JPH1114143A - Hot-water supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the temperature of warm water taken out again with simple controlling configuration. SOLUTION: The equipment is provided with a normal bypass channel, and an opening and closing bypass channel between a water supplying channel and a hot-water supplying channel of a hot-water supplying heat exchanger. A bypass valve is arranged to the opening and closing bypass channel. A temperature sampling part 17 takes in the temperature of the hot water at the outlet of the hot-water supplying heat exchanger at each sampling time. Opening time computing part 20 calculates the increase of the quantity from the side of opening and closing bypass channel necessary from a adjusting the temperature of the hot water coming out from the hot-water supplying heat exchanger to the hot-water supply set up temperature with the value of the opening time of the bypass valve 14. A valve drive control part 22 opens the bypass valve for the opening time at each sampling time, adds the water from the opening and closing bypass channel to the water from the normal bypass channel, and mixes it with hot-water coming out from the hot-water supplying heat exchanger to supply the stable hot-water.

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 provided with means for stabilizing the temperature of re-discharged hot water.

[0002]

2. Description of the Related Art FIG. 5 shows a schematic configuration of a conventional general hot water supply apparatus. In FIG. 1, a water supply pipe 2 of a water supply passage is connected to an inlet side of a hot water supply heat exchanger 1, and a water supply temperature sensor 3 for detecting a water supply temperature and a water supply flow rate (hot water supply flow rate) are connected to the water supply pipe 2. A flow sensor 4 is provided.

A hot water supply pipe 5 functioning as a hot water supply passage is connected to the outlet side of the hot water supply heat exchanger 1, and a hot water supply temperature sensor 6 for detecting the temperature of hot water from the hot water supply heat exchanger 1 is provided in the hot water supply pipe 5. A hot tap 7 is provided at the hot water supply destination of the hot water supply pipe 5.

[0004] A burner 8 is provided below the hot water supply heat exchanger 1, and a combustion fan (not shown) for supplying and exhausting air is provided below the burner 8. A remote control 11 is connected to the control device 10 for controlling the hot water supply operation, and the remote control 11 is provided with a temperature setting device for setting the hot water supply temperature, a display unit for the hot water supply temperature, and the like.

[0005] The control device 10 controls the hot water supply operation as follows. When the tap 7 is opened and the flow rate sensor 4 detects a flow rate equal to or greater than the operating flow rate, the combustion fan is rotated to supply gas to the burner 8 and operate ignition means (not shown) to burn the burner. I do. Then, the amount of gas combustion heat (gas supply amount) is controlled so that the hot water temperature detected by hot water temperature sensor 6 becomes the hot water supply set temperature set by remote controller 11, and hot water at the set temperature is supplied to hot water supply heat exchanger 1. The hot water is supplied to a desired hot water supply place such as a kitchen through the hot water supply pipe 5.

[0006] When the hot water has been used and the tap 7 is closed, the control device 10 receives the off signal from the flow sensor 4 to stop the combustion of the burner 8, and during the post-purge period (when the exhaust gas in the combustion chamber is exhausted). The combustion fan is stopped when the combustion fan is continuously rotated until the end of the period, and the preparation for the next hot water supply is stopped.

[0007]

However, when the temperature of the feed water entering the hot water supply heat exchanger 1 is low or when the set temperature of the hot water supply is low, the surface temperature of the water pipe of the hot water supply heat exchanger 1 becomes low. Then, a phenomenon occurs in which water vapor components in the exhaust gas generated by the combustion of the burner 8 touch the water pipe having a low temperature, and dew condensation occurs on the water pipe surface.

As described above, when dew is formed on the surface of the water pipe of the hot water supply heat exchanger 1, dirt and the like in the air sent from the combustion fan adhere to the dew condensation, thereby accelerating the clogging of the hot water supply heat exchanger 1. Failure occurs. In addition, components in the exhaust gas dissolve into the dew condensation, and the dew condensation takes on a strongly acidic property,
There is a problem that corrosion of the hot water supply heat exchanger 1 is accelerated and the life of the hot water supply heat exchanger 1 is shortened.

In order to prevent such a problem of the occurrence of dew condensation, the applicant has proposed a water heater having a bypass passage as shown in FIG.

The proposed device shown in FIG. 3 is provided with a constant bypass passage 12 and an open / close bypass passage 13 for connecting and connecting the water supply pipe 2 as the water supply passage and the hot water supply pipe 5 as the hot water supply passage.
The constant bypass passage 12 is a passage having no on-off valve,
The open / close bypass passage 13 has a bypass valve 14 for opening / closing a passage such as an electromagnetic valve, and the bypass valve 14 allows the passage 13 to be freely opened / closed.

On the outlet side of the hot water supply heat exchanger 1, a heat exchange outlet temperature sensor 15 for detecting the temperature of hot water exiting the hot water supply heat exchanger 1 is provided.
The hot water supply pipe 5 downstream of the connection between the hot water supply pipe 5 and the bypass passages 12 and 13 is a hot water supply in which hot water from the hot water supply heat exchanger 1 and water from the bypass passages 12 and 13 are mixed. A hot water supply temperature sensor 16 for detecting a temperature is provided.

In the proposed apparatus, in a steady hot water supply operation state, the bypass valve 14 is kept closed, and the hot water flowing out of the hot water supply heat exchanger 1 and the water constantly flowing out of the bypass passage 12 are mixed. Hot water supply temperature is detected by hot water supply temperature sensor 16, and control device 10 controls the amount of combustion heat of the burner so that the detected temperature of hot water supply temperature sensor 16 becomes the hot water supply set temperature set by remote controller 11.

In this combustion operation, the water supplied from the water supply pipe 2 always branches off to the bypass passage 12 and the hot water supply heat exchanger 1 side, so that the flow rate flowing to the hot water supply heat exchanger 1 always flows through the bypass passage 12. The temperature of the hot water in the hot water supply heat exchanger 1 is inevitably increased,
Accordingly, the temperature of the water pipe surface of the hot water supply heat exchanger 1 also increases, so that it is possible to prevent the occurrence of dew condensation on the water pipe surface, and to solve the problem of the conventional dew formation.

By the way, for example, in the graph of FIG.
When the hot water supply set temperature T _st is 40 ° C., the hot water supply heat exchanger 1
The target temperature of the hot water at the outlet is 46.7 ° C. However, immediately after the stop of the hot water supply combustion, the residual heat held by the can body of the hot water supply heat exchanger 1 is transmitted to the retained hot water in the hot water supply heat exchanger 1, and the so-called post-boiling phenomenon causes the remaining heat in the hot water supply heat exchanger. The temperature of the hot water rises above the target temperature of the hot water supply heat exchanger 1 as shown by a curve A in FIG. 4, and in this state, when hot water is re-discharged, as shown by a curve B in FIG. Heat exchanger 1
The actual measured temperature of the hot water supplied by mixing the hot water discharged from the hot water and the water that always passes through the bypass passage 12 becomes an overshoot hot water that is higher than the hot water supply set temperature, causing a problem that the user of the hot water feels unpleasant.

In order to solve the problem of the rise in hot water temperature due to the post-boiling at the time of re-water supply, the applicant has set the bypass valve off temperature Toff (see FIG. 1) to a temperature position higher than the target temperature on the outlet side of the hot water supply heat exchanger 1. 4, the bypass valve ON temperature T _ON (52 ° C. in the example of FIG. 4) is set at a position higher than the OFF temperature Toff, and after the hot water is re-discharged, the outlet of the hot water supply heat exchanger 1 is set. When the temperature detected by the heat exchange outlet temperature sensor 15 on the side exceeds the bypass valve ON temperature, the bypass valve 14 is opened to increase the mixing amount of water, and the temperature of the hot water at the outlet of the hot water supply heat exchanger 1 is changed to the bypass valve. The bypass valve 14 is closed when the temperature becomes equal to or lower than the off-temperature Toff, thereby stabilizing the temperature of the hot water.

By this stabilization control of the hot water temperature, when the hot water temperature at the outlet of the hot water supply heat exchanger 1 exceeds the bypass valve on temperature, the bypass valve 14 is opened to reduce the mixing amount of water. As the temperature increases, the hot water supply temperature decreases, and the temperature becomes along the curve C of the hot water supply temperature when the bypass valve 14 is kept open, so that the temperature of the hot water at the outlet of the hot water supply heat exchanger 1 becomes lower than the bypass valve off temperature. When the bypass valve 14 is closed, as a result, the amount of water to be mixed decreases, the hot water supply temperature rises, and a curve of a temperature pattern D follows the temperature curve B when the bypass valve 14 remains closed. Becomes The temperature pattern of the hot water actually flowing out of the tap 7 is such that after the hot water and the water are mixed, the stirring of the water and the hot water is promoted while passing through the pipe length to the hot tap 7, and the temporal temperature change Has a gentle curve E pattern temperature, and is less affected by the temperature rise due to the after-boiling than the curve B temperature pattern in which the operation by the bypass valve 14 is not performed.
Stabilization of the temperature of the hot water is improved.

However, the method of controlling the opening and closing of the bypass valve 14 by giving the bypass valve _ON temperature TON and the OFF temperature Toff certainly contributes to the stabilization of the refilling hot water temperature. As shown in E, the fluctuation in the vertical direction with respect to the hot water supply set temperature is still large, and a sufficiently satisfactory stabilization of the reheated hot water temperature has not yet been achieved, and improvement thereof is desired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a hot water supply system capable of performing more accurate stabilization control of re-discharged hot water temperature by using a bypass valve 14. It is to provide a device.

[0019]

In order to achieve the above object, the present invention takes the following measures. That is,
In the present invention, a water supply passage is connected to the inlet side of the hot water supply heat exchanger,
A hot water supply passage is connected to the outlet side of the hot water supply heat exchanger, and the water supplied from the water supply passage is heated by the hot water supply heat exchanger into hot water, and the hot water is discharged through the hot water supply passage. A continuous bypass passage connecting and connecting the passages, an open / close bypass passage having a bypass valve for opening and closing the passage, which also connects the water supply passage and the hot water supply passage, and a water supply for detecting a temperature of water supplied to the hot water supply heat exchanger A temperature sensor, a heat exchange outlet temperature sensor for detecting the temperature of the hot water at the outlet of the hot water supply heat exchanger, and a set temperature of the hot water supply obtained by mixing the hot water discharged from the hot water supply heat exchanger and the water passing through the bypass passage. A temperature setting unit to perform, a temperature sampling unit that captures the temperature detected by the heat exchange outlet temperature sensor at every predetermined sampling time, A data storage unit storing an arithmetic relational expression between a bypass flow ratio which is a flow ratio of the bypass passage to the supply water amount and an opening time of a bypass valve provided in the open / close bypass passage, and hot water supply heat exchange by the temperature sampling unit. Each time the temperature information of the hot water at the outlet of the water heater is taken in, the temperature of the hot water at the outlet of the hot water supply heat exchanger taken in, the feed water temperature detected by the feed water temperature sensor, the hot water set temperature set by the temperature setting device, and the An open time calculation unit for calculating the open time of the bypass valve using the calculation relational expression based on the data of the given bypass flow ratio; and each time the open time is calculated by the open time calculation unit, the open valve is operated by the open time. This is a means for solving the problem with a configuration having a valve drive control section that opens and drives within the sampling time.

In the present invention having the above structure, the temperature of the hot water at the outlet of the hot water supply heat exchanger is detected by the heat exchange outlet temperature sensor at every predetermined sampling time after the start of the reheating hot water combustion. The information on the detected temperature is sampled by the temperature sampling unit. And, the temperature of the hot water at the outlet of the sampled hot water supply heat exchanger,
Based on the data of the feed water temperature, the bypass flow rate ratio, and the set temperature of the hot water supply, the open time calculating unit using an arithmetic relational expression that gives in advance the open time of the bypass valve required to produce the hot water for mixing the hot water set temperature. Required by Then, based on the calculation result, the valve drive control unit opens and drives the bypass valve for the opening time, so that an appropriate amount of water for setting the hot water supply temperature is mixed with the hot water that flows out of the hot water supply heat exchanger. Since this mixing operation is performed at every sampling time, appropriate mixing control is performed until almost the post-boiled water has been discharged,
The accuracy of stabilizing the temperature of the hot water is remarkably improved, and the hot water with extremely small fluctuations in the hot water temperature can be discharged again.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. The system configuration of the hot water supply apparatus in this embodiment is the same as that shown in FIG. 3, and the same reference numerals are used for the same parts, and the duplicated description is omitted. What is characteristic in this embodiment is that a control means for driving the bypass valve 14 on and off under a specific configuration without providing the on-temperature T _ON and the off-temperature Toff of the bypass valve 14 is provided. .

FIG. 1 shows a control structure characteristic of this embodiment. This characteristic control configuration
It comprises a temperature sampling unit 17, a timer 18, an open time calculation unit 20, a data storage unit 21, and a valve drive control unit 22.

The temperature sampling section 17 is provided with data on the sampling time in advance, and after the start of hot water supply combustion, the hot water temperature information in the hot water supply heat exchanger 1 is taken in from the heat exchange outlet temperature sensor 15 at each sampling time. . The sampling time given to the temperature sampling unit 17 is given by the minimum subdivision time in consideration of the responsiveness of the heat exchange outlet temperature sensor 15 and the responsiveness of the bypass valve 14.

That is, when detecting the temperature change, the heat exchange outlet temperature sensor 15 sets the temperature after the actual temperature change occurs.
There is a response time until the temperature change can be accurately detected. Similarly, the bypass valve 14 is required to completely open and close the bypass valve 14 when an open / close signal for the bypass valve is output. There is a response time. In the present embodiment,
The response time of the heat exchange outlet temperature sensor 15 and the bypass valve 14 is taken into consideration, and the minimum subdivision time, which is the shortest possible time, is set as the sampling time.

The temperature sampling section 17 is provided with a timer 1
8, the temperature detection information of the heat exchange outlet temperature sensor 15 is fetched every time the sampling time elapses after the start of hot water supply combustion, and the fetched data is added to the open time calculation unit 20.

The hot water supply set temperature T is stored in the data storage section 21.
_st , a temperature T _OUT of hot water in the hot water supply heat exchanger 1, a water supply temperature T _IN , a bypass flow ratio B which is a flow ratio on the bypass passage side to a total water supply amount (a total water supply flow rate), and a bypass valve 14.
The following equation (1), which indicates the relationship between the open time Δt and the sampling time t _s , is stored. The data of the bypass storage ratio B is stored in the data storage unit 21.
, The data of the bypass flow rate ratio Boff when the bypass valve 14 is in the closed state, the bypass valve 14 is data of the bypass flow rate ratio B _ON when the open state is stored in advance. The bypass flow rate ratio Boff is data of the ratio of the flow rate that always passes through the bypass passage 12 to the total feedwater flow rate.
_ON indicates the ratio of the total flow rate on the bypass side passing through the constant bypass passage 12 and the open / close bypass passage 13 to the total supply water flow rate.

[0027] _{T st = {(t s -Δt} ) / t s} {T OUT (1-Boff) + T IN · Boff} + (Δ t / t s) {T OUT (1-B ON) + T IN · B _ON ｝ ... (1)

The open time calculating section 20 calculates the temperature of the heat exchange outlet temperature added from the temperature sampling section 17 every time the detection information of the heat exchange outlet temperature sensor 15 is added from the temperature sampling section 17, that is, every sampling time t _s. The detected value T _OUT of the sensor 15, the feed water temperature T _IN detected by the feed water temperature sensor 16, the hot water set temperature T _st set by the temperature setting device of the remote controller 11, and the bypass stored in the data storage unit 21. flow ratio Boff, and B _oN, captures the data of the sampling time t _s, determined by calculation an opening time Δt of the bypass valve 14 by using the stored in the data storage section 21 (1), the calculation result Valve drive control unit 2
Add to 2.

The valve drive control section 22 drives the bypass valve 14 to open within the sampling time for the open time Δt added from the open time calculation section 20.

FIG. 2 shows the stabilization characteristic of the temperature of the tap water in this embodiment. The curve A is the same as the curve A in the graph shown in FIG. 2 shows the temperature of the hot water at the outlet of the hot water supply heat exchanger 1 from.

Similarly, a curve B shows the mixing hot water supply temperature when the bypass valve 14 is off, and a curve C
Indicates the mixing hot water supply temperature when the bypass valve 14 is open, and these curves B and C are similar to the curves B and C in FIG. 4 described above.

The curve F in FIG. 2 is a mixture of hot and cold water when the bypass valve 14 is opened and controlled by the valve drive control unit 22 for each sampling time for the open time Δt obtained by the open time calculation unit 20. Shows the hot water supply temperature. As shown in FIG. 2, the post-boil temperature of the hot water supply heat exchanger 1 increases with time after the start of re-water supply, and the temperature of the hot water at the outlet of the hot water supply heat exchanger 1 increases. Bypass valve 1
4 is increased accordingly, and as the hot water peak at the outlet of the hot water supply heat exchanger 1 passes, its temperature T
_{Since OUT} decreases, the opening time Δt of the bypass valve 14
Eventually, and the bypass valve 14 finally maintains the closed state.

As shown by the curve F, the hot water and hot water supply temperature fluctuates up and down with respect to the set hot water supply temperature of 40 ° C. The agitation is promoted, and the temperature change over time becomes gradual, and as shown by curve G in FIG. 2, the temperature change above and below the hot water supply set temperature is small, and the change becomes a gradual temperature. The hot water is supplied from tap water tap 7, and FIG.
As is clear from comparison with the curve E shown in FIG.
It became possible to remarkably improve the control accuracy of the temperature of the hot water.

That is, the opening time Δt of the bypass valve 14 obtained by using the above equation (1) is determined by the temperature of the hot water detected by the heat exchange outlet temperature sensor 15 at each sampling time from the outlet of the hot water supply heat exchanger 1. When the hot water exits, the time required to increase the amount of water required to bring the hot water to the hot water supply set temperature is obtained as a time.
2 and the total amount of water in the opening / closing bypass passage 13 is mixed with the hot water flowing out of the hot water supply heat exchanger 1 to obtain hot water at a set hot water supply temperature. As a result of opening the bypass valve 14 intermittently for each sampling time, the hot water temperature fluctuates up and down with respect to the hot water supply set temperature as shown by the curve F in FIG. 2 and is sent out from the mixing position. As described above, the hot water and the stirring of water are promoted while passing through the pipeline leading to the tap 7, and as a result, as shown by the curve G, the re-starting hot water temperature with a small fluctuation in the hot water temperature and almost close to the set hot water supply temperature is obtained. It is done. In the example of FIG. 2, the sampling time t _s is 1
Seconds.

In the combustion control during the hot water supply operation, the temperature of the hot water supplied from the hot water supply heat exchanger 1 and the temperature of the mixed hot water supplied from the bypass passages 12 and 13 are detected by the hot water supply temperature sensor 16.
By adding feedback control for controlling the amount of combustion heat of the burner so that the detected temperature becomes the hot water supply set temperature set by the remote controller 11, more accurate control is performed.

The present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example, in the above embodiment, one (one) opening / closing bypass passage 13 with the bypass valve 14 is provided, but a plurality of opening / closing bypass passages 13 may be provided. In particular, when it is necessary to increase a large amount of water to the amount of water in the bypass passage 12 at all times, the open / close bypass passage 13
Can be easily handled by providing a plurality of. Further, when a plurality of open / close bypass passages 13 are provided, the water use of each open / close bypass passage 13 is performed in order,
It is also possible to equalize the operation of the bypass valves 14 of the opening / closing bypass passages 13 and prevent the life of the bypass valves 14 of the passages 13 from being biased.

Further, in the above embodiment, the bypass valve 14 is constituted by an electromagnetic valve.
If the opening and closing of the passage can be controlled by a control signal, the opening and closing means other than the electromagnetic valve (for example, a valve for opening and closing the passage using an elastic member such as a diaphragm) can be used.

Further, in the above embodiment, one (one) bypass passage 12 is always provided, but a plurality of bypass passages may be provided.

Further, the system configuration of the hot water supply apparatus is not necessarily limited to that shown in FIG. 3, but may be any as long as a bypass path and an open / close bypass path are always provided in parallel with the hot water supply heat exchanger 1. However, other configurations do not matter.

[0040]

According to the present invention, the temperature of hot water at the outlet of the hot water supply heat exchanger is detected at every sampling time, and the mixing amount of water required to make the hot water flowing out of the hot water supply heat exchanger to the hot water supply temperature. Is controlled by the opening time of the bypass valve provided in the opening / closing bypass passage. Therefore, even if the temperature of hot water coming out of the hot water supply heat exchanger due to post-boiling becomes high at the time of re-hot water, The optimum increase of the mixing water amount for solving the problem is obtained as the opening time of the bypass valve, and the bypass valve is opened and controlled for the opening time, so that the mixing water amount for obtaining the hot water at the hot water supply set temperature is accurately supplied and controlled. The Rukoto. Then, this amount of water is mixed with the hot water coming out of the hot water supply heat exchanger, and while passing through the pipeline leading to the hot water supply destination, the hot water and the stirring and mixing of the water are promoted to become hot water with a small temperature fluctuation over time, This eliminates post boiling at the time of re-hot water, makes it possible to obtain a stable re-hot water temperature close to the set hot water supply temperature and with little fluctuation of the hot water temperature, and can significantly improve the control accuracy of the re-hot water temperature. It becomes possible.

Further, the control structure for stabilizing the re-discharged hot water temperature only needs to control the opening time of the bypass valve provided in the open / close bypass passage, so that the control structure is simplified, and the superior performance of the present invention is improved. The effect of being able to provide the hot water supply device at a low cost is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a control operation and a hot water temperature stabilizing characteristic of the embodiment.

FIG. 3 is an explanatory diagram of a system of a hot water supply device according to the embodiment.

FIG. 4 is an explanatory diagram of hot water temperature characteristics when stabilization of hot water is performed using the on-temperature and off-temperature of a bypass valve proposed by the applicant.

FIG. 5 is a schematic explanatory view of a conventional general hot water supply apparatus.

[Explanation of symbols]

 12 Constant bypass passage 13 Open / close bypass passage 14 Bypass valve 15 Heat exchange outlet temperature sensor 17 Temperature sampling unit 20 Open time calculation unit 21 Data storage unit 22 Valve drive control unit

Claims (1)

[Claims] A hot water supply passage is connected to an inlet side of a hot water supply heat exchanger, a hot water supply passage is connected to an outlet side of the hot water supply heat exchanger, and water supplied from the hot water supply passage is heated by the hot water supply heat exchanger. West,
In a hot water supply device that discharges this hot water through a hot water supply passage,
A continuous bypass passage that connects and connects the water supply passage and the hot water supply passage; an open / close bypass passage that similarly connects the water supply passage and the hot water supply passage and has a bypass valve for opening and closing the passage; and a water supply supplied to the hot water supply heat exchanger. A hot water supply temperature sensor that detects the temperature, a heat exchange outlet temperature sensor that detects the temperature of hot water at the outlet of the hot water supply heat exchanger, and a hot water supply obtained by mixing hot water exiting from the hot water supply heat exchanger and water passing through the bypass passage. A temperature setter for setting a set temperature of the temperature, a temperature sampling unit for taking in the detected temperature of the heat exchange outlet temperature sensor at every predetermined sampling time, a hot water supply set temperature, a hot water temperature at the outlet of the hot water supply heat exchanger, and a water supply temperature. And a data storage storing a relational expression between a bypass flow ratio, which is a flow ratio of the bypass passage to the total water supply amount, and an opening time of a bypass valve provided in the open / close bypass passage. Each time temperature information of the hot water at the outlet of the hot water supply heat exchanger is taken in by the temperature sampling unit, the temperature of the hot water at the outlet of the hot water supply heat exchanger taken in and the feed water temperature and temperature setting detected by the feed water temperature sensor. Opening time calculating unit for obtaining the opening time of the bypass valve using the above-mentioned relational expression based on the hot water supply set temperature set by the heater and the data of the bypass flow ratio given in advance, and the opening time is obtained by the opening time calculating unit. And a valve drive control unit that drives the bypass valve to open within the sampling time for each opening time.