JPH0313608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to an automatic mixing device for hot water supply, for example, an automatic mixing device used in a hot water supply system utilizing solar heat.

<Prior art> In hot water supply systems that utilize solar heat, the heat collection situation depends on the weather, so an auxiliary heat source device is required to keep the hot water temperature constant. Previously, an auxiliary heat source was added to a solar hot water supply system and an automatic mixing valve was used to automatically maintain the hot water temperature at a constant level.

FIG. 1 is a diagram of a hot water supply system using a conventional automatic mixing valve, and FIG. 2 is a sectional view of the conventional automatic mixing valve.

In the figure, A is a heat collector, B is a heat storage tank, C is an auxiliary heat source device, D and E are automatic mixing valves, and F is an outlet channel.

If the temperature of the water in the heat storage tank B that has just collected solar heat is lower than the temperature set by the automatic mixing valve D (usually set at 45℃), connect the auxiliary heat source to the connection port 1 as shown in Figure 2. The hot water from the water enters the connection port 2.
Since the hot water from the heat storage tank B comes into the tank, the hot water mixes and flows to the connection port 3 on the outlet side. At this time, the temperature of the mixed water is detected by the sensor 4 on the outlet side, and when the temperature is higher than the set temperature, the sensor 4 expands, so the connecting port opening/closing disk 5 connected to it moves to the left, and the auxiliary heat source device Reduce the amount of hot water from connection port 1 on the C side. When the temperature is lower than the set temperature, the sensor 4 contracts and moves to the right, reducing the amount of hot water from the connection port 2 on the heat storage tank B side and adjusting the hot water temperature to a constant value. 6 is a set temperature adjustment knob.

However, when the temperature of the hot water from the heat storage tank B is higher than the set temperature, it is necessary to mix the hot water temperature with water, and it cannot be adjusted with one automatic mixing valve D.
As shown in the figure, another individual automatic mixing valve E
is necessary. Further, the valve E needs to be operated only when the temperature of the water from the heat storage tank B is higher than the set temperature. That is, if this is not done, when the temperature of hot water from heat storage tank B is lower than the set temperature, after mixing with hot water from auxiliary heat source device C, it will be further mixed with water at valve E.

<Purpose> In view of the above points, the present invention enables hot water on the hot water outlet side to be discharged at a set temperature regardless of whether the hot water temperature from the heat storage tank (main heat source side) is higher or lower than the set temperature, and The purpose of the present invention is to provide an automatic mixing device for hot water supply that can improve the efficiency of the hot water supply system.

<Example> An example of the present invention will be described below based on the drawings. Fig. 3 is a diagram of a solar hot water supply system using the automatic mixing device according to the present invention, Fig. 4 is a circuit diagram of the control device of the automatic mixing device, Fig. 5 is a relay circuit diagram of the control device, and Fig. 6 FIG. 2 is a diagram showing an input/output characteristic curve of a comparison amplifier of the same control device. In FIG. 3, parts that are similar to those of the prior art are designated by the same reference numerals.

In the figure, SV1 is the first switching valve, which is
At a position where the hot water inlet passage 11 on the heat storage tank B side (main heat source side) communicates with the high temperature side hot water temperature 12a, and at a position where the auxiliary hot water passage 13 on the auxiliary heat source device C side communicates with the high temperature side hot water passage 12a. Switching is possible by opening and closing movement of the valve element by electric motor M1.

SV2 is a second switching valve, which is connected to an electric motor M2 at a position where the inlet water path 11 on the heat storage tank B side communicates with the low temperature side hot water path 12b, and at a position where the outlet water path F and the low temperature side hot water path 12b are communicated. Switching is possible by opening and closing the valve.

Furthermore, SV3 is a mixing valve, which is connected to the electric motor M
3, the opening/closing movement of the valve causes the high temperature side water passage 1 to open and close.
Switching is performed so that the hot water or water from the hot water 2a and the low-temperature side hot water passage 12b is mixed and flowed to the outlet hot water passage 14 while adjusting the amount of water passing through the hot water or water. In addition, these switching valves SV1,
SV2 and mixing valve SV3 have conventionally known structures.

In addition, G is the switching valve SV1, SV2 and the mixing valve.
A control device for controlling SV3, and the control device G is a heat storage tank B (main heat source side) as shown in Figs.
The first sensor TS (thermistor) that detects the water temperature
and a second sensor TM that detects the hot water temperature on the hot water outlet side.
(thermistor), a variable resistor 15 for setting the outlet temperature, and a controller 16 for controlling the switching valves SV1, SV2 and the mixing valve SV3 based on signals from these.

As shown in FIG. 4, the controller 16 includes a first comparator amplifier A1 that compares and amplifies the difference between the voltage from the first sensor TS that senses the water temperature on the heat storage tank side and the voltage from the variable resistor 15, and a hot water outlet. The voltage from the second sensor TM that senses temperature and the variable resistor 15
A second comparator amplifier A that compares and amplifies the voltage difference between
2 and the first switching valve by the first comparison amplifier A1.
Relay RY that controls SV1 and second switching valve SV2
1 and the mixing valve SV by a second comparator amplifier A2.
Relays RY2 and RY3 that control 3 are built-in. In FIG. 4, R1, R2, and R3 are resistors, respectively.

Next, the operation will be explained with reference to FIG. 3. The setting variable resistor 15 of the control device G is adjusted to obtain the desired temperature for tapping hot water. For example, if the hot water temperature can be varied between 35 and 55 degrees Celsius, and you want the outlet temperature to be 45 degrees Celsius, the resistance to this temperature is adjusted using the variable resistor 15. The difference between the voltage from the first sensor TS that detects the water temperature in the heat storage tank B and the voltage from the variable resistor 15 is compared and amplified to simultaneously drive the first and second switching valves SV1 and SV2 on the output side. The water temperature in heat storage tank B is now the set temperature (45
℃), the first sensor TS detects this and controls the first and second switching valves SV1 and SV2 to flow as indicated by the solid line arrows via the comparison amplifier A1 in the controller 16. . i.e. mixing valve
Hot water from the heat storage tank B and water from the outlet channel F flow into the SV3, and no water flows from the auxiliary heat source device C at all.

In addition, when the water temperature in the heat storage tank B is lower than the set temperature (45°C), the first sensor TS detects this, and the first and second switching valves SV1,
Control SV2 so that it flows as shown by the broken arrow.
That is, hot water from the heat storage tank B and hot water from the auxiliary heat source device C flow through the mixing valve SV3, and no water flows through the mixing valve SV3.

Regarding the mixing valve SV3, in both cases of hot water from heat storage tank B and hot water from heat storage tank B and hot water from auxiliary heat source device C, the high temperature side is the upper side and the low temperature side is the lower side in Fig. 3. Each flows. In other words, if the hot water is from heat storage tank B, the hot water from heat storage tank B is hot water, and if the hot water is from heat storage tank B and hot water from auxiliary heat source device C, the hot water is from auxiliary heat source device C.
In Figure 3, the hot water is on the upper side, and the lower one is on the lower side. In other words, the inlet side of the mixing valve SV3 has a higher temperature and a lower temperature in the above two modes.

Therefore, looking at the operation of the mixing valve SV3, the mixed water temperature on the outlet side is detected by the second sensor TM, and the voltage detected by this and the voltage by the variable resistor 15 are compared by the second comparator amplifier A2 in the controller 16. and mixing valve
The SV3 is driven to open and close the valve by the motor M3, and in order to prevent hunting drive, the second comparator amplifier A2 uses a comparator amplifier A2 which becomes a dead zone near the set value. That is, the input/output characteristics of the second comparator amplifier A2 have step-like characteristics as shown in FIG. 6b.

If the temperature sensed by the second sensor TM is within a certain range (for example ±3℃) with respect to the set temperature, the mixing valve SV
3 does not drive, and when the upper limit of the above range is exceeded,
Motor M3 is driven to adjust the opening angle of the valve,
The valve works to allow more flow on the low temperature side, and when it reaches that range, the valve stops at that position and mixes in that state. If it still does not fall within the range from the upper limit, motor M
3 continues to drive, operating the valve to fully open the low temperature side and fully close the high temperature side, and in this state, stop the motor using a micro switch or the like and wait for the motor to enter the range.

Further, when the temperature is below the lower limit of the set range, the high temperature side on the inlet side works to flow more during this time, and when it enters the range, the valve stops at that position and mixes in that state. If it is not within the range from the lower limit, motor M3
continues to drive, operates the valve to fully open the high temperature side and fully close the low temperature side, and in this state, the motor is stopped using a micro switch or the like and waits for the motor to enter the range.

Next, the operation of the control circuit diagrams shown in FIGS. 4 and 5 will be explained. First, the setting variable resistor 15 has been adjusted to the desired temperature for tapping hot water, so looking at the input side of the first comparison amplifier A1, the voltage from the variable resistor 15 and the heat storage tank B
The output side relay RY1 is driven by the voltage from the first sensor TS. Now, when the water temperature in heat storage tank B is higher than the set temperature, the resistance value of the first sensor TS becomes smaller, so the voltage entering the first comparison amplifier A1 becomes higher than the set voltage (set value) corresponding to the set temperature. As a result, the output voltage from comparator amplifier A1 becomes high and excites relay RY1. Then, the relay contact RY1 is the first,
The voltage is applied to the terminal a side of the second switching valves SV1 and SV2, and the flow through the first and second switching valves flows as indicated by the solid line arrows in FIG.

Also, when the hot water in heat storage tank B is lower, the sensor
Since the resistance value of TS increases, the first comparator amplifier 1
Since the voltage input to the comparator A1 is low and is lower than the set value, the output voltage from the comparison amplifier A1 is also low. Therefore, relay RY1 remains demagnetized and the relay contacts
RY1 is terminal b of the first and second switching valves SV1 and SV2
Since the voltage is applied to both sides, the flow through the first and second switching valves flows as indicated by the broken line arrows in FIG. First comparison amplifier A
The input/output characteristics of the device 1 are as shown in FIG. 6a.

Next, looking at the inlet side of the second comparator amplifier A2, which has a dead zone, when the temperature of the second sensor TM of the hot water outlet path 14 is high, the resistance value becomes small and the input voltage becomes high. Then, the input voltage is a set voltage (setting range) corresponding to a certain range (for example, ±3°C) with respect to the set temperature.
When the voltage is higher than RY2, the output voltage of the second comparator amplifier A2 becomes high, and only RY2 is excited. and,
The contact RY2 is turned on, and the mixture valve SV3 applies voltage to the terminal a, and the motor M3 is driven, so that the mixture valve SV33 in FIG. 3 allows more flow on the low temperature side.

When the input voltage from the second sensor TM falls within the set range, the output voltage from the comparator amplifier A2 becomes medium, the relay RY2 is demagnetized, and the contact RY2 becomes
OFF, motor M3 stops and mixing valve SV3
will stop at that position.

On the other hand, when the mixing temperature is lower than a certain range with respect to the set temperature, the input voltage to comparator amplifier A2 becomes low, and its output voltage also becomes low, so that relay RY3
The contact RY3 of the relay turns ON, and the voltage is applied to the terminal b of the mixing valve V3, driving the motor M3, and as shown in FIG. 3, the high temperature side flows through the mixing valve SV3 more.

When the second sensor TM enters a certain range with respect to the set temperature, relay RY3 is demagnetized and contact RY
3 is turned OFF and motor M3 stops, so
Mixing valve SV3 stops at that position. As shown in Figure 6b, the input characteristics of the second comparator amplifier A2 have a dead zone in which the output does not change with respect to the input, and in this range relays RY2 and RY3 are both demagnetized and the mixing valve SV3 is not driven and maintains its position. . In this way, the hot water temperature is always maintained at the set temperature by the second sensor TM.

Note that the present invention is not limited to a hot water supply system that uses solar heat as in the above embodiment, but may also be a hot water supply system that uses other heat sources.

<Effects> As is clear from the above description, the present invention provides an automatic mixing device for hot water supply that automatically mixes hot water in a heat storage tank with hot water in an auxiliary heat source device or water in an outlet channel. is connected to a first switching valve and a second switching valve via an inlet channel, the auxiliary heat source device is connected to the first switching valve via an auxiliary hot water channel, and the outlet channel is connected to a second switching valve, The first switching valve is connected to the mixing valve via the high temperature side water path, the second switching valve is connected to the mixing valve via the low temperature side water path, and a first sensor detects the temperature of the hot water in the heat storage tank. and a second sensor that senses the hot water temperature on the outlet side, the first sensor controls the first switching valve and the second switching valve, the second sensor controls the mixing valve, and the first sensor controls the mixing valve. When the detected hot water temperature in the heat storage tank is higher than the set temperature, the first switching valve opens the inlet passage to the high temperature side water passage, and the second switching valve opens the outlet passage to the low temperature side water passage, and the heat storage tank opens. When the water temperature in the tank is lower than the set temperature, the first switching valve opens the auxiliary hot water passage to the high temperature side water passage, the second switching valve opens the hot water inlet passage to the low temperature side water passage, and the mixing valve opens the hot water passage to the low temperature side water passage. When the hot water temperature on the hot water outlet side detected by the second sensor is higher than the set temperature, the hot water in the heat storage tank and the water in the outlet channel are mixed, and when the hot water temperature on the hot water outlet side is lower than the set temperature, the hot water in the heat storage tank is mixed. The hot water from the auxiliary heat source is mixed with the hot water from the auxiliary heat source device.

Therefore, according to the present invention, the hot water from the auxiliary heat source side is used only when the hot water in the heat storage tank is lower than the set temperature, and the hot water in the heat storage tank is used preferentially, thereby improving the efficiency of the hot water supply system. The hot water temperature can always be kept within the set range. Furthermore, in the past, it was impossible to connect a domestic gas instantaneous water heater to a solar hot water tap system due to boiling issues, but with the present invention, water is supplied based on the signal from the first sensor, or water is supplied from the auxiliary heat source side. Even if a gas instantaneous water heater is used as an auxiliary heat source to determine whether to supply hot water, the water will not boil and will not cause any problems.

[Brief explanation of the drawing]

Figure 1 is a diagram of a conventional solar hot water supply system.
Figure 2 is a sectional view of the automatic mixing valve, Figure 3 is a sectional view of the automatic mixing valve.
The figure is a hot water supply system diagram showing an embodiment of the present invention, FIG. 4 is a control circuit diagram of the same control device, FIG. 5 is a relay circuit diagram of the same control device, and FIGS. It is a figure which shows the input-output characteristic of A2. A1, A2: Comparative amplifier, B: Heat storage tank, C: Auxiliary heat source device, F: Outlet channel, G: Control device, SV1,
SV2: Switching valve, SV3: Mixing valve, TS, TM: Sensor, 11: Inlet water path, 12a: High temperature water path, 12
b: Low temperature hot water path, 13: auxiliary hot water path, 14: Outgoing hot water path.

Claims (1)

[Claims] 1. In an automatic mixing device for hot water supply that automatically mixes hot water in a heat storage tank B with hot water in an auxiliary heat source device C or water in an outlet channel F, Through the first switching valve SV
1 and a second switching valve SV2, the auxiliary heat source device C is connected to the first switching valve SV1 via the auxiliary hot water channel 13, the outlet channel F is connected to the second switching valve SV2, and the first switching valve SV2 is connected to the first switching valve SV2. The switching valve SV1 is connected to the mixing valve SV3 via the high temperature side water path 12a, the second switching valve SV2 is connected to the mixing valve SV3 via the low temperature side water path 12b, and the temperature of the hot water in the heat storage tank B is sensed. The first sensor to
TS and a second sensor TM that senses the hot water temperature on the outlet side, the first sensor TS controls the first switching valve SV1 and the second switching valve SV2, and the second sensor TM controls the mixing valve SV3. When the water temperature in the heat storage tank B detected by the first sensor TS is higher than the set temperature, the first switching valve SV1
opens the inlet water path 11 to the high temperature side water path 12a, the second switching valve SV2 opens the outlet path F to the low temperature side water path 12b, and when the water temperature in the heat storage tank B is lower than the set temperature,
The first switching valve SV1 connects the auxiliary hot water path 13 to the high temperature side hot water path 12.
a, the second switching valve SV2 opens the inlet water path 11 to the low temperature side water path 12b, and the mixing valve SV3 opens when the hot water temperature on the outlet side detected by the second sensor TM is higher than the set temperature. The hot water in the heat storage tank B and the water in the outlet channel F are mixed, and when the hot water temperature on the outlet side is lower than the set temperature, the hot water in the heat storage tank B and the hot water in the auxiliary heat source device C are mixed. An automatic mixing device for hot water supply featuring: