JPH0540531A - Mixing device for hot water and cold water - Google Patents

Abstract

PURPOSE:To reduce the variation of the temperature of mixed water at the time when the pressure of a hot water supply pipe and the pressure of a cold water supply pipe change simultaneously and in addition, to the same direction. CONSTITUTION:In the mixing device of hot water and cold water provided with mixing ratio changing means 7, 8 to change the mixing ratio of the hot water from the hot water supply pipe 3 and the cold water from the cold water supply pipe 4, pressure detecting means 12a, 12b to detect the pressure of the hot water supply pipe 3 or the cold water supply pipe 4, and a control means 11 to control the mixing ratio changing means 7, 8 so as to suppress the variation of the temperature of the mixed water based on their detection information, it is constituted so that the control means 11 determines the manipulated variables of the mixing ratio changing means 7, 8 based on the variation of the ratio of the pressure of the cold water supply pipe 4 and the pressure of the hot water supply pipe 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixing ratio changing means for changing a mixing ratio of hot water from a hot water supply passage and water from a water supply passage, and pressure detecting means for detecting a pressure in the hot water supply passage or the water supply passage. Also, the present invention relates to a hot and cold water mixing apparatus including control means for controlling the mixing ratio changing means so as to suppress fluctuations in the mixed hot water temperature based on the detection information.

[0002]

2. Description of the Related Art As a conventional example of such a hot and cold water mixing apparatus (generally called a mixing stopper), there is, for example, one described in the specification and drawings of Japanese Patent Application No. 3-6402 filed previously. This is because the temperature of the mixed hot water caused by the fluctuation of the primary pressure of the hot water supply passage and the water supply passage is only by the feedback control (temperature control) that controls the mixing ratio changing means based on the detection information of the mixed hot water temperature as before. In view of the difficulty of suppressing the fluctuation of the above, the feed forward control (pressure control) for detecting the primary pressure and controlling the mixing ratio changing means in the direction of canceling the change in the mixed hot water temperature due to the change in advance is added. It is a thing.

In the above conventional example, fuzzy control is applied to temperature control and pressure control. Also, regarding an application example of fuzzy control to the above temperature control, Japanese Patent Application No. 2-1
No. 72072 is described in detail.

[0004]

In the above-mentioned conventional example, the pressure change in the hot water supply passage and the pressure change in the water supply passage are detected separately, and if any one of the pressure changes occurs, the mixing ratio is changed as described above. Controlled the means of change. However, for example, even when the pressure of the hot water supply passage and the pressure of the water supply passage increase at the same time, pressure control is performed if any of the pressure change amounts is equal to or greater than a predetermined value. On the contrary, the temperature fluctuation of the mixed hot water may become large as compared with the case of performing. The same applies when the pressure in the hot water supply passage and the pressure in the water supply passage decrease at the same time.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the temperature fluctuation of the mixed hot water when the pressure in the hot water supply passage and the pressure in the hot water supply passage change simultaneously and in the same direction. To do.

[0006]

A hot water mixing apparatus according to the present invention comprises a mixing ratio changing means for changing a mixing ratio of hot water from a hot water supply path and water from the hot water supply path, and a pressure of the hot water supply path or the water supply path. And a control means for controlling the mixing ratio changing means on the basis of the detection information to suppress the fluctuation of the mixed hot water temperature. The characteristic construction of the control means is that the water supply The operation amount of the mixing ratio changing means is determined based on the amount of change in the ratio between the pressure in the passage and the pressure in the hot water supply passage.

[0007]

In the above characteristic construction, the amount of change in the ratio between the pressure in the water supply passage and the pressure in the hot water supply passage (hereinafter referred to as the pressure ratio) has a positive or negative value. For example, when the pressure in the hot water supply passage increases without changing the pressure in the water supply passage, the pressure ratio becomes small, and therefore the amount of change in the pressure ratio becomes a negative value. Conversely, when the pressure in the hot water supply passage decreases, the pressure ratio increases, and the amount of change in the pressure ratio becomes a positive value. The control means determines the operation amount of the mixing ratio changing means based on the change amount of the pressure ratio.

That is, the positive / negative of the change amount of the pressure ratio determines the positive / negative of the operation amount of the mixing ratio changing means, and the magnitude of the change amount of the changing means is determined by the magnitude of the change amount of the pressure ratio. .. For example, if the change amount of the pressure ratio is a positive value, the operation amount of the mixing ratio changing means is a positive value (indicating that the operation amount is a direction that increases the inflow amount of water and decreases the inflow amount of hot water). The magnitude of the operation amount is determined according to the magnitude of the change amount. The magnitude of the manipulated variable corresponds to the rotation speed or rotation time of the motor when the mixing ratio changing means is a valve that is opened and closed by a motor, for example.

As described above, the control for suppressing the temperature rise of the mixed hot water is performed by the operation amount of the mixing ratio changing means determined based on the change amount of the pressure ratio. Therefore, if the primary pressure of the hot water supply channel decreases at the same time as the primary pressure of the water supply channel decreases, and the change amount of the pressure ratio is almost zero, the operation amount of the mixing ratio changing means becomes substantially zero. In this case, both the inflow amount of water and the inflow amount of hot water decrease, and the rate of decrease is almost equal, so it is considered that the temperature of the mixed hot water hardly changes.

[0010]

According to the mixing apparatus of the present invention, when the pressure in the hot water supply passage and the pressure in the water supply passage change at the same time and in the same direction as described above, it is unnecessary to operate the mixing ratio changing means unnecessarily. It is difficult to do so, and it becomes possible to further reduce the fluctuation of the temperature of the mixed hot water in such a case.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a part of the tap water supplied from the water supply pipe to each house is heated to a high temperature by the water heater 1 and pumped to the hot water supply passage 3 by the spherical motor pump 2. Others are directly supplied to the hot and cold water mixing device (mixing stopper) 5 through the water supply passage 4. The mixed hot water mixed by the hot and cold water mixing device 5 is supplied to the joining pipe 6.

The hot and cold water mixing device 5 is provided with a hot water side valve 7 for adjusting the inflow amount of hot water supplied from the hot water supply passage 3 and a water side valve 8 for adjusting the inflow amount of water supplied from the water supply passage 4. Both valves 7 and 8 constitute a mixing ratio changing means for adjusting a mixing ratio of hot water and water. Further, a temperature detecting means (hereinafter referred to as a temperature sensor) 9 for detecting the temperature of the mixed hot water, a flow rate detecting means (hereinafter referred to as a flow rate sensor) 10 for detecting the flow rate of the mixed hot water, and hot water based on these detection information. Control means 11 for controlling the opening / closing of the side valve 7 and the water side valve 8 is provided.

Pressure detecting means (hereinafter referred to as pressure sensor) 12 for detecting the respective pressures in the water supply passage 4 and the hot water supply passage 3
a and 12b are provided, and their detection signals are also input to the control means 11. The hot water valve 7 includes a valve body 7a and a pulse motor 7b for driving the valve body 7a. Similarly, the water side valve 8 includes a valve body 8a and a pulse motor 8b. Control means 11
Controls the opening and closing of the hot water valve 7 and the water valve 8 by controlling the pulse motors 7b and 8b in the forward and reverse directions, and controls the opening and closing speeds of both valves 7 and 8 by controlling the rotation speed thereof.

The control means 11 opens and closes the hot water valve 7 and the hot water valve 8 on the basis of the operating portion 13 for setting the target temperature and the target flow rate of the mixed hot water, and the set value and the detection information of each sensor. The control unit 14 performs control, that is, drive control of the pulse motors 7b and 8b. Pulse motor 7b,
The operation amount of 8b, that is, the rotation direction and the rotation speed are basically such that the deviation between the detected temperature of the temperature sensor 9 and the target temperature is small, and the deviation between the detected flow rate of the flow rate sensor 10 and the target flow rate is small. Is determined (temperature / flow rate control).

Then, based on the detection information of the pressure sensors 12a and 12b, the pulse motor 7 is used to suppress the fluctuation of the temperature of the mixed hot water caused by the pressure fluctuation of the hot water supply passage 3 or the water supply passage 4.
The manipulated variables b and 8b are corrected (pressure control). However, the rotation speed in this pressure control is higher than the rotation speed in the temperature / flow rate control.

The operation amount is determined by fuzzy reasoning for both temperature / flow rate control and pressure control. As shown in the flow chart of FIG. 2, first, the manipulated variables f and k are determined by temperature / flow rate control (process (a)). Details of this processing are described in the specification and drawings of the prior application described above as a conventional example.

The manipulated variable f is a component that drives the pulse motor 7b and the pulse motor 8b to rotate in opposite directions by temperature control, that is, a component that controls the hot water valve 7 and the water valve 8 to open and close in a contradictory manner. .. The manipulated variable k is a component that rotationally drives the pulse motor 7b and the pulse motor 8b in the same direction by controlling the flow rate. In addition, any operation amount is proportional to the number of pulses per second applied to the pulse motor (proportional to the rotation speed. MA
X. 50 pps) and the valve opening direction is set to a positive value.

Next, as shown in treatment (b), the water supply channel 4
Ratio (R =) between the pressure (Pw) and the pressure (Ph) in the hot water supply passage 3
The manipulated variable r is determined based on the change amount (ΔR) of Pw / Ph). That is, fuzzy inference is performed based on the rules shown in FIG. 3, the membership function of the variable ΔR of the antecedent part shown in FIG. 4, and the membership function of the variable r of the antecedent part shown in FIG. It is determined.

This manipulated variable r is a component for rotationally driving the pulse motor 7b and the pulse motor 8b in opposite directions, like the manipulated variable f, and like the manipulated variables f and k, the valve opening direction is positive. Take the value. In addition, as shown in FIG. 9
It is 76 pps, which is an operation amount for rotationally driving the pulse motors 7b, 8b at a higher speed than the operation amounts f, k.

Finally, as shown in the process (C), the hot water valve 7
Of the pulse motor 7b (Fh = -f + k-r) and the amount of operation of the pulse motor 8b of the water side valve 8 (Fw = f + k)
+ R) is calculated, and the pulse motors 7b and 8b are rotationally driven based on the obtained operation amount (rotation direction and rotation speed).

Other examples will be listed below. In the above embodiment, the hot side valve 7 is calculated from the manipulated variables f and k determined by the temperature / flow rate control and the manipulated variable r determined by the pressure control.
And the final manipulated variables Fh and Fw of the water side valve 8 were determined.
Then, each operation amount was the rotation direction and rotation speed of the pulse motor. The present invention is not limited to such an aspect, but may be implemented in an aspect as shown in FIG. 6, for example. The following is a brief description.

In the process (d), the pressure control is performed when the absolute value of the change amount (ΔR) of the pressure ratio obtained in the same manner as in the above embodiment is larger than the predetermined value (C), and otherwise the above operation is performed. Perform the same temperature and flow rate control as in the example. In the pressure control of the process (e), first, the rotation direction of the pulse motor is determined according to the sign of ΔR. The rotation directions of the pulse motor 7b and the pulse motor 8b are opposite to each other.

Next, the rotation time of the pulse motors 7b and 8b is determined as the operation amount by fuzzy inference based on the absolute value of the change amount (ΔR) of the pressure ratio. The rotation speed is constant (30
0 pps), this operation amount is
And the amount of opening / closing movement for opening / closing the water side valve 8 in an antithetical manner.
The larger the absolute value of the change amount (ΔR) of the pressure ratio, the longer the rotation time. Finally, the pulse motors 7b and 8b are rotationally driven at a constant speed according to the rotation direction and the rotation time.

In the above embodiment, the hot water amount control is not always necessary, but only the temperature control for performing the open / close control of the hot water valve 7 and the hot water valve 8 so that the deviation between the detected temperature of the temperature sensor 9 and the target temperature becomes small. However, the present invention can be applied when pressure control is used together.

The temperature / hot water amount control and the pressure control in the above embodiment are not limited to fuzzy control, and may be realized by other control means. For example, a PID control circuit may be configured using an OP amplifier or the like.

The mixing ratio changing means is not limited to the structure of the above-described embodiment, and various changes can be made. For example, when the flow rate control is not performed, or when a flow rate control valve is separately provided, the hot water valve and the water side valve may be integrally configured and open and close at all times.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a hot and cold water mixing apparatus according to an embodiment of the present invention.

[Fig. 2] Flow chart of hot and cold water mixing control

[Figure 3] Fuzzy inference rules

Fig. 4 Membership function of the antecedent part of fuzzy inference

[Figure 5] Consequent part membership function of fuzzy inference

FIG. 6 is a flow chart of hot and cold water mixing control according to another embodiment.

[Explanation of symbols]

 3 Hot Water Supply Channel 4 Water Supply Channel 7, 8 Mixing Ratio Changing Means 11 Control Means 12a, 12b Pressure Detecting Means

Claims (1)

[Claims] 1. A mixing ratio changing means (7, 8) for changing a mixing ratio of hot water from the hot water supply passage (3) and water from the water supply passage (4).
And pressure detection means (12a, 12b) for detecting the pressure in the hot water supply passage (3) or the water supply passage (4), and the mixing ratio changing means () for suppressing fluctuations in the mixed hot water temperature based on the detection information. 7. A hot and cold water mixing device comprising a control means (11) for controlling the hot water supply passage (4) and the hot water supply passage (3). A hot and cold water mixing apparatus configured to determine an operation amount of the mixing ratio changing means (7, 8) based on a change amount.