JPH02231613A - Hot/cool water mixing controller - Google Patents

Abstract

PURPOSE:To attain the satisfactory control of the hot water temperature by detecting a sudden rise of the temperature of the discharged hot water via a changing slope detecting part, fixing forcedly a mixing means at the preceding discharge state of the hot water, and resetting a normal control state when the hot water temperature is stabled. CONSTITUTION:When a changing slope detecting part 11 detects that the overshoot quantity of the discharged hot water temperature reaches a dangerous level based on the derivatives obtained from the preceding data and the present data on the temperature of the hot water supplied from a hot water temperature detection part 7, the driving of a step motor 6 is switched to a position control part 10. On the other hand, the normal control is continued when it is estimated that the rising degree of the temperature of the supplied hot water is small and the overshoot value is not so large. When it is decided that the rising degree of the temperature of the supplied hot water is large and an overshoot state may possibly caused with the normal control, the position of the motor 6 where the hot water temperature approximate to a set level is possibly obtained is estimated. Then the motor 6 is driven at the highest speed so that a mixture valve 5 is set at the estimated position of the motor 6. Thus the danger is reduced for the scalds, etc., due to the overshoot.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention mixes high temperature hot water and water, and is used in showers, washbasins, etc. Or it relates to a hot water mixing control device that produces hot water to be supplied to a bathtub. Conventional technology A conventional hot water mixing control device is as shown in Fig. 4, for example. That is, the hot water side pipe 1 and the water side pipe 2 each join the mixing section 4 via the pressure equalization valve 3. In the mixing section 4, the mixing ratio of hot water and water is adjusted by a mixing valve 5. Figure 5 shows the relationship between the mixing water temperature and the mixing valve position. If the pressure on the hot water side and the water side are the same due to the effect of the pressure equalization valve, the mixed water temperature will be the supplied hot water temperature T, I when the hot water side is fully open, and the supplied water temperature T0 when the water side is fully open, and the temperature between them will be linear. Change. Therefore, the hot water temperature control section 8 provides negative feedback to the step motor 6 as shown in FIG. put on.

Further, the operation of the hot water temperature control section 8 is shown in a flowchart as shown in FIG. First, input the mixed water temperature from the hot water temperature sensor, then manually set the hot water temperature from the hot water temperature setting section, and calculate the temperature deviation E from the following formula. E, Detected temperature - Set temperature Next, from the obtained temperature deviation E, the driving speed DM and driving force direction of the step motor 6 are determined. [Driving speed] Ell≦Dead band DM=0 Dead band<E,≦
Maximum speed range DM-E. xG maximum speed range <E. [Drive direction] E. 〉0 Reverse rotation E, <O Forward rotation (G-gain) With a configuration such as DM-maximum speed or higher, conventional hot water mixing control devices can mix according to the set temperature by controlling the mixing ratio of high temperature field and water. I was getting the temperature of the water. Problems to be Solved by the Invention When hot water is supplied once and not used for a while, the temperature of the hot water in the hot water side piping may drop to a temperature slightly higher than the set temperature. Figure 8 shows the change in supply field temperature in such a case. When hot water near the set temperature is exhausted, the supplied water temperature rises rapidly. At this time, the mixing valve 5 needs to be immediately moved from a valve position suitable for a low water supply facility temperature to a valve position suitable for the changed supply water temperature. Here, the valve is adjusted with an amount of bias proportional to the gradient of change in temperature deviation, but the mixing valve 5 cannot be moved to the optimum valve position instantaneously and takes time. As a result, there was a large overshoot in the hot water temperature, and when a user started using a shower, etc., there was a risk of burns due to the sudden overshoot. The present invention has been made in view of the above problems, and an object of the present invention is to provide a hot water mixing control device that controls the hot water temperature so that it does not affect the human body even if the hot water temperature suddenly fluctuates in steps. Means for Solving the Problems In order to solve the above problems, the present invention provides a mixing means for adjusting the mixing ratio of hot water and water, an isobaric means for keeping the pressure on the field side and the water side uniform, A hot water temperature detecting means for detecting the temperature of the mixed hot water made by the means, a hot water temperature setting means for setting the mixed hot water temperature, and a control established in advance from the output signals of the hot water temperature detecting means and the hot water temperature setting means. A calculation energizing means performs arithmetic processing according to rules, determines the operation amount based on an output signal from the control calculation means and energizes the mixing means, and detects a change gradient of the hot water temperature from the output signal of the hot water temperature detection means. , the detection signal of the change gradient indicates that the water temperature is stable for each setting of the hot water temperature setting means, and when the outputs of the hot water temperature setting means and the hot water temperature detecting means are equal, the position of the mixing means is memorized, and the change slope is detected. Priority is given to the calculation energizing means so that the position indicated by the output signal of the position storage means corresponding to the output signal of the hot water temperature setting means is taken from the time when the output signal of the means indicates a rapid rise in the temperature of the hot water until it becomes stable. and position biasing means for biasing the mixing means. Effect: With the above configuration, high-temperature hot water and water are supplied to the mixing means via the equal pressure means at the same time as hot water starts being tapped. Further, based on the output signals of the hot water temperature setting means and the hot water temperature detecting means, the control calculation means determines the conditions for energizing the mixing means according to a predetermined control rule. Here, conditions are calculated such that, for example, if the detected temperature is very high compared to the set temperature, the temperature will be warmed quickly, and if it is slightly lower than the set temperature, the temperature will be heated slowly.Based on this, the calculation energizing means energizes the mixing means. On the other hand, at the stage when high-temperature water and water are supplied to the mixing means, the pressures are equal to each other by the equal pressure means, so the state quantity of the mixing means with respect to the outlet temperature is determined by the supplied hot water temperature and water temperature. Water temperature. Water temperature does not change drastically if the installation conditions are the same, and seasonal fluctuations occur gradually, so the position where the state quantity of the mixing means is stable is almost the same as when it was used last time. If the high-temperature hot water in the piping on the hot water side is cold at the start of hot water dispensing, the mixing means will operate in a state close to fully open on the hot water side in order to achieve the set hot water temperature. (or the hot water side is fully open). At this point, when the cold hot water is removed and the supplied hot water temperature rises rapidly, the mixing field temperature also rises, and the mixing means is forced by the state energizing means to maintain the previous stable water temperature. state is energized at maximum speed. This state is maintained until the temperature of the mixed water stabilizes, and then the mixing means is returned to the state in which the mixing means is energized by the normal energizing means. Even if there is a slight deviation between the state quantity of the mixing valve when the water temperature is stable between the previous time and this time, only a slight overshoot or undershoot will occur, and it will not cause burns etc. due to large overshoot as in the case of conventional methods. The risk can be greatly reduced. EXAMPLE An example of the present invention will be described below with reference to the drawings. 1st
In the figure, the elements indicated by reference numerals 1 to 9 have the same configuration and operation as those explained in the section of the prior art, so their explanation will be omitted here. At the start of hot water supply, high-temperature hot water is supplied from the hot water side piping 1.The water remaining in the piping connecting the heat source device to this device (hereinafter referred to as dead water) is supplied at the beginning of hot water supply, and then after the hot water supply starts, the hot water is supplied from the hot water side piping 1. High-temperature water is supplied. The temperature of dead water varies and can be anywhere from the temperature of the hot water supplied by the heat source to room temperature depending on the amount of time that has passed since the last time it was used. Therefore, it is necessary to give priority to normal hot water temperature control as long as it does not affect the amount of overshoot when dead water removal is completed. As explained in the section of the prior art, the field temperature control unit 8 operates according to a predetermined control rule so that the set hot water temperature input from the hot water temperature setting unit 9 and the hot water temperature input from the hot water temperature detection unit 7 are equal. Drive step motor 6. (Hereinafter, abbreviated as normal control) On the other hand, the change gradient detection unit 11 calculates the differential amount from the previous data and current data of the hot water temperature input from the hot water temperature detection unit 7, and calculates the overshoot amount of the outlet temperature from the differential amount. If it is determined that the position has reached a level that is considered dangerous to the user, the drive of the step motor 6 is switched to the position control unit 10. As shown in Figure 2, if the increase in the supply hot water temperature is small and overshading is not expected to be significant, normal control is continued; If it is determined that the hot water will overheat to a level that is considered dangerous, the position control unit 10 will adjust the hot water temperature to approximately the set water temperature based on the hot water temperature from the previous hot water tap and the position of the step motor 6. The step motor 6 is estimated to be at the position where the mixing valve 5 is assumed to be at that position, and the step motor 6 is driven at the maximum speed so that the mixing valve 5 is at that position. (Hereinafter abbreviated as dead water control) The change gradient detection section 11 makes the following judgment and switches the drive mode of the step motor 6. [During normal control] ΔT, l Other than that → Normal control jn [During dead water control] Other than that → Dead water control When dead water control is started, the outlet hot water temperature, which has tended to overshoot, forcibly determines the mixing ratio. The device immediately enters a safe state. *When the gradient detection unit 11 determines that the water temperature has stabilized for a certain period of time, it cancels dead water control and enters normal control. At this time, the hot water temperature is the same as the previous hot water temperature and the current hot water temperature. If there is a change in the water source, a slight offset will occur, but
This amount is not a problem compared to the overshoot that would occur if normal control was maintained. (Fig. 3) Effects of the Invention As described above, the hot water mixing control device of the present invention uses the change gradient detection unit to detect a sudden rise in the temperature of the tapped water, and forcibly sets the mixing means to the state at the time of the previous tap. This prevents burns to the user by fixing the temperature to a fixed temperature, preventing overshoot, and returning to normal control after waiting for the water temperature to stabilize. Can reduce the risk of burns, etc.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a hot water mixing control device according to an embodiment of the present invention, FIG. 2 is an overshoot characteristic diagram of the same device, and FIG.
The figure is a characteristic diagram of the device, Figure 4 is a block diagram of a conventional hot water mixing control device, Figure 5 is a characteristic diagram of the state quantity of the mixing means and the temperature of the mixed water, and the sixth figure is the control rule curve of the mixing means. , Fig. 7 is a flowchart of normal control in the same device, and Fig. 8 is a characteristic diagram of outlet hot water temperature when removing dead water in the same device. 1...Hot water side piping, 2...Water side piping, 3
... Pressure equalization valve, 4 ... Mixing means, 5.
...Mixing valve, 6...Step motor, 7
... Hot water temperature detection section, 8... Hot water temperature control section,
9... Hot water temperature setting section, 10... Position control section, l1... Change gradient detection section. Name of agent: Patent attorney Shigetaka Awano Name/Figure 1! /-Single side piping 216 I piping 3 -゜゛ Equal pressure. I L Box 41 Mixing Step 5 =-- La Biai Zuri B-Stay Z7'' Motor 7-R Numaichi Detection Section 8 --- 514 Abuse Control L Wholesale Section (Installation Medium H#'4- 9-4 Temperature setting part lθ One plant i division # part 4 Fig. Fig. Fig.

Claims (1)

[Claims] A mixing means for adjusting the mixing ratio of hot water and water, an equal pressure means for keeping the pressure on the hot water side and the water side uniform, and a hot water temperature detection means for detecting the temperature of the mixed hot water made by the mixing means. , a hot water temperature setting means for setting a mixed hot water temperature, a calculation process according to a preset control rule from the output signals of the hot water temperature detection means and the hot water temperature setting means, and an output from the control calculation means. calculation energizing means that determines an operation amount based on the signal and energizes the mixing means; and detecting a change gradient of the hot water temperature from the output signal of the hot water temperature detecting means, and for each setting of the hot water temperature setting means. When the detection signal of the change gradient indicates that the hot water temperature is stable and the output signals of the hot water temperature detection means and the hot water temperature setting means are equal, the position of the mixing means is stored, and the output signal of the change slope detection means is gives priority over the calculation energizing means to the position indicated by the output signal of the position storage means corresponding to the output signal of the hot water temperature setting means from the time when the temperature of the outlet hot water shows a sudden rise until it becomes stable. and positional biasing means for biasing the mixing means at a maximum speed.