JPH0718563B2 - Hot water mixing controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hot / cold water heater and a hot / cold water mixing control device used in a hot / cold water mixing device, and particularly to a hot / cold water temperature when a preset hot water temperature is set high. The present invention relates to a hot / cold water mixing control device that has improved stability.

(Prior Art) Conventionally, in the hot and cold water mixing control device, the operation control of the servo motor that drives the mixing valve is performed by, for example, setting the drive pulse width of the servo motor to the temperature deviation between the mixed hot water and the set hot water regardless of the set hot water temperature. Is calculated in proportion to and the result is output to the drive circuit of the servo motor to drive the servo motor.

(Problems to be Solved by the Invention) In such a conventional hot and cold water mixing control device, when the difference between the incoming water temperature and the set hot water temperature is large, the mixed hot water temperature is greatly changed by a slight movement of the servomotor. There is a problem that the higher the temperature is set, the more likely it is that hunting will occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hot and cold water mixing control device capable of performing stable hot and cold water mixing control even when the set hot water temperature is high.

(Means for Solving Problems) A hot and cold water mixing control device according to the present invention is a mixing valve that adjusts a mixing ratio of hot water and water, a servomotor that drives the mixing valve, and a hot water temperature detector that detects a mixed hot water temperature. , A hot water temperature setting device for setting a mixed hot water temperature, a temperature deviation from the hot water temperature detector and the hot water temperature setting device, and a first urging unit for calculating a drive pulse width of the servo motor in proportion to the temperature deviation. An amount setting section, a second urging amount setting section for calculating a drive pulse width smaller than the driving pulse width calculated by the first urging amount setting section, and a set hot water temperature set by the hot water temperature setting section. A reference deviation value setting unit that sets a large temperature difference when the temperature deviation is high and a small temperature difference when the setting temperature is low, and is set by the first bias amount setting unit when the temperature deviation is larger than the reference deviation value. The servo motor is driven with the calculated drive pulse width, and the temperature deviation exceeds the reference deviation value. When it is smaller, the control circuit unit is configured to drive the servo motor with the drive pulse width calculated by the second bias amount setting unit.

(Operation) With this configuration, when the temperature deviation between the set hot water temperature and the mixed hot water temperature is larger than the reference deviation value, the drive pulse width of the servo motor is increased by the first bias amount setting unit, and the operation of the mixing valve is increased. When the speed is increased to make the control sensitivity more sensitive and the temperature deviation between the set hot water temperature and the mixed hot water temperature becomes smaller than the reference deviation value, the second bias amount setting unit calculates it in the first bias amount setting unit. The sensitivity of control becomes insensitive by calculating a driving pulse width smaller than the driving pulse width and driving the servo motor with this driving pulse. Since the reference deviation value is set large in the high temperature set hot water temperature range and set low in the low temperature set hot water temperature region, when the set hot water temperature belongs to the low temperature temperature region, the mixed hot water temperature is set. The control sensitivity is sensitive until the temperature is fairly close to the temperature, and the mixed hot water temperature can approach the set hot water temperature in a short time. Further, when the set hot water temperature belongs to a high temperature range, the control sensitivity is switched to insensitive when the mixed hot water temperature and the set hot water temperature are slightly apart from each other, so that hunting is less likely to occur and control stability is improved. Will be increased.

(Example) Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a control block diagram thereof. In Fig. 1, (1)
Is a hot water supply circuit constituted by a heating path (3) passing through the heat exchanger (2) and a bypass path (4) in parallel with the heat exchanger (2). (5) is a heating device such as a burner for heating the heat exchanger (2), and (6) is a capacity control device such as a gas proportional valve for controlling the amount of heat generated by the heating device (5). (7) is a water temperature detector that is provided on the inlet side of the hot water supply circuit (1) to detect the water supply temperature, and (8) is hot water that is provided on the outlet side of the hot water supply circuit (1) to detect the mixed hot water temperature. It is a temperature detector. (9) is a flow rate detector for detecting the flow rate to the heat exchanger (2), which is arranged in the heating path (3). Reference numeral (10) is a mixing valve provided in the bypass passage (4) for controlling the amount of bypass water to adjust the mixing ratio of hot water and water. (11) is a temperature setting device. (12) is a control circuit section. (15) is a water governor that limits the maximum flow rate. Next, in FIG. 2, the control circuit section (12) makes the hot water temperature slightly higher than the set hot water temperature based on the signals from the water temperature detector (7), the flow rate detector (9) and the temperature setting device (11). Heat quantity control unit that calculates gas quantity (13)
And the set hot water temperature (TS) set by the temperature setter (11) and the mixed hot water temperature (TM) detected by the hot water temperature detector (8) to obtain the temperature deviation (TS-TM) A deviation detector (16),
The higher the set hot water temperature (TS) is, the larger the standard deviation TS-M is set by the set hot water temperature (TS) set by the temperature setter (11). For example, TS ≧ 60 ° C. → TS-M = a ° C., 60> TS ≧ 50 → TS−
M = b ° C, 50> TS ≧ 45 → TS-M = c ° C, 45> TS → TS-M
= D ° C (a>b>c> d), the standard deviation value setting section (17) and the temperature deviation (TS-TM) according to the set hot water temperature (TS)
Deviation comparison section (1
8), the first biasing amount setting unit (19) that operates when the temperature deviation exceeds the reference deviation value according to the comparison result of the deviation comparing unit (18), and the first bias amount setting unit (19) that operates when the temperature deviation is less than the reference value. The second bias amount setting unit (20) and the first and second bias amount setting units (1
9), and includes an energizing amount output section (21) that outputs the drive pulse width of the servo motor calculated in (20) as a PWM output to the drive IC (22) of the servo motor (23) that is the drive means. . Note the first biasing amount setting unit (19), the drive pulse width (TPLS) TPLS = (TS- TM) 2/2 ( where the fundamental period is 200ms
In the case of, the maximum pulse width is 128 ms)
In the energizing amount setting unit (20), when the temperature deviation is relatively large with a pulse width smaller than the driving pulse width calculated by the first energizing amount setting unit, the driving pulse width is set to a constant width of Ams (several 10 ma), If the temperature deviation is small, double the PWM cycle and the drive pulse width is Bms every cycle within the range not exceeding the above Ams (B <A).
It is set to increase sequentially from Ams to Ams.

With this configuration, the set hot water temperature is, for example, 45 ° C to 50 ° C.
If the mixed hot water temperature is close to the set temperature (TS ± c) ° C, the drive pulse width of the servo motor is proportional to the set deviation by the first energizing amount setting section (19). Once set, the control sensitivity is sensitive and the mixed hot water temperature can approach the set hot water temperature in a short time. Further, when the set hot water temperature belongs to a high temperature range of, for example, 60 ° C. or higher, the second bias amount setting unit (when the mixed hot water temperature and the set hot water temperature are slightly different (TS ± a) ° C. By 20), the drive pulse width of the servo motor is set to a small value and the control sensitivity is switched to insensitive, so the control sensitivity in the region where the influence of control is large becomes insensitive and hunting is less likely to occur.
The stability of control will be improved.

(Effects of the Invention) As described above, according to the present invention, when the temperature deviation of the servomotor driving the mixing valve exceeds the reference deviation value, the pulse proportional to the temperature deviation is generated by the first bias amount setting means. If the temperature deviation is less than the standard deviation value, the second
The biasing amount setting means drives with a pulse width smaller than the pulse width calculated by the first biasing amount setting means, and the reference deviation value is set larger as the set hot water temperature increases.
When the set hot water temperature is low, control can be performed in a short time until the difference between the set hot water temperature and the mixed hot water temperature becomes small. Further, when the set hot water temperature is high and the difference between the set hot water temperature and the mixed hot water temperature is still a little different, the operation of the mixing valve is delayed, so that hunting is less likely to occur and the control stability is enhanced.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a control circuit section of the same example. (8) …… Hot water temperature detector (10) …… Mixing valve (11) …… Hot water temperature setter (17) …… Standard deviation value setting unit (19) …… First energizing amount setting unit (20) ...... Second bias amount setting section (23) ...... Servomotor

Claims (1)

[Claims] 1. A mixing valve for adjusting the mixing ratio of hot water and water, a servomotor for driving the mixing valve, a hot water temperature detector for detecting the hot water temperature, a hot water temperature setting device for setting the hot water temperature, and the hot water temperature. First, a temperature deviation is obtained from a detector and a hot water temperature setting device, and a drive pulse width of the servo motor is calculated in proportion to the temperature deviation.
A biasing amount setting unit, a second biasing amount setting unit that calculates a drive pulse width smaller than a driving pulse width calculated by the first biasing amount setting unit, and a set hot water set by the hot water temperature setting device. A reference deviation value setting unit that sets a large temperature difference when the temperature is high and a small temperature difference when the set temperature is low, and sets the first bias amount when the temperature deviation is larger than the reference deviation value. The control circuit unit drives the servo motor with the drive pulse width calculated by the section, and drives the servo motor with the drive pulse width calculated by the second bias amount setting unit when the temperature deviation is smaller than the reference deviation value. Hot and cold water mixing control device.