JP3805595B2 - Hot water temperature control method and hot water supply apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water supply temperature control method and a hot water supply apparatus for controlling a hot water supply temperature by adjusting a control position of a mixing valve.
[0002]
[Prior art]
Conventionally, as shown in FIG. 4, a bypass pipe 53 that communicates the water supply pipe 51 and the hot water supply pipe 52 connected to the heat exchanger 50 is provided, and the hot water supplied from the heat exchanger 50 and the bypass pipe 53 are provided. A so-called mixing type that controls the temperature of hot water supplied downstream of the junction by adjusting the mixing ratio with the supplied water by a mixing valve 54 provided at the junction of the hot water supply pipe 52 and the bypass pipe 53. A hot water supply apparatus is known.
[0003]
In such a hot water supply device, a water flow switch 55 that detects the presence or absence of water supplied to the water supply pipe 51, a water supply temperature sensor 56 that detects the temperature of water supplied to the water supply pipe 51, and hot water discharged from the heat exchanger 50. A heat exchange temperature sensor 57 for detecting the temperature of the hot water and a hot water supply temperature sensor 58 for detecting the temperature of hot water supplied to the downstream side of the joining point of the hot water supply pipe 52 and the bypass pipe 53 are provided.
[0004]
While the water flow switch 55 detects that water is being supplied to the water supply pipe 51, the remote controller 61 sets the detected temperature T _out of the hot water supply temperature sensor 58 (hereinafter referred to as the actual hot water supply temperature T _out ). The control position of the mixing valve 54 is adjusted by the controller 60 so as to coincide with the target hot water supply temperature _Tset .
[0005]
Controller 60, and the temperature T _in of the water supplied to the water supply pipe 51 detected by the water temperature sensor 56, the temperature T _h of the hot water supplied from the heat exchanger 50 as detected by the heat exchanger temperature sensor 57 By recognizing, it is possible to calculate a necessary mixing ratio R _n that is a mixing ratio necessary for performing the hot water supply of the actual hot water supply temperature T _out to the target hot water supply temperature T _set .
[0006]
Then, by adjusting the control position of the mixing valve 54 so as to obtain the necessary mixing ratio R _n calculated in this way, the controller 60 can match the actual hot water supply temperature _Tout with the target hot water supply temperature _Tset. . However, in practice, since the mixing valve 54 has a positioning error that varies depending on the individual, it is difficult for the controller 60 to immediately operate the control position of the mixing valve 54 to a control position where the required mixing ratio R _n can be obtained.
[0007]
That is, the controller 60 has a data table 62 that holds the correspondence relationship between the control position of the mixing valve 54 and the mixing ratio that is assumed to be determined according to the control position, but according to the required mixing ratio R _n . Even if the control position of the mixing valve 54 is obtained from the data table 62 and the mixing valve 54 is operated to the control position, the actually set mixing ratio does not become the required mixing ratio R _n due to the positioning error described above. . Therefore, the actual hot water supply temperature _Tout does not coincide with the target hot water supply temperature _Tset .
[0008]
Therefore, the controller 60 performs PI control based on the following equations (1) and (2) so as to eliminate the deviation ΔT (= T _set −T _out ) between the actual hot water temperature T _out and the target hot water temperature T _set. I was going. Note that P ₁ in the formula (1) and I _{1 in the} formula (2) are constants determined by experiments, and P and I are calculated in units of control steps of the stepping motor 59 that changes the control position of the mixing valve 54. Is done.
[0009]
P = P ₁ × (T _set −T _out ) (1)
I = I ₁ × ∫ (T _set −T _out ) (2)
In PI control, P and I are calculated by the above formulas (1) and (2), and the control position of the mixing valve 54 is moved by P + I steps, so that the above-described deviation ΔT is reduced.
[0010]
However, the relationship between the control position of the mixing valve 54 and the actual mixing ratio determined according to the control position is not constant due to individual variations of the mixing valve 54. For this reason, the constants P ₁ and I ₁ need to be determined in consideration of such individual variations of the mixing valve 54. However, even if variations occur through experiments or the like, the actual hot water supply temperature _Tout is quickly set to the target hot water supply temperature T. There is an inconvenience that man-hours are required to determine the constants P ₁ and I ₁ that can be matched with _set . Further, when a mixing valve exceeding the assumed range of variation is used, PI control based on the inappropriate constants P ₁ and I ₁ is performed on the mixing valve, so the actual hot water supply temperature T _out Has a disadvantage that it takes a long time to coincide with the target hot water supply temperature _Tset .
[0011]
[Problems to be solved by the invention]
The present invention eliminates the above inconveniences, and even when the relationship between the control position of the mixing valve and the actual mixing ratio determined by the control position varies depending on the individual mixing valve, the hot water supply temperature is quickly changed to the target hot water supply temperature. It is an object of the present invention to provide a hot water supply temperature control method and a hot water supply device that can be matched.
[0012]
[Means for Solving the Problems]
The present invention has been made to achieve the above object, and the hot water supply temperature control method of the present invention is generated by heating from water supplied from the water supply pipe by a water supply pipe and a heat exchanger connected to the hot water supply pipe. The mixing ratio of the hot water supplied to the hot water supply pipe and the water supplied to the hot water supply pipe via a bypass pipe that bypasses the heat exchanger and connects the hot water supply pipe and the hot water supply pipe, By adjusting and controlling the control position of the mixing valve that varies the mixing ratio, the temperature of hot water supplied to the downstream side of the joining point of the hot water supply pipe with the bypass pipe is matched with a predetermined target hot water supply temperature. The present invention relates to an improvement in a method for controlling a hot water supply temperature.
[0013]
And the assumed mixing ratio which is a mixing ratio according to the control position of the mixing valve obtained from a data table storing the relationship between the control position of the mixing valve and the mixing ratio assumed to be determined according to the control position Water supplied from the water supply pipe based on the temperature of the hot water supplied from the heat exchanger and the temperature of the hot water supplied downstream of the junction with the bypass pipe of the hot water supply pipe Based on the temperature of the water calculated in this way and the temperature of hot water supplied from the heat exchanger, a necessary mixing ratio that is a mixing ratio necessary for obtaining the target hot water supply temperature is calculated. Then, by setting the control position of the mixing valve to the control position obtained from the data table in accordance with the required mixing ratio, the hot water supplied to the downstream side of the junction with the bypass pipe of the hot water supply pipe Temperature is given Characterized in that to match the target hot water temperature.
[0014]
According to this invention, first, the assumed mixing ratio obtained from the data table, the temperature of hot water supplied from the heat exchanger, and the downstream side of the joining point of the bypass pipe of the hot water supply pipe are supplied. The temperature of the water supplied from the water supply pipe is calculated based on the temperature of the hot water. And the temperature of the water calculated in this way reflects the error of the actual mixing ratio (hereinafter referred to as the actual mixing ratio) determined by the assumed mixing ratio and the control position of the mixing valve. For example, when the mixing ratio is a ratio of the flow rate of water supplied from the bypass pipe to the flow rate of hot water supplied from the heat exchanger, the calculation is performed when the assumed mixing ratio is larger than the actual mixing ratio. The temperature of the water is actually lower than the temperature of the water supplied to the water supply pipe. Conversely, when the assumed mixing ratio is smaller than the actual mixing ratio, the calculated water temperature is higher than the temperature of the water actually supplied to the water supply pipe.
[0015]
Therefore, the required mixing ratio calculated based on the temperature of water calculated in this way and the temperature of hot water supplied from the heat exchanger is the difference between the assumed mixing ratio and the actual mixing ratio. The mixing ratio is eliminated. Therefore, when the control position of the mixing valve is set to the control position obtained from the data table according to the required mixing ratio, the difference between the assumed mixing ratio and the actual mixing ratio varies due to individual variation of the mixing valve Even so, the temperature of hot water supplied to the downstream side of the joining point of the hot water supply pipe with the bypass pipe can be quickly set to a predetermined target hot water supply temperature.
[0016]
The hot water supply apparatus of the present invention, which is a specific embodiment of the above-described hot water supply temperature control method of the present invention, is connected to a water supply pipe and a hot water supply pipe, and is generated by heating water supplied from the water supply pipe. A heat exchanger that supplies hot water to the hot water supply pipe, a bypass pipe that bypasses the heat exchanger and communicates the water supply pipe and the hot water supply pipe, hot water supplied from the heat exchanger to the hot water supply pipe, A mixing valve that adjusts a mixing ratio of water supplied from the water supply pipe to the hot water supply pipe through the bypass pipe, a heat exchanger temperature sensor that detects a temperature of hot water supplied from the heat exchanger, and the hot water supply A hot water temperature sensor for detecting the temperature of hot water supplied to the downstream side of the joining point of the pipe with the bypass pipe, and the mixing valve so that the detected temperature of the hot water temperature sensor coincides with a predetermined target hot water temperature. Adjust the control position to control the mixing ratio And a hot water temperature control means.
[0017]
A data table storing a correspondence relationship between the control position of the mixing valve and the mixing ratio assumed to be determined according to the control position; a detected temperature of the heat exchanger temperature sensor; and a detected temperature of the hot water supply temperature sensor And a water supply temperature calculation means for calculating a temperature of water supplied from the water supply pipe based on an assumed mixing ratio that is a mixing ratio obtained from the data table according to the control position of the mixing valve, and the water supply Necessary mixing ratio calculating means for calculating a necessary mixing ratio that is a mixing ratio necessary for obtaining the target hot water supply temperature based on the temperature of water calculated by the temperature calculating means and the temperature detected by the heat exchange temperature sensor And the hot water temperature control means sets the control position of the mixing valve to the control position obtained from the data table in accordance with the required mixing ratio. Detection temperature of Sa is characterized in that to match with the target hot-water supply temperature.
[0018]
According to this invention, first, based on the detected temperature of the heat exchanger temperature sensor, the detected temperature of the hot water supply temperature sensor, and the assumed mixing ratio according to the control position of the mixing valve determined by the data table. The temperature of water supplied from the water supply pipe is calculated by the water supply temperature calculation means. The water temperature thus calculated reflects the difference between the assumed mixing ratio and the actual mixing ratio (hereinafter referred to as the actual mixing ratio) determined by the control position of the mixing valve, as described above. Become.
[0019]
Therefore, the required mixing ratio calculated by the required mixing ratio calculating means based on the water temperature calculated by the water supply temperature calculating means is the hot water supply caused by the difference between the assumed mixing ratio and the actual mixing ratio. The mixing ratio cancels the difference between the temperature detected by the temperature sensor and the target hot water supply temperature. Accordingly, the hot water supply temperature control means sets the control position of the mixing valve to the control position obtained from the data table in accordance with the required mixing ratio, so that the assumed mixing ratio and the actual mixing ratio are varied depending on individual variations of the mixing valve. Even when the difference from the ratio varies, the temperature of hot water supplied downstream of the joining point of the hot water pipe and the bypass pipe detected by the hot water temperature sensor is quickly matched with the target hot water temperature. be able to.
[0020]
Further, when the hot water supply apparatus is in a standby state before the start of hot water supply, the required mixing ratio calculating means sets the temperature of the water calculated by the water supply temperature calculating means to be higher than the temperature of the water that is normally supplied. The required mixing ratio is calculated on the assumption that the temperature is the initial feed water temperature, and the hot water supply control means obtains the control position of the mixing valve from the data table in accordance with the calculated required mixing ratio. It is a control position.
[0021]
In the present invention, the required mixing ratio calculated by the required mixing ratio calculating means according to the initial feed water temperature is the required mixing ratio calculated according to the normal temperature of water supplied from the water supply pipe. Rather, the amount of hot water supplied from the heat exchanger is reduced. Therefore, when the hot water supply apparatus is in a standby state, the hot water supply control means sets the control position of the mixing valve to a control position according to the required mixing ratio calculation means calculated based on the initial water supply temperature. Thus, when hot water supply is started, it is possible to prevent abnormally high temperature hot water from being supplied to the downstream side of the junction of the hot water supply pipe and the bypass pipe.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
An example of an embodiment of the present invention will be described with reference to FIGS. 1 is an overall configuration diagram of the hot water supply apparatus of the present invention, FIG. 2 is a flowchart showing a control procedure of hot water temperature in the hot water supply apparatus shown in FIG. 1, and FIG. 3 is a control of hot water temperature in the hot water supply apparatus shown in FIG. It is the graph which showed the execution result.
[0023]
Referring to FIG. 1, a hot water supply apparatus of the present invention bypasses hot water supply heat exchanger 1 and hot water supply pipe 2 and hot water supply pipe 3 connected to hot water supply heat exchanger 1 (corresponding to the heat exchanger of the present invention). The hot water supplied from the hot water supply heat exchanger 1 and the bypass pipe 4 are provided at the joining point of the hot water pipe 3 and the bypass pipe 4. The mixing valve 5 for adjusting the mixing ratio with the water to be supplied and the water flow switch 6 for detecting the presence or absence of the water supplied to the water supply pipe 2 are provided.
[0024]
Furthermore, the hot water supply apparatus includes a water supply temperature sensor 7 that detects the temperature of water supplied to the water supply pipe 2, a heat exchanger temperature sensor 8 that detects the temperature of hot water supplied from the hot water supply heat exchanger 1, and a hot water supply pipe. The hot water supply temperature sensor 9 for detecting the temperature of hot water supplied downstream of the junction with the 3 bypass pipe 4, the stepping motor 10 for adjusting the control position of the mixing valve 5, and the operation of the hot water supply device are controlled. A controller 11 and a remote controller 12 for a user to instruct the operation of the hot water supply device are provided.
[0025]
In the present embodiment, the ratio of the flow rate of water supplied from the bypass pipe 4 when the flow rate of hot water supplied from the hot water supply heat exchanger 1 is set to 1 is the hot water supplied from the hot water supply heat exchanger 1. And the mixing ratio of water supplied from the bypass pipe 4.
[0026]
Hot water is supplied to the hot water supply heat exchanger 1 through a hot water circulation pipe 21 from the heat source machine 20, and the heat source machine 20 circulates hot water in the hot water circulation pipe 21 and hot water in the hot water circulation pipe 21. And a circulating heat exchanger 22 that heats the gas by a burner 24. The heat source unit 20 adjusts the combustion amount of the burner 24 through the hot water circulation pipe 21 so that the temperature of the hot water stored in the hot water supply heat exchanger 1 is maintained at a predetermined temperature (for example, 80 ° C.). While controlling the temperature of the hot water supplied to the hot water supply heat exchanger 1, the operation of the pump 23 is controlled to control the amount of hot water supplied to the hot water supply heat exchanger 1 through the hot water circulation pipe 21. As a result, hot water having a substantially constant temperature (80 ° C.) is supplied from the hot water supply heat exchanger 1 to the hot water supply pipe 3 at a substantially constant pressure.
[0027]
The controller 11 sets the temperature T _{out of} hot water supplied to the downstream of the junction with the bypass pipe 4 of the hot water supply pipe 3 detected by the hot water supply temperature sensor 9 (hereinafter referred to as the actual hot water supply temperature T _out ) by the remote controller 12. to match the target hot-water supply temperature T _set which is set in accordance with the hot water supply temperature control means 31 for outputting a position control signal P _cm to the motor driver 30, the control position V _p and the control position V _p of the mixing valve 5 A data table 32 storing a correspondence relationship with an assumed mixing ratio R _s that is assumed to be set.
[0028]
Furthermore, the controller 11 obtains the hot water supplied from the hot water supply heat exchanger 1, which is detected by the thermal exchange temperature sensor 8 temperature T _h (hereinafter, the hot water temperature T _h hereinafter) by the actual hot-water supply temperature T _out and the data table 32 From the assumed mixing ratio R _s according to the control position V _p of the mixing valve 5, the feed water temperature calculating means 33 for calculating the temperature T _{inc of the} water supplied to the feed water pipe 2 (hereinafter referred to as the calculated feed water temperature T _inc ). Based on the tapping temperature T _h , the actual hot water temperature T _out, and the calculated hot water temperature T _inc , the necessary mixing ratio R _n , which is a mixing ratio necessary to match the actual hot water temperature T _out with the target hot water temperature T _set, is _set. And a necessary mixing ratio calculating means 34 for calculating.
[0029]
The position control signal P _cm output from the hot water supply temperature control means 31 to the motor driver 30 is in accordance with the control position V _p of the mixing valve 5. In this embodiment, the hot water supply temperature control means 31 is the stepping motor 10. the rotational position by controlling the range of 0 to 2000 steps, to adjust the control position V _p of the mixing valve 5.
[0030]
Here, the controller 11 calculates the following equation (1) from the temperature T _{in of} water supplied to the water supply pipe detected by the water supply temperature sensor 7 (hereinafter referred to as the actual water supply temperature T _in ) and the tapping temperature T _h. 3) it is possible to calculate the required mixture ratio R _nr a mixture ratio required to the actual hot-water supply temperature T _out is equal to the target hot-water supply temperature T _{the set.}
[0031]
R _nr = (T _h −T _in ) / (T _set −T _in ) −1 (3)
Then, the assumed mixing ratio R _S according to the control position V _p of the mixing valve 5 obtained from the data table 32 and the actual mixing ratio set according to the control position V _p of the mixing valve 5 (hereinafter, the actual mixing ratio). if R of _r) and match, the control position V _p of the mixing valve 5 by the control position determined from the data table 32 in accordance with the required mixture ratio R _nr, target actual hot-water supply temperature T _out It can be made to coincide with the hot water supply temperature _Tset .
[0032]
However, in practice, the control position V _p of the mixing valve 5 is controlled by the control step of the stepping motor 10 due to the influence of the eigenvalues a and b that vary depending on the individual mixing valve 5 as represented by the following equation (4). Even if the numbers are the same, they are not constant.
[0033]
V _p = a × number of steps + b (4)
Therefore, the assumed mixing ratio R _s and the actual mixing ratio R _r with respect to the control position V _p of the mixing valve 5 do not coincide with each other, and the control position of the mixing valve 5 corresponding to the necessary mixing ratio R _nr calculated by the above equation (3). the determined by the data table 32, also outputs a position control signal P _cm corresponding to the control position to the motor driver 30, the actual mixing ratio R _r that is set in the required mixing for including errors due to the above formula (4) It is not the ratio R _nr . Therefore, the actual hot water supply temperature _Tout cannot be matched with the target hot water supply temperature _Tset .
[0034]
Therefore, the controller 11 performs processing for causing the actual hot-water supply temperature T _out in consideration of the error between the assumed mixing ratio R _s and the actual mixing ratio R _r is equal to the target hot-water supply temperature T _{The set.} Hereinafter, this process will be described with reference to the flowchart of FIG.
[0035]
Referring to FIG. 2, when energization of the hot water supply device is started in STEP 1, the hot water supply device enters a standby state. Then, proceeding to STEP 2, the controller 11 sets an initial value (corresponding to the initial feed water temperature of the present invention) of a calculated feed water temperature T _inc described later to 25 ° C.
[0036]
Then, while the water flow switch 6 is ON in the next STEP 3, that is, while water is being supplied to the water supply pipe 2, the controller 11 repeatedly executes STEP 4 to STEP 7. STEP4 is a treatment with water temperature calculation section 33, the feed water temperature calculation section 33 was determined from the data table 32 in response to tapping temperature T _h and the control position V _p of the current actual hot-water supply temperature T _out and mixing valve 5 Based on the assumed mixing ratio R _s , the temperature of the water supplied from the water supply pipe 2 (hereinafter referred to as the calculated water supply temperature T _inc ) is calculated by the following equation (5).
[0037]
T _inc = {(1 + R _s ) × T _out −T _h } / R _s (5)
Here, the calculated feed water temperature T _inc reflects an error between the assumed mixing ratio R _s and the actual mixing ratio R _r . That is, when the assumed mixing ratio R _s is greater than the actual mixing ratio R _r , the calculated feed water temperature T _inc is lower than the actual feed water temperature T _in , and conversely, the assumed mixing ratio R _s is greater than the actual mixing ratio R _r . Is smaller, the calculated feed water temperature T _inc is higher than the actual feed water temperature T _in .
[0038]
Continued STEP5 is a process by requiring the mixing ratio calculating unit 34, required mixing ratio calculating means 34 from the calculated feedwater temperature T _inc and the hot water temperature T _h, the following equation (6), the actual hot-water supply temperature T _out A required mixing ratio R _ns that is a mixing ratio required to match the target hot water supply temperature T _set is calculated.
[0039]
R _ns = (T _h −T _inc ) / (T _set −T _inc ) −1 (6)
Thus, when the required mixing ratio R _ns is calculated based on the calculated feed water temperature T _inc , the calculated required mixing ratio R _ns is different from the required mixing ratio R _nr calculated by the above-described equation (3), Instead of the actual mixing ratio R _r , the assumed mixing ratio R _{s including an} error is obtained.
[0040]
For this reason, the control position V _p of the mixing valve 5 corresponding to the required mixing ratio R _ns calculated by the above formula (5) is obtained from the data table 32, and the mixing valve 5 is set to the control position V _p , so that the actual hot water supply temperature T _out can be matched with the target hot water supply temperature T _set .
[0041]
Therefore, at the next STEP 6, the hot water temperature control means 31 _obtains the control position of the mixing valve 5 corresponding to the required mixing ratio R _ns from the data table 32, and at the next STEP 7, the position command signal P _cm corresponding to the control position. Is output to the motor driver 30. Thus, the drive signal from the motor driver 30 to the stepping motor 10 is output, the control position V _p of the mixing valve 5 is operated to control a position corresponding to the required mixture ratio R _ns. Or by repeating the process of STEP4~STEP7 described, it is possible to quickly match the actual hot-water supply temperature T _out at the target hot-water supply temperature T _{The set.}
[0042]
FIG. 3 shows an example in which the above processing from STEP 4 to STEP 7 is executed when the initial value of the calculated feed water temperature T _inc is 10 ° C. and the target hot water supply temperature T _set is 45 ° C. The solid line represents the solid line. The hot water supply temperature T _out , the dotted line indicates the target hot water supply temperature T _set , and the alternate long and short dash line indicates the assumed mixing ratio R _s . FIG. 3 shows that the setting of the assumed mixing ratio R _s decreases as the number of times of processing from STEP 4 to STEP 7 progresses, and the actual hot water temperature T _out quickly converges to the target hot water temperature T _{set accordingly} .
[0043]
In addition, after energization is started in STEP 1, when the water flow switch 6 is OFF in STEP 3, that is, in a standby state where water is not supplied to the water supply pipe 2, the flow branches from STEP 3 to STEP 5, The necessary mixing ratio calculating means 34 calculates the necessary mixing ratio R _ns assuming that the calculated feed water temperature T _inc is an initial value (25 ° C.). Thereby, when the hot water supply apparatus is in the standby state, the control position V _p of the mixing valve 5 is held at a position corresponding to the initial value (25 ° C.), and hot water supply is started with the actual mixing ratio R _r being extremely small. Thus, abnormally high temperature hot water is prevented from being supplied downstream of the hot water supply pipe 3.
[0044]
Further, when water supply to the water supply pipe 2 is stopped after the water flow switch 6 is turned ON in STEP 3 and the water supply pipe 2 is stopped, the necessary mixing ratio R _ns is calculated from the calculated water supply temperature T _inc at the time of stop, and the mixing is performed. The valve 5 is held at a control position V _p corresponding to the R _ns . Therefore, also in this case, it is possible to prevent the hot water supply from being started in a state where the actual mixing ratio R _r is extremely small and abnormally hot water to be supplied downstream of the hot water supply pipe 3.
[0045]
In addition, as an initial value in STEP2 of FIG. 2, the water supply temperature T _inc calculated in STEP4 immediately before the previous hot water supply stop may be used instead of the fixed value (25 ° C.). In this case, since it is considered that there is not much difference between the water supply temperature at the previous hot water supply stop and the water supply temperature at the time of hot water supply restart, the control position V _p of the mixing valve 5 during the hot water supply stop is set to the actual water supply temperature. It is possible to operate in the vicinity of the control position according to the above. Therefore, when the hot water supply is resumed, it is possible to stabilize faster real hot-water supply temperature T _out at the target hot-water supply temperature T _{The set.}
[0046]
Moreover, in this Embodiment, although the hot water supply heat exchanger 1 which keeps the hot water stored with the hot water supplied from the heat source machine 20 constant (80 degreeC) was used as a heat exchanger of this invention, a gas burner or an electric heater A heat exchanger that heats the water supplied from the water supply pipe 2 may be used.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a hot water supply apparatus of the present invention.
FIG. 2 is a flowchart showing a hot water supply temperature control procedure in the hot water supply apparatus shown in FIG. 1;
3 is a graph showing an execution result of hot water temperature control in the hot water supply apparatus shown in FIG. 1;
FIG. 4 is an overall configuration diagram of a conventional hot water supply apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hot water supply heat exchanger, 2 ... Water supply pipe, 3 ... Hot water supply pipe, 4 ... Bypass pipe, 5 ... Mixing valve, 6 ... Water flow switch, 7 ... Water supply temperature sensor, 8 ... Heat exchange temperature sensor, 9 ... Hot water supply temperature sensor DESCRIPTION OF SYMBOLS 10 ... Stepping motor, 11 ... Controller, 12 ... Remote control, 20 ... Heat source machine

Claims (3)

Hot water generated by heating from the water supplied from the water supply pipe by a heat exchanger connected to the water supply pipe and the hot water supply pipe and supplied to the hot water supply pipe; bypassing the heat exchanger; the water supply pipe and the hot water supply The bypass ratio of the hot water supply pipe is controlled by adjusting the control position of the mixing valve that varies the mixing ratio with the water supplied to the hot water supply pipe via a bypass pipe communicating with the pipe. In the hot water temperature control method for matching the temperature of hot water supplied to the downstream side of the junction with the pipe with a predetermined target hot water temperature,
An assumed mixing ratio, which is a mixing ratio according to the control position of the mixing valve, obtained from a data table storing the relationship between the control position of the mixing valve and the mixing ratio assumed to be determined according to the control position; Based on the temperature of the hot water supplied from the heat exchanger and the temperature of the hot water supplied to the downstream side of the junction with the bypass pipe of the hot water supply pipe, the temperature of the water supplied from the water supply pipe is Calculate
Based on the temperature of water calculated in this way and the temperature of hot water supplied from the heat exchanger, a required mixing ratio that is a mixing ratio required to obtain the target hot water supply temperature is calculated,
By setting the control position of the mixing valve to the control position obtained from the data table in accordance with the required mixing ratio, the temperature of hot water supplied to the downstream side of the joining point of the hot water supply pipe with the bypass pipe is predetermined. The hot water temperature control method is characterized in that it matches the target hot water temperature. A heat exchanger connected to the water supply pipe and the hot water supply pipe and supplying hot water generated by heating water supplied from the water supply pipe to the hot water supply pipe; bypassing the heat exchanger; the water supply pipe and the hot water supply A bypass pipe communicating with the pipe, and a mixing valve for adjusting a mixing ratio of hot water supplied from the heat exchanger to the hot water supply pipe and water supplied from the water supply pipe via the bypass pipe to the hot water supply pipe; A hot water temperature sensor for detecting the temperature of hot water supplied from the heat exchanger, and a hot water temperature sensor for detecting the temperature of hot water supplied downstream of the junction of the hot water pipe and the bypass pipe, In a hot water supply apparatus comprising hot water temperature control means for controlling the mixing ratio by adjusting the control position of the mixing valve so that the detected temperature of the hot water temperature sensor coincides with a predetermined target hot water temperature.
A data table storing a correspondence relationship between the control position of the mixing valve and the mixing ratio assumed to be determined according to the control position;
Based on the detected temperature of the heat exchanger temperature sensor, the detected temperature of the hot water supply temperature sensor, and the assumed mixing ratio that is the mixing ratio obtained from the data table according to the control position of the mixing valve, from the water supply pipe Water supply temperature calculation means for calculating the temperature of the supplied water;
Necessary mixing ratio for calculating a necessary mixing ratio, which is a mixing ratio necessary for obtaining the target hot water supply temperature, based on the temperature of water calculated by the water supply temperature calculating means and the temperature detected by the heat exchange temperature sensor A calculating means,
The hot water temperature control means sets the control position of the mixing valve to a control position obtained from the data table according to the required mixing ratio, so that the detected temperature of the hot water temperature sensor coincides with the target hot water temperature. A hot water supply apparatus characterized by the above. When the hot water supply apparatus is in a standby state before the start of hot water supply, the required mixing ratio calculating means sets an initial water supply in which the temperature of the water calculated by the water supply temperature calculating means is set higher than the temperature of water normally supplied The required mixing ratio is calculated on the assumption that it is a temperature, and the hot water supply control means determines the control position of the mixing valve from the data table according to the required mixing ratio thus calculated. The hot water supply apparatus according to claim 2, wherein:

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