JPH0462338A - Hot water mixing device - Google Patents

Abstract

PURPOSE:To obtain a hot water mixing device which maintains mixed hot water virtually at a constant temperature even when an attempt is made to change flow rate setting dramatically by allowing a control means to make ON/OFF control of both a hot water valve and a water valve in order to obtain mixed hot water at targeted temperature when a limit detection means detects either the hot water valve or the water valve is under a full-opened or full-closed limit condition. CONSTITUTION:A control device 9 determines a manipulated variable f based on fuzzy theory from deviation T-t between preset hot water temperature and detected temperature t and variation and a manipulated variable k from deviation Q-q between preset flow rate Q and detected flow rate q. When a limit detection means 15 detects full opening or full closing of a hot water valve 3 or a water valve 4, the control device 9 is arranged to mask the manipulated variable k and open and close the hot water valve 3 and the water valve 4 only based on the manipulated variable f. Only when mixed hot water at the preset temperature is called for, both the valves 3 and 4 are opened and closed. When the water valve 4 is full-opened, it is necessary to avoid a rise in the temperature of mixed hot water. Even when the preset flow rate is changed unexpectedly and the hot water valve or the water valve 4 is full- closed, the utmost effort must be made to inhibit temperature change.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a hot water temperature setting means for setting a target temperature of mixed hot water, a flow rate setting means for setting a target flow rate of mixed hot water, and a flow rate setting means for setting a target flow rate of mixed hot water. a water flow valve to adjust, a water flow valve to adjust the inflow amount of water, a hot water temperature detection means to detect the actual temperature of the mixed hot water, a flow rate detection means to detect the actual flow rate of the mixed hot water, and the actual temperature; The hot water mixing apparatus includes a control means for controlling opening and closing of the hot water flow valve and the water flow valve based on the actual flow rate, the target temperature, and the target flow rate.

[Conventional technology]

The above-mentioned hot water mixing device used in hot water supply equipment such as bathrooms can obtain mixed hot water at a set temperature and in a set amount using only a water flow valve and a hot water volume valve, so it is possible to reduce costs. , has already been proposed by the applicant of the present invention.

[Problem to be solved by the invention]

However, in the hot water mixing device described above, when the target flow rate is changed and set to suddenly increase, the target temperature and target flow rate cannot be satisfied even if the hot water flow valve is fully opened, and as a result, the mixed hot water In some cases, the temperature was significantly lower than the target temperature, causing discomfort to users of the mixed water. On the other hand, if the target flow rate is suddenly reduced, the temperature control will not be able to keep up with the flow rate, resulting in hot water coming out at times, and there is a risk that the user of the mixed hot water may suffer burns. Even outside of the extreme cases mentioned above, the effect of sudden changes in the target flow rate on the temperature of the mixed hot water was significant, and there was room for improvement.

In view of the above, it is an object of the present invention to provide a hot water mixing device in which the temperature of the resulting mixed hot water is kept almost constant even if the target flow rate is suddenly changed. Another purpose is to quickly bring the temperature of the mixed hot water to the target temperature at the start of hot water dispensing or when the target temperature is set to be significantly changed.

[Means to solve the problem]

The hot water mixing device according to the present invention includes: a hot water temperature setting means for setting a target temperature of mixed hot water; a flow rate setting means for setting a target flow rate of mixed hot water; a water flow valve that adjusts the water flow rate, a hot water temperature detection means that detects the actual temperature of the mixed hot water, a flow rate detection means that detects the actual flow rate of the mixed hot water, the target temperature, the target flow rate, the actual temperature,
and a control means for controlling opening/closing of the hot water flow valve and the water flow valve based on the actual flow rate.
The characteristic configuration is that the limit detection means detects that either the water flow valve or the water flow valve is in a fully open or fully open limit state, and as the limit state is detected,
The control means is configured to control opening and closing of both valves only to obtain mixed hot water at the target temperature.

A second characteristic configuration is that in the first characteristic configuration, when at least one of the target temperature and the target flow rate is changed and set by the hot water temperature setting means or the flow rate setting means, the mixed hot water at the target flow rate is changed. The control means is configured to resume control of the two valves to obtain the desired result.

A third characteristic configuration is that in the first or second characteristic configuration, the mixed hot water at the target temperature is further provided in a range in which the absolute value of the deviation between the target temperature and the actual temperature exceeds a predetermined value. The control means is configured to control the opening and closing of both valves only to obtain the following.

[For production]

According to the first characteristic configuration, upon detecting that either the limit detection means, the hot water flow valve, or the water flow valve is fully open or in a fully open limit state, the control means controls the flow rate of the mixed hot water. Instead, the opening and closing of both valves are controlled only to obtain mixed hot water at the target temperature.

According to the second characteristic configuration, in the above state, when at least one of the target temperature and the target flow rate is changed and set by the hot water temperature setting means or the flow rate setting means, the control means obtains mixed hot water at the target flow rate. The control of both valves is resumed.

According to the third characteristic configuration, in a range in which the absolute value of the deviation between the target temperature and the actual temperature exceeds a predetermined value, the control means controls the opening and closing of both the valves only to obtain mixed hot water at the target temperature. do.

〔Effect of the invention〕

According to the first characteristic configuration, for example, when the target flow rate is changed and set to suddenly increase, when the hot water flow valve becomes fully open,
Since the control for obtaining mixed hot water at the target flow rate is stopped and only the control for obtaining mixed hot water at the target temperature is performed, it is now possible to avoid a drop in the hot water temperature of the mixed hot water. Similarly, if the water flow valve becomes fully open, or if the target flow rate is suddenly changed to a decreasing direction and the water flow valve becomes fully closed, the temperature drop or rise of the mixed hot water will be reduced. We have now developed a hot water mixing device that avoids this problem and maintains a constant temperature.

According to the second characteristic configuration, when the first characteristic configuration only controls to obtain mixed hot water at the target temperature, if the flow rate setting means is operated to decrease the target flow rate, or If the hot water temperature setting means is operated to lower the target temperature, control for obtaining mixed hot water at the target flow rate is automatically restarted, which is convenient in practice.

According to the third characteristic configuration, when the actual temperature is far away from the target temperature at the start of hot water dispensing or when the target temperature is set to be significantly changed, the target flow rate remains unchanged until the deviation becomes equal to or less than a predetermined value. As a result, only the control to obtain the mixed hot water at the target temperature is performed without performing the control to obtain the mixed hot water at the target temperature.As a result, the target temperature can be reached quickly.

〔Example〕

An embodiment in which the hot water mixing device according to the present invention is applied to a bath shower will be described below. FIG. 1 shows the system diagram. High-temperature hot water produced by a water heater is supplied to the hot water mixing device (C) from an inlet channel (1), and low-temperature water is supplied from an inlet channel (2). The flow of the supplied hot water and water is restricted by the hot water flow valve (3) and the water flow valve (4), respectively, and then mixed to form mixed hot water, which is then sent from the shower (6) connected to the tip of the hot water supply path (5). The bath is served.

There is a hot water temperature sensor (7) in the hot water supply path inside the hot water mixing device (C).
and a flow rate sensor (8) are provided, which respectively detect the temperature and flow rate of the mixed hot water and provide the detected information to the control device (9). An operation panel (P) equipped with a hot water temperature setting device (10), a flow rate setting device (11), and an operation switch (12) is connected to the control device (9).

The operation and control procedure is as follows. First, turn on the operation switch (12) on the operation panel (P), and turn on the water temperature setting device (1).
0) to set the target temperature (hereinafter referred to as set water temperature), and the flow rate setting device (11) to set the target flow rate (hereinafter referred to as set flow rate). At this time, the hot water volume valve (3) and the water volume valve (4) are initialized to predetermined opening degrees. Then take a shower (
6) Open the hand operated valve (13) provided. Then, the hot water supply detector (14) provided in the hot water supply path inside the hot water mixing device (C) detects the start of hot water supply and provides a hot water supply start signal to the control device (9). The control device (9) has a hot water temperature sensor (7
) and flow rate sensor (8), and set the actual temperature (hereinafter referred to as detected water temperature) and actual flow rate (hereinafter referred to as detected flow rate) detected by these sensors (7) and (8). Opening/closing control of the water flow valve (3) and water flow valve (4) is performed so that the temperature and flow rate approach the set flow rate. When the hand-operated valve (13) is closed to stop hot water, the control device (9)
stops the above-mentioned control in response to a hot water supply stop signal from the hot water supply detector (14).

Next, the opening/closing control of the hot water volume valve (3) and the water volume valve (4) will be explained. As shown in the control block diagram of Fig. 2, the control device (9) calculates the difference (Tt) between the set hot water temperature (T) and the detected hot water temperature (1) and the amount of change Δ(Tt). The manipulated variable f is determined by fuzzy inference. Also, set flow rate (Q)
From the deviation (Q-q) of the detected flow rate (q), the manipulated variable k is determined by fuzzy inference. A specific example of fuzzy inference will be described later.

In this embodiment, the manipulated variables f and k correspond to the rotational speed of the motor that drives the water flow valve (3) and the water flow valve (4), and are therefore proportional to the opening/closing speed of both valves (3) and (4).

Here, f is the operation amount for controlling the opening and closing of the water flow valve (3) and the water flow valve (4) in opposite directions, and k is the operation amount for controlling the opening and closing of the water flow valve (3) and water flow valve (4) in opposite directions.
4) is the amount of operation that controls opening and closing in the same direction.

That is, the amount of operation of the hot water amount valve is (-f+k), and the amount of operation of the water amount valve is (f+k). Here, for both f and k, a positive value means the direction in which the valve opens, and a negative value means the direction in which the valve closes.

If the above-mentioned control is expressed in a flowchart from the start to the stop of hot water dispensing of the shower (6), it will be as shown in FIG. 3. In the figure, a loop including fuzzy inference is executed at regular intervals.

Next, an embodiment of the fuzzy controller for determining the operation amount of the hot water volume valve (3) and the water volume valve (4) will be described. Here, the fuzzy controller refers to a combination of a plurality of control rules and a fuzzy inference section. The fuzzy controller of this embodiment is a first fuzzy controller (
20) and a second fuzzy controller (21);
The fuzzy controller (20) determines the operation amount f from the hot water temperature deviation A=(T-t) and its change amount ΔA, and the second fuzzy controller (21) determines the flow rate deviation B=(Q-q). The manipulated variable k is determined from

First, the first fuzzy controller (20) will be explained. The control rule has an antecedent part described by two fuzzy variables A1ΔA, whose membership functions are shown in FIGS. 4 and 5, respectively.

Furthermore, the manipulated variable f that describes the consequent part of the control rule is assumed to be a set of discrete singletons, as shown by the membership function in FIG. The control rules described by these fuzzy variables are, for example, IF A=pb & ΔA=pb
THENf=nb, or in this example, variable A can take 7
A control rule is defined for determining the manipulated variable f for 35 combinations of the value of ΔA and the five possible values of the variable ΔA.

If the value of the variable A is taken in the vertical direction and the value of the variable ΔA is taken in the horizontal direction, and the relationship with the manipulated variable f is expressed in a matrix table, the result will be as shown in Table 1.

Table 1 ΔA The first fuzzy controller (20) stores the control rules in the table format shown in Table 1, and the temperature deviation A and its variation Δ
Based on the input of A, the manipulated variable f based on the control rule is determined by table lookup. In this case, the degree of conformity of the input quantities A and ΔA to each control rule is determined by the membership function (
The smaller of the degrees of conformity (grade) to the control rules (FIGS. 4 and 5) is taken as the degree of conformity to the control rule. The manipulated variable f obtained as a result is weighted by the degree of adaptation. Then, the weighted average of the manipulated variables f obtained from each control rule is set as the manipulated variable f determined by the first fuzzy controller (20).

This will be explained below using specific numerical values. If A=6
[C], ΔA = 1.5 ('C), then the fourth
From the figure, A conforms to both pm and ps with grade 0.3. Further, as shown in FIG. 5, ΔA matches both pb and ps with a grade of 0.5. Therefore, the four types of control rules surrounded by double lines in Table 1 will be applied, and when calculating the manipulated variable f for each, from the top left, Clockwise, 0.3 nb.

They are 0.3nb, 0.3nm, and 0.3nm. If we substitute specific numerical values for each value of the manipulated variable f from Figure 6 and take the weighted average, we get f = (0,3X(-50)+0.3X(-50))
+0.3X(-15)+〇, 3x(-15))/(0,
3+0.3+0.3+0.3)=-32.5 [ppsl. This is the operation amount determined by the first fuzzy control example (20) from the hot water temperature deviation A = 6 ji C] and its variation ΔA = 1.5 ji C].

Next, the second fuzzy controller (21) will be explained focusing on the differences from the first fuzzy controller (20).

The second fuzzy controller (21) is described by only the antecedent part of the control rule or one fuzzy variable B, and its membership function is shown in FIG. Similar to the first fuzzy controller (20), the membership function of the manipulated variable of the consequent part of the control rule is expressed as a discrete singleton, which is shown in FIG. The control rules are expressed as, for example, IF B=pb THEN k=pb, and the relationship between B and k for the five control rules is shown in Table 2.

Below in Table 2, the process of fuzzy inference will be explained using specific numerical values, similar to the explanation of the first fuzzy controller (20). If B=10 [1/min], then from FIG. 7, B matches pb with a grade of 0.3 and matches ps with a grade of 0.7. Therefore, two control rules in Table 2 are applied, and the manipulated variable = 0.3 pb and = 0.7 ps are determined for each. From Figure 8, if we substitute specific numerical values for each position of the manipulated variable f and take the weighted average, we get k = (0,3X15+0.7X5)/(0,3+0
．． 7)"8 [ppSl. This is the manipulated variable obtained by the second fuzzy controller (21) from the flow rate deviation B=10 [1/mlnl.

From the manipulated variable f = -32,5 [ppSl determined by the first fuzzy controller (20) in this way and the manipulated variable k''8 [ppSl] determined by the second fuzzy controller (21), as shown in Fig. 2 As shown in the figure, the operation amount of the water flow valve (3) is t + k = 4
0.5 [pps] and the operation amount f + k = -24,5 [ppSl] of the water flow valve (4) are determined.

In this way, the control device (9) controls the water flow valve (3) in the opening direction at a speed proportional to the manipulated variable [40,5], and also controls the water flow valve (4) by the manipulated variable [-24,5]. control in the closing direction at a speed proportional to . As a result, the water temperature deviation A=(T-
t) becomes smaller, the flow rate deviation B=(Q-q) is adjusted to become smaller.

Next, limit control and transient control other than the steady-state control described above will be explained with reference to the flowchart of FIG. FIG. 9 is a flow chart showing steady-state control in FIG. 3 with limit control and transient control added.

First, whether it is limit control or whether the hot water mixing device of this embodiment has either the hot water flow valve (3) or the water flow valve (4) in the fully open or fully open limit state as shown in FIG. Limit detection means (15) for detection is provided. When the limit detection means (15) detects the limit state and provides the information to the control device (9), the control device (9) masks the manipulated variable k determined by the second fuzzy controller. Opening/closing control of the water flow valve (3) and water flow valve (4) is performed only by the operation amount f determined by the second fuzzy controller (
(See Figure 9 (a) and (b)). That is, ignoring the flow rate deviation B, both valves (3) are used only to obtain mixed hot water at the set hot water temperature.
, (4) Control opening and closing.

By performing such limit control, for example, when the set flow rate is changed to suddenly increase, the hot water flow valve (3)
When the tank is fully opened, the control for obtaining mixed hot water at the target flow rate stops, and only the control for obtaining mixed hot water at the target temperature is performed, so that a drop in the temperature of the mixed hot water can be avoided.

Conversely, when the water flow valve (4) is fully open, an increase in the temperature of the mixed hot water can be avoided. Even when the set flow rate is suddenly reduced and the hot water flow valve (3) or water flow valve (4) is fully open, it is possible to similarly suppress the change in hot water temperature as much as possible.

Once the above-mentioned limit control is entered, the hot water temperature setting device (10)
Alternatively, steady control is not returned until at least one of the set hot water temperature or the set flow rate is changed by the flow rate setting device (11). In other words, the control based on the flow rate deviation is restarted by the above changed settings (see FIG. 9(c)). However, in reality, unless the above-mentioned change setting is made in the direction of lowering the target temperature or lowering the target flow rate, it is impossible to escape from the above-mentioned limit control.

Next, transient control will be explained. In the hot water mixing device of this embodiment, the absolute value of the hot water temperature deviation A is a predetermined value (5°C).
In the range exceeding the above limit control, the second
Masking the operation amount k obtained from the fuzzy controller, the water flow valve (3) is controlled only by the operation amount f obtained from the second fuzzy controller.
) and the opening/closing control of the water flow valve (4) (see Figure 9 (d)).

With such transient control, when starting hot water dispensing or when the set hot water temperature is significantly changed, the flow rate deviation B is ignored until the hot water temperature deviation falls below a predetermined value (5°C). Both valves (3) only to obtain mixed hot water at the set hot water temperature;
(4) Control opening and closing.

As a result, the target temperature can be reached quickly.

[Another example]

In the above-mentioned embodiment, the hot water temperature deviation, which is the criterion for determining whether or not to perform transient control, was set at 5°C, or it may be possible to set any suitable hot water temperature deviation, not limited to 5°C. Not even. Further, this standard hot water temperature deviation may be changed over and set using a dip switch or the like.

In addition, for limit control, a hot water flow valve (3) and a water flow valve (4) are installed.
), the limit state may be detected by changes in the excitation current of the motor that drives the valve, without providing a sensor for detecting the limit position on the valve. In other words, when the valve is driven to the limit state, the excitation current of the motor increases as the load increases, so it is determined that the valve has reached the limit state when the excitation current exceeds a predetermined amount for a certain amount of time. can do.

In this case, it goes without saying that excitation is stopped to protect the valve motor that has reached its limit state.

It should be noted that the present invention is not limited to the structure shown in the accompanying drawings by adding reference numerals in the claims for convenient comparison with the drawings.

[Brief explanation of the drawing]

1 to 9 are diagrams relating to a hot water control device according to an embodiment of the present invention, in which FIG. 1 is an example of its application, FIG. 2 is a control block diagram, and FIGS. 3 and 9 are diagrams of a control device. Flowchart, 4th
Figures 8 through 8 show membership functions of fuzzy variables. (3)...Hot water flow valve, (4)...Water flow valve, (7)...Hot water temperature detection means, (8)...
・Flow rate detection means, (9)... Control means, (10
)...Hot water temperature setting means, (11)...Flow rate setting means, (15)...Limit detection means.

Claims (1)

[Claims] 1. Hot water temperature setting means (10) for setting the target temperature of mixed hot water
and a flow rate setting means (11) for setting the target flow rate of the mixed hot water.
, a hot water flow valve (3) for adjusting the inflow amount of hot water, a water flow valve (4) for adjusting the inflow amount of water, a hot water temperature detection means (7) for detecting the actual temperature of the mixed hot water, and a hot water temperature detection means (7) for detecting the actual temperature of the mixed hot water. A flow rate detection means (8) that detects the actual flow rate of hot water, and opens and closes the hot water flow valve (3) and the water flow valve (4) based on the target temperature, the target flow rate, the actual temperature, and the actual flow rate. Control means to control (
9), the hot water mixing device comprising: the hot water flow valve (3);
or limit detection means (15) for detecting that any of the water flow valves (4) is in a fully open or fully closed limit state;
) detects the limit state, the control means (9) is configured to control opening and closing of both the valves (3) and (4) only in order to obtain mixed hot water at the target temperature. A hot water mixing device. 2. When at least one of the target temperature and the target flow rate is changed and set by the hot water temperature setting means (10) or the flow rate setting means (11), the two valves for obtaining mixed hot water at the target flow rate ( The hot water mixing device according to claim 1, wherein the control device (9) is configured to restart the control in steps 3) and (4). 3. Control opening and closing of both valves (3) and (4) only in order to obtain mixed hot water at the target temperature in a range in which the absolute value of the deviation between the target temperature and the actual temperature exceeds a predetermined value. The hot water mixing device according to claim 1 or claim 2, wherein the control device (9) is configured so as to.