JP3622568B2 - 1 can 2 water channel water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a single can / two water channel water heater. In particular, the present invention relates to a single can / two water channel water heater provided with a boiling prevention function for a hot water channel when bathing.
[0002]
[Prior art]
By storing the heat exchanger of the bath reheating circuit and the heat exchanger of the hot water supply passage in one heat exchange can body, the heat exchange heating of the two systems can be performed by one heat exchange can body. In the one can two water channel water heater configured as described above, the water staying in the heat exchanger of the water heater channel may immediately boil during the bath reheating operation.
[0003]
Therefore, conventionally, a circulation circuit is formed by connecting the water supply side piping and the hot water supply side piping of the hot water supply passage by a bypass pipe outside the heat exchange can body, and when the bath is refurbished alone, the heat exchanger of the hot water supply passage The hot water heated in is naturally circulated in a circulation circuit between the bypass pipe and the hot water in the hot water supply passage is made difficult to boil.
[0004]
Furthermore, the temperature of hot water in the heat exchanger of the hot water supply channel is detected by a boiling prevention sensor located near the inlet (incoming water) of the heat exchanger, and the boiling prevention sensor keeps a constant boiling during bath reheating operation. When a temperature higher than the dangerous temperature is detected, the combustion operation in the heat exchange can body is temporarily stopped.
[0005]
[Problems to be solved by the invention]
When detecting the temperature of hot water in the hot water supply path with a temperature sensor for preventing boiling in the vicinity of the inlet of the heat exchanger, the temperature of the hot water in the circulation circuit is still sufficient as after hot water is supplied during reheating. When the circulation circuit is high and no circulation occurs, the hot water temperature is the highest in the vicinity of the inlet of the heat exchanger, and the maximum temperature in the hot water supply path can be accurately detected by the temperature sensor for boiling prevention. .
[0006]
On the other hand, when hot water is not supplied during the reheating operation period, the hot water temperature is highest at the highest position in the circulation circuit because circulation occurs in the circulation circuit. Since the position where the hot water temperature is highest is located at a position shifted to the inflow side from the position where the temperature sensor for boiling prevention is provided, in such a situation, the temperature sensor for boiling prevention raises the maximum hot water temperature in the circulation circuit. It cannot be detected.
[0007]
For this reason, when the circulation circuit is circulated, the maximum hot water temperature in the circulation circuit cannot be accurately detected. Therefore, when the boiling prevention temperature sensor detects, there is a risk of boiling. The boiling dangerous temperature to be set cannot be set too high. For this reason, conventionally, the boiling boiling temperature is set to a low value such as 75 ° C., for example. Specifically, when the boiling prevention sensor detects 75 ° C. or higher, the combustion operation of the burner is stopped, and when the detected temperature of the boiling prevention sensor falls to 70 ° C. or lower, the combustion operation is started again.
[0008]
However, in the conventional boiling prevention method, when the 20 ° C. water in the bathtub is reclaimed to the set temperature of 42 ° C., the bath renewal operation is performed from the beginning to the end of the bath renewal operation period. (When no hot water supply is used), for example, an average bath output of 8960 kcal / hour is obtained, whereas when hot water is supplied from the hot water supply circuit during the bath reheating operation period, the average bath output is, for example, 6000 kcal. The time was reduced until the hour and the driving time was long.
[0009]
The present invention has been made in view of the drawbacks of the above-described conventional example, and the object of the present invention is to enclose the heat exchanger of the bath reheating circuit and the heat exchanger of the hot water supply path in one heat exchange can. In one can two water channel water heater, it is to optimize the judgment level of the danger of boiling by detecting the state of the hot water supply side at the time of bath renewal operation.
[0010]
[Means for solving the problems and their functions]
1 can 2 water channel water heater of Claim 1 is a heat exchanger of a hot water supply channel, and a heat exchanger of a bath reheating circuit are stored in one heat exchange can body, and the hot water supply channel inside and outside the heat exchange can body 1 can 2 water channel water heater provided with a circulation circuit for circulating hot water flowing through the heat exchanger, means for detecting whether hot water is circulating in the circulation circuit, hot water in the circulation circuit And a means for changing a boiling danger temperature for preventing boiling of hot water in the hot water supply path according to the presence or absence of circulation of the hot water.
[0011]
In the 1-can 2-water-channel water heater according to claim 1, when the circulation circuit is circulated during the bath reheating operation, the detection accuracy of the maximum hot water temperature in the circulation circuit is low. . On the other hand, when there is no circulation in the circulation circuit, the maximum temperature in the circulation circuit can be accurately detected. Therefore, it is possible to optimize the judgment level of the danger of boiling by changing the value of the boiling danger temperature according to the presence or absence of circulation in the circulation circuit (that is, the accuracy of detecting the maximum temperature in the circulation circuit). it can.
[0012]
The one-can two-channel water heater according to claim 2 is configured so that the circulation circuit in the one-can two-water heater as described in claim 1 is provided outside a heat exchange can body, and a water supply side portion and a tapping side portion of the hot water passage. The means for detecting whether hot water is circulating in the circulation circuit is provided in the hot water supply passage with at least a part of the heat exchanger of the hot water supply passage. It is characterized by comprising at least two temperature sensors.
[0013]
In the 1 can / two water channel water heater according to claim 2, in the case of the bath reheating operation, there is no circulation after the hot water is discharged from the hot water channel, and there is a circulation in the circulation circuit. Then, since the temperature distribution of the hot water in the circulation circuit is different, it is possible to determine whether or not it is after the hot water from the detection values of the two temperature sensors.
[0014]
Moreover, in the 1 can 2 water channel water heater of Claim 2, a circulation circuit is formed using the bypass path for bypassing a part of water which flows into a hot water path, without letting a heat exchanger pass. can do. The means for detecting the direction of hot water flowing in the heat exchanger of the hot water supply path can also be configured using an existing temperature sensor in the hot water heater. Therefore, the configuration of the water heater can be simplified and the cost can be reduced.
[0015]
The can of 2 water heaters of Claim 3 is the detection result of the means which detects whether the hot water is circulating in the said circulation circuit in the 1 can 2 water heater of Claim 1 or 2 If it is determined whether or not it is a bath recuperation operation after using hot water supply, and it is determined that it is a bath replenishment operation after using hot water supply, it is not determined that it is a bath renewal operation after using hot water supply It is characterized in that it is changed to a boiling dangerous temperature that is higher than that of the case.
[0016]
In the 1-can 2-water-channel water heater according to claim 3, when it is determined that the reheating operation is performed after using the hot water supply, the hot water is changed during the bath reheating operation because the temperature is changed to a high boiling danger temperature. In this case, the frequency of combustion stop of the burner can be reduced. Therefore, the change in the bath output can be reduced between when the hot water is supplied during the bath reheating operation and when the hot water is not supplied.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is an overall configuration diagram showing a single can / two water channel water heater according to an embodiment of the present invention. Moreover, FIG.2 and FIG.3 is the front view and sectional drawing which show the actual structure of this 1 can 2 water channel water heater. The heat exchange can body 1 formed in a rectangular tube shape by a copper plate or the like is provided with a burner 2 at an upper portion thereof and a blower 9 for supplying combustion air to the burner 2. A heat exchanger 15 that constitutes a part of the hot water supply passage 11 and a heat exchanger 30 that constitutes a part of the bath reheating circuit 26 are disposed in the lower part of the heat exchange can 1.
[0018]
The burner 2 is an oil burner, and includes an oil spray nozzle 3 such as a return type nozzle, an oil supply pipe 4 for supplying oil to the oil spray nozzle 3, and an oil return for recovering oil from the oil spray nozzle 3. An oil supply pump 5, an electromagnetic valve 6, an oil temperature sensor 7, and the like including an electromagnetic pump provided in the pipe 8, the oil supply pipe 4, and the like are provided.
[0019]
The blower 9 is provided with a rotation speed sensor 10 and the like. In principle, the amount of oil sprayed by the burner 2 is FF controlled and FB controlled. The amount of air blown by the blower 9 is in principle controlled by FF control. Next to the heat exchange can 1, an exhaust tower 22 for discharging the combustion gas in the heat exchange can 1 is provided.
[0020]
The hot water supply path 11 includes a water inlet pipe 12 directly connected to the water supply, a heat exchanger 15 and a hot water outlet pipe 17. A bypass pipe 19 branches from the water inlet pipe 12, and the bypass pipe 19 and the hot water outlet pipe are provided. 17 has joined. In addition, a circulation circuit 21 is configured by a portion downstream of the bypass pipe 19 of the water inlet pipe 12, a portion of the heat exchanger 15 and the outlet pipe 17 upstream of the bypass pipe 19, and the bypass pipe 19. In the hot water supply path 11, a water inlet temperature sensor 13 and a water inlet flow rate sensor 14 are provided in the water inlet pipe 12.
[0021]
Further, a boiling-prevention temperature sensor 16 is provided at the 12 heat exchanger inlet portions of the water inlet pipe (more precisely, a portion that enters the heat exchanger a little more than the inlet). Further, a can body temperature sensor 18 is provided in the tapping pipe 17 on the upstream side of the bypass path. The bypass pipe 19 is provided with a flow rate proportional control valve 20. Further, on the downstream side of the bypass pipe 19, the hot water discharge pipe 17 is provided with an overflow prevention device 23 and a hot water temperature sensor 24. The hot water pipe 17 is a pipe for supplying hot water to a kitchen, a washroom, etc., and a currant or the like is connected to the end of the pipe.
[0022]
The bath reheating circuit 26 guides the bathtub water from the bathtub (not shown) to the heat exchange can 1, the heat exchanger 30, and the bathtub water heated by the heat exchanger 30 to the bathtub. It is comprised from the pipe | tube 31. FIG. Reference numeral 32 denotes a circulation pump. The return pipe 27 is provided with a bath temperature sensor 28, a water flow switch 29, and the like.
[0023]
In the actual structure, as shown in FIGS. 2 and 3, the heat exchanger 15 of the hot water supply passage 11 and the heat exchanger 30 of the bath reheating circuit 26 are integrally provided at the lower part in the heat exchange can 1. . The inlet pipe 12 of the hot water supply channel 11 is led from above the box body 25 to the upper outer peripheral surface of the heat exchange can body 1, and the return pipe 27 of the bath chase circuit 26 is connected to the heat exchange can body 1 from the back surface of the box body 25. The water intake pipe 12 and the return pipe 27 are both wound around the outer peripheral surface of the heat exchange can body 1. In this way, the heat exchange can body 1 is overheated by winding the water intake pipe 12 and the return pipe 27 around the outer peripheral surface of the heat exchange can body 1.
[0024]
The water intake pipe 12 and the return pipe 27 wound around the outer peripheral surface of the heat exchange can 1 are connected to the upper ends of the heat exchangers 15 and 30, respectively. Further, the hot water pipe 17 connected to the lower end of the heat exchanger 15 is piped upward and drawn out to the upper surface of the box 25. The forward pipe 31 connected to the lower end portion of the heat exchanger 30 is drawn from the back surface of the box body 25. In addition, in the upper part of the box, the water inlet pipe and the hot water outlet pipe are communicated with each other by a bypass pipe.
[0025]
Control of the entire can of 1 canal water heater is performed by a controller 33 incorporating a microcomputer. Now, when the main switch of the hot water supply operation is turned on, for example, the currant at the end of the hot water discharge pipe 17 is opened, and the hot water supply operation starts when the incoming water flow rate sensor 14 of the incoming water pipe 12 detects the minimum operating flow rate or more. The combustion by the burner 2 is started. The controller 33 inputs information such as the hot water supply set temperature set by the remote controller, the incoming water temperature detected by the incoming water temperature sensor 13, the incoming water flow rate detected by the incoming water flow rate sensor 14, etc. The number is calculated, and the combustion of the burner 2 is FF-controlled by the number of hot water. The number of tapping water is the amount of heat required to raise 1 liter of water by 25 ° C. per minute. Then, the actual hot water supply temperature is compared with the set hot water supply temperature, and the combustion of the burner 2 is FB-controlled so that the difference becomes small.
[0026]
Also, when a bath rebirth operation is input from the remote controller, the controller 33 starts driving the circulation pump 32, and when the water flow switch 29 detects a water flow, the burner 2 starts a combustion operation, and the temperature of the bath water becomes the bath temperature. Combustion is performed until the set temperature is reached.
[0027]
When the bath reheating operation is started in this manner, not only the heat exchanger 30 of the bath reheating circuit 26 but also the heat exchanger 15 of the hot water supply passage 11 is simultaneously heated by the combustion of the burner 2. At this time, if the hot water in the hot water supply passage 11 is closed and the hot water in the heat exchanger 15 cannot move, the hot water in the heat exchanger 15 boils in a short time. However, in this embodiment, since the circulation pipe 21 is formed by connecting the water inlet pipe 12 and the hot water outlet pipe 17 with the bypass pipe 19, when the heat exchanger 15 is heated, the heated hot water becomes the heat exchanger 15. The inside moves from the bottom to the top, and circulates in the circulation circuit 21 in the direction shown by the solid arrows in FIGS. As a result, not only the hot water in the heat exchanger 15 is heated, but the entire hot water in the circulation circuit 21 is heated by the heat exchanger 15 and further dissipates heat while circulating in the circulation circuit 21, so Even in the case of the solitary operation, the hot water in the hot water supply passage 11 is less likely to boil.
[0028]
Further, in this single can / two water heater, when the temperature sensor 16 for preventing boiling detects the risk of boiling of hot water in the hot water supply path 11 during the bath reheating operation, there is a risk of boiling. The combustion operation of the burner 2 is temporarily stopped, and the combustion operation is resumed when the temperature of the hot water in the hot water supply passage 11 is lowered. In addition, it is determined whether or not the hot water is discharged from the hot water discharge pipe 17 by the boiling temperature sensor 16 and the can temperature sensor 18, and the risk of boiling is determined by detecting the state of the hot water supply passage 11 side. The judgment standard (boiling danger temperature) is changed to stabilize the bath output.
[0029]
First, the principle of determining whether or not the hot water is discharged on the hot water supply path side during the chasing operation will be described. When the karan or the like is opened and the hot water is discharged from the hot water discharge pipe 17, the water flowing into the heat exchanger 15 from the incoming water pipe 12 is heated, and the heated hot water is sent out to the hot water discharge pipe 17 to enter the hot water supply path 11. The hot water flows in the direction indicated by the broken line in FIG. As shown in FIG. 1, the boiling temperature sensor 16 is provided on the water inlet pipe 12 side, and the can body temperature sensor 18 is provided on the hot water outlet pipe 17 side. The detected temperature Th of the can temperature sensor 18 provided is higher than the detected temperature Tb of the boiling prevention temperature sensor 16 provided in the water inlet pipe 12 (Tb <Th).
[0030]
After the hot water supply is stopped, the hot water temperature in the heat exchanger 15 is still maintained at a high temperature, so that circulation does not occur immediately in the circulation circuit 21, and therefore the temperature gradient as described above is present in the circulation circuit. The detection temperature Tb of the boiling prevention temperature sensor 16 is kept as it is, and is kept below the detection temperature Th of the can body temperature sensor 18 (Tb ≦ Th).
[0031]
On the other hand, in this 1 can / two water heater, since the inlet pipe 12 is connected to the upper end of the heat exchanger 15 and the outlet pipe 17 is connected to the lower end of the heat exchanger 15, the hot water temperature in the circulation circuit 21 is reduced. When low, circulation occurs in the circulation circuit 21. When hot water circulates in the circulation circuit 21, the hot water heated by the heat exchanger 15 flows out to the inlet pipe 12, and the hot water radiated by the circulation circuit 21 flows into the heat exchanger 15. As a result, in the vicinity of the heat exchanger 15, hot water naturally circulates in the direction of the tapping pipe 17 → the heat exchanger 15 → the inlet pipe 12 as shown by solid arrows in FIGS. (Reverse circulation). As shown in FIG. 2, the boiling temperature sensor 16 is provided on the inlet pipe 12 side, and the can body temperature sensor 18 is provided on the outlet pipe 17 side. When the temperature is low, the detected temperature Th of the can body temperature sensor 18 provided in the tapping pipe 17 is smaller than the detected temperature Tb of the boiling prevention temperature sensor 16 provided in the water inlet pipe 12 (Tb> Th). ).
[0032]
Based on this principle, during the bath reheating operation, the detected temperature Th of the can body temperature sensor 18 and the detected temperature Tb of the boiling prevention temperature sensor 16 are sampled, and the detected temperatures Th and Tb are compared. If Tb ≦ Th, After hot water supply, if Tb> Th, it can be determined that circulation is in progress.
[0033]
In this way, if it is determined that Tb> Th during circulation in the bath renewal operation, the controller 33 sets the boiling dangerous temperature as a reference on the low temperature side. For example, the combustion of the burner 2 is stopped when the detected temperature Tb of the boiling prevention temperature sensor 16 becomes 75 ° C. or higher, and the combustion of the burner 2 is resumed when the detected temperature Tb of the boiling prevention temperature sensor 16 becomes 70 ° C. or lower.
[0034]
In addition, if it is determined that the hot water is being discharged because Tb ≦ Th during the bath reheating operation, the controller 33 sets the boiling dangerous temperature as a reference on the high temperature side. For example, combustion of the burner 2 is stopped when the detected temperature Tb of the boiling prevention temperature sensor 16 becomes 95 ° C. or higher, and combustion of the burner 2 is restarted when the detected temperature Tb of the boiling prevention temperature sensor 16 becomes 90 ° C. or lower.
[0035]
Conventionally, during the reheating operation, the combustion of the burner 2 is stopped and restarted according to the same standard both when the hot water is discharged from the hot water pipe 17 and when the hot water is not discharged (during circulation). Compared to the case where no hot water was supplied during the operation, the bath output decreased when the hot water was supplied during the chasing operation. That is, conventionally, a low value (about 75 ° C.) is uniformly used as the boiling danger temperature. When hot water is supplied during the reheating operation, the boiling prevention temperature sensor 16 is provided in the circulation circuit 21. Therefore, if the low boiling point temperature is used, combustion is frequently stopped and the average bath output is reduced.
[0036]
When the circulation after the hot water does not occur, the detection accuracy of the maximum hot water temperature in the circulation circuit is higher than when the circulation occurs. Therefore, when there is no circulation after tapping, the boiling temperature is increased (for example, about 95 ° C), and when circulation is occurring, the boiling temperature is decreased (for example, about 75 ° C). Thus, the burner combustion stop frequency can be made comparable, and the bath output can be stabilized regardless of the presence or absence of hot water supply during the chasing operation.
[0037]
However, conventionally, there has been no method for detecting whether hot water is circulating in the circulation circuit, so a low value must be used as the boiling boiling temperature even after hot water supply. In the single can / two water heater of the present invention, the presence / absence of circulation can be determined from the detected temperatures of the boiling prevention temperature sensor 16 and the can body temperature sensor 18, so that an appropriate boiling dangerous temperature can be determined according to the presence / absence of circulation. It became possible to switch to the value of, and it became possible to stabilize the bath output. In fact, when using the above boiling dangerous temperature value, a bath of approximately 8960 kcal / hour, which is necessary for heating the bath water from 20 ° C. to 42 ° C., both when the hot water is discharged and when not hot water is used. The output was stabilized.
[0038]
In the above embodiment, two temperature sensors (boiling prevention temperature sensor 16 and can body temperature sensor 18) are used as means for determining the presence or absence of circulation, but by providing a water flow switch or the like in the bypass pipe 19, The presence or absence of circulation in the circulation circuit 21 can also be determined.
[0039]
【The invention's effect】
According to the 1 can / two water heater of claim 1, when the circulation circuit is circulated during the bath reheating operation period, the detection accuracy of the maximum hot water temperature in the circulation circuit is low. On the other hand, when there is no circulation in the circulation circuit, the maximum temperature in the circulation circuit can be accurately detected. Therefore, it is possible to optimize the judgment level of the danger of boiling by changing the value of the boiling danger temperature according to the presence or absence of circulation in the circulation circuit (that is, the accuracy of detecting the maximum temperature in the circulation circuit). it can. And since it is possible to change the boiling danger temperature depending on whether the hot water is taken out from the hot water supply path, it is possible to obtain a stable bath output regardless of whether the hot water is taken out from the hot water supply path when bathing. It becomes possible.
[0040]
According to the one can two water channel hot water supply device according to claim 2, in the case of the bath reheating operation, when there is no circulation after the hot water is discharged from the hot water supply channel and when the circulation occurs in the circulation circuit Since the temperature gradient of the hot water temperature in the circulation circuit is different, it is possible to determine whether or not it is after the hot water from the detection values of these two temperature sensors.
[0041]
Moreover, according to the 1 can 2 water channel water heater of Claim 2, a circulation circuit is formed using the bypass path for bypassing a part of water which flows into a hot water path without letting a heat exchanger pass. be able to. The means for detecting the direction of hot water flowing in the heat exchanger of the hot water supply path can also be configured using an existing temperature sensor in the hot water heater. Therefore, the configuration of the water heater can be simplified and the cost can be reduced.
[0042]
According to the 1 can / two-channel water heater according to claim 3, when it is determined that the reheating operation is performed after using the hot water supply, the hot water is changed during the bath reheating operation because the temperature is changed to a high boiling danger temperature. In this case, the burner combustion stop frequency can be reduced. Therefore, the change in the bath output can be reduced between when the hot water is supplied during the bath reheating operation and when the hot water is not supplied.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a single can / two water heater according to an embodiment of the present invention.
FIG. 2 is a front view showing a specific structure of the above-described one can two water channel water heater.
FIG. 3 is a cross-sectional view of the single can / two water channel water heater shown in FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat exchange can body 2 Burner 9 Blower 11 Hot water supply path 12 Intake pipe 15 Heat exchanger of hot water supply path 16 Boiling prevention temperature sensor 17 Hot water discharge pipe 18 Can body temperature sensor 19 Bypass pipe 21 Circulation circuit 26 Bath tracking circuit 27 Return pipe 30 Heat exchanger for bath reheating circuit 31 Outward pipe

Claims (3)

A circulation circuit for circulating hot water flowing into the heat exchanger of the hot water supply path inside and outside the heat exchange can body, in which the heat exchanger of the hot water supply path and the heat exchanger of the bath reheating circuit are housed in one heat exchange can body In the 1 can 2 water channel water heater provided with
Means for detecting whether hot water is circulating in the circulation circuit;
1 can 2 water channel water heater provided with the means to change boiling danger temperature for preventing boiling of the hot water in the hot water supply path according to the presence or absence of hot water circulation in the circulation circuit. The circulation circuit is configured by connecting a water supply side portion and a hot water discharge side portion of the hot water supply path by a bypass path outside the heat exchange can body,
The means for detecting whether hot water is circulating in the circulation circuit is constituted by at least two temperature sensors provided in the hot water supply passage with at least a part of the heat exchanger of the hot water supply passage. The can of 1 canal water heater of Claim 1 characterized by the above-mentioned. Based on the detection result of the means for detecting whether or not hot water is circulating in the circulation circuit, it is determined whether or not the bath recuperation operation after use of hot water supply, and the bath replenishment after use of hot water supply When judged, it is made to change to the boiling dangerous temperature of higher temperature than the case where it is not judged that it is a bath reheating operation after hot water supply use, The claim 1, 2, or 3 characterized by the above-mentioned. 1 can 2 water heater.

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