JPS6326825B2 - - 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 set temperature is changed during use, for example, it is necessary to increase the amount of water, and in this case, hysteresis occurs due to rattling in the drive unit or the connection between the drive unit and the valve, so this is not the best option. The drawback was that it was not possible to control the amount of water.

The present invention eliminates such drawbacks, and controls the amount of water by calculating the maximum amount of water possible depending on the capacity of the heating device, thereby preventing a drop in hot water temperature due to an excessive amount of water. This system corrects the amount of water and quickly controls the amount of water to stabilize the temperature of the water.

The present invention includes a heat exchanger that is heated by a heating device and exchanges heat with running water, a water flow controller that is driven by a drive device to control the amount of water flowing through the heat exchanger, and a water flow rate controller that controls the temperature of hot water discharged from the heat exchanger. A hot water temperature setting section to be set, an inlet water temperature detector and a hot water temperature detector provided respectively on the inlet side and the outlet side of the heat exchanger, and this hot water temperature detector and the hot water outlet temperature setting section or the inlet water temperature detector. A water amount calculation section that calculates a set water amount based on a signal from the hot water temperature setting section, a water amount storage section that stores the set water amount of this water amount calculation section, and a previous set water amount stored in this water amount storage section and the water amount calculation section. A drive direction determining unit that compares set water volumes and determines whether to drive the drive device in a water volume increase direction or a water volume decrease direction; a drive direction storage unit that stores a drive direction signal output from this drive direction determination unit; a drive direction calculation section comprising a water amount correction section that corrects the currently set water amount when the previous drive direction stored in the direction storage section and the current drive direction output from the drive direction determination section are different; The apparatus includes a water amount setting section that controls the drive device based on a signal from a drive direction calculation section.

This prevents the occurrence of hysteresis due to play or rattling in the drive device or the connecting portion between this device and the water flow rate controller, and controls the amount of water to an optimum level.

Examples thereof will be described below with reference to the accompanying 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 displacing it. 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 is passed through a heating controller 25 by a gas supply 24 and combusted in a heating device 26 . 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 a hot water temperature setting section 28, a heating control section 29, a water amount calculation section 30, a timer 31, and a driving direction detection section 3.
2. Consists of a water amount control section 34 consisting of a water amount setting section 33, and the water amount calculation section 30 includes a water amount initial calculation section 3.
0a and a water amount recalculation section 30b. The hot water temperature is controlled by the hot water temperature setting section 2, which is composed of a variable resistor, etc.
8 and the hot water temperature detector 23 are calculated by the heating control unit 29, and the heating controller 25 is driven by known PID control to adjust the calorific value of the heating device 26, thereby performing heat exchange. The hot water temperature of the vessel 14 is kept constant. For water flow control, the respective signals from the outlet hot water temperature setting section 28 and the incoming water temperature detector 22 are calculated by the water flow initial calculation section 30a, the drive direction calculation section 32 corrects the water flow due to the change in drive direction, and the water flow rate setting section 33 drives the water flow. This is done by setting a time and sending 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 calculation unit 30a, and the drive unit 21 rotates the control valve 17 of the water quantity controller 1 to adjust 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 water flow recalculation section 30b calculates the signals from the hot water temperature setting section 28 and the hot water temperature detector 23 via the timer 31.
The water amount is set by the water amount setting section 33 via the water amount setting section 33 to drive the drive device 21. The drive direction calculation section 32 includes a water amount storage section 32a, a drive direction determination section 32b, a drive direction storage section 32c, and a water amount correction section 32d. The water amount calculating section 30 calculates the set water amount according to the inlet water temperature and hot water outlet temperature settings as described above. This calculation is performed every time the inlet water temperature changes or the outlet temperature setting is changed, and the calculated set water amount value is stored in the water amount storage section 32a. And water amount calculation section 30
When a new calculation is performed, the drive direction determination unit 32b compares the current set water volume based on this calculation with the previous set water volume stored in the water volume storage unit 32a. Further, the drive direction determining section 32b determines whether to increase or decrease the water amount from the two water settings described above, that is, determines in which direction the drive device 21 should be driven. Drive direction storage section 32c
stores the direction in which the driving device 21 is driven, and the water amount correction section 32d stores the driving direction storage section 32c.
The previous driving direction stored in the driving direction determination unit 3
When the current driving direction outputted from 2b is different, a water amount correction signal is added to the water amount setting section 33 and the signal is sent out. The magnitude of the added signal is set in consideration of the magnitude of the bump (play gap) of the gear 19, the magnitude of mechanical play occurring at the connection between the gear 19 and the control valve 17, and the like.

Next, the operation will be explained. When the power is turned on, signals from the outlet water temperature setting section 28 and the incoming water temperature detector 22 are taken in, and calculations are performed in the water amount initial calculation section 30a. In the water amount initial calculation 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 calculation section 30a sends a drive signal proportional to the temperature difference between the hot water outlet temperature and the inlet water temperature or from the reference point to the water amount setting section 33 via the drive direction calculation section 32 to drive the drive device 21. , the control valve 17 rotates to initialize the water amount. Figure 3 shows the water volume setting value relative to the output of the motor 20 of the drive device 21. The water volume is inversely proportional to the motor output, and curves A and B are for cases in which the motor output is increased and decreased, respectively. The mechanical play of the drive device 21 causes hysteresis. 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 water amount recalculation section 30b using the respective signals of the outlet hot water temperature setting section 28 and the outlet hot water temperature detector 23 via the timer 31. The timer 31 sets the length of the heating time delay between the heating device 26 and the heat exchanger 14. The water amount recalculation section 30b drives the drive device 21 via the drive direction calculation section 32 and the water amount setting section 33 if the temperature difference between the hot water supply setting temperature and the actual hot water supply temperature is greater than a certain set range. Drive direction calculation unit 32
In this case, the driving direction in which the driving device 21 was driven immediately before is memorized, and if the signal calculated by the water amount recalculation section 30b is the same driving direction, that signal is sent to the water amount setting section 34, and a different driving direction is stored. In the case of the direction, a signal for hysteresis is added to the signal and sent to the water amount setting section 33. The signal from the water amount setting section 33 drives the drive device 21, and the water amount is controlled by the water amount controller 1. In this way, the amount of water is controlled until the hot water temperature and the set hot water temperature become equal.

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 detector 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 section 28 are calculated by the water amount initial calculation section 30a,
The driving direction calculating section 32 calculates an additional signal based on the driving direction in the water amount setting section 33 and outputs it to the driving device 21 .

As described above, the present invention is applicable when the driving direction of the drive device is different from the driving direction immediately before driven by the signal from the hot water outlet temperature setting unit and the set water volume of the water volume calculation unit that calculates the incoming water temperature signal or the hot water output temperature signal. is equipped with a drive direction calculation unit that adds a set signal to the water volume calculation unit signal to drive the drive device, which prevents hysteresis caused by mechanical play in the drive device and allows for fine adjustment. The amount of water can be controlled. In addition, since hysteresis can be eliminated, the mechanical play of the drive device can be set to a large amount, which increases the tolerance for machining accuracy, which not only makes processing and assembly easier, but also increases the reliability of the drive device. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a hot water supply heating control device showing an embodiment of the present invention, FIG. 2 is a block diagram of the same control, and FIG. 3 is a graph showing characteristics of water flow control. 1...Water flow controller, 14...Heat exchanger, 21...
... Drive device, 22 ... Inlet water temperature detector, 23 ...
Hot water temperature detector, 25... Heating controller, 26...
Heating device, 27... Hot water supply controller, 28... Hot water temperature setting section, 29... Heating control section, 30... Water amount calculation section, 30a... Water amount initial calculation section, 30b... Water amount recalculation section, 31... ...Timer, 32... Drive direction calculation section, 33... Water amount setting section, 34... Water amount control section.

Claims (1)

[Claims] 1. A heat exchanger that is heated by a heating device and exchanges heat with running water, a water flow controller that is driven by a drive device to control the amount of water flowing through this heat exchanger, and a temperature of hot water discharged from the heat exchanger is set. a hot water outlet temperature setting section, an incoming water temperature detector and a hot water outlet temperature detector provided respectively on the inlet side and the outlet side of the heat exchanger, the outlet hot water temperature detector, the outlet hot water temperature setting section or the incoming water temperature detector, and the outlet hot water temperature detector; A water amount calculation section that calculates a set water amount based on a signal from the temperature setting section, a water amount storage section that stores the set water amount of this water amount calculation section, and a previous set water amount stored in this water amount storage section and the set water amount of the water amount calculation section. a driving direction determining section that compares the values and determines whether to drive the drive device in the direction of increasing water volume or decreasing the amount of water; a driving direction storage section that stores the driving direction signal output from the driving direction determining section; and this driving direction storage. a drive direction calculation section comprising a water amount correction section that corrects the currently set water amount when the previous drive direction stored in the drive direction differs from the current drive direction output from the drive direction determination section; A hot water heating control device including a water amount setting section that controls the drive device based on a signal from a calculation section.