JP5414606B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system.

  The hot water supply system disclosed in Patent Document 1 includes a power generation unit, a hot water storage tank, a mixer, and a heating unit. In this hot water supply system, the power generation unit and the hot water storage tank are connected by a circulation path, and hot water heated by the heat generated by the power generation unit is stored in the hot water storage tank. The hot water stored in the hot water tank is supplied to the mixer and mixed with tap water in the mixer to adjust the temperature.

  When the hot water supplied from the hot water tank is higher than the hot water supply set temperature, the hot water supplied from the hot water tank and tap water are mixed so that the hot water supply set temperature is reached, and the mixed hot water passes through the heating section. Hot water is supplied. When the hot water supplied from the hot water storage tank is lower than the hot water supply set temperature, the heating unit performs a heating operation, and the hot water heated by the heating unit is supplied. The heating amount of the heating unit has a minimum heating amount and a minimum temperature rise. Therefore, when the hot water supplied from the hot water storage tank is lower than the hot water supply set temperature, mixing is performed such that the temperature of the mixed water after mixing in the mixer becomes a temperature obtained by subtracting the minimum temperature rise from the hot water supply set temperature (that is, mixing). The outlet temperature of the vessel is lowered), and the heating unit starts the heating operation. As a result, hot water heated to the hot water supply set temperature is supplied.

  In this hot water supply system, the heating operation is started at the timing when the mixed water whose temperature has been lowered by the mixer should have moved to the heating section. That is, the heating operation is started at the timing when the hot water supply amount after the temperature is lowered by the mixer becomes equal to the pipe capacity from the mixer to the heating unit. Actually, since a preparation period is required from the start instruction of the heating operation until the heating is actually started, the start instruction of the heating operation is output in consideration of this preparation period. Thereby, even when the hot water stored in the hot water tank is completely consumed during hot water supply, the hot water adjusted to the hot water supply set temperature can be continuously supplied.

  In the conventional hot water supply system, the hot water storage tank, the mixer, and the heating unit are integrated in advance, and the piping capacity from the mixer to the heating unit is determined in advance. Therefore, the output timing of the heating operation start command can be determined based on the known pipe capacity. However, when connecting the mixer and the heating unit at the construction site, it is necessary to derive the piping capacity from the mixer to the heating unit. In Patent Document 1, in order to derive the pipe capacity from the mixer to the heating unit, when hot water is supplied using hot water in the hot water tank, the water temperature at the outlet of the mixer reaches an approximate value of the hot water supply set temperature. A technique for determining the pipe capacity from the mixer outlet to the outlet of the heating unit based on the time required for the water temperature at the outlet of the heating unit to reach this approximate value and the flow rate of the mixed water is disclosed.

  In a normal hot water system, the mixed water is also sent to the bathtub. A hot water path for supplying mixed water to the bathtub is connected to the mixed water pipe downstream of the heating unit.

JP 2005-274055 A

  The pipe capacity from the mixer to the heating unit can be derived by the method described in Patent Document 1, but in this method, the user cannot use the hot water supply system to supply hot water. I can't figure it out. Until then, it is not possible to determine the start time of the heating operation using the pipe capacity.

  In the hot water supply system, prior to the user actually using the hot water supply system, a bath trial operation is performed in which the mixed water is supplied from the mixed water pipe to the bathtub through the hot water path. If the pipe capacity can be derived using this bath trial operation, the pipe capacity can be derived before the user uses the hot water supply system. However, the conventional hot water supply system does not consider this possibility at all.

  The present invention has been made in view of such circumstances, and its purpose is to heat from a mixer by utilizing a bath trial operation for supplying mixed water to a bathtub when the piping capacity of the hot water supply system is not set in advance. It is in providing the hot-water supply system which can derive | lead-out the pipe capacity to a part.

The hot water supply system of the present invention includes a hot water tank, a mixer, a heating unit, and a hot water beam path. The mixer mixes the stored water flowing out of the hot water tank and the tap water, and the heating unit heats the mixed water flowing out of the mixer. The hot water path supplies mixed water that has passed through the heating unit to the bathtub. The hot water supply system further includes first detection means for detecting the temperature of the mixed water in the vicinity of the outlet of the mixer, and second detection means for detecting the temperature of the mixed water in the vicinity of the heating unit. The hot water supply system includes storage means for storing a bath trial operation program and control means for executing the bath trial operation program.
The bath trial run program
(1) While supplying mixed water from the hot water path to the bathtub,
(2) Change the mixing ratio of the mixer,
(3) specifying a time difference between a time when the water temperature detected by the first detection means reaches a predetermined temperature and a time when the water temperature detected by the second detection means reaches the predetermined temperature;
(4) Specify the mixed water flow rate,
(5) A process for deriving the pipe capacity from the vicinity of the mixer outlet to the vicinity of the heating unit from the time difference specified in (3) and the flow rate specified in (4) is included.

  The arrangement position of the second detection means may be in the vicinity of the heating unit, may be in the vicinity of the inlet of the heating unit, may be in the intermediate position of the heating unit, or in the vicinity of the outlet of the heating unit. Also good. By taking a heat-resistant measure, a temperature detecting means can be installed at an intermediate position of the heating unit. The connection point between the hot water path and the mixed water pipe can be set at an arbitrary position downstream of the second detection means. Mixed water refers to water that flows out of the mixer and may be hot water or cold water. Moreover, all the mixed water may be stored water, and all the mixed water may be tap water. The process of deriving the pipe capacity from the time difference and the flow rate may be a process of multiplying the time difference by an average flow rate within the time difference, or a process of integrating the flow rate per unit time over the time difference.

At the time of construction of the hot water supply system, a bath trial operation is performed in which the mixed water that has flowed out of the mixer and passed through the heating unit is supplied to the bathtub. With the above configuration, the pipe capacity from the vicinity of the outlet of the mixer to the vicinity of the heating unit is derived during the bath trial operation. Even if the pipe capacity is not set in advance, the pipe capacity from the vicinity of the outlet of the mixer to the vicinity of the heating unit can be derived using any necessary bath trial operation. As a result, when the user actually uses the hot water supply system, the start timing of the heating operation of the heating unit can be determined based on the pipe capacity already derived.
In particular, when a hot water supply system is constructed by connecting a mixer and a water heater at a construction site, it is difficult to grasp the piping capacity from the vicinity of the outlet of the mixer to the vicinity of the heating unit. Therefore, it is effective to derive the pipe capacity by the above configuration.

Some hot water supply systems having a hot water path have a function of retreating when the bathtub water supplied to the bathtub is cooled. In this type of hot water supply system, in addition to the hot water supply heating unit that heats the mixed water flowing through the mixed water piping, a second heating unit that directly or indirectly heats the bathtub water is provided. Or there is a thing provided with the 2nd heating part for heating other than the heating part for hot-water supply.
When the second heating unit is provided, the hot water supply heating unit and the second heating unit are often arranged adjacent to each other.

  When the second heating unit is disposed adjacent to the hot water supply heating unit, the bath trial operation program executes the above (1) to (5) while the second heating unit is performing the heating operation. It is preferable to include a process and a process of executing (1) to (5) while the second heating unit is not performing a heating operation.

  The physical piping capacity from the mixer to the heating unit does not change between when the second heating unit is performing a heating operation and when the heating operation is not performed. However, the optimum value of the flow rate from the start of mixing so that the temperature of the mixed water becomes a temperature obtained by subtracting the minimum temperature rise from the hot water supply set temperature until the heating unit starts the heating operation is determined by the second heating unit. It is different between the case where the operation is performed and the case where the heating operation is not performed. When the second heating unit is performing a heating operation and when the heating operation is not performed, the ambient temperature conditions are different, and when the second heating unit is performing a heating operation, When the time from the start of operation of the heating unit until the heating by the heating unit for hot water supply becomes effective is short, when the second heating unit is not performing the heating operation, the hot water supply from the start of operation of the heating unit for hot water supply It takes a long time for the heating by the heating unit to become effective. The pipe capacity referred to in this specification is not the physical pipe capacity from the mixer to the heating part, but corresponds to the accumulated water amount required for the temperature change occurring in the mixer to occur in the heating part. An approximate value.

  The process of executing the above (1) to (5) while the second heating unit is performing the heating operation, and the process of (1) to (5) while the second heating unit is not performing the heating operation. When the second heating unit is in the heating operation, the pipe capacity useful for determining the optimal control timing of the hot water heating unit and the second heating unit in the heating operation are provided. If not, it is possible to obtain each of the pipe capacities useful for determining the optimal control timing of the hot water supply heating section.

During the hot water supply, the temperature of the hot water stored in the hot water storage tank may rise and exceed the hot water supply set temperature. In this case, the hot water supplied from the hot water storage tank can be adjusted to the hot water supply set temperature by mixing with tap water, and there is no need to heat in the heating section. In this case, the mixing water is switched from a state where the temperature of the mixed water is a temperature obtained by subtracting the minimum temperature rise from the hot water supply set temperature to a state where the mixed water is set so as to be the hot water supply set temperature. To stop.
In this case as well, a time difference is required from when the mixing ratio of the mixer is switched to when heating of the heating unit is stopped, and it is necessary to know the pipe capacity from the mixer to the heating unit.

  When the heating unit is in the heating operation and when it is not in the heating operation, the ambient temperature conditions are different, and the piping capacity necessary to determine the heating start timing of the heating unit and the heating unit The piping capacity necessary to determine the heating stop timing is slightly different.

By switching from the cold water hot water beam operation to the hot water hot water beam operation, the pipe capacity may be derived based on the above time difference when the water temperature detected by each detection means rises. In the present specification, this is called a pipe capacity at the time of temperature increase. Alternatively, the pipe capacity may be derived based on the above time difference when the water temperature detected by each detecting means is lowered by switching from the hot water hot water operation to the cold water hot water operation. In this specification, this is called piping capacity at the time of cooling.
The pipe capacity at the time of temperature rise is suitable for determining the heating stop timing of the heating unit. The pipe capacity during cooling is suitable for determining the heating start timing of the heating unit.

Strictly speaking, there are the following four types of pipe capacities for determining the control timing of the heating section.
a) Piping capacity during cooling when the second heating unit is in a heating operation.
b) The pipe capacity at the time of temperature rise during the heating operation of the second heating unit.
c) Piping capacity during cooling when the second heating unit is in non-heating operation.
d) The pipe capacity at the time of temperature rise when the second heating unit is in the non-heating operation.
Although a) to d) are approximate, they are slightly different.
The invention of claim 2 is characterized in that at least a), b) and c), d) are determined separately. It may be determined by dividing into four types a), b), c), and d), or may be measured by dividing into an average value of a) and b) and an average value of c) and d). .
On the other hand, the invention of claim 1 includes a case where only the average values of a) to d) are measured. Or it includes the case where any one of a) to d) is measured and represented. In the case of measuring separately, it includes not only the case of claim 2 but also the measurement divided into the average values of a) and c) and the average values of b) and d).

In the bath trial operation program, the mixing ratio of the mixer is switched between a mixing ratio at which the temperature of the mixed water becomes the hot water beam setting temperature and a mixing ratio at which the temperature rise by the heating unit is reduced from the hot water setting temperature. However, it may be switched between cold water hot water operation in which stored water: tap water is set to 0: 1 and hot water hot water beam operation in which stored water: tap water is set to 1: 0.
According to the said structure, the water temperature detected by each detection means can be changed a lot. Therefore, the time when the water temperature detected by each detecting means becomes the predetermined temperature can be specified more accurately, and the time difference can be specified more accurately. As a result, the pipe capacity can be derived more accurately.

In the hot water supply system, the predetermined temperature is preferably set to a temperature between the temperature of the tap water and the temperature of the stored water.
According to the said structure, the water temperature which each detection means detects reaches the said predetermined temperature in the transition period from which the temperature of tap water changes to the temperature of stored water, or the transition period from which the temperature of stored water changes to the temperature of tap water. When detected in a transition period in which the temperature change width per unit time is large, the time when the water temperature detected by each detection means reaches the predetermined temperature can be specified more accurately, and the time difference can be specified more accurately. be able to. As a result, the pipe capacity can be derived more accurately.

  According to the hot water supply system of the present invention, when the pipe capacity of the hot water supply system is not set in advance, the pipe capacity from the vicinity of the mixer to the vicinity of the heating unit is derived using the bath trial operation for supplying water to the bathtub. be able to. An index for determining the control timing of the heating unit can be obtained before the user actually uses the hot water supply system without wasting water.

The system diagram of the hot-water supply system of an Example. The flowchart which shows the execution procedure of the bath trial run program of an Example. The flowchart which shows the execution procedure of the hot water operation of an Example. The change pattern of the detection temperature of the mixing thermistor and tapping thermistor of an Example is shown.

The technical features of the embodiments described below are listed.
(Characteristic 1) In hot water hot water operation, the water stored at about 60 ° C. is passed.
(Characteristic 2) In the hot water hot water operation, the mixed water adjusted to the hot water set temperature is sent to the bathtub.
(Feature 3) In cold water hot water operation, tap water is passed.
(Characteristic 4) With the second heating unit burning, a) switching from hot water hot water beam operation to cold water hot water beam operation; b) switching from cold water hot water beam operation to hot water hot water beam operation; In a state where the second heating unit is not combusted, c) switching from hot water hot water beam operation to cold water hot water beam operation and d) switching from cold water hot water beam operation to hot water hot water beam operation are performed. The second heating unit determines the heating start timing during the heating operation with the piping capacity obtained in a), and the second heating unit determines the heating stop timing during the heating operation with the piping capacity obtained in b). The second heating unit determines the heating start timing during the non-heating operation with the pipe capacity obtained in c), and the second heating unit performs the heating during the non-heating operation with the pipe capacity obtained in d). Determine the stop timing.
(Characteristic 5) In the bath trial operation, hot water hot water operation and cold water hot water operation are alternately performed at a flow rate suitable for a shower.

  An embodiment embodying the hot water supply system of the present invention will be described with reference to FIGS. FIG. 1 is a system diagram of a hot water supply system 10, and the flow of water and heat medium is indicated by arrows. As shown in FIG. 1, the hot water supply system 10 includes a hot water storage unit 20, a heat pump unit 40, a heat source unit 50, and a controller 11. The hot water supply system 10 is constructed by connecting the units 20, 40, 50 on site at the time of construction, and supplies hot water to the hot water tap 80 and the bathtub 72. Supplying hot water to the bathtub 72 is called hot water. In the present embodiment, cold water may be supplied to the bathtub 72. In this case, it will be called hot water.

  In the heat pump unit 40, the discharge side A of the compressor 41, the four-way valve 42, the heat medium passage 43a of the first heat exchanger 43, the expansion valve 44, the second heat exchanger 45, the four-way valve 42, and the return of the compressor 41. The sides B are connected in order by the heat medium pipe 46, and the heat medium circulates in this order. The first heat exchanger 43 includes a heat medium passage 43a and a circulating water passage 43b. A fan 45 a is installed in the vicinity of the second heat exchanger 45. The second heat exchanger 45 performs heat exchange between the outside air sent by the fan 45a and the heat medium. A defrosting path 47 is connected between the heat medium pipe 46 between the discharge side A of the compressor 41 and the four-way valve 42 and the heat medium pipe 46 between the expansion valve 44 and the second heat exchanger 45. ing. In the defrosting path 47, a defrosting valve 47a is provided.

  A circulation forward path connection path 48 is connected to the inlet side of the circulating water flow path 43b of the first heat exchanger 43, and a circulation return path connection path 49 is connected to the outlet side. The circulation path connection path 48 is provided with an inlet side thermistor 48a, and the circulation path connection path 49 is provided with an outlet side thermistor 49a. The inlet side thermistor 48a detects the temperature of the circulating water flowing into the circulating water flow path 43b, and the outlet side thermistor 49a detects the temperature of the circulating water flowing out of the circulating water flow path 43b. Actually, each thermistor 48a, 49a outputs a detection signal corresponding to the water temperature, and this signal is input to the controller 11 to detect the water temperature. In the following description, the expression that a thermistor or sensor detects actually means that the temperature or the flow rate of water is detected by inputting these detection signals to the controller 11.

  The hot water storage unit 20 includes a hot water storage tank 21 and a mixer 24. A water supply path 22 for supplying tap water to the hot water tank 21 is connected to the bottom of the hot water tank 21. In the vicinity of the tap water inlet 22 a of the water supply path 22, a pressure reducing valve 23 is provided. A water supply path 26 for mixing of the mixer 24 is connected to the water supply path 22 on the downstream side of the pressure reducing valve 23. The mixing water supply path 26 is provided with a water supply control valve 26a. The pressure reducing valve 23 adjusts the water supply pressure to the hot water storage tank 21 and the mixer 24. When the hot water in the hot water storage tank 21 decreases or the water supply control valve 26a opens, the downstream pressure of the pressure reducing valve 23 decreases. The pressure reducing valve 23 opens when the downstream pressure decreases, and tries to maintain the pressure at a predetermined pressure regulation value. For this reason, when the hot water in the hot water storage tank 21 decreases or the water supply control valve 26a of the mixer 24 is opened, tap water is supplied thereto.

  In the water supply path 22, a drainage path 31 is connected downstream of the connection portion of the mixing water supply path 26. A drain valve 32 is provided in the middle of the drain path 31. The drain valve 32 can be manually opened and closed. When the drain valve 32 is opened, the water in the hot water tank 21 is drained to the outside through the drain path 31.

  One end of a circulation outward path 33 is connected to the bottom of the hot water tank 21, and one end of a circulation return path 34 is connected to the upper part of the hot water tank 21. The other end of the circulation outward path 33 is connected to the circulation outward path connection path 48 of the heat pump unit 40, and the other end of the circulation return path 34 is connected to the circulation return path connection path 49. A circulation thermistor 36 and a circulation pump 37 are provided in the circulation outward path 33. The outward thermistor 36 detects the temperature of the water that has flowed out of the hot water storage tank 21 into the circulation outward path 33. When the circulation pump 37 is driven, water is sucked out from the lower part of the hot water storage tank 21 to the circulation forward path 33, and this water flows through the circulating water flow path 43 b and is returned to the upper part of the hot water storage tank 21 through the circulation return path 34. In this way, a circulation path between the hot water tank 21 and the heat pump unit 40 is configured. A pressure release path 38 is connected in the middle of the circulation return path 34, and a relief valve 38 a is provided in the pressure release path 38. The valve opening pressure of the relief valve 38 a is set slightly higher than the pressure regulation value of the pressure reducing valve 23. When the pressure regulation of the pressure reducing valve 23 becomes impossible, the relief valve 38a is opened to prevent the pressure in the hot water storage tank 21 from exceeding the pressure that can withstand pressure. In the hot water storage tank 21, an upper thermistor 39 is attached to a predetermined amount (for example, 30 liters) from the upper end. The upper thermistor 39 detects the water temperature at the upper part of the hot water tank 21.

The mixer 24 includes a warm water path 25, a mixing water supply path 26, and a first mixing path (mixed water pipe) 27. The hot water path 25 is connected to the upper part of the hot water tank 21. The warm water path 25 is provided with a warm water control valve 25a, a warm water flow rate sensor 25b, and a warm water thermistor 25c. The hot water control valve 25 a adjusts the flow rate of hot water flowing from the hot water tank 21 to the hot water path 25. The warm water flow sensor 25b and the warm water thermistor 25c detect the flow rate and temperature of the warm water flowing through the warm water path 25. The mixing water supply path 26 is connected to the water supply path 22 as described above. The mixing water supply path 26 is provided with the above-described water supply control valve 26a, a water supply flow rate sensor 26b, and a water supply thermistor 26c. The water supply control valve 26 a adjusts the flow rate of tap water flowing through the mixing water supply path 26. The water supply flow rate sensor 26b and the water supply thermistor 26c detect the flow rate and temperature of the tap water flowing through the mixing water supply path 26.
The hot water path 25 and the mixing water supply path 26 merge and are connected to a first mixing path (mixed water pipe) 27. The first mixing path 27 is provided with a mixing thermistor (an example of the first detecting means) 27 a that detects the temperature of the mixed water flowing through the first mixing path 27.
Is provided.

  The hot water storage unit 20 further includes a first hot water supply path 29. A hot water supply thermistor 29 a is provided in the first hot water supply path 29. A hot water tap 80 is connected to the tip of the first hot water supply path 29. The hot-water tap 80 is disposed in a bathroom, a washroom, a kitchen, etc. (in FIG. 1, the plurality of hot-water taps 80 are represented by one). The middle of the first mixing path 27 and the middle of the first hot water supply path 29 are connected by a hot water supply bypass path 28. The hot water supply bypass path 28 is provided with a bypass control valve 28a. When the bypass control valve 28a is opened, the mixed water that has flowed through the first mixing path 27 flows from the hot water supply bypass path 28 to the first hot water supply path 29, and when the bypass control valve 28a is closed, the mixed water 27 flows through the first mixing path 27. The flowing mixed water flows to the second mixing path 52 of the heat source unit 50 described later.

  The heat source unit 50 includes a hot water heater 51. The water heater 51 includes a hot water supply heat exchanger (an embodiment of the heating unit) 53, a hot water supply burner 54, a reheating heat exchanger (an example of the second heating unit) 76, a second burner 78, and the like. I have. The inlet side of the hot water supply heat exchanger 53 is connected to the first mixing path 27 of the hot water storage unit 20 via the second mixing path 52. The mixed water flows into the hot water supply heat exchanger 53 through the second mixing path 52. The second mixing path 52 is provided with a water thermistor 52a, a hot water supply amount sensor 52b, and a water amount servo 52c. The incoming water thermistor 52a and the hot water supply amount sensor 52b detect the temperature and flow rate of the water flowing through the second mixing path 52, respectively. The water amount servo 52c adjusts the flow rate of water flowing through the second mixing path 52. The gas combustion burner 54 heats the hot water supply heat exchanger 53. The outlet side of the hot water supply heat exchanger 53 is connected to the first hot water supply path 29 via the second hot water supply path 55. Hot water flowing through the hot water supply heat exchanger 53 is supplied from the hot water tap 80 through the second hot water supply path 55 and the first hot water supply path 29. In the second hot water supply path 55, a can body thermistor 56 is provided in the vicinity of the outlet of the hot water supply heat exchanger 53, and a hot water thermistor (an example of the second detection means) 57 is provided downstream thereof. . The hot water thermistor 57 is disposed in the vicinity of the hot water supply heat exchanger 53.

  A heat source unit bypass path 58 is connected between the downstream side of the water amount servo 52 c in the second mixing path 52 and between the can body thermistor 56 and the hot water thermistor 57 in the second hot water supply path 55. A heat source unit bypass control valve 59 is provided at a connection portion between the second mixing path 52 and the heat source unit bypass path 58. By adjusting the opening degree of the heat source unit bypass control valve 59, a part of the water flowing through the second mixing path 52 flows into the heat source unit bypass path 58, and the flow rate thereof is adjusted.

  One end of a hot water path 70 is connected to the downstream side of the hot water thermistor 57 of the second hot water supply path 55. The other end of the hot water path 70 is connected to a bath circulation path 71. The hot water path 70 is provided with a hot water valve 70a and a hot water amount sensor 70b. The bath circulation path 71 extends from the junction with the first flow path 76a extending from the bathtub 72 to the hot water path 70 and the hot water path 70 to the bathtub 72 through the reheating heat exchanger 76. The extending second flow path 76b is provided. The bath circulation path 71 circulates bathtub water between the bathtub 72 and the reheating heat exchanger 76. In the bath circulation path 71, a water pressure sensor 79, a bath pump 73, a water flow switch 74, a bathing thermistor 75, a reheating heat exchanger 76, and a bath return thermistor 77 are provided in this order.

When the hot water valve 70a is opened, the mixed water that has passed through the hot water supply heat exchanger 53 is supplied to the bathtub 72 from both the first flow path 76a and the second flow path 76b, as indicated by broken line arrows. When the bath pump 73 is not operated, the mixed water is allowed to flow backward.
When the bath pump 73 is driven, the hot water in the bathtub 72 flows through the bath circulation path 71 and flows through the reheating heat exchanger 76 as indicated by the solid arrow, and is heated by the second burner 78. The bathing thermistor 75 detects the temperature of the bath water flowing into the bath circulation path 71 from the bath 72, and the bath return thermistor 77 is the temperature of the bath water after being heated by the reheating heat exchanger 76. Is detected.

The controller 11 includes a CPU, a ROM, a RAM, and the like. A ROM (storage means) stores a bath trial operation program and a use operation program. The RAM temporarily stores various signals input to the controller 11 and various data generated in the course of execution of processing by the CPU. Specifically, the RAM includes various thermistors 25c, 26c, 27a, 29a, 36, 48a, 49a, 52a, 56, 57, 75, 77, water sensors 25b, 26b, 52b, 70b, and a water flow switch 74. These detection signals are input, and these pieces of information are temporarily stored. In the controller 11, a CPU (control means) outputs a drive signal to each control valve of the hot water storage unit 20 and the heat source unit 50 and various devices of the heat pump unit 40 based on information stored in the ROM or RAM. The controller 11 is provided with a bath trial operation switch 16. When performing the bath test operation, the bath test operation switch 16 is set to the ON state by the installer. The controller 11 is provided with a display screen 17 and displays that the bath trial operation program is being executed.
Further, the remote controller 13 is provided with switches and buttons for operating the hot water supply system 10, a liquid crystal display for displaying the operation state of the hot water supply system 10, and the information set by the remote controller 13 is input to the controller 11. Is done. The user can set the hot water supply set temperature, the hot water set temperature, and the hot water set water level by using the remote controller 13. The controller 11 performs control so as to perform a use operation that actually uses the hot water supply system 10 and a bath test operation. In addition, in the hot water supply system 10, a bath trial operation is performed at the time of construction, and then a use operation is performed. Here, the use operation will be described first.

(Operation during use operation)
The hot water supply system 10 performs a use operation for executing hot water storage, hot water supply, hot water filling, and reheating. The controller 11 controls the use operation. If a heating system using hot water is installed, heating operation is also executed.
In the use operation program,
(1) The water in the hot water tank 21 is heated by the heat pump unit 40 to be hot hot water, and the hot water is stored in the hot water tank 21;
(2) The first hot water supply operation is performed in which the mixed water adjusted to the hot water supply set temperature by the mixer 24 is supplied from the hot water tap 80 through the hot water supply bypass path 28.
(3) The second hot water supply operation in which the mixed water adjusted to a temperature lower than the hot water supply set temperature by the mixer 24 is heated to the hot water supply set temperature and supplied from the hot water tap 80 when passing through the hot water supply heat exchanger 53. Do;
(4) Hot water adjusted to the hot water setting temperature by the mixer 24 or hot water adjusted to the hot water setting temperature by heating with the hot water supply heat exchanger 53 is supplied to the bathtub 72;
(5) The bathtub water is heated by the reheating heat exchanger 76.
The first hot water supply operation may be switched to the second hot water supply operation while being heated by the reheating heat exchanger 76, or the second hot water supply operation may be switched from the second hot water supply operation to the second hot water supply operation while being heated by the reheating heat exchanger 76. There is a case where the operation is switched to the 1 hot water supply operation, and there is a case where the operation is switched from the first hot water supply operation to the second hot water supply operation while not being heated by the reheating heat exchanger 76. There is also a case where the second hot water supply operation is switched to the first hot water supply operation during the period when it is not.

First, hot water is stored in the hot water storage tank 21 by operating the heat pump unit 40. In the heat pump unit 40, when the heat medium that has been compressed by the compressor 41 and raised in temperature flows through the heat medium passage 43 a of the first heat exchanger 43, the circulating water that flows through the circulation water passage 43 b is heated. The heat medium flowing out from the heat medium flow path 43a is expanded and cooled by the expansion valve 44, and when it flows through the second heat exchanger 45, the heat medium absorbs heat from the outside air and rises in temperature. The heated heating medium flows into the compressor 41 and is compressed again to further increase the temperature.
Further, in the heat pump unit 40, as indicated by the broken line arrow, the high temperature heat medium discharged from the compressor 41 with the defrost valve 47a temporarily opened in order to defrost the second heat exchanger 45 is defrosted. It flows through the path 47 to the second heat exchanger 45.

  In the hot water storage unit 20, the circulation pump 37 is operated, and the water in the hot water storage tank 21 is sucked out from the bottom of the hot water storage tank 21 to the circulation forward path 33. The water sucked into the circulation forward path 33 is heated and increases in temperature when passing through the circulation water flow path 43b of the first heat exchanger 43 of the heat pump unit 40. The hot water whose temperature has risen flows through the circulation return path 34 and is returned to the upper part of the hot water tank 21. By this circulation, the hot water storage tank 21 forms a temperature stratification in which a high-temperature layer is laminated on the cold water layer. When hot hot water continues to be returned to the hot water storage tank 21, the thickness (depth) of the high temperature layer gradually increases, and when the hot water is fully stored, the hot water hot water is stored in the entire hot water storage tank 21. . Even if the hot water storage tank 21 is not fully stored, by forming a temperature stratification, hot hot water is sent out to the hot water path 25 connected to the upper part of the hot water storage tank 21.

  The first hot water supply operation and the second hot water supply operation are performed as follows. When the detected water temperature of the upper thermistor 39 of the hot water tank 21 is equal to or higher than a reference temperature that is higher than the set hot water temperature set by the remote controller 13, the first hot water supply operation is performed. In the first hot water supply operation, the controller 11 opens the bypass control valve 28a and fully closes the water amount servo 52c. The controller 11 adjusts the opening degree of the hot water control valve 25a and the opening degree of the water supply control valve 26a so that the water temperature detected by the mixing thermistor 27a becomes the hot water supply set temperature. The mixed water adjusted to the hot water supply set temperature flows through the first mixing path 27, and then hot water is supplied from the hot water tap 80 through the hot water supply bypass path 28 and the first hot water supply path 29.

  On the other hand, when the detected water temperature of the upper thermistor 39 is lower than the reference temperature, the second hot water supply operation is performed. In the second hot water supply operation, the controller 11 fully closes the bypass control valve 28a and sets the water amount servo 52c to a predetermined opening. The controller 11 opens the opening of the hot water control valve 25a and the opening of the water supply control valve 26a so that the water temperature detected by the mixed thermistor 27a is lower than the hot water supply set temperature by a temperature increase by the hot water heat exchanger 53. Adjust the degree. The mixed water adjusted to a temperature lower than the hot water supply set temperature flows through the first mixing path 27, flows through the second mixing path 52 of the heat source unit 50, flows into the hot water supply heat exchanger 53, and is heated by the burner 54. The In the hot water supply heat exchanger 53, the water temperature detected by the can body thermistor 56 provided at the outlet of the hot water supply heat exchanger 53 is controlled to be 60 ° C. or higher. Thereby, it can suppress that dew condensation water generate | occur | produces in piping. When the hot water supply set temperature is lower than 60 ° C., the opening degree of the heat source unit bypass control valve 59 is controlled so that the water temperature detected by the hot water thermistor 57 becomes the hot water supply set temperature. Part of the mixed water flowing through the second mixing path 52 flows into the second hot water supply path 55 through the heat source unit bypass path 58, and the water of 60 ° C. or higher and the hot water supply heat exchanger 53 flowing through the hot water supply heat exchanger 53 It is mixed with low-temperature water that does not flow to become hot water at a hot water supply set temperature. In this way, the hot water adjusted to the hot water supply set temperature is supplied from the hot water tap 80 through the second hot water supply path 55 and the first hot water supply path 29. Thereby, even when the hot water stored in the hot water storage tank 21 is completely consumed during the first hot water supply operation, the hot water adjusted to the hot water supply set temperature can be continuously supplied.

  When switching between the first hot water supply operation and the second hot water supply operation, the controller 11 controls the burner 54 as follows. When switching from the first hot water supply operation to the second hot water supply operation is performed, the controller 11 outputs an ignition command to the burner 54 in the extinguished state. The controller 11 ignites the burner 54 at the timing when the mixed water having a temperature lower than the hot water supply heat exchanger 53 by the temperature rise by the hot water heat exchanger 53 moves to the hot water heat exchanger 53. That is, the burner 54 is ignited at a timing when the amount of hot water flowing after the temperature is lowered by the mixer 24 becomes equal to the piping capacity from the mixer 24 to the vicinity of the hot water heat exchanger 53. In this embodiment, the pipe capacity from the mixing thermistor 27a to the hot water thermistor 57 is used as the pipe capacity from the mixer 24 to the vicinity of the hot water supply heat exchanger 53. More specifically, the ignition timing of the burner 54 is determined by using a temperature drop piping capacity Vw described later. More specifically, when the second burner 78 is in combustion, the ignition timing of the burner 54 is adjusted using the pipe temperature Vw during cooling, and when the second burner 78 is in non-combustion, it is not combusting. The ignition timing of the burner 54 is adjusted by using the pipe temperature Vw at the time of cooling. Actually, since the pre-purge operation is performed from the ignition command of the burner 54 until the ignition is started, the controller 11 outputs the ignition command to the burner 54 in consideration of the period required for the pre-purge operation.

  On the other hand, when switching from the second hot water supply operation to the first hot water supply operation is performed, the controller 11 extinguishes the burner 54 in an ignited state. The controller 11 extinguishes the burner 54 at the timing when the mixed water at the hot water supply set temperature moves to the vicinity of the hot water supply heat exchanger 53. That is, at the timing when the amount of hot water flowing after the temperature of the mixed water mixed by the mixer 24 is raised to the hot water supply set temperature becomes equal to the pipe capacity from the mixer 24 to the vicinity of the heat exchanger 53 for hot water supply. The burner 54 is extinguished (heating operation is stopped). Specifically, the fire extinguishing time of the burner 54 is determined by using a pipe capacity Vh at the time of temperature increase described later. More specifically, if the second burner 78 is in combustion, the fire extinguishing timing of the burner 54 is adjusted using the pipe temperature Vh at the time of heating during combustion, and if the second burner 78 is not in combustion, non-combustion is performed. The fire extinguishing timing of the burner 54 is adjusted using the pipe temperature Vh at the time of temperature rise. The burner 54 extinguishes fire at the timing when the fire extinguishing command is output from the controller 11.

  When hot water operation is performed on the bathtub 72, the second hot water supply operation is performed by replacing the hot water supply set temperature with the hot water set temperature. When a hot water request for the bathtub 72 is input to the remote controller 13, the controller 11 opens the hot water valve 70 a to supply hot water to the bathtub 72. Hot water that has flowed from the second hot water supply path 55 through the hot water path 70 is supplied to the bathtub 72 through the first flow path 76a and the second flow path 76b, as indicated by the broken line arrows. Hot water corresponding to the hot water set temperature set by the remote controller 13 is supplied to the bathtub 72.

  If the temperature of the bath water stored in the bathtub 72 decreases, the bath pump 73 is operated and the second burner 78 is ignited. The bath water is replenished and the hot water returns to the set temperature.

(Operation during bath trial operation)
As described above, in the hot water supply system 10 of the present embodiment, the ignition timing and extinguishing of the burner 54 are based on the pipe capacity from the mixed thermistor 27a to the hot water thermistor 57 when switching between the first hot water supply operation and the second hot water supply operation. Decide when. Since the hot water supply system 10 of the present embodiment is constructed by connecting the hot water storage unit 20 and the heat source unit 50 on site, the piping capacity from the mixed thermistor 27a to the hot water thermistor 57 is not set in advance. In the present embodiment, the pipe capacity is derived using a bath trial operation performed after the construction of the hot water supply system 10.

The bath trial run program
(1) While supplying the mixed water flowing out of the mixer 24 to the bathtub 72 through the hot water path 70, (2) changing the mixing ratio of the mixer 24;
(3) specifying a time difference between a time when the water temperature detected by the mixed thermistor 27a reaches a predetermined temperature and a time when the water temperature detected by the tapping thermistor 57 reaches a predetermined temperature;
(4) specify the flow rate of water after changing the mixing ratio of the mixer 24;
(5) A process for deriving the pipe capacity from the vicinity of the outlet of the mixer 24 to the vicinity of the hot water supply heat exchanger 53 from the time difference specified in (3) and the flow rate specified in (4) is provided.
During the execution of the above (2) and (3), the burner 54 is not ignited. Moreover, said (2) and (3) are implemented in both the state which the 2nd burner is burning, and the state which is not burning. In this embodiment, the process (5) is performed by integrating the flow rate per unit time over a time difference. (5) may be performed by multiplying the time difference by the average flow rate within the time difference.

  2 to 3 are flowcharts showing the execution procedure of the bath trial operation program. The controller 11 performs a bath trial operation of the hot water supply system 10 according to the flowcharts shown in FIGS. FIG. 4 is a timing chart showing a change pattern of the detected temperature of the mixed thermistor 27a (solid line A) and a change pattern of the detected temperature of the hot water thermistor 57 (broken line B) during execution of the bath trial operation program.

  As shown in FIG. 2, it is monitored in step S2 that the operator operates the bath trial operation switch 16 to ON. The bath trial operation switch 16 is used only by a construction contractor during construction or maintenance. Since the bath test operation switch 16 is not provided in the remote controller 13, it is possible to prevent the user from pressing the bath test operation switch 16 by mistake.

  When the bath trial operation switch 16 is turned on, the detected water temperature of the upper thermistor 39 of the hot water storage tank 21 is higher than the reference temperature (the temperature at which the hot water beam set temperature may be set, and is set to 60 ° C. in this embodiment. Is determined) (S4). The hot water stored in the hot water storage tank 21 is heated by operating the heat pump unit 40 in the same manner as in the use operation. After confirming that hot water of the reference temperature or higher is stored in the upper part of the hot water tank 21, the trial operation processing after step S6 is performed. While hot water of a reference temperature or higher is not stored in the upper part of the hot water storage tank 21 (during NO in S4), it waits for heating by the heat pump unit 40, and the trial operation processing after step S6 is performed.

  If YES is determined in step S4, cold water is sent to the bathtub 72 by 10 liters in step S6. In this case, the hot water control valve 25a is set in a fully closed state, the water supply control valve 26a is set in a fully open state, the bypass control valve 28a is set in a fully closed state, and the hot water valve 70a is opened. The tap water that has flowed through the mixing water supply path 26, the first mixing path 27, the second mixing path 52, and the hot water supply heat exchanger 53 is supplied to the bathtub 72 through the hot water path 70. By first executing step S6, tap water is introduced into the above pipes, and the temperature of the thermistor installed in these pipes is made equal to the temperature of the tap water.

Next, the process proceeds to step S8, and the bath pump 73 is operated. The bathtub 72 is provided with a hole to which the first flow path 76a and the second flow path 76b are connected. If the water level in the bathtub reaches the hole, the water flow switch 74 detects the water flow by operating the bath pump 73.
If the test run program is performed in a state where the bathtub water is not accumulated in the bathtub 72, the water level in the bathtub does not reach the hole even if 10 liters is poured in step S6. Therefore, step S10 is initially NO. If step S10 is NO, the process returns to step S6, and the hot water is poured again by 10 liters. Repeat the process of pouring hot water for 10 liters until the water level in the bathtub reaches the hole. If the accumulated amount of hot water until the water level in the bathtub reaches the hole exceeds 500 liters (if S36 is YES), some abnormality has occurred, and the process proceeds to an abnormality process (S38).

  When the water level in the bathtub reaches the hole, step S10 becomes YES. At this time, the value detected by the water pressure sensor 79 when the water level in the bathtub coincides with the hole becomes clear, and the pressure is set as the reference water level (S12).

When the water level in the bathtub coincides with the hole, 40 liters of water is further poured (step S14), and the second burner 78 is burned to raise the water level to a state where a reheating operation is possible.
Next, the counter k for alternately performing the process of hot water pouring while the second burner 78 is burning and repelling and the process of hot water pouring while the second burner 78 is not combusting are set to 0. Is set (S16). In step S18, the counter k is increased by 1.

  In step S20, it is determined whether the counter k is even or odd. When step S20 is performed first, k = 1, step S20 becomes YES, and the second burner 78 is ignited. Along with this, the bath pump 73 is operated to start chasing the bathtub water. While the second burner 78 is burning, the process of step S24 is performed.

  In step S24, 20 liters of hot water is added. In this process, as described with reference to FIG. 3, hot water hot water and cold water hot water are alternately carried out, and when switching from hot water hot water to cold water hot water, the pipe capacity during cooling is measured, and cold water hot water When switching from hot water hot water to hot water, measure pipe capacity at elevated temperature. When step S24 is executed for the first time, the pipe capacity during cooling and the pipe capacity during temperature rise are measured while the second burner 78 is burning.

  When the 20 liter hot water operation is completed in step S24, the second burner 78 is extinguished (S26), and the water level is detected (S28). While the current water level detected in step S28 is less than the set water level (while NO in S30), the process returns to step S18. When step S18 is executed for the second time, the counter k = 2, step S20 becomes NO, step S22 is skipped, and step S24 is executed. When step S24 is executed for the second time, while the second burner 78 is not combusting, the temperature-decreasing pipe capacity and the temperature-rising pipe capacity are measured.

By the processing of steps S20 and S22, step 24 is alternately switched between the case where it is performed while the second burner 78 is burning and the case where it is performed while the second burner 78 is not burning.
In this way, a) the pipe capacity during cooling when the second burner 78 is burning, b) the pipe capacity during heating when the second burner 78 is burning, and c) the second burner 78. The pipe capacity at the time of lowering when no is burned and the pipe capacity at the time of rising when the second burner 78 is not burning are measured.

  When the current water level detected in step S28 is equal to or higher than the set water level (YES in S30), the temperature of the bathtub water is compared with the hot water set temperature (S32), and if it is lower than the hot water set temperature (YES in S32). If there is), the second burner 78 is burned and the bath pump 73 is operated. Bathtub water circulates in the bath circulation path 71 and is heated by the second burner 78. When heated to the hot water set temperature, S32 becomes NO, the second burner 78 is extinguished, and the bath pump 73 is stopped. As described above, the hot water adjusted to the hot water set temperature is stored in the bathtub 72 until the set water level is reached. This completes the bath trial run.

  FIG. 3 shows the details of the hot water operation procedure executed in step S24. In step S50, the bypass control valve 28a is fully closed and the hot water valve 70a is fully opened. In step S52, the hot water control valve 25a is fully closed and the water supply control valve 26a is fully opened. Thereby, tap water flows through the mixed thermistor 27 a, tap water flows through the hot water thermistor 57, and tap water is supplied to the bathtub 72. When both the mixed thermistor 27a and the hot water thermistor 57 measure the temperature of the tap water, the difference between the two becomes small, and step S54 becomes YES. Until step S54 becomes YES, tap water is allowed to flow through the hot water path and the like, and the mixed thermistor 27a and the hot water thermistor 57 are stabilized at the temperature of the tap water.

  When the temperature of the hot water path or the like is stabilized at the temperature of the tap water, step S56 is performed. In step S56, the hot water control valve 25a is fully opened, and the water supply control valve 26a is fully closed. Thereby, warm water flows through the mixed thermistor 27 a, warm water flows through the hot water thermistor 57, and hot water is supplied to the bathtub 72.

  In step S58, it is determined whether or not the water temperature detected by the mixing thermistor 27a is equal to or higher than the first predetermined temperature T1. The first predetermined temperature T1 is set to a temperature 5 ° C. lower than the temperature of the water stored detected by the upper thermistor 39. For example, if the temperature of the stored water is 60 ° C., the first predetermined temperature T1 is set to 55 ° C. The determination in step S58 is repeated until the water temperature detected by the mixing thermistor 27a becomes equal to or higher than the first predetermined temperature T1. In FIG. 4, graph A shows a change pattern of the water temperature detected by the mixed thermistor 27a with respect to time. When the water temperature detected by the mixed thermistor 27a reaches the first predetermined temperature T1 at time th1, it is determined in step S58 of FIG. 3 that the water temperature detected by the mixed thermistor 27a has become equal to or higher than the first predetermined temperature T1. . By this determination, it moves to step S60 and starts counting the accumulated water amount.

  Next, the process proceeds to step S62, and it is determined whether or not the water temperature detected by the hot water thermistor 57 is equal to or higher than the first predetermined temperature T1. The determination in step S62 is repeated until the water temperature detected by the hot water thermistor 57 becomes equal to or higher than the first predetermined temperature T1. In FIG. 4, a graph B shows a change pattern of the water temperature detected by the tapping thermistor 57 with respect to time. When the water temperature detected by the hot water thermistor 57 reaches the first predetermined temperature T1 at time th2, it is determined in step S62 in FIG. 4 that the water temperature detected by the hot water thermistor 57 has become equal to or higher than the first predetermined temperature T1. By this determination, it moves to step S64 and stops counting the accumulated water amount. The accumulated water amount measured in step S64 is such that the water temperature detected by the tapping thermistor 57 becomes equal to or higher than the first predetermined temperature T1 from the time th1 when the water temperature detected by the mixed thermistor 27a becomes equal to or higher than the first predetermined temperature T1. It is equal to the value calculated from the time difference from the time th2 and the flow rate (measured by the hot water supply amount sensor 52b) between them. The integrated quantity obtained from the time difference and the flow rate is equal to the integrated water quantity counted in step S64. In step S64, the pipe capacity at the time of temperature rise is measured.

  In steps S58 and S62, it is not determined whether the water temperature detected by the mixing thermistor 27a and the tapping thermistor 57 has reached the temperature of the stored water, but becomes the first predetermined temperature T1 that is 5 ° C. lower than the temperature of the stored water. It is determined whether or not. Therefore, as shown in FIG. 4, the water temperature detected by the mixed thermistor 27a and the hot water thermistor 57 reaches the first predetermined temperature T1 in a transition period in which the water temperature changes from the tap water temperature before the start of the bath trial operation to the stored water temperature. The time when the water temperature detected by the mixed thermistor 27a and the tapping thermistor 57 reaches the first predetermined temperature T1 in order to specify the time using the first predetermined temperature T1 appearing in the transition period in which the temperature change width per unit time is large. Can be identified more accurately. Therefore, the time difference Δ (th2−th1) between the warm water first time th1 and the warm water second time th2 can also be specified more accurately, and the pipe capacity flowing during that time can be accurately measured.

  In step S56, all of the mixed water is stored, and high-temperature water of, for example, about 60 ° C. can be circulated from the first mixing path 27 to the second mixing path 52. Since high-temperature water can be circulated from the first mixing path 27 to the second mixing path 52, the detected water temperatures of the mixing thermistor 27a and the hot water thermistor 57 can be greatly changed. Therefore, the time when the detected water temperature of the mixed thermistor 27a and the hot water thermistor 57 becomes the first predetermined temperature T1 can be specified more accurately.

  The temperature increase pipe capacity Vh derived in step S64 is used to determine the fire extinguishing timing of the burner 54 in order to change from the second hot water supply operation to the first hot water supply operation. That is, in the second hot water supply operation, the temperature of the water flowing out of the mixer 24 is lower than the hot water supply set temperature, and the water flowing out of the mixer 24 is heated when flowing through the hot water supply heat exchanger 53. When the detected water temperature of the upper thermistor 39 of the hot water tank 21 rises and exceeds a reference temperature higher than the hot water set temperature, the temperature of the water flowing out of the mixer 24 rises to reach the hot water set temperature, and the burner 54 is extinguished. Switch to the first hot water supply operation. By switching from cold water hot water beam operation to hot water hot water beam operation in the bath trial operation program, the detected temperature of the mixed thermistor 27a and hot water thermistor 57 rises when piping is switched from the second hot water supply operation to the first hot water supply operation. This is similar to the situation in which the detected water temperature of the mixed thermistor 27a and the hot water thermistor 57 rises due to the rising temperature of the flowing water. Therefore, in determining the fire extinguishing time of the burner 54, the fire extinguishing time can be appropriately determined by using the pipe capacity Vh at the time of temperature increase.

  In the above embodiment, the hot water stored in the hot water storage tank 21 is supplied to the bathtub 72 without being mixed with the tap water during the hot water hot water operation. Instead, the hot water stored in the hot water storage tank 21 and tap water may be mixed and the mixed hot water adjusted to the hot water set temperature may be supplied to the bathtub 72. In this case, in step S56, the opening degree of the hot water control valve 25a and the opening degree of the water supply control valve 26a are adjusted to an opening degree at which the mixed hot water temperature becomes equal to the hot water set temperature. In step S58, the detected temperature of the mixed thermistor 27a is compared with a temperature lower by 5 ° C. than the hot water set temperature. In step S62, the temperature detected by the hot water thermistor 57 is compared with a temperature lower by 5 ° C. than the hot water set temperature. Also by this, the pipe capacity at the time of temperature rise can be detected.

  When the hot water hot water operation is continued, step S65 in FIG. 3 becomes YES, and the process proceeds to step S66. If step S66 becomes NO, it will move to step S68 and will perform cold water hot water operation. In the cold water hot water operation, as shown in step S68, the hot water control valve 25a is controlled to a fully closed state, and the water supply control valve 26a is controlled to a fully open state. As a result, only tap water flows from the first mixing path 27 to the second mixing path 52. In FIG. 4, cold water hot water operation is started at time t2.

  Next, the process proceeds to step S70, and it is determined whether or not the water temperature detected by the mixing thermistor 27a is equal to or lower than the second predetermined temperature T2. The second predetermined temperature T2 is set to a temperature 5 ° C. higher than the water temperature detected by the water supply thermistor 26c, that is, a temperature 5 ° C. higher than the tap water temperature Tw. The determination in step S70 is repeated until the water temperature detected by the mixing thermistor 27a becomes equal to or lower than the second predetermined temperature T2. As shown in FIG. 4, when the water temperature detected by the mixed thermistor 27a reaches the second predetermined temperature T2 at time tw1, step S70 in FIG. 3 becomes YES, and counting of the integrated water amount is started.

  Next, the process proceeds to step S74, and it is determined whether or not the water temperature detected by the hot water thermistor 57 is equal to or lower than the second predetermined temperature T2. The determination in step S74 is repeatedly performed until the water temperature detected by the hot water thermistor 57 becomes equal to or lower than the second predetermined temperature T2. As shown in FIG. 4, when the water temperature detected by the tapping thermistor 57 reaches the second predetermined temperature T2 at time tw2, it is determined that the water temperature detected by the tapping thermistor 57 has become equal to or lower than the second predetermined temperature T2. Thereby, it moves to step S76 and stops counting of the integrated water amount. The accumulated water amount measured in step S76 is such that the water temperature detected by the tapping thermistor 57 becomes equal to or lower than the second predetermined temperature T2 from the timing tw1 when the water temperature detected by the mixed thermistor 27a becomes equal to or lower than the second predetermined temperature T2. It is equal to a value calculated from the time difference from the timing tw2 and the flow rate (measured by the hot water supply amount sensor 52b) between them. The integrated quantity obtained from the time difference and the flow rate is equal to the integrated water quantity counted in step S76. In step S76, the pipe capacity during cooling is measured.

  In the cold water hot water operation, the tap water is allowed to flow from the first mixing path 27 to the second hot water supply path 55. In steps S70 and S74, the water temperature detected by the mixing thermistor 27a and the hot water thermistor 57 is the tap water. Instead of determining whether or not the temperature Tw (water temperature detected by the water supply thermistor 26c) has been reached, it is determined whether or not the temperature has reached a second predetermined temperature T2 that is 5 ° C. higher than the temperature Tw of tap water. Therefore, as shown in FIG. 4, the water temperature detected by the mixed thermistor 27a and the tapping thermistor 57 reaches the second predetermined temperature T2 in the transition period when the temperature changes from the reference temperature to the tap water temperature Tw. The time when the water temperature detected by the mixed thermistor 27a and the tapping thermistor 57 reaches the second predetermined temperature T2 in order to specify the time using the second predetermined temperature T2 that appears in a transition period in which the temperature change width per unit time is large. Can be accurately identified. Therefore, the cold water time difference Δ (tw2−tw1) between the cold water first time tw1 and the cold water second time tw2 can also be accurately specified.

  The temperature drop piping capacity Vw derived in step S76 is used to determine the ignition timing of the burner 54 when the first hot water supply operation is changed to the second hot water supply operation. That is, in the first hot water supply operation, the temperature of the water flowing out of the mixer 24 is the hot water supply set temperature, and when the detected water temperature of the upper thermistor 39 of the hot water storage tank 21 is decreased, the temperature of the mixed water flowing out of the mixer 24 is also decreased. As a result, the burner 54 is ignited. When switching from hot water hot water operation to cold water hot water operation in the bath trial operation program, the first mixing path 27 and the second mixing path 52 change from a state where hot water is stored to a state where tap water flows. The temperature of the mixed water flowing through these pipes decreases. This situation is similar to the state of switching from the first hot water supply operation to the second hot water supply operation. Therefore, when the ignition timing of the burner 54 is determined, the ignition timing can be appropriately determined by using the temperature drop piping capacity Vw.

  If the cold water hot water operation is continued, step S77 in FIG. 3 becomes YES, and the process proceeds to step S78. If the planned amount is reached in step S78, it is determined that step S24 in FIG. 2 is completed, and the process proceeds to step S26 and subsequent steps in FIG. While the amount of hot water is less than the scheduled amount, step S78 is NO, the process proceeds to step S56, and the hot water hot water beam operation is executed again.

In the present embodiment, the pipe capacity from the mixed thermistor 27 a to the hot water thermistor 57 is derived using a bath trial operation for supplying water to the bathtub 72. To be exact, a) the pipe capacity during the temperature drop when the second heating unit 76 is in the heating operation, b) the pipe capacity during the temperature rise when the second heating unit 76 is in the heating operation, and c) the second heating part is non- The pipe capacity at the time of temperature reduction during the heating operation and the pipe capacity at the time of temperature rise when the second heating unit is in the non-heating operation are derived.
When the second heating unit 76 is in the heating operation, the fire extinguishing timing of the burner 54 is determined using the pipe capacity at the time of temperature increase during the heating operation, and the ignition of the burner 54 is determined using the pipe capacity at the time of temperature drop during the heating operation. Decide when. When the second heating unit 76 is in the non-heating operation, the fire extinguishing timing of the burner 54 is determined using the pipe capacity during temperature rise during the non-heating operation, and the burner is used using the pipe capacity during temperature reduction during the non-heating operation. 54 ignition timing is determined.

  In this embodiment, since the hot water storage unit 20 and the heat source unit 50 are assembled at the time of construction, the pipe capacity cannot be grasped in advance. However, according to the present embodiment, the pipe capacity from the vicinity of the outlet of the mixer 24 to the vicinity of the hot water supply heat exchanger 53 can be derived before the user uses the hot water supply system. Therefore, when the user uses the hot water supply system 10, the ignition and extinguishing timing of the burner 54 that heats the hot water supply heat exchanger 53 can be appropriately determined based on the pipe capacity already derived.

(Other examples)
In the above-described embodiment, the hot water hot water operation and the cold water hot water operation are repeatedly performed alternately during the bath test operation. However, the hot water hot water operation and the cold water hot water operation may be executed once. When performing multiple times, the average value of the pipe temperature at the time of temperature rise derived by the multiple hot water hot water beam operations is used to determine the fire extinguishing timing of the burner 54, and multiple cold water hot water is used. You may make it use the value which averaged the pipe capacity at the time of temperature fall derived | led-out by beam operation in order to determine the ignition timing of the burner 54. FIG. Further, the pipe capacity at the time of temperature rise and the pipe capacity at the time of temperature drop may not be distinguished, and the average value thereof may be used as the pipe capacity. Similarly, the pipe capacity may or may not be distinguished depending on whether or not the second burner 78 is combusted.

  In the bath trial operation program of the above embodiment, the flow rate detected by the hot water flow sensor 25b when the hot water control valve 25a is fully opened, or the flow rate detected by the feed water flow sensor 26b when the water supply control valve 26a is fully opened. Is used to derive the pipe capacity. However, without fully opening these control valves 25a and 26a, for example, the opening degree of the hot water control valve 25a may be adjusted so that the flow rate detected by the hot water flow rate sensor 25b becomes a desired flow rate. Then, the opening degree of the water supply control valve 26a may be adjusted so that the flow rate detected by the water supply flow rate sensor 26b becomes a desired flow rate. Alternatively, the pipe capacity may be calculated from the flow rate measured by the hot water supply amount sensor 52b, or the flow rate may be adjusted by the water amount servo 52c.

In particular, the flow rate of mixed water at the time of bath trial operation may be set to the shower flow rate. When using the shower, it is particularly required that the temperature of the hot water to be supplied is stable. By setting the shower flow rate, the pipe capacity can be derived by passing water at the same flow rate as in the situation where stabilization of the hot water supply temperature is required. Therefore, if the ignition timing and fire extinguishing timing of the burner are determined based on the derived pipe capacity, the temperature of the hot water is stabilized in a situation where the temperature of the hot water is particularly required to be stable. Can be made.
In the bath trial operation program of the above embodiment, only the stored water or only the tap water is passed through the first mixing path 27, the second mixing path 52, and the hot water path 70. You may make it let the mixed water containing both flow.

In the bath trial operation program of the above embodiment, tap water is passed through the second mixing path 52 and the hot water path 70 when the bath trial operation start condition is satisfied. For this reason, even when the pipe temperatures of the first mixing path 27 and the second mixing path 52 are not uniform due to the influence of the surrounding environment or the like, it can be made uniform by passing tap water. Therefore, after the initial temperatures detected by the mixing thermistor 27a and the hot water thermistor 57 are made uniform, the hot water hot water operation can be executed. This process can be omitted.
In this embodiment, the bath water is directly heated by the second burner 78, but the heating medium for heating the bath water may be heated by the second burner 78. Further, the heating medium may be heated by the second burner 78.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. In the present embodiment, the hot water beam path 70 branches off from the mixing path on the downstream side of the hot water supply heat exchanger 53, but even if it branches off from the mixing path on the upstream side near the hot water supply heat exchanger 53. Good. For example, the incoming water thermistor 52a may be disposed in the vicinity of the hot water supply heat exchanger 53, and the hot water beam path 70 may be branched between the incoming water thermistor 52a and the hot water supply heat exchanger 53.
In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

10: Hot water supply system 11: Controller 13: Remote control 16: Bath trial operation switch 17: Display screen 20: Hot water storage unit 21: Hot water storage tank 22: Water supply path 22a: Tap water inlet 23: Pressure reducing valve 24: Mixer 25: Hot water path 25a: Hot water control valve 25b: Hot water flow sensor 25c: Hot water thermistor 26: Mixing water supply path 26a: Water supply control valve 26b: Water supply flow sensor 26c: Water supply thermistor 27: First mixing path 27a: Mixing thermistor (first detection means)
28: Hot water supply bypass path 28a: Bypass control valve 29: First hot water supply path 29a: Hot water supply thermistor 31: Drainage path 32: Drainage valve 33: Circulation return path 34: Circulation return path 36: Outbound thermistor 37: Circulation pump 38: Pressure release path 38a : Relief valve 39: Upper thermistor 40: Heat pump unit 41: Compressor 42: Four-way valve 43: First heat exchanger 43a: Heat medium channel 43b: Circulating water channel 44: Expansion valve 45: Second heat exchanger 45a: Fan 46: Heat medium pipe 47: Defrost path 47a: Defrost valve 48: Circulation forward path connection path 48a: Inlet thermistor 49: Circulation return path connection path 49a: Outlet thermistor 50: Heat source unit 51: Water heater 52: Second Mixing path 52a: incoming water thermistor 52b: hot water supply amount sensor 52c: water amount servo 53: hot water supply heat exchanger (heating unit)
54: Hot water supply burner 55: Second hot water supply path 56: Can body thermistor 57: Hot water discharge thermistor (second detection means)
58: Heat source unit bypass path 59: Heat source unit bypass control valve 70: Hot water path 70a: Hot water valve 70b: Hot water sensor 71: Bath circulation path 72: Bath 73: Bath pump 74: Water switch 75: Bath thermistor 76: Reheating heat exchanger (second heating unit)
76a: 1st flow path 76b: 2nd flow path 77: Bath return thermistor 78: 2nd burner 79: Water pressure sensor 80: Hot water tap

Claims (4)

A hot water tank,
A mixer that mixes the stored water and tap water flowing out of the hot water tank;
A heating unit for heating the mixed water flowing out of the mixer;
A hot water path for supplying the mixed water that has passed through the heating section to the bathtub,
First detection means for detecting the temperature of the mixed water in the vicinity of the outlet of the mixer;
Second detection means for detecting the temperature of the mixed water in the vicinity of the heating unit;
Storage means for storing a bath trial operation program;
Control means for executing the bath trial operation program,
The bath trial run program
(1) Open a path for supplying mixed water from the hot water path to the bathtub,
(2) changing the mixing ratio of the mixer;
(3) specifying a time difference between a time when the water temperature detected by the first detection means reaches a predetermined temperature and a time when the water temperature detected by the second detection means reaches the predetermined temperature;
(4) Specify the flow rate of the mixed water,
(5) including a process of deriving a pipe capacity from the vicinity of the mixer outlet to the vicinity of the heating unit from the time difference and the flow rate ,
The hot water supply system , wherein the processes (1) to (5) are performed before the amount of mixed water supplied to the bathtub reaches a predetermined amount . A second heating unit is disposed adjacent to the heating unit;
The bath trial operation program includes a process of executing the above (1) to (5) while the second heating unit is performing a heating operation, and the above while the second heating unit is not performing a heating operation ( The hot water supply system according to claim 1, further comprising a process for executing (1) to (5).   The bath trial operation program switches the mixing ratio of the mixer between a cold water hot water operation in which storage water: tap water is 0: 1 and a hot water hot water operation in which storage water: tap water is 1: 0. The hot water supply system according to claim 1 or 2.   The hot water supply system according to any one of claims 1 to 3, wherein the predetermined temperature is set to a temperature between the temperature of the tap water and the temperature of the stored water.

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