JPH0145542B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to hot water supply temperature control in an instantaneous water heater, and is to automatically control the amount of hot water supplied to perform temperature control.

A hot water temperature control device that adjusts the heating input in an instant hot water heater and controls the hot water temperature is a well-known technology.
There was a problem in which the temperature of the hot water would drop if an excessive amount of water was supplied that exceeded the heating capacity of the water heater. It is already known that in order to solve this problem, the amount of water is maximized before heating, and after a certain period of heating, if the input to the heater is at the maximum and the outlet temperature is lower than the set temperature, the amount of water is reduced. However, if the amount of water is reduced too much, the maximum combustion amount may not be secured,
In order to prevent the amount of water from being reduced too much, hot water must be supplied from the maximum amount of water and the amount of water must be gradually reduced, which has the disadvantage of requiring a long time to stabilize the amount of water.

The present invention eliminates this drawback, and by controlling the amount of water, it prevents water from flowing beyond the heating capacity of the heating device and causing the water temperature to drop, thereby ensuring the maximum amount of heating at all times. The purpose is to obtain the same water temperature as the setting.

In order to achieve this object, the present invention detects the outlet temperature of the heat exchanger heated by the heating device with a temperature sensor, and detects when the heating amount of the heating device is maximum and the output temperature is equal to the signal of the outlet hot water temperature setting section. The heating controller calculates the signal and controls the heating controller, and when the hot water temperature is lower than the set temperature by a predetermined amount, the driving device is controlled to reduce the water flow rate of the water flow controller to increase the hot water temperature; In addition, when the heating amount of the heating device is detected and the heating amount is smaller than the maximum heating capacity by a predetermined amount, the drive device is controlled to increase the water amount of the water flow controller to ensure the maximum heating amount and always maintain the maximum heating amount. An example of this method will be explained below with reference to the attached drawings.

In FIG. 1, reference numeral 1 denotes a water flow controller, in which water enters a valve chamber 3 from an inflow path 2 and flows into a primary chamber 6 through a gap between a control valve 4 and a control hole 5. 7 is control valve 4
The other side of the diaphragm cooperates with the diaphragm to form a secondary chamber 8, and the secondary chamber 8 is provided with a control spring 9 to bias it toward the primary chamber 6. The water flowing into the primary chamber 6 passes through a differential pressure generating section 13 formed by a differential pressure hole 10, a differential pressure valve 11, and a differential pressure spring 12, and is supplied to the outside through a heat exchanger 14 and a hot water outlet pipe 15.
A first continuous passage 16 that communicates the primary chamber 6 and the secondary chamber 8
is provided with a control valve 17, and a second communication passage 18 that communicates the secondary chamber 8 and the differential pressure generating section 13 is provided with a throttle 18.
A is provided. The aforementioned control valve 17 is rotated by a drive device 21 consisting of a gearbox 19 and a motor 20, and its opening degree changes. The pressure in the secondary chamber 8 is determined by the partial pressure of the control valve 17 and the throttle 18a, and can be changed by rotating the control valve 17. By adjusting the pressure in the secondary chamber 8, the control valve 4 can be adjusted. The amount of water can be controlled by displacement. Reference numeral 22 denotes an inlet water temperature detector whose position is not particularly limited as long as it can detect the water temperature on the inlet side of the heat exchanger 14. The water that has passed through the water flow controller 1 having the above configuration is heated by the heat exchanger 14, and the temperature of the hot water is detected by the hot water temperature detector 23 of the hot water tap 15. The gas passes through the heating controller 25 from the gas supply path 24 and is combusted in the heating device 26, and the heating amount detector 25a detects the current of the heating controller 25. Heating controller 2
5 consists of a valve body 25b and a casing 25c,
The valve body 25b has a control valve hole 25d, and the valve body 25
e is displaced integrally with the diaphragm 25f, and the pressure receiving area of the plunger 25h, which is displaced by the current of the diaphragm 25f and the coil 25g, is almost equal.
The fuel pressure is controlled by balancing the controlled pressure of the fuel with the force exerted on the valve body 25e and the electromagnetic force of the plunger 25h and coil 25g. That is, the fuel pressure can be determined by detecting the current flowing through the coil 25g. The heating amount detector 25a detects the above-mentioned current, and sends out a comparison signal with a current value that supplies a preset maximum heating amount. A hot water supply controller 27 controls the heating controller 25 and the drive device 21.

In the block diagram of Fig. 2, hot water controller 2
7 is composed of a hot water temperature setting section 28, a heating controller 29, a water flow control section 30, and a timer 31.
The water flow control section 30 includes a water flow recontrol section 30b that includes a water flow initial control section 30a, a decrease instruction section 30b', and an increase instruction section 30b''.The hot water outlet temperature control section is configured with a variable resistor and the like. 28 and the hot water temperature detector 23 are transmitted to the heating control unit 29.
The temperature of hot water discharged from the heat exchanger 14 is kept constant by driving the heating controller 25 using known PID control and adjusting the calorific value of the heating device 26. For water flow control, each signal from the outlet hot water temperature setting section 28 and the incoming water temperature detector 22 is transmitted to the water flow initial control section 30.
a and sends a drive signal to the drive device 21. The capacity of the heating device 26 (including the capacity of the heat exchanger 14) is set in the water quantity initial control unit 30a, and the drive unit 21 rotates the control valve 17 of the water quantity controller 1 to control the pressure in the secondary chamber 8. Adjust and control the amount of water. There is another control mode for water flow control, in which the drive device 21 is driven by a water flow recontrol section 30b that calculates signals from the hot water temperature setting section 28 and the hot water temperature detection section 23 via a timer 31.

In addition, the water amount recontrol unit 30b includes a heating amount detector 25.
The signal a is transmitted via a timer 31.

The water flow recontrol unit 30b consists of a decrease instruction unit 30b' and an increase instruction unit 30b''.The decrease instruction unit 30b' compares the signals from the hot water temperature setting unit 28 and the hot water temperature detector 23, and determines that the hot water temperature is lower than a predetermined value. When the amount of water is decreasing, the drive device 21 is driven to reduce the amount of water, and the increase instruction section 30b'' compares the current detected by the heating amount detector 25a with the maximum heating amount setting section 32 set in advance to increase the amount of heating. When the amount of water is smaller than the maximum heating amount by a predetermined amount, the maximum heating amount setting section 32 that drives the drive device 21 to increase the amount of water is set by a resistor, or if a microcomputer is used in the control circuit. It is written in the memory element in advance.

Next, the operation will be explained. When the power is turned on, signals from the hot water outlet temperature setting section 28 and the incoming water temperature detector 22 are taken in, and calculations are performed in the water amount initial control section 30a. In the water amount initial control section 30a, the heating capacity of the heating device 26 is set in advance. For example, when a microprocessor is used for control, it is programmed in advance and written into the memory element. The water amount initial control unit 30a sends out a drive signal proportional to the temperature difference between the hot water outlet temperature and the inlet water temperature from a certain reference point to drive the drive device 21, and the control valve 17 rotates to initialize the water amount. . The amount of water is set by the control valve 17 of the water amount controller 1, and then when the user starts water flow, combustion in the heating device 26 starts and after a slight delay, the temperature of the hot water rises. The deviation of the outlet hot water temperature with respect to the outlet hot water temperature setting is calculated by the respective signals of the outlet hot water temperature setting section 28 and the outlet hot water temperature detector 23 in the decrease instruction section 30b' of the water amount recontrol section 30b via the timer 31a. The timer 31a sets the length of the heating time delay between the heating device 26 and the heat exchanger 14. The unit 30b' that instructs the water flow rate re-control unit 30b to decrease decreases the water volume of the water volume controller 1 by driving the drive device 21 if the temperature difference between the hot water supply setting temperature and the actual hot water supply temperature exceeds a set range. .

Due to this decrease in the amount of water in the water amount controller 1, the amount of water flowing to the heat exchanger 14 decreases, and the temperature of the hot water increases. In this way, the amount of water is reduced until the tapped water temperature and the set temperature are equal, and the optimum amount of water is reached, that is, the heating device 2
6 is the maximum heating amount, and the hot water temperature is controlled to be equal to the set temperature. On the other hand, if the water volume is reduced too much by the above-mentioned initial setting of the water volume or resetting of the hot water temperature detection, that is, if the water volume is controlled to be less than the heating capacity, the hot water can be drawn out by adjusting the capacity of the heating controller 25. The temperature will be equal to the set temperature. However, at this time, the amount of heating is not the maximum, but a value that is somewhat reduced relative to the maximum capacity. The amount of heating can be determined based on the current flowing through the heating controller 25. That is, when the heating amount detector 25a detects that the heating amount is reduced by a predetermined amount from the maximum heating amount, the increase instruction section 30b'' of the water amount recontroller 30b via the timer 31b The drive device 21 is driven to increase the amount of water in the water amount controller 1. The increase in water amount increases the load on the heat exchanger 14 and increases the amount of heating, and the heating device 26 heats the hot water while keeping the hot water temperature at the set temperature. The heating amount reaches its maximum capacity.In PID control, the heating amount changes rapidly due to the differential term, and a slight change in the heating load may cause the heating amount to decrease below the maximum heating amount.This sudden change may cause a malfunction. If this is the case, the increase instruction section 30b'' of the water amount recontrol section 31b may output an output only when the heating amount has decreased by a predetermined amount from the maximum heating amount for a predetermined period of time.

In order to limit the amount of water by the user, it is necessary to adjust the capacity of the heating device 26 in order to control the temperature of the hot water. In this case, the hot water temperature setting section 28 and the hot water temperature detection section 2
The heating controller 29 calculates the deviation of each of the three signals, and the heating controller 25 adjusts the heating amount to control the tapping temperature to be equal to the set temperature.

Additionally, if the user changes the hot water temperature setting beyond a certain limit, the water flow control will be reset.
The respective signals of the incoming water temperature detector 22 and the outgoing water temperature setting unit 28 are calculated by the water amount initial control unit 30a,
Output to the drive device 21.

As described above, the present invention detects the outlet temperature of the heat exchanger heated by the heating device with the temperature detector, calculates the signal of the outlet temperature setting section and the signal of the outlet temperature in the heating control section, and heats In addition to controlling the controller,
When the heating amount of the heating device is maximum and the hot water outlet temperature is lower than the set temperature by a predetermined amount, the drive device is controlled to reduce the amount of water in the water flow controller, and the hot water temperature is increased to increase the hot water temperature by flowing water that exceeds the heating capacity. In addition, when the heating amount of the heating device is detected and the heating amount is smaller than the maximum heating capacity by a predetermined amount, the drive device is controlled to increase the water amount of the water flow controller to ensure the heating amount. Therefore, the maximum amount of heating can always be controlled to the optimum amount of water. Furthermore, it is of high practical value since it is not necessary to start from the maximum initial water volume, and the time required for the water volume to stabilize at the optimum water volume is short.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the invention, and FIG. 2 is a control block diagram showing an embodiment of the invention. 1...Water flow controller, 14...Heat exchanger, 21...
... Drive device, 22 ... Inlet water temperature detector, 23 ...
Hot water temperature detector, 25... Heating controller, 25a...
... Heating amount detector, 26 ... Heating device, 27 ... Hot water supply controller, 28 ... Hot water temperature setting section, 29 ... Heating control section, 30 ... Water flow control section, 30a ... Water flow initial control section, 30b ...Water flow recontrol section, 30b'...
...Decrease instruction section, 30b''...Increase instruction section, 31...
Timed device.

Claims (1)

[Scope of Claims] 1. A water flow controller having a drive device, a heat exchanger connected to the water flow controller, a heating device for the heat exchanger, a heating controller for the heating device, and the heating device a hot water supply controller comprising a heating amount detector for detecting the heating amount of the water, a hot water temperature detector, a heating control section for controlling the heating controller, a hot water temperature setting section, and a water amount control section; comprising: a reduction instruction section that drives the drive device to reduce the amount of water based on a comparison signal from the hot water temperature setting section and the hot water temperature detector; and a signal detected by the heating amount detector and the set maximum heating amount value; and an increase instruction section that drives the drive device to increase the amount of water based on the comparison signal. 2. The hot water heating control device according to claim 1, which controls a water flow rate controller before heating the heating device based on signals from an inlet water temperature detector provided on the inlet side of the heat exchanger and a hot water outlet temperature setting unit. .