calculates the heating capacity of the heating device 27.
Set the maximum amount of water that guarantees the hot water temperature set in step 9. After that, when the water flow is started, the water amount detector 3 detects the amount of water supplied, and when the amount of water supplied reaches a predetermined amount (ignition start water amount) or more, fuel is supplied to the heating device 27 and the ignition operation is performed to turn off the heating device. 27 combustion begins. The ignition starting water amount can be changed by a preset constant value or by a signal from the outlet hot water temperature setting device 29. When the water supply pressure is high and a large amount of water is supplied, the deviation between the signal of the water flow detector a and the signal of the water flow setting calculation section 30b is calculated by the water flow control calculation section 30c, and the water flow control drive device 16 is operated. The main control valve 5 of the water flow rate controller 1 is driven to displace the water flow rate controller 1 to control the water flow rate.

The heating amount of the heating device 27 is adjusted by the heating controller 26. The heating controller 26 is controlled by the value of the heating load calculated by the hot water temperature control calculation unit 30d based on the difference between the signal from the outlet hot water temperature setting device 29 and the signal from the incoming water temperature detector 28 and the signal from the water flow rate detector 3. Further, correction is made using a deviation signal between the hot water outlet temperature setter 29 and the hot water outlet temperature detector 13, and finally a hot water outlet temperature equal to the hot water outlet temperature setting is obtained. The hot water temperature control calculation unit 30d ignites the heating device 27 with a heating amount smaller than the above-mentioned heating load value in order to prevent an explosion sound, or with a predetermined amount of heat after ignition to increase the heating rate when the hot water temperature rises. It is also possible to perform control such as supplying a heating amount that is greater than the above-mentioned heating load value.

The timer section 30e of the hot water supply controller 30 measures the time elapsed since the signal from the water amount detector 3 reached the above-mentioned ignition water amount or less. That is, the elapsed time after the hot water supply is stopped is measured, and a predetermined time correction is applied to the bypass control valve 9 depending on the magnitude of the value. The bypass control valve 9 is displaced by a predetermined amount in the closing direction from the normal set value after a long time has elapsed since hot water supply has stopped, and is displaced by a predetermined amount in the open direction from the set value when hot water is resupplied within a short time after the hot water supply has stopped. When resupplying hot water after a long time has elapsed after stopping hot water supply, including at the start of initial use, a bypass water amount is supplied smaller than the preset value for a predetermined period of time after restarting hot water supply, and the hot water outlet temperature is determined by the heat capacity of the cooled heat exchanger 8. Improve the start-up delay. In addition, when hot water is reheated for a short time after hot water supply is stopped, a larger amount of bypass water is supplied than when setting a predetermined time after restarting hot water supply, thereby improving the transient rise in the outlet temperature caused by the heat capacity of the heated heat exchanger 8. . Keep the hot water temperature setting constant 1. FIG. 4 shows the relationship between the water supply interval after the hot water supply is stopped and the correction ratio from the bypass water flow rate setting value in the case where the water supply is stopped.

Effects of the Invention As described above, the present invention provides heat exchange in a water heater that drives a heating controller based on the deviation between a hot water outlet temperature setting device and a hot water outlet temperature detector, and controls the heating amount of the heating device to heat the heat exchanger. The opening degree of the bypass control valve installed in the bypass path that bypasses the vessel is controlled according to the signal from the hot water temperature setting device.
The following effects can be obtained.

(1) When the hot water outlet temperature setting is high, most of the total water supply is passed through the heat exchanger, so there is no risk of boiling, and bypass water flow control is performed immediately after the hot water outlet temperature is set, so for example, heat exchange・Compared to those that detect boiling by temperature, there is no detection delay and it is highly safe.

(2) When setting a low hot water temperature that allows a large amount of water to be supplied, only the amount of bypass water increases and the pressure loss in the heat exchanger does not increase, so a large amount of water can be discharged at low water supply pressure.

(3) The ratio of the water supply amount between the heat exchanger and the bypass path does not change even when the user suddenly opens and closes the faucet or the water supply pressure fluctuates, so transient hot water temperature fluctuations are small.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a hot water supply control device showing an embodiment of the present invention, FIG. 2 is a block diagram showing control signals of the device, and FIG.
The figure is a characteristic diagram showing the relationship between the bypass control valve and the amount of bypass water with respect to the hot water outlet temperature setting value of the same apparatus, and FIG. 8. Heat exchanger, 9-... Bypass control valve, 1°.
・・Bypass path, 13 ・Output hot water temperature detector, 26・・−
Heating controller, 27... Heating device, 29... Hot water temperature detector, 30... Hot water supply controller, 30e... Timing unit. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure=3rgJ

Claims (2)

[Claims] (1) a heat exchanger, a heating device for the heat exchanger, a heating controller for the heating device, a bypass path that bypasses the heat exchanger, and a bypass control valve provided in the bypass path; A hot water supply controller comprising: a hot water supply controller that calculates signals from a hot water outlet temperature setter and a hot water outlet temperature detector to control the heating controller, and controls the opening degree of the bypass control valve according to the signal of the hot water outlet temperature setter. Control device. (2) The hot water supply control device according to claim 1, wherein the hot water supply controller has a timing section that corrects the opening degree of the bypass control valve at the initial stage of water flow according to the time from the end of hot water supply to the resupply of hot water. .