JP2011127897A - Automatic hot water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic hot water supply device capable of stably controlling a hot water supply temperature from a mixing valve (for example, shower) of high priority, even when a driving condition of the mixing valve (for example, shower) of high priority is changed. <P>SOLUTION: In this automatic hot water supply device including a plurality of mixing valves (general hot water supply-side mixing valve 2a, bath hot water supply-side mixing valve 2b) for mixing hot water from a hot water flow channel and water from a water flow channel, and supplying hot water from a hot water supply passage, temperature sensors 12a-12d respectively detecting a fluid temperature of the hot water flow channel, a fluid temperature of the water flow channel and a fluid temperature of the hot water supply passage, and a control section 10 for controlling the mixing valves on the basis of results of detections by the temperature sensors 12a-12d and data input in advance, the control section 10 corrects controlled variable of the mixing valves on the basis of openings of the mixing valves and a ratio of flow rates of hot water and water of the fluid supplied from the mixing valves. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an automatic hot water supply apparatus that mixes hot water and water at a desired temperature with a mixing valve and supplies hot water to a bath, a kitchen, or the like.

  As a conventional automatic hot water supply apparatus, for example, if the temperature T2 detected by the bathtub temperature sensor 32 immediately after the start of hot hot water is 40 ° C., the deviation ΔT2> 10 ° C. from the setting 80 ° C. The high-speed driving is performed at a driving speed v2 = 15 [opening% / s] so that the opening degree θ2 of the hot water is increased. As the flow rate increases, the amount of hot water supplied to the general faucet hot water supply path 6 decreases rapidly, but at the same time, the faucet mixing valve 61 is driven so as to increase the opening θ1, so that the faucet mixing valve 61 The ratio of hot water to water to be mixed is larger on the hot water side, and the hot water supply in the general faucet hot water channel 1 generated by the rapid decrease in the amount of hot water supplied from the hot water flow channel 1 to the general faucet hot water supply channel 6. Prevents temperature undershoot The absolute amount of the undershoot can be reduced and the generation time can be shortened, where the driving speed v1 ′ of the faucet mixing valve 61 is determined according to the driving speed v1 of the bathtub mixing valve 31, Although the absolute value is obtained experimentally, it is preferable to make it slower than the driving speed of the bathtub mixing valve 31, for example, driving at a speed half that of the bathtub mixing valve 31. This has been proposed.

Japanese Patent Laying-Open No. 2005-172257 (paragraph numbers 0036 and 0037, FIG. 1)

  For example, in Patent Document 1, the driving speed of a high-impact mixing valve (for example, when there is a shower and bath hot water, the bath side having a large hot water flow rate becomes a high-impact mixing valve) is changed to a low-impact mixing valve ( For example, the method of reflecting in the driving speed of the shower) tries to eliminate inconveniences such as overshooting, undershooting or hunting of hot water temperature when two or more mixing valves operate simultaneously (simultaneous hot water supply). The control time period for controlling is not considered. The change in hot water temperature after the start of simultaneous hot water supply or after the end of simultaneous hot water supply is very fast, and there is a problem that inconveniences such as overshoot of the hot water temperature cannot be solved if the control time period is slow. Furthermore, in order to reflect the driving speed of the mixing valve with high influence on the mixing valve with low influence, when the controllability of the mixing valve with low influence is more important (the temperature changes because the hot water is directly supplied to the human body such as a shower). In other words, when the priority of the low-impact mixing valve is higher, problems such as hot water temperature overshoot from the higher-priority mixing valve may continue for a long time. .

  Further, for example, in Patent Document 1, it is necessary to experimentally determine the driving speed of the mixing valve having a low influence. Therefore, depending on the combination of conditions such as hot water temperature, water temperature, and set temperature, the driving speed becomes inappropriate, and there is a problem that inconveniences such as overshooting of hot water temperature occur. In addition, it takes a lot of time to carry out a test that covers all the conditions that can be assumed, resulting in a high development load and cost. Furthermore, in order to reflect the driving speed of the mixing valve with high influence on the mixing valve with low influence, when the controllability of the mixing valve with low influence is more important (the temperature changes because the hot water is directly supplied to the human body such as a shower). In other words, there is a possibility that the control valve is not properly controlled when the priority is higher in the mixing valve having a lower influence.

  The present invention has been made to solve the above-described problems. Even when the driving condition of a high-priority mixing valve (for example, a shower) changes, the high-priority mixing valve (for example, a shower) An automatic hot water supply apparatus capable of stably controlling the hot water supply temperature is obtained.

  An automatic hot water supply apparatus according to the present invention includes a plurality of mixing valves that mix hot water from a hot water channel and water from a water channel and supply hot water from the hot water channel, fluid temperature of the hot water channel, fluid of the water channel An automatic hot water supply apparatus comprising temperature detection means for detecting the temperature and the fluid temperature of the hot water supply passage, and control means for controlling the mixing valve based on the detection result of the temperature detection means and pre-input data The control means corrects the control amount of the mixing valve based on the opening degree of the mixing valve and the hot water flow rate ratio of the fluid supplied from the mixing valve.

  In this invention, the control amount of the mixing valve is corrected based on the opening of the mixing valve and the hot water flow rate ratio of the fluid supplied from the mixing valve, so that the hot water supply temperature from the high priority mixing valve can be stabilized. Can be controlled.

It is a block diagram of the automatic hot water supply apparatus in embodiment of this invention. It is a control block diagram of the automatic hot water supply apparatus in embodiment of this invention. It is a control flow at the time of the simultaneous hot water supply start in embodiment of this invention. It is a control flow at the time of completion | finish of the simultaneous hot water supply in embodiment of this invention. It is a related figure of the theoretical valve opening degree and warm water flow ratio in the embodiment of this invention. It is a related figure of the opening degree of the general hot water supply side mixing valve 2a and the hot water flow rate ratio in the embodiment of the present invention. It is a related figure of the change rate of the general hot water supply temperature at the time of the simultaneous hot water supply start in this embodiment of this invention, and elapsed time. It is a relationship figure between simultaneous hot-water supply correction coefficient Km of bath hot-water supply side mixing valve 2b and en of general hot-water supply side mixing valve 2a in an embodiment of this invention. FIG. 4 is a relationship diagram between the opening degree of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b, the general hot water supply temperature, and the bath hot water temperature in the embodiment of the present invention (Km not applied). It is a relationship figure (with application of Km) of the opening degree of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b, the general hot water supply temperature, and the bath hot water temperature in the embodiment of the present invention.

Embodiment FIG. 1 is a block diagram of an automatic water heater in an embodiment of the present invention. This automatic hot water supply apparatus includes a hot water storage unit A and a heat source unit B.
The hot water storage unit A includes a hot water storage tank 1, a general hot water supply side mixing valve 2a, a bath side mixing valve 2b, a pressure reducing valve 3, an electromagnetic valve 4, and a control unit 10 corresponding to the control means of the present invention. The hot water storage tank 1 is a can made of metal such as stainless steel, for example, and is provided with a heat insulating material (not shown) around the hot water storage tank 1 to keep the hot water heated by the heat source unit B for a long time. it can. B is a heat source unit and has a built-in heater (not shown) such as a heat exchanger for heating and heating water such as city water to a target hot water storage temperature. The heat source unit is a heat pump using, for example, carbon dioxide as a refrigerant. Further, instead of the heat pump, the heating source may be replaced with an electric heater or the like, or the heating source may be built in the hot water storage tank 1.

  1 is a bathtub for storing hot water supplied from the bath-side mixing valve 2b, and 6 is a mixture of hot water supplied from the general hot-water mixing valve 2a and water supplied from a water source. Mixing tap for hot water supply. The mixing plug 6 may be connected to a shower (not shown). Reference numeral 7 denotes a remote controller capable of inputting / outputting information to / from the automatic hot water supply apparatus (for example, setting of a hot water supply temperature, starting or stopping of hot water supply to a bathtub). A plurality of remote controllers 7 may be installed such as for baths and kitchens.

  The water supplied from the water source passes through the piping and is branched and sent to the lower part of the hot water storage tank 1, the general hot water supply side mixing valve 2a, the bath side mixing valve 2b, and the mixing plug 6. The water supplied from the water source to the general hot water supply side mixing valve 2a and the bath side mixing valve 2b flows through the same pipe partway, and then branches to be sent to the general hot water supply side mixing valve 2a and the bath side mixing valve 2b. The lower part of the hot water tank 1 and the heat source unit B are connected by a pipe, and the water stored in the lower part of the hot water tank 1 is sent to the heat source unit B through this pipe. The water sent to the heat source unit B is heated to a target temperature and then returned to the upper part of the hot water storage tank 1 through a pipe connected from the heat source unit B to the upper part of the hot water storage tank 1. The upper part of the hot water storage tank 1 is connected with piping to the general hot water supply side mixing valve 2a and the bath side mixing valve 2b, and the hot water stored in the upper part of the hot water storage tank 1 is branched into two branches to the general hot water supply side mixing valve 2a. It is sent to the bath-side mixing valve 2b.

  The general hot water supply side mixing valve 2a and the bath side mixing valve 2b are mixing valves that drive the valve body by a driving source such as a servo motor. By adjusting the opening of the mixing valve by moving the valve body, the mixing ratio of hot water and water is adjusted, and the hot water supply temperature is controlled. The water sent from the water source and the hot water sent from the hot water storage tank 1 are mixed by the general hot water supply side mixing valve 2a and the bath side mixing valve 2b to become hot water of a predetermined temperature, respectively, and the mixing plug 6 and the bathtub 5 respectively. Hot water is supplied. A solenoid valve 4 is provided in a pipe connecting the bath-side mixing valve 2 b and the bathtub 5. When the electromagnetic valve 4 is opened, the hot water supplied from the bath-side mixing valve 2b is stored in the bathtub. In the mixing tap 6, hot water supplied from the general hot water supply side mixing valve 2a is mixed with water sent from a water source, and hot water at a desired temperature is used.

  In this embodiment, the mixer tap 6 is configured as a single unit. However, the mixer tap is connected to, for example, a kitchen faucet, a bathroom faucet or shower, and is provided with a plurality of mixer taps. May be. Moreover, although the hot water storage tank 1 is configured as one, it may be configured such that two or more hot water storage tanks are connected in series or in parallel.

  The pipes connecting the constituent elements of the hot water storage unit A are provided with temperature sensors 12a to 12d and flow rate sensors 11a and 11b corresponding to the temperature detecting means of the present invention. The temperature sensor 12a detects a hot water supply temperature of hot water supplied from the general hot water supply side mixing valve 2a to the mixing tap 6. The temperature sensor 12b detects a hot water supply temperature of hot water supplied from the bath-side mixing valve 2b to the bathtub 5. The temperature sensor 12c detects the temperature of water sent from the water source to the general hot water supply side mixing valve 2a and the bath side mixing valve 2b. The temperature sensor 12d detects the temperature of the hot water sent from the hot water storage tank 1 to the general hot water supply side mixing valve 2a and the bath side mixing valve 2b. The flow rate sensor 11a detects the flow rate of hot water sent from the general hot water supply side mixing valve 2a to the mixing tap 6. The flow rate sensor 11b detects the flow rate of hot water sent from the bath side mixing valve 2b to the bathtub 5.

  In the present embodiment, the temperature sensor 12d is provided in the pipe at the top of the hot water storage tank 1, but may be provided on the surface of the can body of the hot water storage tank 1. It is good also as a structure which detects the temperature of the hot water stored in the hot water storage tank 1 directly. Moreover, as a method of installing the temperature sensors 12a to 12d in the pipe, a method of brazing, welding, or fixing the folder to the pipe surface, a method of installing the sensor in the pipe so as to directly measure the water temperature, and the like. Various methods are possible.

  FIG. 2 is a control configuration diagram of the automatic water heater in the present embodiment. The heat source unit B, the general hot water supply side mixing valve 2a, the bath side mixing valve 2b, the electromagnetic valve 4, the remote controller 7, the flow rate sensors 11a and 11b, and the temperature sensors 12a to 12d are connected to the control unit 10 through a communication cable. Signals can be exchanged. Note that communication between the control unit 10 and the sensors may be via wireless communication.

  The control unit 10 is built in the hot water storage unit A, and includes a calculation unit, a drive unit, a transmission / reception unit, a storage unit, an output unit, and an input unit. The calculation unit performs calculation, comparison, determination, and the like based on the flow rate and water temperature at each location detected by the flow rate sensors 11a and 11b and the temperature sensors 12a to 12d. The drive unit drives the general hot water supply side mixing valve 2a, the bath side mixing valve 2b, and the electromagnetic valve 4 based on the calculation result obtained by the calculation unit. The transmission / reception unit transmits an operation command or the like to the heat source unit. Processing in the calculation unit and the driving unit is performed by a microcomputer provided in the control unit 10. The storage unit is, for example, a semiconductor memory provided in the control unit 10. The results obtained by the calculation unit, the functions and tables for calculating the driving conditions for driving the general hot water supply side mixing valve 2a, the bath side mixing valve 2b, and the electromagnetic valve 4, and the data input by the remote control 7 are It is stored in the storage unit. The contents stored in these storage units can be referred to or rewritten as necessary.

  In the output unit, the processing result by the microcomputer is displayed on an LED, a monitor or the like, or a warning sound is generated. In addition, a processing result by the microcomputer is output to a remote place by a communication means (not shown) such as a telephone line, a LAN line, or wireless. In the input unit, data information from the remote controller 7 or the like is input to the storage unit. Further, data information from a communication means (not shown) such as a telephone line, a LAN line, and a radio is input to the storage unit.

  In this embodiment, the control unit 10 is built in the hot water storage unit A. However, the main control unit is provided in the hot water storage unit A, and the sub control unit having a part of the function of the control unit is provided in the heat source unit B. It is good also as a structure which performs a cooperation process by performing data communication between a sub-control part. A configuration in which the remote controller 7 has a part of the function of the control unit 10 or a configuration in which the control unit 10 is provided outside may be employed.

  Next, the hot water supply operation will be described. The temperature of the hot water stored in the hot water storage tank 1 can be preset with the remote controller 7. The hot water heated to the set temperature by the heat source unit B in the midnight time zone is stored in the hot water storage tank 1. Further, the hot water supply temperature to the mixing tap 6 and the hot water supply temperature to the bathtub 5 can be set in advance by the remote controller 7.

  First, general hot water supply (hot water supply to the mixing tap 6) operation will be described. When the mixing plug 6 is opened, the control unit 10 detects the temperature of hot water supplied to the general hot water supply side (mixing plug 6) with the temperature sensor 12a. The control unit 10 controls the opening degree of the general hot water supply side mixing valve 2a so that the temperature detected by the temperature sensor 12a becomes the set hot water supply temperature, and the hot water supplied from the upper part of the hot water storage tank 1 and the water source are supplied. Mix the resulting water at a suitable temperature.

Then, bath hot water supply (hot water supply to the bathtub 5) operation | movement is demonstrated. There are four patterns of bath water supply operations, such as hot water filling, high temperature hot water, addition hot water, and water injection.
Each hot water supply operation will be described below.

  In order to perform filling, a filling switch (not shown) of the remote controller 7 is pressed. Upon receiving a hot water filling command from the remote controller 7, the control unit 10 controls the opening of the hot water supply side mixing valve 2b so that the temperature detected by the temperature sensor 12b becomes the hot water supply temperature to the set bathtub, and electromagnetic Open the valve 4 and start filling the bathtub 5 with water. After the hot water filling to the bathtub 5 is started, the integrated flow rate is counted by the flow sensor 11b, and the hot water filling is continued until the amount of the hot water bath set in advance by the remote controller 7 is reached. When the accumulated flow reaches the set amount of hot water in the bathtub, the solenoid valve 4 is closed to complete the hot water filling.

  In order to perform hot hot water supply when the temperature of hot water in the bathtub 5 falls, a hot hot water supply switch (not shown) of the remote controller 7 is pressed. The control unit 10 that has received a high-temperature hot water instruction from the remote controller 7 controls the opening degree of the bath hot water mixing valve 2b so that the temperature detected by the temperature sensor 12b is high (for example, 60 ° C.), and the electromagnetic valve 4 To start hot hot water supply to the bathtub 5. After the hot water supply to the bathtub 5 is started, the integrated flow rate is counted by the flow sensor 11b, and when reaching a certain amount (for example, 20 L), the solenoid valve 9 is closed to complete the hot water supply.

  In order to add hot water when the amount of hot water in the bathtub 5 decreases, a hot water switch (not shown) is pushed with the remote controller 7. The control unit 10 that has received a command for adding hot water from the remote controller 7 controls the opening degree of the hot water supply side mixing valve 2b so that the temperature detected by the temperature sensor 12b becomes the hot water supply temperature to the set bathtub, and electromagnetic The valve 4 is opened to start adding hot water to the bathtub 5. After the start of adding hot water to the bathtub 5, the integrated flow rate is counted by the flow sensor 11b, and when reaching a certain amount (for example, 20L), the solenoid valve 4 is closed to complete the adding hot water.

  In order to perform water injection, the water injection switch of the remote controller 7 is pressed. Upon receiving the water injection command from the remote controller 7, the control unit 10 controls the opening degree of the hot water supply side mixing valve 2b so that the temperature detected by the temperature sensor 12b becomes the water temperature, and opens the electromagnetic valve 4 to the bathtub 5. Start pouring water. After the start of water injection into the bathtub 5, the integrated flow rate is counted by the flow sensor 11b, and when reaching a certain amount (for example, 20L), the electromagnetic valve 4 is closed to complete the water injection.

Depending on the use conditions of the automatic water heater, general hot water and bath hot water may be performed simultaneously. The control flow at the time of starting simultaneous hot water supply at this time is shown in FIG. Moreover, the control flow at the time of completion | finish of simultaneous hot-water supply is shown in FIG.
FIG. 3 is a control flow at the start of simultaneous hot water supply. The initial state of this figure is a single hot water supply state of general hot water supply only. In ST1, the opening degree of the general hot water supply side mixing valve 2a is controlled so that the hot water temperature detected by the temperature sensor 12a becomes the set temperature. The opening degree control of the general hot water supply side mixing valve 2a is performed by feedback control (details will be described later) according to the deviation amount between the current hot water supply temperature and the set temperature. In ST2, it is determined whether there is a hot water bath. In addition, the presence or absence of hot water supply of general hot water supply and bath hot water supply can be determined from the flow rates detected by the flow rate sensors 11a and 11b. If it is determined in ST2 that there is bath hot water supply, the process proceeds to ST3.

  In ST3, it is determined whether or not bath hot water supply has just started. As a determination method, for example, the determination from ST1 to ST5 is performed according to the control flow shown in FIG. 3 at a constant control time period ΔT. In the previous determination, there is no bath hot water supply (flow rate sensor 11b output = 0), and in this determination, if there is bath hot water supply (flow rate sensor 11b output> 0), it is determined that bath hot water supply has just started. If it is determined in ST3 that the bath hot water supply has just started, the opening degree of the bath hot water side mixing valve 2b is set to the designated initial opening degree in ST4. When it is determined in ST3 that it is not immediately after the start of bath hot water supply (after the setting of the opening degree of the bath hot water side mixing valve 2b to the designated initial opening degree), the temperature sensor 12b detects in ST5 The opening degree of the hot water supply side mixing valve 2b is controlled so that the temperature to be set becomes the set temperature. The opening degree control of the bath hot water supply side mixing valve 2b is performed by feedback control (details will be described later) according to the deviation amount between the current hot water supply temperature and the set temperature, similarly to the opening degree control of the general hot water supply side mixing valve 2a.

  Here, the designated initial opening degree of ST4 is a hot water supply side mixing valve 2b (priority is higher) in which the hot water temperature on the general hot water supply side (high priority) does not change as much as possible even when simultaneous hot water supply starts or ends. Low) and is often near the center (opening 50%) of the opening of the hot water supply side mixing valve 2b. General hot water supply immediately after the start of bath hot water supply (immediately after the start of simultaneous hot water supply) by setting the opening of the bath hot water supply side mixing valve 2b to the specified initial opening immediately after the start of bath hot water supply (immediately after the start of simultaneous hot water supply) Hunting, overshoot, or undershoot of the hot water supply temperature of the side mixing valve 2a can be prevented. Pipe pressure loss due to pipe routing from hot water storage tank 1 to general hot water supply side mixing valve 2a and bath hot water supply side mixing valve 2b, and pipe pressure loss due to pipe routing from water source to general hot water supply side mixing valve 2a and bath hot water supply side mixing valve 2b Depending on the balance, the designated initial opening may not be near the center of the opening of the hot water supply side mixing valve 2b. In this case, the designated initial opening degree of the hot water supply side mixing valve 2b may be determined in advance by a test. In addition, when the specified initial opening degree is dependent on the absolute flow rate, the flow rate ratio, the set temperature, or the like of general hot water and bath water supply, the specified initial opening degree may be set as a function of these. The definition of priority will be described later.

  FIG. 4 is a control flow at the end of simultaneous hot water supply. The initial state in this figure is a state where general hot water supply and bath hot water supply are performed simultaneously. In ST6, the opening degree of the general hot water supply side mixing valve 2a is controlled so that the hot water temperature detected by the temperature sensor 12a becomes the set temperature. The opening degree control of the general hot water supply side mixing valve 2a is performed by feedback control (details will be described later) according to the deviation amount between the current hot water supply temperature and the set temperature. In ST7, it is determined whether or not the bath water supply has ended. As a determination method, for example, the determination from ST6 to ST10 is performed according to the control flow shown in FIG. 4 at a constant control time period ΔT. In the previous determination, bath hot water is present (flow sensor 11b output> 0), and in this determination, bath hot water is determined not to be present (flow sensor 11b output = 0). If bath hot water supply is not completed, the process proceeds to ST10, and the opening degree of the bath hot water side mixing valve 2b is controlled so that the hot water supply temperature detected by the temperature sensor 12b becomes the set temperature. When bath hot water supply is completed, the process proceeds to ST8, and the solenoid valve 4 on the bath side is closed. At this time, the opening degree of the bath hot water supply side mixing valve 2b may be left as it is, or may be a predetermined opening degree determined in advance. In ST9, the opening degree of the general hot water supply side mixing valve 2a is set to the theoretical valve opening degree for the set temperature shown below. After setting the opening degree of the general hot water supply side mixing valve 2a to the theoretical valve opening degree, the process returns to ST6 again, and the general hot water supply temperature is controlled to the set temperature.

The theoretical valve opening STr of the general hot water supply side mixing valve 2a is obtained by the following equation.
STr = (Ts−Tw) / (Th−Tw) (1)
Here, Ts [° C.] is a set temperature (general hot water temperature set by the remote controller 7), and Th [° C.] is hot water sent from the hot water storage tank 1 detected by the temperature sensor 12d to the general hot water supply side mixing valve 2a. And Tw [° C.] are temperatures of water sent from the water source detected by the temperature sensor 12c to the general hot water supply side mixing valve 2a. The value of the theoretical valve opening STr is in the range of 0 (opening 0%) to 1 (opening 100%). The state where the value of the theoretical valve opening STr is 0 (opening 0%) is a state in which the port on the water source side is fully opened (that is, water from the water source is supplied). The state where the value of the theoretical valve opening STr is 1 (opening 100%) is a state in which the port on the hot water storage tank 1 side is fully opened (that is, hot water from the hot water storage tank 1 is supplied).

The theoretical valve opening is generally defined by the difference in thermal energy between the set temperature and water supplied from the water source to the general hot water supply side mixing valve 2a, and from the hot water and water source supplied from the hot water storage tank 1 to the general hot water supply side mixing valve 2a. It is a ratio with the thermal energy difference with the water supplied to the hot water supply side mixing valve 2a. In practice, the density of water decreases as the temperature increases, and the specific heat changes with temperature. As for the mixing valve, the relationship between the opening and the flow rate ratio is not proportional due to individual characteristics. This theoretical opening STr is a theoretical opening that does not take into account differences in density and specific heat due to differences in water temperature and mixing valve characteristics. In this case, the theoretical valve opening STr is equal to the hot water flow rate ratio XHr shown in the following equation. FIG. 5 shows the relationship between the theoretical valve opening STr and the hot water flow rate ratio XHr.
XHr = Qq / (Qq + Qw) (2)
Here, Qq is the flow rate of high-temperature hot water sent from the hot water storage tank 1 to the general hot water supply side mixing valve 2a, and Qw is the flow rate of water sent from the water source to the general hot water supply side mixing valve 2a.

  In the present embodiment, the simultaneous operation start operation in which the bath water supply is started from the single hot water supply state of the general hot water supply, and the simultaneous operation end operation in which only the bath water supply is stopped from the state in which the general hot water supply and the bath hot water supply are performed simultaneously. Although explained, even when the relationship between general hot water supply and bath hot water supply is reversed, the same control can be performed.

Next, the opening degree control method of the general hot water supply side mixing valve 2a in the present embodiment will be described. The hot water supply side mixing valve 2b is also controlled by a similar control method. The opening control method of the general hot water supply side mixing valve 2a in the present embodiment is proportional to the deviation between the set temperature (the general hot water temperature set by the remote controller 7) and the actual hot water temperature, as shown in the following equation. It is based on feedback control multiplied by.
MV (n) = MV (n-1) + dMV (3)
Here, MV (n) represents the opening degree of the general hot water supply side mixing valve 2a set this time, and MV (n-1) represents the opening degree of the general hot water supply side mixing valve 2a set last time. DMV represents the corrected opening degree of the general hot water supply side mixing valve 2a, that is, the feedback amount.

The corrected opening dMV is expressed by the following equation.
dMV = Z ・ Ki ・ Km ・ en (4)
en = Ts−Tq [° C.] (5)
Here, en is the deviation amount between the set temperature and the actual hot water temperature, Ki is the control gain, Km is the simultaneous hot water correction coefficient, and Tq is the actual hot water temperature.

  Then, the characteristic of the opening degree control method of the general hot water supply side mixing valve 2a which improved the temperature followability with respect to the preset temperature of general hot water supply is demonstrated. When simultaneous hot water supply starts or ends, hunting, overshooting, or undershooting of general hot water supply temperature with high priority becomes a problem. Therefore, in order to improve the temperature followability with respect to the set temperature of the general hot water supply with high priority, high followability with respect to the change in the driving condition of the general hot water supply side mixing valve 2a, early response to the temperature change of the general hot water supply, and general hot water supply The opening degree interlocking control of the general hot water supply side mixing valve 2a and the opening degree of the hot water supply side mixing valve 2b at the start of simultaneous hot water supply and bath hot water supply was improved.

A control method for improving high followability with respect to changes in the driving conditions of the general hot water supply side mixing valve 2a will be described below.
FIG. 6 shows the relationship between the actual opening degree STn of the hot water supply side mixing valve 2a and the hot water flow rate ratio XHn. FIG. 6 also shows the relationship between the theoretical valve opening STr and the hot water flow rate ratio XHr in FIG. The hot water flow rate ratio XHn was obtained using the following equation obtained from equations (1) and (2).
XHn = (Tq−Tw) / (Th−Tw) (6)
Here, Tq [° C.] is a general hot water supply temperature detected by the temperature sensor 12a.

  The actual hot water flow rate ratio XHn deviates from the slope γ (= 1) line (the position of XHs in the figure) with respect to the opening degree STn of the general hot water supply side mixing valve 2a, and deviates from the theoretical hot water flow rate ratio XHs. It will shift by dXH. This is because the relationship between the opening degree STn of the general hot water supply side mixing valve 2a and the hot water flow rate ratio XHn is affected by various driving conditions of the general hot water supply side mixing valve 2a. For example, the difference in density and specific heat due to the difference in water temperature, the characteristics of the general hot water supply side mixing valve 2a (the relationship between the opening degree and the flow rate ratio is not proportional), or the hot water storage tank 1 is supplied to the general hot water supply side mixing valve 2a. And the pressure difference of water supplied from the hot water source to the general hot water supply side mixing valve 2a. Among these drive conditions for the general hot water supply side mixing valve 2a, the pressure difference between the hot water supplied from the hot water storage tank 1 to the general hot water supply side mixing valve 2a and the water supplied from the water source to the general hot water supply side mixing valve 2a is particularly large. . For example, when a hot water supply operation for bath hot water is performed during the general hot water supply, the pressure of the high temperature hot water supplied from the hot water storage tank 1 to the general hot water supply side mixing valve 2a decreases. For this reason, the flow rate of hot water decreases, the hot water flow rate ratio approaches zero, and the general hot water supply temperature becomes close to the temperature of water supplied from the water source.

Therefore, in the method for controlling the opening degree of the general hot water supply side mixing valve 2a in the present embodiment, the coordinates of the “mixing valve opening degree-warm water flow rate ratio” are obtained from the relationship between the actual opening degree of the general hot water supply side mixing valve 2a and the hot water flow rate ratio XHn. On the plane (FIG. 6), the corrected inclination (α, β in FIG. 6) suitable for the operating conditions at that time is obtained, and the corrected opening degree dMV ′ (feedback amount) of the general hot water supply side mixing valve 2a is obtained. Specifically, as shown in FIG. 6, when the actual hot water flow rate ratio XHn is smaller than the theoretical hot water flow rate ratio XHs, that is, when the general hot water supply temperature is lower than the set temperature, the correction opening of the general hot water supply side mixing valve 2a is performed. The degree dMV ′ is obtained using the correction slope α. The corrected opening degree dMV ′ of the general hot water supply side mixing valve 2a is expressed by the following equation.
dMV ′ = A · dXH / α = Ki / α · en = Z · Ki · en (7)
Where dXH = (Ts−Tq) / (Th−Tw) = en / (Th−Tw) (8)
Ki = A / (Th−Tw) (9)
Z = 1 / α = (1-STn) / (1-XHn) (10)
It is. Further, A in equation (7) is a constant, and en represents the deviation amount between the set temperature in equation (5) and the actual hot water supply temperature. The simultaneous hot water supply correction coefficient (Km shown in the equation (4)) of the correction opening degree dMV ′ of the general hot water supply side mixing valve 2a is 1.

The correction slopes α and β are selectively used based on the current valve characteristics depending on the sign of en. When en ≧ 0, that is, when the general hot water supply temperature is lower than the set temperature, correction is performed to make the opening of the general hot water supply side mixing valve 2a larger (open) than STn, and therefore, the correction gradient α is used. When en <0, that is, when the general hot water supply temperature is higher than the set temperature, correction is performed to make the opening degree of the general hot water supply side mixing valve 2a smaller (close) than STn, so the correction slope β is used. Therefore, when en <0, equation (10) becomes the following equation.
Z = 1 / β = (STn-0) / (XHn-0) (11)

  In the automatic hot water supply apparatus controlled in this way, the corrected opening degree dMV ′ according to the driving condition of the general hot water supply side mixing valve 2a from the relationship between the actual opening degree STn of the general hot water supply side mixing valve 2a and the hot water flow rate ratio XHn. By obtaining (feedback amount) and substituting it into the corrected opening degree (dMV) of equation (3), it is possible to improve high followability with respect to changes in the driving conditions of the general hot water supply side mixing valve 2a. Therefore, it is possible to control the general hot water temperature accurately by suppressing hunting, overshooting or undershooting of the general hot water temperature having a high priority when simultaneous hot water supply starts or ends. Further, even if a design change occurs such as a change in the type of the general hot water supply side mixing valve 2a or a change in the piping arrangement in the hot water storage unit A, the control software can be handled without changing.

  Further, in obtaining the corrected opening degree dMV ′ of the general hot water supply side mixing valve 2a, the temperature Th of high-temperature hot water sent from the hot water storage tank 1 to the general hot water supply side mixing valve 2a and the temperature of water sent from the water source to the general hot water supply side mixing valve 2a. Since Tw is used, when the correction opening degree dMV ′ is increased, the general hot water temperature having a high priority causes hunting or the like. Conversely, even when the correction opening degree dMV ′ is increased, the general priority is high. For example, when the hot water supply temperature is not affected, the correction opening degree dMV ′ capable of quickly controlling the opening degree of the general hot water supply side mixing valve 2a can be obtained in accordance with the driving conditions of the general hot water supply side mixing valve 2a.

  In the case of single hot water supply for general hot water supply, the opening degree of the general hot water supply side mixing valve 2a at which the hot water supply temperature becomes the set temperature is close to the theoretical valve opening degree STr. By controlling to return to the theoretical valve opening STr once, the general hot water temperature can be stably maintained even in the transient change of the general hot water temperature at the end of the simultaneous hot water supply.

A control method for quickly dealing with a temperature change in general hot water supply will be described below.
FIG. 7 is a relationship diagram between the rate of change of the general hot water temperature and the elapsed time at the start of simultaneous hot water supply in the embodiment of the present invention. This figure shows a general hot water supply temperature when simultaneous hot water supply of general hot water and bath hot water is started from a single hot water supply of general hot water in a state in which the opening degree of both of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b is fixed. The change with time is shown. The horizontal axis is the elapsed time, and simultaneous hot water supply is started at the time of 0 [sec] (stable hot water supply state of general hot water alone before 0 [sec]). The vertical axis represents the rate of change of the general hot water supply temperature, with 0 [sec] being the reference for the rate of change 0 (0%), and the state where the general hot water temperature is stable after simultaneous hot water supply is 100%. The change of the general hot water temperature after the start of the simultaneous hot water supply is very fast, and the time until the rate of change reaches 63.2% of the stable state is about 0.1 to 0.3 [sec]. In order to control the opening degree of the general hot water supply side mixing valve 2a following the change in the general hot water temperature, the control time period ΔT needs to be at least 0.1 to 0.3 [sec] or less.

In the automatic hot water supply apparatus controlled in this way, the opening time of the general hot water supply side mixing valve 2a is controlled at a control time period ΔT of at least 0.1 to 0.3 [sec] or less, so that the simultaneous hot water supply is started. It is possible to quickly cope with disturbances such as a transient change in the general hot water temperature and a sudden change in the hot water flow rate. Therefore, it is possible to control the general hot water temperature accurately by suppressing overshoot and undershoot of the general hot water temperature having a high priority as much as possible.
Similarly, by controlling the opening of the hot water supply side mixing valve 2b at a control time period ΔT of at least 0.1 to 0.3 [sec] or less, a transient change in the hot water temperature at the start of simultaneous hot water supply, It is possible to respond quickly to disturbances such as a rapid change in the hot water flow rate. Accordingly, it is possible to control the general hot water temperature accurately by suppressing overshoot and undershoot as much as possible even for the bath hot water temperature having a low priority.

A control method for improving the interlock control of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b at the start of simultaneous hot water supply will be described below.
In simultaneous hot water supply of general hot water supply and bath hot water supply, the opening degree of both the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b affects the controllability of the hot water supply temperature. In the simultaneous hot water supply of general hot water and bath hot water, the required degree of stability of each hot water temperature is different, and there is a possibility that danger or discomfort may occur if the hot water temperature changes suddenly during use, such as showering and hand washing General hot water supply has a higher priority. In the case of bath hot water supply, since hot water is supplied into the bathtub, there is little possibility of danger or discomfort even if it takes some time to stabilize the temperature, and the priority is low. In such a case, even if the hot water supply temperature controllability of the low-priority bath hot water supply side mixing valve 2b is sacrificed somewhat, the hot water supply temperature controllability of the general hot water supply side mixing valve 2a with high priority is emphasized. It is desirable for the control to be able to minimize the change in the hot water supply temperature.

  In addition, when the simultaneous hot water supply is started and finished, the opening degree of the general hot water supply side mixing valve 2a (or the bath hot water supply side mixing valve 2b) is theoretically determined to return to the single hot water supply of the general hot water supply (or bath hot water) at the end of the simultaneous hot water supply. Close to the valve opening STr, it is easy to predict the opening. However, when the simultaneous hot water supply starts, the flow rate of the hot water supplied from the hot water storage tank 1 to the general hot water supply side mixing valve 2a and the water supplied from the water source to the general hot water supply side mixing valve 2a change abruptly. difficult. Therefore, at the start of simultaneous hot water supply, the hot water supply temperature overshoots until the hot water temperature of the general hot water supply side and the hot water supply side mixing valve 2b and the opening of the hot water supply side mixing valve 2b are stabilized. It is desirable to perform control while taking into consideration the opening degree of the general hot water supply side mixing valve 2a and the effects of the mixing valves of both the hot water supply side mixing valve 2b.

  FIG. 8 shows the simultaneous hot water supply correction coefficient Km (formula (4)) of the bath hot water supply side mixing valve 2b (lower priority) in the present embodiment and en of the general hot water supply side mixing valve 2a (higher priority). FIG. 6 is a relationship diagram between a set temperature and a deviation amount between actual hot water supply temperatures). The horizontal axis represents the absolute value of en of the general hot water supply side mixing valve 2a (higher priority), and the vertical axis represents the simultaneous hot water supply correction coefficient Km of the bath hot water mixing valve 2b (lower priority). When the absolute value of en of the general hot water supply side mixing valve 2a (which has higher priority) is close to zero and the general hot water temperature can be controlled to the set temperature, the simultaneous hot water supply correction coefficient Km is 1 (no correction) It is close to (equal). As the absolute value of en of the general hot water supply side mixing valve 2a (higher priority) increases, the simultaneous hot water supply correction coefficient Km of the bath hot water mixing valve 2b (lower priority) approaches 0 (priority becomes lower). The amount of opening adjustment of the low hot water supply side mixing valve 2b is small). When the absolute value of en of the general hot water supply side mixing valve 2a (higher priority) is equal to or greater than a preset value F (for example, F = 5 ° C.), the bath hot water mixing valve 2b (lower priority) is simultaneously used. The hot water supply correction coefficient Km becomes 0 (the opening degree adjustment of the hot water supply side mixing valve 2b having a low priority is stopped).

  In the automatic hot water supply apparatus controlled in this way, when the deviation amount en of the general hot water supply side mixing valve 2a (higher priority) increases, the bath hot water supply side mixing valve 2b (lower priority) By regulating the opening degree adjustment amount, it is possible to suppress the amount of overshoot and undershoot of the hot water supply temperature of the general hot water supply side mixing valve 2a (which has higher priority). When the deviation amount en of the general hot water supply side mixing valve 2a (higher priority) is small, the opening adjustment amount of the bath hot water mixing valve 2b (lower priority) is not regulated. In order to control, the opening degree control of the bath hot water side mixing valve 2b (low priority) can be quickly performed. That is, the hot water supply temperature of the bath hot water supply side mixing valve 2b (which has a lower priority) can be quickly controlled to the target temperature.

  FIG. 9 shows the opening degrees of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b when the simultaneous hot water supply correction coefficient Km is not applied to the opening degree control of the bath hot water supply side mixing valve 2b (which has a lower priority). It is a related figure with general hot-water supply temperature and bath hot-water supply temperature, (a) is a relation figure of the opening degree of general hot-water supply side mixing valve 2a and bath hot-water supply side mixing valve 2b, and elapsed time, (b) is general hot-water supply temperature And the relationship figure of bath hot-water supply temperature and elapsed time is shown. FIG. 10 shows the opening of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b when the simultaneous hot water supply correction coefficient Km is applied to the opening degree control of the bath hot water side mixing valve 2b (which has a lower priority). (A) is a relationship diagram between the opening of the general hot water supply side mixing valve 2a and the bath hot water side mixing valve 2b and the elapsed time, and (b) is a general diagram. The relationship figure of hot water supply temperature and bath hot water supply temperature, and elapsed time is shown.

  When the simultaneous hot water supply correction coefficient Km is not applied, the opening degrees of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b are controlled independently. The amount of undershoot in the hot water supply temperature is large. However, when the simultaneous hot water supply correction coefficient Km is applied, the amount of change in the opening degree of the hot water supply side mixing valve 2b becomes smaller as en of general hot water (the amount of deviation between the set temperature and the actual hot water temperature) increases. The undershoot amount of the general hot water temperature is small. When applying the simultaneous hot water supply correction coefficient Km, the time until the bath hot water temperature reaches a stable time is slightly longer. However, as described above, it is more important to ensure the hot water temperature stability of general hot water with a high priority. Yes, and there is no problem because shortening the time to stabilization on the bath side is not an important factor.

  In the present embodiment, the drive speeds of the valve bodies of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b are not changed, but the magnitude of the deviation amount en between the target set temperature and the actual hot water supply temperature is not changed. Accordingly, the driving speed may be controlled. For example, when the deviation amount en is large, the driving speed is increased to increase the convergence speed to the target set temperature, and when the deviation amount en is small, the driving speed is decreased to prevent hunting or the like.

  In addition to the opening control of the general hot water supply side mixing valve 2a and the bath hot water supply side mixing valve 2b in this embodiment, the driving conditions such as the set temperature of each mixing valve, the temperature of water supplied from the water source, or the flow rate are set. Accordingly, a method of moving to a predetermined valve opening in advance (feed forward control) may be used in combination at the start or end of simultaneous hot water supply. Here, the predetermined valve opening is determined in advance based on a test or a detailed simulation result, and is stored in the storage means of the control unit 10. Further, this feedforward control may be a method that is used limited to some conditions.

  DESCRIPTION OF SYMBOLS 1 Hot water storage tank, 2a General hot water supply side mixing valve, 2b Bath hot water supply side mixing valve, 3 Pressure reducing valve, 4 Solenoid valve, 5 Bathtub, 6 Mixing plug, 7 Remote control, 10 Control part, 11a, b Flow sensor, 12a-12d Temperature Sensor, A hot water storage unit, B heat source unit.

Claims (6)

A plurality of mixing valves for mixing hot water from the hot water channel and water from the water channel and supplying hot water from the hot water supply channel;
Temperature detecting means for detecting the fluid temperature of the hot water channel, the fluid temperature of the water channel, and the fluid temperature of the hot water channel,
In an automatic hot water supply apparatus comprising a control means for controlling the mixing valve based on the detection result of the temperature detection means and pre-input data,
The control means includes
The control amount of the mixing valve is
An automatic hot water supply apparatus that corrects based on an opening degree of the mixing valve and a hot water flow rate ratio of fluid supplied from the mixing valve. The hot water flow rate ratio is
The mixing temperature of the fluid flowing through the hot water channel and the fluid flowing through the water channel in the fluid flowing through the hot water channel, calculated from at least the fluid temperatures of the hot water channel, the water channel, and the hot water channel The automatic hot water supply apparatus according to claim 1, wherein the automatic hot water supply apparatus is a ratio. Comprising flow rate detection means for detecting the flow rate of the fluid flowing through the hot water supply path,
The automatic hot water supply apparatus according to claim 1 or 2, wherein the mixing valve is controlled in accordance with a flow rate of the hot water supply passage. The control means includes
The correction opening of the mixing valve is
The automatic hot water supply apparatus according to any one of claims 1 to 3, wherein the automatic hot water supply apparatus is obtained based on at least a fluid temperature of the hot water channel and a fluid temperature of the water channel.   The automatic hot water supply apparatus according to any one of claims 1 to 4, wherein the control means controls the driving speed of the mixing valve in accordance with a deviation amount between a target hot water supply temperature and an actual hot water supply temperature. The control means includes
Based on the temperature of the hot water channel, the temperature of the water channel, and the target hot water temperature,
6. The initial opening degree of the mixing valve at the start or end of simultaneous operation when two or more mixing valves are simultaneously operated is controlled to a predetermined opening degree. The automatic hot water supply apparatus as described in.

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