Instantaneous hot water supply system

Abstract

To provide an instantaneous hot water supply system capable of suppressing an increase in running cost while quickly supplying hot water of a target temperature to a user.SOLUTION: In an instantaneous hot water supply system, an operation control part is configured so as to perform a preheating treatment for operating a circulation pump and a heating part for instantaneous hot water from a preheating start time before only a prescribed set preheating period from a target instantaneous hot water corresponding time such that the temperature of hot water measured by a hot water temperature sensor becomes a target temperature at the target instantaneous hot water corresponding time corresponding to a start time of an instantaneous hot water correspondence time zone or corresponding to a time before only a set allowance time from the start time. The operation control part measures a required heating period until the temperature of hot water measured by the hot water temperature sensor becomes the target temperature after starting the preheating treatment at the preheating start time, and performs a preheating period setting processing for making the length of the set preheating period in the next preheating treatment to be performed approach the length of the required heating time.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an instant hot water supply system. [Background technology]

[0002] Patent Document 1 (JP Patent Publication 2000-018626A) describes an instant hot water unit that is configured to supply hot water immediately when the hot water tap is opened. Specifically, the instant hot water supply unit described in the cited document 1 describes an instant hot water response process that, in an instant hot water operation mode, when the hot water tap (first tap 28) is closed and the hot water supply heating section (heat source device 12) is not operating to supply hot water, takes in the hot water temperature of the instant hot water circulation circuit (circulation pipe 15, return pipe 17) detected by the hot water temperature sensor (temperature sensor 24), compares the hot water temperature detected by the hot water temperature sensor with a preset hot water outlet set temperature, and operates the circulation pump (23) when the hot water temperature in the instant hot water circulation circuit drops below the set temperature. This instant hot water response process creates a state in which hot water of high temperature is stagnating in the instant hot water circulation circuit including the hot water supply path between the hot water tap and the water heater, that is, a state in which hot water of high temperature can be supplied immediately when the hot water tap is opened.

[0003] There are also instant hot water supply systems that execute the instant hot water processing described above only during certain time periods. For example, Patent Document 2 (JP 2017-187194 A) describes a system that allows users to set the instant hot water response time period during which the instant hot water response processing is executed using a remote control. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-018626 A [Patent Document 2] JP 2017-187194 A Summary of the Invention [Problem to be solved by the invention]

[0005] An instant hot water supply system such as that described in Patent Document 2 not only creates a state in which high-temperature hot water can be supplied quickly during the set instant hot water response time period, but also has the advantage of eliminating the need to perform instant hot water response processing during other times, which means that running costs can be reduced.

[0006] In addition, in an instant hot water supply system such as that described in Patent Document 2, it is necessary to be in a state where high-temperature hot water can be supplied promptly at the start time of the set instant hot water availability time slot. Therefore, it is necessary to perform a pre-heating process to heat the hot water in the instant hot water circulation circuit before the start time of the instant hot water availability time slot. For example, it is necessary to perform the pre-heating process from the pre-heating start time that is a set pre-heating period before the start time of the instant hot water availability time slot.

[0007] However, when performing the above-mentioned pre-heating process, the heating period required from the start of heating the hot water in the instant hot water circulation circuit until the hot water reaches the target temperature varies depending on the length of the hot water supply circuit in each facility such as a residence and the water supply temperature at that time. Therefore, if the set pre-heating period is shorter than necessary, the hot water in the instant hot water circulation circuit has not yet reached the target temperature at the start time of the instant hot water time slot, and hot water at the target temperature cannot be quickly supplied to users. On the other hand, if the set pre-heating period is longer than necessary, the hot water in the instant hot water circulation circuit has already reached the target temperature well before the start time of the instant hot water time slot, and running costs increase.

[0008] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an instant hot water supply system that can quickly supply hot water at a target temperature to users while suppressing increases in running costs. [Means for solving the problem]

[0009] The instant hot water supply system according to the present invention for achieving the above object comprises a hot water supply heating section which heats the water to be supplied, a water supply passage through which the water to be supplied to the hot water supply heating section flows, a hot water supply passage through which the hot water heated by the hot water supply heating section flows while being supplied to a hot water tap, an instant hot water circulation circuit including at least a portion of the hot water supply passage and through which hot water is circulated, a circulation pump which circulates the hot water in the instant hot water circulation circuit, an instant hot water heating section which heats the hot water circulating in the instant hot water circulation circuit, a hot water temperature sensor which measures the temperature of the hot water in the instant hot water circulation circuit, an input receiving section which receives input of settings for instant hot water hours, and an operation control section, The operation control unit is an instant hot water supply system that performs an instant hot water response process during the instant hot water response time period to operate the circulation pump and the instant hot water heating unit so that the temperature of the hot water measured by the hot water temperature sensor becomes a target temperature, The operation control unit is configured to perform a pre-heating process to operate the circulation pump and the instant hot water heating unit from a pre-heating start time that is a predetermined set pre-heating period before the target instant hot water response time so that the temperature of the hot water measured by the hot water temperature sensor becomes the target temperature at a target instant hot water response time that corresponds to the start time of the instant hot water response time period or a time that is a set margin period before the start time of the instant hot water response time period, The operation control unit starts the pre-heating process at the pre-heating start time, and then measures the required heating period until the temperature of the hot water measured by the hot water temperature sensor reaches the target temperature, and performs a pre-heating period setting process to approximate the length of the set pre-heating period for the next pre-heating process to the length of the required heating period.

[0010] According to the above characteristic configuration, the operation control unit performs a pre-heating process to operate the circulation pump and the instant-hot water heating unit from a pre-heating start time that is a predetermined set pre-heating period before the target instant-hot water response time, so that the temperature of the hot water measured by the hot water temperature sensor will reach the target temperature at the target instant-hot water response time that corresponds to the start time of the accepted instant-hot water response time period or the time that is a set margin period before the start time. As a result, it is highly likely that the system will be in place to quickly supply hot water at the target temperature to users at the start time of the instant-hot water response time period. Furthermore, if the target instant-hot water availability time is set to a time a set margin period earlier than the start time of the accepted instant-hot water availability time slot rather than the start time of that time slot, even if the heating period required for the hot water temperature measured by the hot water temperature sensor during the pre-heating process to reach the target temperature has changed from the previous pre-heating process, it is even more likely that the system will be ready to quickly supply hot water at the target temperature to the user at the start time of the instant-hot water availability time slot.

[0011] Furthermore, the operation control unit performs a pre-heating period setting process to measure the required heating period until the hot water temperature measured by the hot water temperature sensor reaches the target temperature after starting the pre-heating process at the pre-heating start time, and to set the length of the set pre-heating period for the next pre-heating process to be close to the required heating period. In other words, even if the length of the required heating period until the hot water temperature measured by the hot water temperature sensor reaches the target temperature after starting the pre-heating process at the pre-heating start time changes due to the influence of the water supply temperature in the facility such as a dwelling where the instant hot water supply system is installed, an appropriate set pre-heating period length that takes such influence into consideration is determined each time the pre-heating process is performed. Then, when the pre-heating process is performed, the hot water temperature measured by the hot water temperature sensor becomes the target temperature without significantly shifting back and forth in time from the target instant hot water response time corresponding to the start time of the accepted instant hot water response time period or the time before the start time by the set margin period. Therefore, an instantaneous hot water supply system can be provided that can quickly supply hot water at a target temperature to users while suppressing increases in running costs.

[0012] Another characteristic configuration of the instant hot water supply system of the present invention is that, in the pre-heating period setting process, the operation control unit sets the length of the set pre-heating period for the next pre-heating process to be performed to be the same as the length of the required heating period for the pre-heating process currently performed.

[0013] There is a high possibility that the length of the heating period required for the next pre-heating treatment will be approximately the same as the length of the heating period required for the current pre-heating treatment. Therefore, in this characteristic configuration, the operation control unit sets the length of the set pre-heating period for the next pre-heating process to be performed equal to the length of the required heating period for the current pre-heating process in the pre-heating period setting process. As a result, when the next pre-heating process is performed, the hot water temperature is more likely to reach the target temperature at a time close to the target instant hot water response time.

[0014] Another characteristic configuration of the instant hot water supply system according to the present invention is that the operation control unit, in the pre-heating period setting process, When the length of the required heating period in the currently performed pre-heating treatment is longer than the length of the set pre-heating period in the currently performed pre-heating treatment by at least a reference period, the length of the set pre-heating period in the next pre-heating treatment is set to be longer by the reference period; When the length of the required heating period in the currently performed pre-heating treatment is shorter than the length of the set pre-heating period in the currently performed pre-heating treatment by at least the reference period, the length of the set pre-heating period in the next pre-heating treatment is set shorter by the reference period; When the length of the required heating period in the pre-heating process performed this time is longer than the length of the set pre-heating period in the pre-heating process performed this time by less than the reference period or is shorter than the length of the set pre-heating period in the pre-heating process performed next time by less than the reference period, the length of the set pre-heating period in the pre-heating process to be performed next time is not changed.

[0015] According to the above characteristic configuration, if the difference between the length of the required heating period in the currently performed pre-heating process and the length of the set pre-heating period is equal to or greater than the length of the reference period, that is, if the length of the currently set pre-heating period cannot be said to be appropriate, the operation control unit appropriately changes the length of the set pre-heating period, so that the length of the set pre-heating period in the next pre-heating process approaches the length of the required heating period in the currently performed pre-heating process. On the other hand, if the difference between the length of the required heating period in the currently performed pre-heating process and the length of the set pre-heating period is less than the length of the reference period, that is, if the length of the currently set pre-heating period is set to an appropriate length, the operation control unit does not change the length of the set pre-heating period in the next pre-heating process to be performed in the pre-heating period setting process, thereby making it possible to avoid changing the length of the set pre-heating period more than necessary.

[0016] Another characteristic configuration of the instant hot water supply system of the present invention is that if the pre-heating process has not been performed for a certain period of time because the instant hot water response time zone has not been set or because the instant hot water response process has not been performed, the operation control unit sets the set pre-heating period to a predetermined initial value.

[0017] If the instant hot water compatible time zone is not set, or if the instant hot water compatible process itself is not performed, the pre-heating process is not performed. If the pre-heating process is not performed for a certain period of time or more, that is, if the pre-heating period setting process is not performed for a certain period of time or more, the set heating period will remain unchanged for a certain period of time or more. In other words, there is a high possibility that the length of the set heating period is not appropriate. Therefore, in this characteristic configuration, if the pre-heating process is not performed for a certain period of time because the instant hot water compatible time zone is not set or the instant hot water compatible process is not performed, the operation control unit sets the set pre-heating period to a predetermined initial value. As a result, it is possible to prevent the length of the set heating period from becoming extremely inappropriate.

[0018] Another characteristic configuration of the instant hot water supply system according to the present invention is that the input receiving unit can receive a setting input of a plurality of instant hot water supply time periods that do not overlap with each other in a day, The operation control unit performs the pre-heating process corresponding to each of the plurality of instant hot water compatible time periods, and performs the pre-heating period setting process separately for each of the plurality of instant hot water compatible time periods.

[0019] According to the above characteristic configuration, it is possible to set an appropriate heating period for each of a plurality of time periods during the day, such as a morning time period and a daytime time period, in which the water supply temperature, for example, is different.

[0020] Another characteristic configuration of the instant hot water supply system of the present invention is that the operation control unit is configured to execute, as the pre-heating process, a first pre-heating process that is performed from the pre-heating start time for the set pre-heating period, and a second pre-heating process that is performed from an advanced pre-heating start time that is an advanced period before the pre-heating start time for the set pre-heating period so that the temperature of the hot water measured by the hot water temperature sensor becomes the target temperature, and thereafter, until the instant hot water start time, operates the circulation pump and the instant hot water heating unit so that the temperature of the hot water measured by the hot water temperature sensor becomes the target temperature; and when a time-of-day rate is adopted as the fee system for the energy source used in the instant hot water heating unit, the operation control unit compares a first cost of energy used in the instant hot water heating unit when the first pre-heating process is executed with a second cost of energy used in the instant hot water heating unit when the second pre-heating process is executed, and when the second cost is smaller than the first cost, executes the second pre-heating process as the pre-heating process.

[0021] According to the above characteristic configuration, the costs associated with operating the instant hot water supply system are compared in each case, namely, when the set pre-heating period is set based on the pre-heating start time, and when the advanced pre-heating start time is set so that the set pre-heating period falls during a discount time period in the time-of-use pricing system, and the instant hot water supply system is operated in a manner that has lower operating costs, thereby reducing the costs associated with operating the instant hot water supply system. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram showing the configuration of an instant hot water supply system. [Diagram 2] FIG. 1 is a diagram illustrating a pre-heating process and a hot water ready process. [Diagram 3]11 is a flowchart illustrating a pre-heating period setting process. [Figure 4] 11 is a diagram illustrating the pre-heating process and the instant hot water process when the required heating period is shorter than the set pre-heating period. FIG. [Diagram 5] FIG. 11 is a diagram illustrating the first pre-heating process and the instant hot water process in a case where the set pre-heating start period is set based on previous operation data so that the required heating period and the set pre-heating period are the same period. [Figure 6] FIG. 11 is a diagram illustrating a second pre-heating process and an immediate hot water process in a case where the pre-heating process is performed ahead of the pre-heating start time. [Figure 7] 13 is a flowchart for determining whether to set an advanced pre-heating start time instead of the pre-heating start time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] FIG. 1 is a diagram showing the configuration of an instant hot water supply system. As shown in the figure, the instant hot water supply system includes a water heater G and an instant hot water unit H that supply hot water to a hot water tap 1 in a kitchen or a washroom. The water heater G is installed, for example, outdoors, and the instant hot water unit H is installed, for example, outdoors or indoors. In this embodiment, the hot water tap 1 is a mixer-type hot water tap that mixes hot water and cold water. Note that the water heater G may also have a function of supplying hot water to a bathtub (not shown) in addition to the hot water tap 1, but in this embodiment, details of the configuration for supplying hot water to the bathtub will be omitted.

[0024] The water heater G is equipped with a hot water supply side control unit Cg that controls the operation of the water heater G. The instant hot water unit H is equipped with a unit side control unit Ch that controls the operation of the instant hot water unit H. The hot water supply side control unit Cg and the unit side control unit Ch are connected to freely communicate various information via a communication line D. In this embodiment, the hot water supply side control unit Cg and the unit side control unit Ch constitute an operation control unit C that executes the instant hot water response process, pre-heating process, and pre-heating period setting process described below.

[0025] The instant hot water supply system includes a remote control R having an input reception unit T that receives various setting inputs and control commands from, for example, a user or an external server. The remote control R may be a main remote control installed in the kitchen or a bathroom remote control installed in the bathroom.

[0026] For example, the input reception unit T can receive instructions to execute and stop the instant hot water processing from a user. When the operation control unit C receives an instruction to execute the instant hot water processing, it constantly performs the instant hot water processing described below, and when it receives an instruction to stop the instant hot water processing (or does not receive an instruction to execute the processing), it does not perform the instant hot water processing.

[0027] The input receiving unit T can receive setting and canceling inputs for the instant hot water time period during which the instant hot water processing is performed, for example, from a user or an external server. For example, if a user wants hot water at the target temperature to be supplied quickly only between 7:00 and 9:00 in the morning, the user can set the time period from 7:00 to 9:00 as the instant hot water processing time period. In this case, the operation control unit C performs the instant hot water processing during the instant hot water processing time period, and does not perform the instant hot water processing during times other than the instant hot water processing time period.

[0028] The instant hot water supply system includes a hot water supply heating section A that heats the water to be supplied, a water supply passage 2 through which the water to be supplied to the hot water supply heating section A flows, and a hot water supply passage 3 through which the hot water heated by the hot water supply heating section A flows while being supplied to the hot water tap 1. In the instant hot water supply system, a branched water supply passage 4 branching off from the water supply passage 2 is connected to the hot water tap 1, and hot water and cold water are mixed at the hot water tap 1, which is a mixer tap.

[0029] The hot water heating section A includes a hot water heat exchanger 5 provided in a heating flow path 5a whose inlet side is connected to the water supply path 2 and whose outlet side is connected to the hot water supply path 3, a hot water burner 6 for heating the hot water heat exchanger 5, and a hot water blower fan 7 for supplying combustion air to the hot water burner 6, and is configured to heat the hot water flowing through the heating flow path 5a with the combustion gas from the hot water burner 6. In Fig. 1, Z1 indicates the connection point between the water supply path 2 and the heating flow path 5a, and Z2 indicates the connection point between the hot water path 3 and the heating flow path 5a.

[0030] A hot water supply side gas supply passage 8 that supplies fuel gas such as city gas is connected to the hot water supply burner 6 provided in the hot water supply heating section A. An electromagnetic gas proportional valve 9 that adjusts the amount of fuel gas supplied, and an on-off valve 10 that turns on and off the supply of fuel gas are provided in the hot water supply side gas supply passage 8. Although not shown in the figure, an igniter for ignition and a flame rod for detecting ignition are provided near the hot water supply burner 6.

[0031] A water supply thermistor 11 for detecting the water supply temperature and a water volume sensor 12 for detecting the water supply volume are provided in a flow path portion of the heating flow path 5a on the side of the hot water supply heat exchanger 5 where the water supply path 2 is located. A hot water supply thermistor 13 for detecting the temperature of hot water is provided in a flow path portion of the heating flow path 5a on the side of the hot water supply heat exchanger 5 where the hot water supply path 3 is located.

[0032] A user can input settings into the remote control R to command the start and stop of operation of the water heater G. When a user has input settings into the remote control R to command the start of operation of the water heater G, the hot water supply side control unit Cg in the operation control unit C executes a hot water supply operation to supply hot water from the hot water tap 1 when the hot water tap 1 is opened. Specifically, the hot water supply side control unit Cg executes the hot water supply operation when the amount of water detected by the water volume sensor 12 reaches or exceeds a predetermined amount for ignition. Note that when a user has input settings into the remote control R to command the stop of operation of the water heater G, operation of the water heater G will not start even if the user opens the hot water tap 1 and the flow rate reaches or exceeds the set flow rate.

[0033] During hot water supply operation, the hot water supply side control unit Cg drives the hot water supply blower fan 7 in the hot water supply heating unit A, then opens the on / off valve 10 and ignites the hot water supply burner 6 using an igniter, and performs a process of adjusting the opening degree of the gas proportional valve 9 based on the set target temperature, the water volume detected by the water volume sensor 12, the supply water temperature detected by the water supply thermistor 11, and the outlet hot water temperature detected by the hot water supply thermistor 13, so that the outlet hot water temperature detected by the hot water supply thermistor 13 becomes the set target temperature. Furthermore, when the water flow is no longer detected by the water volume sensor 12, the hot water supply side control unit Cg closes the on-off valve 10 to stop the combustion of the hot water supply burner 6, stops the hot water supply blower fan 7, and terminates the hot water supply operation.

[0034] The water heater G is equipped with a heat medium heating section B that heats the heat medium to be circulated and supplied to heat consuming terminals such as floor heating devices and bathroom heater / dryer machines. The instant hot water unit H is equipped with a heat exchanger 21 as an instant hot water heating section K to which the heat medium heated in the heat medium heating section B is circulated and supplied. This heat exchanger 21 is a liquid-liquid heat exchanger that exchanges heat between the heat medium and hot water. The water heater G is equipped with a heat medium circulation circuit L for circulating the heat medium via the heat medium heating section B, and a heat medium circulation pump 22 for circulating the heat medium through the heat medium circulation circuit L.

[0035] The heat medium heating section B includes a heat medium heating heat exchanger 25 disposed midway through the heat medium circulation circuit L, a heat medium heating burner 26 for heating the heat medium heating heat exchanger 25, and a heat medium blower fan 27 for supplying combustion air to the heat medium heating burner 26, and is configured to heat the heat medium flowing through the heat medium circulation circuit L with the combustion gas of the heat medium heating burner 26. The heat medium heating heat exchanger 25 is connected to the inlet side with the heat medium return path 23 of the heat medium circulation circuit L and to the outlet side with the heat medium forward path 24 of the heat medium circulation circuit L.

[0036] A heat medium side gas supply passage 28 for supplying fuel gas such as city gas is connected to the heat medium heating burner 26 equipped in the heat medium heating section B. An electromagnetic heat medium side gas proportional valve 29 for adjusting the amount of fuel gas supplied and a heat medium side on / off valve 30 for turning on and off the supply of fuel gas are provided in the heat medium side gas supply passage 28. Although not shown in the figure, an igniter for ignition and a flame rod for detecting ignition are provided near the heat medium heating burner 26.

[0037] A heat medium return header 31 is provided at the inlet end of the heat medium return path 23, and a heat medium forward header 32 is provided at the outlet end of the heat medium forward path 24. A heat medium terminal forward path 33 is provided for supplying the heat medium from the heat medium forward header 32 to the heat exchanger 21, and a heat medium terminal return path 34 is provided for supplying the heat medium from the heat exchanger 21 to the heat medium return header 31. A thermal valve 35 is provided in the heat medium terminal forward path 33 to switch the supply of the heat medium on and off.

[0038] The heat medium return path 23 is provided with an expansion tank 36 and the heat medium circulating pump 22 described above, and the heat medium forward path 24 is provided with a heat medium thermistor 37 that detects the temperature of the heat medium being supplied. Between the heat medium forward header 32 and the heat medium return header 31, a heat medium terminal forward path 33 and a heat medium terminal return path 34 for circulating the heat medium between other heat consuming terminals are provided, but detailed explanations are omitted in this embodiment. Also, when the thermal valve 35 is closed, a connecting path is provided for short-circuiting the heat medium in the heat medium forward path 24 to the heat medium return path 23, but description thereof is omitted in this embodiment.

[0039] The instant hot water supply system includes at least a part of the hot water supply path 3, an instant hot water circulation circuit J in which hot water circulates, a circulation pump 15 for circulating hot water in the instant hot water supply path J, an instant hot water heating unit K for heating the hot water circulating in the instant hot water supply path J, and a hot water temperature sensor M for measuring the temperature of the hot water in the instant hot water supply path J. In this embodiment, the instant hot water supply path J is an annular flow path composed of the hot water supply path 3 and a hot water supply side return path 38 that connects the hot water tap side end point of the hot water supply path 3 (a point located near the hot water tap 1, i.e., the downstream end point of the hot water supply path 3) and an upstream point in the hot water supply path 3 (a point located near the connection point Z2 between the hot water supply path 3 and the heating flow path 5a, i.e., the upstream end point of the hot water supply path 3). In this embodiment, the hot water supply side return path 38 is provided in a state of passing through the inside of the instant hot water unit H. A hot water supply side check valve 39 for preventing backflow is provided in the hot water supply passage 3 at a location upstream of the connection point of the hot water supply side return passage 38.

[0040] A circulation pump 15 that circulates hot water in the instant hot water circulation circuit J, and a heat exchanger 21 as an instant hot water heating section K that heats hot water in the instant hot water circulation circuit J are provided in a portion of the hot water supply side return path 38 that is located inside the instant hot water unit H. In addition, a return temperature sensor 40 is provided as a hot water temperature sensor M, which is located in a portion of the hot water supply side return path 38 that is located inside the instant hot water unit H. The position at which the return temperature sensor 40 is provided can be changed as appropriate.

[0041] That is, the instant hot water circulation circuit J is provided with a circulation pump 15, an instant hot water heating section K, and a hot water temperature sensor M (return temperature sensor 40). In addition, a unit-side check valve 16 for preventing backflow is provided downstream of the circulation pump 15 in the water supply-side return path 14 located inside the instant hot water unit H.

[0042] An air release valve 17 and an accumulator 18 for absorbing the expansion of hot water are provided in the flow path portion between the hot water supply side end portion of the hot water supply side return path 38 and the circulation pump 15.

[0043] Therefore, the operation control unit C is configured to operate the circulation pump 15 to circulate hot water inside the instant hot water circulation circuit J, and to heat the hot water inside the instant hot water circulation circuit J to a target temperature (e.g., 60°C) by operating the instant hot water heating unit K (heat exchanger 21) to heat it.

[0044] [Instant hot water treatment] The operation control unit C performs an instant hot water response process during the instant hot water response time period, which operates the circulation pump 15 and the instant hot water heating unit K so that the temperature of the hot water measured by the return temperature sensor 40, which serves as the hot water temperature sensor M, reaches the target temperature.

[0045] For example, the hot water supply side control unit Cg operates the heat medium circulation pump 22 to circulate the heat medium, and also operates the heat medium blower fan 27 while burning the heat medium heating burner 26, and adjusts the opening of the heat medium side gas proportional valve 29 so that the temperature detected by the heat medium thermistor 37 becomes the heat medium supply temperature (for example, 65°C). In addition, the hot water supply side control unit Cg opens the thermal valve 35 to circulate the heat medium to the heat exchanger 21. Also, the unit side control unit Ch operates the circulation pump 15 to circulate hot water in the instant hot water circulation circuit J. As a result, the heat exchanger 21 as the instant hot water heating unit K is supplied with the high-temperature heat medium heated in the heat medium heating unit B and the hot water circulating in the instant hot water circulation circuit J, and heat exchange between them (i.e., heating of the hot water circulating in the instant hot water circulation circuit J) is performed. This state is the state in which the instant hot water heating unit K is operated.

[0046] In addition, as an instant hot water processing, when the temperature detected by the return temperature sensor 40 drops below a set heating start temperature that is lower than the target temperature (for example, 60°C) by a set temperature (for example, 5°C) with the circulation pump 15 stopped and the heat exchanger 21 stopped, the operation control unit C repeatedly executes a process of operating the circulation pump 15 and heating the heat exchanger 21, and then stopping the operation of the circulation pump 15 and stopping the heating operation of the heat exchanger 21 when the temperature of the hot water in the instant hot water circulation circuit J detected by the return temperature sensor 40 reaches the target temperature (for example, 60°C). Note that it is possible to appropriately set what conditions are met to operate the circulation pump 15 and heat the heat exchanger 21, and what conditions are met to stop the operation of the circulation pump 15 and stop the heating operation of the heat exchanger 21.

[0047] In addition, when the operation control unit C executes hot water supply operation because the water volume detected by the water volume sensor 12 becomes equal to or greater than the predetermined amount for ignition, if the instant hot water response process is being executed, the operation control unit C suspends the instant hot water response process until the hot water supply operation is terminated, and does not start execution of the instant hot water response process while the hot water supply operation is being executed.

[0048] [Pre-heating process, pre-heating period setting process] As described above, if a user wants hot water at the target temperature to be supplied quickly only between 7:00 and 9:00 in the morning, and sets the time period as the instant hot water time slot, it is necessary to prepare a system that can quickly supply hot water at the target temperature to the user at the start time of the instant hot water time slot. In other words, it is necessary to keep hot water at the target temperature pooled in the instant hot water circulation circuit J.

[0049] Therefore, the operation control unit C performs a pre-heating process by operating the circulation pump 15 and the instant-hot water heating unit K from a pre-heating start time that is a predetermined set pre-heating period before the target instant-hot water response time T1, which corresponds to the start time of the instant-hot water response time zone or the time before the start time by the set margin period, so that the temperature of the hot water measured by the return temperature sensor 40 will reach the target temperature.The operation control unit C then ends the pre-heating process when the temperature of the hot water measured by the return temperature sensor 40 reaches the target temperature.

[0050] 2 is a diagram for explaining the pre-heating process and the hot water supply process. In the illustrated example, the hot water supply time period is set from time Ts to time Te. Therefore, the operation control unit C performs the hot water supply process during the hot water supply time period from time Ts to time Te.

[0051] In addition, the operation control unit C performs a pre-heating process by operating the circulation pump 15 and the instant hot water heating unit K from a pre-heating start time T0, which is a predetermined set pre-heating period before the target instant hot water response time T1, so that the temperature of the hot water measured by the return temperature sensor 40 will reach the target temperature at the target instant hot water response time T1, which corresponds to a time before the start time Ts of the instant hot water response time period by a set margin period. As illustrated in Fig. 2, the temperature of the hot water measured by the return temperature sensor 40 starts to rise from the pre-heating start time T0 and reaches the target temperature at time T2. In Fig. 2, the pre-heating process is depicted up to time Ts, but the operation control unit C ends the pre-heating process when the temperature of the hot water measured by the return temperature sensor 40 reaches the target temperature, and thereafter performs the instant hot water response process.

[0052] The length of the set margin period can be set appropriately, and the length of the set margin period may be zero. In other words, the start time Ts of the instant hot water availability time zone may be set as the target instant hot water availability time.

[0053] In this case, the operation control unit C performs a pre-heating period setting process as shown in the flowchart of Fig. 3. As described below, the pre-heating period setting process is a process that measures a required heating period until the temperature of the hot water measured by the return temperature sensor 40 reaches a target temperature after the pre-heating process is started at the pre-heating start time T0, and makes the length of the set pre-heating period for the next pre-heating process approach the length of the required heating period.

[0054] In step #10 of Fig. 3, the operation control unit C starts timing the period from the start of the preliminary heating process. Then, in step #11, the operation control unit C determines whether the hot water temperature measured by the return temperature sensor 40 has reached the target temperature. Then, if the hot water temperature measured by the return temperature sensor 40 has not reached the target temperature, the operation control unit C repeats this step #11.

[0055] When the hot water temperature measured by the return temperature sensor 40 reaches the target temperature, the operation control unit C proceeds to step #12 and brings the length of the set pre-heating period for the next pre-heating process closer to the length of the required heating period. For example, the length of the required heating period for the next pre-heating process is likely to be similar to the length of the required heating period for the current pre-heating process. Therefore, in the pre-heating period setting process, the operation control unit C sets the length of the set pre-heating period for the next pre-heating process to be the same as the length of the required heating period for the current pre-heating process. As a result, when the next pre-heating process is performed, there is an increased possibility that the temperature of the hot water will reach the target temperature at a time close to the target ready-to-heat time. In the example shown in Fig. 2, the time T2 at which the hot water temperature reaches the target temperature is later than the target instant-hot water compatible time T1, and in the example shown in Fig. 4, the time T2 at which the hot water temperature reaches the target temperature is earlier than the target instant-hot water compatible time T1, but in either case, the next time pre-heating is performed, it is highly likely that the time T2 at which the hot water temperature measured by the return temperature sensor 40 reaches the target temperature will be close to the target instant-hot water compatible time T1, as shown in Fig. 5. If no set margin period is set, it is highly likely that the time at which the hot water temperature measured by the return temperature sensor 40 reaches the target temperature will be close to the start time of the instant-hot water compatible time period.

[0056] As described above, the operation control unit C performs a pre-heating process of operating the circulation pump 15 and the instant hot water heating unit K from the pre-heating start time a predetermined set pre-heating period before the target instant hot water response time so that the hot water temperature measured by the return temperature sensor 40 (hot water temperature sensor M) will reach the target temperature at the target instant hot water response time corresponding to the start time of the accepted instant hot water response time period or a time a set margin period before the start time. As a result, there is a high possibility that the system will be ready to quickly supply hot water at the target temperature to users at the start time of the instant hot water response time period. Furthermore, if the target instant-hot water availability time is set to a time that is a set margin period earlier than the start time of the accepted instant-hot water availability time slot rather than the start time of that time slot, even if the heating period required for the temperature of the hot water measured by the return temperature sensor 40 during the pre-heating process to reach the target temperature has changed from the previous pre-heating process, it is even more likely that the system will be ready to quickly supply hot water at the target temperature to the user at the start time of the instant-hot water availability time slot.

[0057] Furthermore, the operation control unit C performs a pre-heating period setting process to measure the required heating period until the temperature of hot water measured by the return temperature sensor 40 reaches the target temperature after starting the pre-heating process at the pre-heating start time, and to set the length of the set pre-heating period for the next pre-heating process to be close to the required heating period. In other words, even if the length of the required heating period until the temperature of hot water measured by the return temperature sensor 40 reaches the target temperature after starting the pre-heating process at the pre-heating start time changes due to the influence of the water supply temperature in the facility such as a dwelling where the instant hot water supply system is installed, an appropriate set pre-heating period length considering the influence is determined each time the pre-heating process is performed. Then, when the pre-heating process is performed, the temperature of hot water measured by the return temperature sensor 40 becomes the target temperature without being significantly earlier or later in time from the target instant hot water response time corresponding to the start time of the accepted instant hot water response time period or the time before the start time by the set margin period. Therefore, it is possible to provide an instant hot water supply system that can quickly supply hot water at the target temperature to users while suppressing an increase in running costs.

[0058] <Another embodiment> In the above embodiment, a specific example of the configuration of the instant hot water supply system has been described, but the configuration can be modified as appropriate. For example, the heat medium heating section B described in the above embodiment may be omitted, and the heat medium heated in the hot water heating section A may be supplied to the instant hot water heating section K. In addition, the instant hot water heating section K may be housed inside the housing of the water heater G.

[0059] In the above embodiment, an example has been described in which the hot water heating section A and the heat transfer medium heating section B use gas as an energy source to heat water and the heat transfer medium by the heat of combustion. However, the energy source of the hot water heating section A and the heat transfer medium heating section B may be something other than gas, such as electricity.

[0060] In the above embodiment, the operation control unit C is configured from the hot water supply side control unit Cg and the unit side control unit Ch, but the unit side control unit Ch may be omitted and the operation control unit C may be configured only by the hot water supply side control unit Cg. In other words, the unit side control unit Ch may be omitted, for example, so that the hot water supply side control unit Cg directly controls the operation of the circulation pump 15.

[0061] In the above embodiment, the contents of the pre-heating period setting process may be changed as appropriate. For example, the operation control unit C may perform a process in which, in the pre-heating period setting process, if the length of the required heating period in the currently performed pre-heating process is longer than the length of the set pre-heating period in the currently performed pre-heating process by at least a reference period (e.g., 5 minutes), the operation control unit C sets the length of the set pre-heating period in the pre-heating process to be performed next to be longer by the reference period, if the length of the required heating period in the currently performed pre-heating process is shorter than the length of the set pre-heating period in the currently performed pre-heating process by at least the reference period, the operation control unit C sets the length of the set pre-heating period in the next pre-heating process to be shorter by the reference period, and if the length of the required heating period in the currently performed pre-heating process is longer than the length of the set pre-heating period in the currently performed pre-heating process by less than the reference period (5 minutes) or shorter than the reference period, the operation control unit C does not change the length of the set pre-heating period in the next pre-heating process. That is, if the difference between the length of the required heating period in the currently performed pre-heating process and the length of the set pre-heating period is equal to or greater than the length of the reference period, i.e., if the length of the currently set pre-heating period cannot be said to be appropriate, the operation control unit C changes the length of the set pre-heating period as appropriate. As a result, the length of the set pre-heating period in the next pre-heating process approaches the length of the required heating period in the currently performed pre-heating process. On the other hand, if the difference between the length of the required heating period in the currently performed pre-heating process and the length of the set pre-heating period is less than the length of the reference period, i.e., if the length of the currently set pre-heating period is set to an appropriate length, the operation control unit C does not change the length of the set pre-heating period in the next pre-heating process in the pre-heating period setting process. As a result, it is possible to avoid changing the length of the set pre-heating period more than necessary.

[0062] In the above embodiment, the operation control unit C may set the set pre-heating period to a predetermined initial value when the pre-heating process is not performed for a certain period or more because the immediate hot water compatible time zone is not set or the immediate hot water compatible process is not performed. For example, when the immediate hot water compatible time zone is not set or the immediate hot water compatible process itself is not performed, the pre-heating process is not performed. And when the pre-heating process is not performed for a certain period or more, that is, when the pre-heating period setting process is not performed for a certain period or more, the set time heating period will pass without being changed for a certain period or more. In other words, the length of the set time heating period is likely to be inappropriate. Therefore, when the pre-heating process is not performed for a certain period or more (for example, 30 days or more) because the immediate hot water compatible time zone is not set or the immediate hot water compatible process is not performed, the operation control unit C sets the set pre-heating period to a predetermined initial value. As a result, the length of the set time heating period can be prevented from becoming extremely inappropriate.

[0063] In the above embodiment, the input receiving unit T may receive a setting input for multiple instant hot water compatible time periods that do not overlap with each other within a day. The operation control unit C may then perform a pre-heating process corresponding to each of the multiple instant hot water compatible time periods, and may also perform a pre-heating period setting process for each of the multiple time periods separately. For example, an appropriate set heating period can be set for each of multiple time periods in a day that differ, for example, in the water supply temperature, such as a morning time period (e.g., 7:00-9:00, etc.) and a daytime time period (e.g., 12:00-13:00, etc.). Furthermore, if a set margin period is provided, a set margin period can be set for each of the multiple time periods.

[0064] [Pre-heating based on hourly rates] Electric power companies and gas companies may adopt time-of-day rates that discount the charges for the energy sources, electricity and gas, depending on the time of day they are supplied. In this case, the charges for using the energy source are divided into a regular rate and a discounted rate depending on the time of day the energy source is used. In this application, the time periods during which the charge for using the energy source is the regular rate are referred to as regular time periods, and the time periods during which the charge for using the energy source is the discounted rate are referred to as discount time periods.

[0065] In consideration of such time-of-day charges, the operation control unit C of the present invention is configured to be able to execute a first pre-heating process and a second pre-heating process as the pre-heating process.

[0066] The first pre-heating process is a processing method performed during a set pre-heating period from the pre-heating start time T0 to the target instant hot water response time T1, which is also the time when the temperature of the hot water reaches the target temperature.The second pre-heating process is a processing method performed during a set pre-heating period from the advanced pre-heating start time T0', which is an advanced period before the pre-heating start time T0, to the time T2 when the temperature of the hot water reaches the target temperature, so that the temperature of the hot water measured by the hot water temperature sensor becomes the target temperature, and thereafter, until the target instant hot water response time T1, the circulation pump and the instant hot water heating unit are operated so that the temperature of the hot water measured by the hot water temperature sensor becomes the target temperature. After the first pre-heating process and the second pre-heating process are completed, the process transitions to an immediate hot water process, and reheating is performed so that the temperature of the hot water is maintained close to the target temperature.

[0067] FIG. 6 is a diagram illustrating the second pre-heating process and the hot water ready process in the second pre-heating process.

[0068] In addition, the operation control unit of the present invention compares a first cost G1 of energy used in the instant hot water heating section when the first pre-heating process is performed with a second cost G2 of energy used in the instant hot water heating section when the second pre-heating process is performed, and when the second cost is smaller than the first cost, performs the second pre-heating process as the pre-heating process.

[0069] The first cost G1 and the second cost G2 are calculated using the following formulas. First cost G1 = V × W1 / Q / R × S1 Second cost G2 = V × W1 / Q / R × S2 + V × W2 × n / Q / R × S1

[0070] However, the letters used in the calculation have the following meanings: V: Water volume held by the instant hot water supply system W1: The temperature difference between the water temperature in the instantaneous hot water supply system at the pre-heating start time or the advanced pre-heating start time and the target temperature W2: Temperature difference between reheating temperature and target temperature n:(T1-T2) / Tc Q: Unit conversion factor (kCal / kWh or kCal / m 3 ) R: Thermal efficiency of instant hot water systems S1: Normal charge for energy source during normal hours (yen / kWh or yen / m 3 ) S2: Discounted energy charges during discounted time periods (yen / kWh or yen / m 3 )

[0071] However, as shown in Figure 6, Tc is the time it takes for the hot water, which has been heated to the target temperature, to rise further due to residual heat, then be cooled by heat radiation, reach the reheating temperature, and be reheated to reach the target temperature again.

[0072] As shown in the flowchart of FIG. 7, the operation control unit C changes the pre-heating start time in accordance with the result of comparison between the first cost G1 and the second cost G2. 7, the user inputs in advance the regular time period and regular fee, and the discount time period and discount fee in the input reception unit T. Note that the time-period fee for the energy source is not limited to being input by the user to the input reception unit T, but may be configured to have the input reception unit T read information on the Internet via an external server. In step #22, when a user sets a certain time period as an immediate hot water time period, in step #23, the operation control unit C calculates the energy costs of the first cost G1 and the second cost G2. Then, in step #24, the calculated first cost G1 and the second cost G2 are compared, and if the second cost G2 is cheaper, as in step #25, the advance pre-heating start time T0' is set instead of the pre-heating start time T0 so that the set pre-heating period overlaps with at least a part of the discount time period. If the first cost G1 and the second cost G2 are compared, and the first cost G1 is cheaper, as in step #26, the pre-heating start time T0 is not changed.

[0073] When the time-specific rate for an energy source has multiple discount time periods with different discount rates for each discount time period, the cheapest second cost G2 is calculated based on the normal time periods and normal rates and all discount time periods and discount rates, and if the calculated second cost G2 is cheaper than the first cost G1, the advanced pre-heating start time T0' is set so that the cost of operating the instant hot water supply system is G2.

[0074] In the above embodiment, the instant hot water supply system of the present invention has been described using specific numerical examples. However, these numerical values ​​are given for illustrative purposes and can be changed as appropriate.

[0075] The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided that no contradiction arises. Furthermore, the embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0076] INDUSTRIAL APPLICABILITY The present invention can be used in an instant hot water supply system that can quickly supply hot water at a target temperature to users while suppressing increases in running costs. [Explanation of symbols]

[0077] 1: Hot water tap 2: Water supply channel 3: Hot water supply line 15: Circulation pump 40: Return temperature sensor (hot water temperature sensor M) A: Hot water heating section C: Operation control unit Cg: Hot water supply control section Ch: Unit side control section J: Instant hot water circulation circuit K: Heating part for instant hot water T: Input reception section

Claims

1. the instant hot water supply system comprises a hot water supply heating section which heats the water to be supplied, a water supply passage through which the water to be supplied to the hot water supply heating section flows, a hot water supply passage through which the hot water heated by the hot water supply heating section flows while being supplied to a hot water tap, an instant hot water circulation circuit which includes at least a portion of the hot water supply passage and through which hot water is circulated, a circulation pump which circulates the hot water in the instant hot water circulation circuit, an instant hot water heating section which heats the hot water circulating in the instant hot water circulation circuit, a hot water temperature sensor which measures the temperature of the hot water in the instant hot water circulation circuit, an input receiving section which receives input of settings for an instant hot water time period, and an operation control section; The operation control unit is an instant hot water supply system that performs an instant hot water response process during the instant hot water response time period to operate the circulation pump and the instant hot water heating unit so that the temperature of the hot water measured by the hot water temperature sensor becomes a target temperature, The operation control unit is configured to perform a pre-heating process to operate the circulation pump and the instant hot water heating unit from a pre-heating start time that is a predetermined set pre-heating period before the target instant hot water response time so that the temperature of the hot water measured by the hot water temperature sensor becomes the target temperature at a target instant hot water response time that corresponds to the start time of the instant hot water response time period or a time that is a set margin period before the start time of the instant hot water response time period, The operation control unit of this instant hot water supply system starts the pre-heating process at the pre-heating start time, and then measures the required heating period until the temperature of the hot water measured by the hot water temperature sensor reaches the target temperature, and performs a pre-heating period setting process to approximate the length of the set pre-heating period for the next pre-heating process to the length of the required heating period.

2. The instant hot water supply system according to claim 1, wherein the operation control unit, in the pre-heating period setting process, sets the length of the set pre-heating period for the next pre-heating process to be performed to be the same as the length of the required heating period for the pre-heating process currently performed.

3. The operation control unit, in the pre-heating period setting process, When the length of the required heating period in the currently performed pre-heating treatment is longer than the length of the set pre-heating period in the currently performed pre-heating treatment by at least a reference period, the length of the set pre-heating period in the next pre-heating treatment is set to be longer by the reference period; When the length of the required heating period in the currently performed pre-heating treatment is shorter than the length of the set pre-heating period in the currently performed pre-heating treatment by at least the reference period, the length of the set pre-heating period in the next pre-heating treatment is set shorter by the reference period; 2. The instant hot water supply system of claim 1, wherein if the length of the required heating period in the currently performed pre-heating process is longer than the length of the set pre-heating period in the currently performed pre-heating process by less than the reference period or shorter than the length of the set pre-heating period in the currently performed pre-heating process by less than the reference period, the length of the set pre-heating period in the next pre-heating process is not changed.

4. The instant hot water supply system of any one of claims 1 to 3, wherein the operation control unit sets the set pre-heating period to a predetermined initial value when the pre-heating process has not been performed for a certain period of time because the instant hot water response time zone has not been set or because the instant hot water response process has not been performed.

5. The input receiving unit can receive a setting input of a plurality of instant hot water corresponding time periods that do not overlap with each other in a day, The instant hot water supply system according to any one of claims 1 to 3, wherein the operation control unit performs the pre-heating process corresponding to each of the multiple instant hot water response time periods and performs the pre-heating period setting process separately for each of the multiple instant hot water response time periods.

6. The operation control unit is configured to execute, as the pre-heating process, a first pre-heating process performed from the pre-heating start time for the set pre-heating period, and a second pre-heating process performed from an advanced pre-heating start time that is an advanced period before the pre-heating start time for the set pre-heating period so that the temperature of the hot water measured by the hot water temperature sensor becomes the target temperature, and thereafter, until the target instant hot water compatible time, operate the circulation pump and the instant hot water heating unit so that the temperature of the hot water measured by the hot water temperature sensor becomes the target temperature. The instant hot water supply system of any one of claims 1 to 3, wherein the operation control unit, when a time-of-day rate is adopted for the fee system of the energy source used in the instant hot water heating unit, compares a first cost of energy used in the instant hot water heating unit when the first pre-heating process is executed with a second cost of energy used in the instant hot water heating unit when the second pre-heating process is executed, and when the second cost is smaller than the first cost, executes the second pre-heating process as the pre-heating process.

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