JPH06272957A - Circulating insulation type hot-water apparatus - Google Patents

Abstract

PURPOSE:To prevent fluctuations of hot water delivery temperatures at an initial stage of hot-water supply due to a time-lag of a water temperature sens ing in a hot-water mixing type hot-water apparatus provided with circulating insulation functions. CONSTITUTION:A storage element 61 for storing water temperature sensed in a preceeding hot-water supply is provided in a hot-water initial condition changing element 60. When hot-water supply is started, a water temperature sensing output element 62 outputs first water temperature which has been stored, and thereafter, as soon as water temperature sensing output corresponding to new water temperature is obtained, the element 62 outputs water temperature TC which is sensed by a water temperature sensor 12. In an initial stage of hot-water supply, a heating control element 50 controls amounts of heating of a heat exchanger based on water temperature sensed at the time of preceeding hot-water supply and a mixing valve control element 70 controls hot-water mixing ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply device having a circulating heat retention function, and particularly to hot water temperature at the start of hot water discharge by temporarily correcting the heating amount at the start of hot water supply and the mixing ratio of the hot and cold water mixing valve. The present invention relates to a hot water supply device with reduced fluctuation.

[0002]

2. Description of the Related Art A circulation line is formed by connecting a terminal side of a hot water supply line and a water inlet side of a heat exchanger with a return line, and a circulation pump provided in the return line or the like is operated to operate in the circulation line. By heating the hot water that circulates through the heat exchanger while circulating the hot water, the hot water in the circulation path can be kept at an appropriate temperature, and the hot water can be quickly discharged from the hot water tap connected to the hot water supply conduit. The circulation warming type hot water supply device as described above is disclosed in JP-B-2-18432, JP-B-3-28663, and JP-B-3-2866.
It is known from Japanese Patent Publication No. 4 and the like.

Further, in the above Japanese Patent Publication No. 3-28664, the amount of heat required to boil the circulating hot and cold water to a set temperature (hereinafter simply referred to as the required amount of heat) is calculated, and an interval corresponding to the calculated amount of heat is calculated. , A technique for maintaining the heat retention of hot water by intermittently burning a burner for a certain time is described.

There is also known a hot water supply device in which water and hot water heated by a heat exchanger are mixed by a hot and cold water mixing valve to supply hot and cold water having a set temperature. In this water heater, water is added to hot water to obtain hot water having a desired temperature, so that the rising temperature of the hot water can be raised quickly. Further, this hot and cold water mixing type hot water supply device has an advantage that a large amount of hot and cold water can be supplied by increasing the temperature on the hot water side and increasing the amount of water.

[0005]

However, the hot water supply for controlling the heating amount in the heating unit and the hot and cold water mixing ratio in the hot and cold water mixing valve based on the hot water temperature detected by the hot water temperature detecting unit constituted by using a thermistor or the like. In the water heater, there is a problem described below because there is a time delay in detecting the incoming water temperature when the circulating heat retention mode is switched to the hot water supply mode.

FIG. 6 is a graph showing the detection response characteristics of the incoming water temperature detecting portion (water temperature sensor). For example, hot water is started from a state where the temperature is kept at 40 ° C.
It is assumed that 0 ° C water reaches the incoming water temperature detection unit. The detection output does not immediately decrease due to the influence of the heat capacity of the heat-sensitive element such as the thermistor that constitutes the incoming water temperature detection unit and the heat capacity of the peripheral piping. Assuming that the time at which 10 ° C. water reaches the heat exchanger is t1, it is necessary to heat at a heating amount corresponding to the incoming water temperature of 10 ° C. at time t1, but as shown in FIG. 1, the detected temperature TC at time t1 is Since the temperature is 38 ° C., the heating amount becomes insufficient, and the hot water supply temperature drops significantly below the set temperature.

If the time at which the water at 10 ° C. reaches the hot and cold water mixing valve is t2, it is necessary to control the mixing valve at a mixing ratio according to the incoming water temperature of 10 ° C. at time T2, as shown in FIG. Since the detected temperature TC at time t2 is 37 ° C., the mixing ratio on the water side becomes too large, and the temperature of the mixed hot water becomes significantly lower than the set temperature.

This will be described in detail. When the hot water mixing ratio is calculated by the following formula and the hot water mixing valve is controlled, (TS-TC) / (TH-TC) TS: set temperature TH : Outlet temperature of heat exchanger TC: Temperature detected by water temperature detector When each value at time t2 (TH = 41 ° C. as an example) is input to the above equation to obtain the mixing ratio, (40-37) / ( 41-37) = 0.75.

However, since the temperature of the water actually reaching the hot and cold water mixing valve is 10 ° C., the actual mixed hot water temperature T
M is TM = 0.75 * (41-10) + 10 = 33.25, which is about 33 ° C., and the mixed hot water having a temperature about 7 ° C. lower than the set temperature is supplied. Further, when performing intermittent combustion during circulation heating, the detected water temperature TC is, for example, 3
Since it fluctuates between 9 and 41 ° C, TS = TH or TH
= TC sometimes occurred.

When the warming mode is switched to the hot water supply mode in such a state, the mixing ratio on the hot water side may be calculated to be 0 or ∞ (uncontrollable) even temporarily, and the control of the hot and cold water mixing valve may be unsuccessful. In addition to becoming stable, the amount of hot water passing through the heat exchanger also becomes unstable, which in turn causes fluctuations in the outlet temperature of the heat exchanger and the temperature of the mixed hot water.

The present invention has been made to solve such a problem, and an object thereof is to provide a circulating heat retaining type hot water supply apparatus in which fluctuations in the hot water discharge temperature immediately after the start of hot water supply are reduced.

[0012]

In order to solve the above-mentioned problems, a circulation warming type hot water supply apparatus according to a first aspect of the present invention connects a terminal end of a hot water supply pipe and a water supply pipe with a return pipe, A circulation path is formed by the heat exchanger, the hot water supply pipe, and the return pipe, and when the hot water tap connected to the hot water supply pipe is not in use, the circulation pump installed in the return pipe is operated. The hot water temperature in the circulation path is maintained within a predetermined temperature range by appropriately performing a circulation heat retention operation in which the hot water in the circulation path is circulated and heated by a heat exchanger, and when the hot water tap is used, The required amount of heat is calculated based on at least the temperature of water entering the heat exchanger detected by the detector and the set temperature set by the temperature setter to heat the heat exchanger to supply hot water at the set temperature. In the circulation warming type hot water supply device, Heating the heat exchanger with a constant amount of heat, characterized by comprising a hot water supply initial heat changing means for heating the subsequent heat exchanger with the required amount of heat the calculated.

A storage means for storing the water temperature detected at the time of hot water supply last time may be provided, and the predetermined heat quantity may be calculated based on the stored content of the storage means and the set temperature.

According to a third aspect of the present invention, there is provided a circulating hot water supply system in which a hot and cold water mixing valve is provided on the hot water outlet side of the heat exchanger to connect the hot water heated by the heat exchanger and the water inlet side of the heat exchanger. The water from the water is mixed and supplied to the hot water supply pipe, and the end portion of the hot water supply pipe and the water supply pipe are connected by a return pipe to provide a water supply pipe, a heat exchanger, a hot and cold water mixing valve, and hot water supply. In the non-hot water supply state where the circulation path is formed by the pipeline and the return pipeline, and the hot water tap connected to the hot water supply pipeline is not used, the circulation pump installed in the return pipeline is operated The temperature of the hot water in the circulation path is kept within a predetermined temperature range by appropriately performing a circulation heat-insulation operation in which the water is circulated while being heated by a heat exchanger, and the water temperature detector detects when the hot water tap is used. Based on at least the temperature of the water entering the heat exchanger and the set temperature set by the temperature setter. And heat the heat exchanger by calculating the required heat quantity, and control the mixing ratio of the hot and cold water mixing valve based on at least the incoming water temperature and the preset temperature to supply hot water at the preset temperature. In the hot water supply apparatus, the hot water mixing valve is controlled to a predetermined mixing ratio at the start of hot water supply, and then the mixing ratio of the hot water mixing valve is controlled based on at least the inlet temperature and the set temperature. It is characterized by having means.

A storage means for storing the water temperature detected at the time of hot water supply last time may be provided, and the predetermined mixing ratio may be calculated based on the storage content of the storage means and the set temperature.

[0016]

In the circulation warming type hot water supply apparatus according to the first aspect, the heat exchanger is heated with a predetermined amount of heat at the start of hot water supply, and thereafter, for example, after the water temperature detection output corresponding to a new water temperature is obtained, The required heat quantity is calculated based on at least the detected water temperature and the set temperature, and heating is performed based on the calculated necessary heat quantity. When entering the hot water supply state, the temperature of the water entering the heat exchanger falls from the warming temperature to the temperature of the water, but there is a delay in the detection time of the water temperature detection unit, so the actual temperature of the incoming water and the detected temperature do not match immediately after the start of hot water supply. Instead, a higher temperature is detected. Therefore, the amount of heat calculated based on the detected water temperature is insufficient to lower the hot water outlet temperature. However, by heating based on the predetermined amount of heat in the initial stage of starting hot water supply, it is possible to prevent the hot water temperature from decreasing at the start of hot water discharge.

It should be noted that the detected water temperature in the hot water supply state of the previous time is stored, and the calorific value is calculated based on the stored water temperature at the start of a new hot water supply, so that an appropriate temperature of hot water is supplied from the start of the hot water supply. it can.

In the circulation warming type hot water supply apparatus according to the third aspect, the hot water mixing valve is controlled to a predetermined mixing ratio at the start of hot water supply, and thereafter, for example, a water temperature detection output corresponding to a new water temperature is obtained. Calculates a mixing ratio based on at least the detected water temperature and the set temperature, and controls the mixing ratio of the hot and cold water mixing valve based on the calculated mixing ratio. When entering the hot water supply state, the temperature of the water entering the heat exchanger falls from the warming temperature to the temperature of the water, but there is a delay in the detection time of the water temperature detection unit, so the actual temperature of the incoming water and the detected temperature do not match immediately after the start of hot water supply. Instead, a higher temperature is detected. Therefore, in the mixing ratio calculated based on the detected water temperature, the mixing ratio on the hot water side decreases and the hot water outlet temperature decreases, but in the initial stage of hot water supply start, the mixing ratio of the hot and cold water mixing valve is set based on the predetermined mixing ratio. As a result, it is possible to prevent a decrease in the hot water discharge temperature at the start of hot water supply.

It is to be noted that the detected water temperature in the hot water supply state of the last time is stored and the mixing ratio is calculated based on the stored water temperature at the start of a new hot water supply, so that the hot water having an appropriate temperature from the start of the hot water supply can be obtained. Can be supplied.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram of a circulating warm water heater according to the present invention. This hot water supply device 1 is a hot water / water mixing type hot water supply device, and when the hot water tap 2 is opened,
The hot water obtained by heating the water supplied from the water supply pipe 3 with the heat exchanger 4 and the water supplied from the bypass pipe 5 are mixed by the hot water mixing valve 6, and the mixed hot water is supplied to the hot water supply pipe 7. In the non-hot water supply state in which the hot water supply tap 2 is closed and the hot water supply tap 2 is closed, the circulation pump 9 is provided in the return pipe 8 that connects the terminal side of the hot water supply pipe 7 and the water supply pipe 3. By operating the heat exchanger 4, the hot and cold water mixing valve 6, the hot water supply pipe 7, the return pipe 8, and the water supply pipe 3a downstream of the connection between the water supply pipe 3 and the return pipe 8. The hot water in the passage 10 is appropriately heated by the heat exchanger 4 while being circulated, so that the hot water in the circulation passage 10 can be maintained at a predetermined temperature.

The controller 11 is provided with an input of the heat exchanger 4 detected by the water temperature sensor 12 and the flow rate sensor 13 provided in the water supply pipe 3a on the downstream side of the connection between the water supply pipe 3 and the return pipe 8. Side water temperature TC and flow rate Q, hot water outlet temperature TH detected by hot water outlet temperature sensor 14 provided on the hot water outlet side of heat exchanger 4, and mixed temperature sensor 15 provided downstream of hot and cold water mixing valve 5. The mixed temperature TM and the set temperature TS of the heat retention operation switch 16 and the temperature setter 17 are input,
While controlling the operation of the circulation pump 9, the gas pipe 18
The combustion of the burner 21 is controlled by adjusting the opening and closing of the gas on-off valve 19 and the gas proportional valve 20 and the valve opening degree.

The hot and cold water mixing valve 6 changes the mixing ratio of hot water and water based on the mixing valve drive command supplied from the controller 11. The hot and cold water mixing valve 6 is provided with a valve position detector and outputs a signal related to the valve position. Each of the water temperature sensor 12, the hot water temperature sensor 14, and the mixed temperature sensor 15 is configured to output a voltage signal corresponding to the water temperature, the hot water temperature, etc., by using a thermosensitive element such as a thermistor. And
A digital signal corresponding to temperature is converted by a D / A converter (not shown) provided in the controller 11. As the flow rate sensor 13, a sensor that outputs a pulse signal having a cycle corresponding to the flow rate is used, and the detection output thereof is provided in the controller 11 and is converted by a conversion circuit (not shown) into a digital signal corresponding to the flow rate.

The controller 11 is constructed by using a microcomputer system, and has a hot water supply use detecting unit 30.
1, a circulation heat retention operation control unit 40, a heating control unit 50, a hot water supply initial condition changing unit 60, and a mixing valve control unit 70.

FIG. 2 is a functional block configuration diagram of the controller. The hot water supply use detecting means 30 detects whether hot water is being discharged from the hot water tap 2 based on the flow rate Q detected by the flow rate sensor 13, and outputs information 30a relating to the hot water supply state. 31, a hot water supply determination flow rate storage means 32 when the pump is stopped, and a hot water supply determination flow rate storage means 33 when the pump is operating.

The hot water supply use determining means 31 determines whether or not the circulation pump 9 is in an operating state, based on the circulation heat retention operation request 40a output from the circulation heat retention operation control unit 40. When the circulation pump 9 is not operating, the hot water supply use determination flow rate QPoff when the pump is stopped, which is supplied from the hot water supply determination flow rate storage unit 32 when the pump is stopped (for example, 1 per minute)
Flow rate Q detected by the flow rate sensor 13
And the detected flow rate Q is the hot water supply use determination flow rate QPoff
When it exceeds the value, it is determined that the hot water is being used from the hot water tap 2, and the information 30a indicating the hot water using state is shown.
Is output. When the circulation pump 9 is operating, the hot water supply use determination flow rate QPon during pump operation supplied from the hot water supply determination flow rate storage unit 33 during pump operation is compared with the detected flow rate Q, and the detected flow rate Q is determined by the pump. When the hot water supply use determination flow rate QPon during operation is exceeded, it is determined that the hot water supply is in use, and information 30a indicating the hot water use is output.
The hot water supply use determination flow rate QPon during the pump operation is set to a flow rate (for example, 3 to 3.5 liters per minute) larger than the circulation flow rate during the circulation pump operation (for example, 2 liters per minute).

The circulation heat retention operation control section 40 comprises a circulation start / stop judging means 41 and a pump drive circuit 42. The circulation start / stop determination means 41 confirms that the heat retention operation switch 16 is set to the heat retention operation state and that the hot water supply state is not supplied based on the information 30a indicating the hot water supply state supplied from the hot water supply use detection unit 30. If determined, the water temperature TC detected by the water temperature sensor 12 is monitored. When the water temperature TC is lower than the set temperature TS set by the temperature setter 17 by a predetermined temperature (for example, 3 ° C.) or more, the circulation heat retention operation request 40
Output a. Further, when the water temperature TC almost reaches the set temperature TS, the output of the circulation heat retention operation request 40a is stopped. When the circulation heat retention operation request 40a is output, the pump drive circuit 42 operates the circulation pump 9 to circulate the hot water in the circulation path 10.

The heating control unit 50 includes a necessary heat amount calculating means 51 for calculating the necessary heat amount FF of the feedforward system, a heat amount correcting means 52 for synthesizing the heat amount of the feedback system with the necessary heat amount FF, and outputting a heating heat amount FO. Combustion control means 53 for controlling combustion of the burner 21 based on the amount of heat of heating FO
With.

The required heat amount calculating means 51 calculates the required heat amount FF by multiplying the deviation Q between the set temperature TS and the water temperature TCO supplied from the hot water supply initial condition changing unit 60 by the flow rate Q. The heat quantity correction means 52 determines whether the required heat quantity FF is excessive or insufficient based on the deviation between the set temperature TS and the mixing temperature TM detected by the mixing temperature sensor 15, and the heating heat quantity FO corrected to the necessary heat quantity FF.
Is output.

FIG. 3 is a block diagram showing a specific example of the combustion control means. The combustion control means 53 is configured to perform intermittent combustion control in the circulation heat retention operation state and proportional combustion control in the hot water supply use state, and the heat quantity-valve opening degree conversion means 5 is used.
4, proportional valve drive means 55, and heat quantity-cycle conversion means 56
And an on-off valve drive means 57.

When the heat quantity / valve opening degree conversion means 54 receives the circulation heat retention operation request 40a, it outputs a preset valve opening signal 53a for intermittent combustion to inform the hot water supply state 30a.
Is in the hot water supply state, the valve opening signal 53a corresponding to the heating heat quantity FO is output. The proportional valve driving means 55 drives the gas proportional valve 20 so that the valve opening of the gas proportional valve 20 becomes the valve opening specified by the valve opening signal 53a.

When the circulating heat retention operation request 40a is received, the heat quantity-cycle conversion means 56 outputs the combustion / fire extinguishing command 56a based on the combustion time and the fire extinguishing time set in advance corresponding to the heating heat quantity FO, and opens and closes. The opening / closing of the gas on-off valve 19 is controlled via the valve drive means 57 to perform intermittent combustion in which combustion and extinction are repeated. Further, this heat quantity-cycle conversion means 56
When the information 30a related to the hot water supply state is the hot water supply state,
The command 56a related to combustion is output to output the on-off valve drive means 57.
The gas on-off valve 19 is held in the open state via the.

The hot water supply initial condition changing section 60 shown in FIG. 2 constitutes a hot water supply initial heat quantity changing means for heating the heat exchanger with a predetermined heat quantity at the start of hot water supply, and the hot water mixing valve is set to a predetermined mixing ratio at the start of hot water supply. It constitutes a hot water supply initial mixing ratio changing means for controlling.

The hot water supply initial condition changing unit 60 outputs a water temperature TCK stored in the storage unit 61 for storing the water temperature TC when the hot water supply state is in effect, and the water temperature TCK stored in the storage unit 61 at the beginning of the hot water supply state. The water temperature output part 62 which outputs the water temperature TC detected by 12 is provided.

The storage section 61 stores information 30a relating to the hot water supply state.
When the hot water supply state is determined based on the water temperature TC, the water temperature TC detected by the water temperature sensor 12 is set at a predetermined time interval (for example, 2
Every 50 milliseconds), when the change in the water temperature TC is within a predetermined value (for example, within 1 ° C), the water temperature TCK at that time
Is configured to store. When the water temperature TC detected in the hot water supply use state shows a stable value for a predetermined time (for example, 20 seconds), the storage unit 61 stores the water temperature TC at that time.
K may be stored. If the hot water supply is stopped before the detected water temperature TC stabilizes, the water temperature TCK at the time when the hot water supply is stopped may be stored. When the duration of the hot water supply state is short (for example, within 5 seconds) and the water temperature TC is not stable during the hot water supply, the water temperature data may not be updated.

The water temperature output unit 62 uses the information 3 on the hot water supply state.
When 0a changes from the hot water supply state to the hot water supply state, the storage unit 6
Select the water temperature TCK stored in 1 and use this as the water temperature data T
First output as CO. Then, the water temperature output unit 62
After comparing the water temperature TC detected by the water temperature sensor 12 with the water temperature TCK stored at the time of hot water supply last time, after the difference between the detected water temperature TC and the stored water temperature TCK falls within a predetermined range (for example, within 1 ° C.), the water temperature The water temperature TC detected by the sensor 12 is directly output as the water temperature data TCK. The water temperature output unit 62 includes a timer unit that is activated at the start of hot water supply, outputs the stored water temperature TCK at the beginning of hot water supply, and detects the detected water temperature after the hot water supply continues for a predetermined time (for example, 5 seconds). The configuration may be such that the TC is output as it is. The water temperature output unit 62 also detects the detected water temperature T.
The temperature change of C per unit time is a predetermined value (for example, 0.5
After the temperature falls within (° C.), the detected water temperature TC may be output as it is.

The mixing valve control section 70 comprises a target valve position calculation section 71 for calculating the target valve position and a mixing valve drive section 72 for driving the hot and cold water mixing valve 6. The target valve position calculation unit 71 is
The target valve position is calculated based on the hot water temperature TH detected by the hot water temperature sensor 14, the set temperature TS set by the temperature setting device 17, and the water temperature TCO supplied via the hot water supply initial condition changing means 60. The target valve position signal XS is output.

The mixing valve drive unit 72 outputs the target valve position signal XS.
And feedback control of the valve position of the hot and cold water mixing valve 6 based on the signal X related to the actual valve position detected by the valve position detection unit 22, and the target valve based on the deviation between the set temperature TS and the hot water temperature TH. The position signal XS is corrected and the hot and cold water mixing valve 6 is driven to adjust the hot and cold water mixing ratio.

Next, the operation of the above configuration will be described. When the heat retention operation switch 16 is set to the heat retention operation state and the hot water tap 2 is not used, the water temperature T
If C is lower than the set temperature TS by a predetermined temperature or more,
The circulation heat retention operation control means 40 outputs the circulation heat retention operation request 40a, operates the circulation pump 9, and circulates the hot water in the circulation path 10. The heating control unit 50 that receives the circulation heat retention operation request 40a calculates the amount of heat required for circulation heat retention, intermittently burns the burner 21, and heats the hot water in the circulation path 10.
As a result, the hot water in the circulation path 10 is maintained at the set temperature TS.

When hot water is discharged from the hot water tap 2, the hot water use detection unit 30 detects that hot water supply has started based on the flow rate Q and outputs information 30a relating to the hot water supply state. When the hot water supply is started, the hot water supply initial condition changing unit 60 stores in the storage unit 61.
The water temperature TCK at the previous hot water storage stored in the water temperature data TCO
First, and then the water temperature T detected by the water temperature sensor 12
When C becomes able to correctly detect the temperature of the water supplied from the water supply pipe 3 from the heat retention temperature, the water temperature sensor 12
The detected water temperature TC of is output as it is.

When hot water supply is started, the temperature of the water entering the heat exchanger 4 changes from the temperature (for example, 40 ° C.) at the time of heat retention and heating to the water supply conduit 3
Changes to the temperature of the water supplied from the water temperature sensor 12
The detected water temperature TC of No. cannot immediately respond to the temperature change.
Therefore, if the heating heat quantity FO and the mixing ratio of the hot and cold water mixing valve 6 are set based on the detected water temperature TC, the hot water supply temperature will be lower than the set temperature TS, but the water temperature sensor 12 is supplied from the water supply pipe line 3. Until the temperature of the hot water can be correctly detected, the heating amount and the mixing ratio of hot and cold water are set based on the water temperature TCK detected in the previous hot water supply state, so it is possible to supply hot water of a desired temperature from the beginning of hot water supply. it can.

In this embodiment, as the hot water supply initial condition changing unit 60, the initial heating condition and the initial mixing ratio at the time of new hot water supply are set based on the water temperature stored at the time of the previous hot water supply. FF required for hot water supply
Alternatively, the heating amount of heat FO and the target valve position signal XS or the output signal of the mixing valve drive unit 72 at the time of hot water supply at the previous time are stored respectively, and at the start of the next hot water supply, the amount of heating and the amount of hot and cold water are stored based on the stored contents. It may be configured to set the mixing ratio. However, with the configuration in which the heating amount and the mixing ratio of hot water at the time of hot water supply at the previous time are stored, when the set temperature TS is changed in the hot water supply stopped state, the change cannot be dealt with. On the other hand, the configuration in which the water temperature data at the time of hot water supply at the previous time is stored has an advantage of being able to cope with a change in the set temperature TS.

FIG. 4 is a block diagram showing another embodiment of the hot water supply initial heat quantity changing means. The hot water supply initial heat quantity changing means 80 changes the required heat quantity FF supplied to the heat quantity correcting means 52 in the heating control section 50 at the initial stage of starting hot water supply. The hot water supply initial heat quantity setting means 81 and the timer means. 82 and a heat quantity selection means 83.

The hot water supply initial heat quantity setting means 81 is provided with a table that stores preset hot water supply heat quantity data for each set temperature TS, and outputs an initial heat quantity FS corresponding to the set temperature TS. The timer means 82 uses the information 30 on the hot water supply state.
The heat quantity selection means 83 selects the initial heat quantity FS for a certain time (for example, 3 seconds) from the time when hot water supply is started based on a, and thereafter, the necessary heat quantity FF calculated by the necessary heat quantity calculation means 51. Is controlled to select the heat quantity correction means 52.

With the above-described structure, since the heat exchanger 4 is heated based on the initial heat quantity FS preset corresponding to the set temperature TS at the beginning of hot water supply, the water temperature sensor 12
Even if the detected water temperature TC is close to the heat retention temperature, it is possible to prevent the heating amount from becoming insufficient.

FIG. 5 is a block diagram showing another embodiment of the hot water supply initial mixing ratio changing means. The hot water supply initial mixing ratio changing means 90 changes the target valve position signal XS supplied to the mixing valve drive unit 72 in the mixing valve control unit 70 at the initial stage of starting hot water supply. Means 91, timer means 92, and target valve position signal selection means 93 are provided.

The hot water supply initial mixing ratio setting means 91 is provided with a table storing hot water supply initial mixing ratio data (hot water supplying initial valve position data) preset for each set temperature TS, and the hot water supply initial mixing ratio corresponding to the set temperature TS. (Hot water initial valve position signal) XA is output. In the timer means 92, the target valve position signal selecting means 93 selects the hot water supply initial mixing ratio XA for a certain time (for example, 3 seconds) from the time when the hot water supply is started based on the information 30a relating to the hot water supply state. After that, the target valve position signal X calculated by the target valve position calculation unit 71 is controlled to be selected.

With the above-described structure, in the initial stage of hot water supply start, the hot and cold water mixing ratio of the hot and cold water mixing valve 6 is based on the hot water supply initial mixing ratio (hot water supplying initial valve position signal) XA preset corresponding to the set temperature TS. Since the (valve position) is set, even if the detected water temperature TC is close to the heat retention temperature, the mixing ratio on the hot water side does not decrease and the hot water supply temperature does not decrease.

[0048]

As described above, in the circulation warming type hot water supply apparatus according to the first aspect, the heat exchanger is heated with a predetermined amount of heat at the start of hot water supply, and thereafter, for example, a water temperature detection output corresponding to a new water temperature is obtained. After that, since the heat exchanger was heated with the required heat quantity calculated based on the detected water temperature and the set temperature, the heating amount is insufficient until the water temperature detection unit detects the correct temperature. It is possible to solve the problem of the prior art that the temperature of the hot water supplied from the hot water tap decreases.

By storing the water temperature in the previous hot water supply state and calculating the predetermined amount of heat based on the stored water temperature, it is possible to supply hot water at an appropriate temperature from the start of hot water discharge.

In the circulation warming type hot water supply apparatus according to the third aspect, the hot water mixing valve is controlled to a predetermined mixing ratio at the start of hot water supply, and thereafter, for example, a water temperature detection output corresponding to a new water temperature is obtained. Is configured to control the mixing ratio of the hot and cold water mixing valve based on the mixing ratio calculated based on the detected water temperature and the set temperature, the mixing ratio on the water side until the water temperature detection unit detects the correct temperature. Can be reduced, and the problem of the prior art that the temperature of the hot water supplied from the hot water tap can be reduced can be solved.

The water temperature in the previous hot water supply state is stored, and a predetermined mixing ratio is calculated based on the stored water temperature, so that hot water of an appropriate temperature is supplied from the start of tapping.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a circulating warm water heater according to the present invention.

FIG. 2 is a functional block configuration diagram of a controller.

FIG. 3 is a block diagram showing a specific example of combustion control means.

FIG. 4 is a block diagram showing another embodiment of the hot water supply initial heat quantity changing means.

FIG. 5 is a block diagram showing another embodiment of the hot water supply initial mixing ratio changing means.

FIG. 6 is a graph showing the detection response characteristic of the incoming water temperature detection unit (water temperature sensor).

[Explanation of symbols]

 1 Circulating warm water heater 2 Hot water tap 3 Water supply pipe 4 Heat exchanger 5 Bypass pipe 6 Hot water mixing valve 7 Hot water supply pipe 8 Return pipe 9 Circulation pump 10 Circulation pipe 11 Controller 12 Water temperature sensor 13 Flow rate sensor 14 Hot water temperature Sensor 15 Mixing temperature sensor 16 Heat retention operation switch 17 Temperature setting device 30 Hot water supply usage detection unit 40 Circulation heat retention operation control unit 50 Heating control unit 60 Hot water supply initial condition change unit 61 Storage unit 62 Water temperature output unit 80 Hot water supply initial heat quantity change unit 90 Hot water supply initial Mixing ratio changing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinji Miura 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Nihon Yupro Co., Ltd. (72) Tetsuro Takada 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo No. Nihon Yupro Co., Ltd. (72) Inventor Hikaru Hira-gun 43-1 Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Nihon Yupro Co., Ltd.

Claims (4)

[Claims] 1. A return pipe connecting the end of the hot water supply pipe and the water supply pipe to form a circulation path by the water supply pipe, the heat exchanger, the hot water supply pipe, and the return pipe. In the non-hot water supply state where the connected hot water tap is not used, operate the circulation pump installed in the return line to circulate the hot and cold water in the circulation line and perform the circulating heat retention operation by heating with the heat exchanger as appropriate. In addition, while maintaining the hot water temperature in the circulation path within the specified temperature range, and in the hot water supply state where the hot water tap is used, the temperature of water entering the heat exchanger detected by the water temperature detector and the setting set by the temperature setting device are set. In a circulating warm water heater that calculates the required amount of heat based on at least the temperature and heats the heat exchanger to supply hot water at the set temperature, heat the heat exchanger with a predetermined amount of heat when starting hot water supply. , Then heat the heat exchanger with the calculated heat requirement Circulating heat insulating type hot water supply apparatus characterized by having a hot water supply initial heat changing means for. 2. The storage means for storing the water temperature detected at the time of hot water supply last time is provided, and the predetermined heat quantity is calculated based on the storage content of the storage means and the set temperature. Circulating warm water heater. 3. A hot water supply pipe provided with a hot and cold water mixing valve on the hot water outlet side of the heat exchanger to mix the hot water heated by the heat exchanger with the water from the water supply pipe connected to the hot water inlet side of the heat exchanger. In addition to supplying water to the channel, connect the end of the hot water supply line and the water supply line with a return line to form a circulation line by the water supply line, the heat exchanger, the hot and cold water mixing valve, the hot water supply line, and the return line. In the non-hot water supply state in which the hot water tap formed and connected to the hot water supply pipe is not used, the circulation pump installed in the return pipe is operated to heat the water in the circulation pipe while circulating the hot water. By properly performing circulation warming operation, the temperature of the hot water in the circulation path is kept within a predetermined temperature range, and in the hot water supply state where the hot water tap is used, the temperature of the water entering the heat exchanger detected by the water temperature detector and the temperature Calculate the required heat quantity based on at least the set temperature set by the setter and add the heat exchanger. In a circulation warming type hot water supply device which heats and controls the mixing ratio of the hot and cold water mixing valve based on at least the incoming water temperature and the preset temperature to supply hot water of a preset temperature, A circulation warming type having a hot water supply initial mixing ratio changing means for controlling the mixing ratio of the mixing valve of the hot and cold water mixing valve based on at least the inlet temperature and the set temperature. Water heater. 4. A storage means for storing the water temperature detected at the time of hot water supply last time is provided, and the predetermined mixing ratio is calculated based on the storage content of the storage means and the set temperature. The circulating warm water heater described.