JP2004108675A - Hot water storage type hot water supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage type hot water supply apparatus ensuring the stop of operation when a temperature of bathtub water exceeds a set temperature. <P>SOLUTION: This hot water supply apparatus has: a hot water storage tank 2; a stored hot water circulation circuit 6 of the hot water storage tank 2; a circulation pump 8 circulating stored hot water; a heat exchanger 7 exchanging heat between an external liquid and the stored hot water taken out of the hot water storage tank 2; an external liquid circulation circuit 11 circulating the external liquid; a circulation pump 12 circulating the external liquid; a temperature detection means 15c detecting an external liquid temperature; a control part 50 controlling operation of the respective circulation pumps 8, 12 according to the temperature detected by the temperature detection means 15c; and an excessive temperature rise prevention device 17 forcibly stopping the operation of the circulation pumps 8, 12 independently of the control part 50 when the temperature detected by the temperature detection means 15c is not less than a prescribed temperature higher than an abnormality decision temperature at which the control part 50 stops the operation of the circulation pumps 8, 12. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a hot water supply type water heater provided with a heat exchanger for exchanging heat between hot water taken out of a hot water storage tank and an external liquid taken out of an external heat load.
[0002]
[Prior art]
In a conventional hot water storage type water heater with a bathtub reheating function, at the time of reheating the bathtub water, the circulation pump is operated to take out the stored water from the upper part of the hot water storage tank into the circulation circuit, and the bathtub water exchanger is used. Heat exchange with the bathtub, and reheat the bathtub water while detecting the temperature of the bathtub water. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
JP 2001-108292 A
[Problems to be solved by the invention]
However, in the conventional configuration as described above, if the temperature sensor for detecting the temperature of the bathtub water fails, or if the microcomputer of the control unit runs away, the reheating operation does not stop, and the temperature of the bathtub water decreases. There is a problem that the temperature rises abnormally higher than the set temperature.
[0005]
The present invention has been made to solve the above-described problems, and has an object to provide a hot-water storage type water heater that can reliably stop operation when the temperature of bathtub water rises above a set temperature. I do.
[0006]
[Means for Solving the Problems]
A hot-water storage type hot water supply device according to the present invention is a hot-water storage tank that is supplied with water from a lower part and is discharged from an upper part, and the hot-water storage tank is heated by a heating means, and the hot-water storage water taken out from an upper part of the hot-water storage tank is stored in the hot water storage tank A hot water circulation circuit for returning to the tank, a circulation pump for circulating the hot water taken out of the hot water tank into the hot water circulation circuit, a heat exchanger for exchanging heat between the hot water taken out of the hot water tank and an external liquid, An external liquid circulation circuit that circulates the external liquid, a circulation pump that circulates the external liquid through the external liquid circulation circuit, a temperature detection unit that detects the temperature of the external liquid, and a temperature detection unit that detects the temperature of the external liquid. A control unit for controlling the operation of each of the circulating pumps, and an external liquid temperature detected by the temperature detecting means is determined by an abnormality determination temperature at which the control unit stops operating the circulating pump. When have above a predetermined temperature, in which a safety control device for forcibly stopping the operation of the control unit and independently of the circulation pump.
[0007]
Further, the safety control device is mounted on the external liquid circulation circuit away from the heat exchanger in the external liquid circulation circuit.
[0008]
Further, the safety control device is configured to, when operated, cut off an electric circuit of the circulation pump and forcibly stop the operation of the circulation pump.
[0009]
Further, the safety control device operates when an external liquid temperature becomes 60 ° C. or higher.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a hot water supply type water heater showing a first embodiment of the present invention, and FIG. 2 is a power supply circuit diagram of main components.
In FIG. 1, a hot water storage tank 2 is provided in a hot water supply body 1, and a heating element 4 for heating hot water is attached to the hot water storage tank 2. A water supply pipe 3 is connected to a lower portion of the hot water storage tank 2. The water supply pipe 3 is provided with a pressure reducing valve 3 a, and a hot water supply pipe 5 is connected to an upper part of the hot water storage tank 2. A relief valve 5 a is provided in the hot water supply pipe 5, and a hot water circulation circuit 6 is connected to upper and lower portions of the hot water storage tank 2. The hot water circulation circuit 6 exchanges heat between hot water stored in the hot water storage tank 2 and hot water in the bathtub 10 which is an external heat load. The hot water in the hot water storage tank 2 is supplied to the hot water circulation circuit 6. It comprises a circulating pump 8 for circulating and a circulating flow adjusting valve 9 for adjusting the circulating flow of hot water passing through the hot water circulation circuit 6. A bathtub water circulation circuit 11 is connected to the bathtub 10, and the bathtub water circulation circuit 11 includes a bathtub water circulation circuit 11a, a circulation pump 12 for circulating bathtub water, the heat exchanger 7, and a bathtub water return circulation circuit 11b. The bathtub water circulation circuit 11a is provided with an overheat prevention device 17 as a safety control device.
[0011]
The overheat prevention device 17 is of a type that is manually operated and returns to the normal operation because it operates at the time of abnormality. When the overheat prevention device 17 operates, the power supply to the circulation pumps 8 and 12 is shut off. Is done.
Further, the water heater main body 1 and the bathtub 10 are connected by a bathtub water outlet pipe port 18a and a bathtub water return pipe port 18b.
The mounting of the overheat prevention device 17 on the bathtub water circulation circuit 11a is performed at a position where the heat is hardly affected by the heat exchanger 7, that is, in the vicinity of the bathtub water piping port 18a far from the heat exchanger 7. Mounting is less likely to cause malfunction.
[0012]
Temperature sensors 14a and 14b for detecting the temperature of hot water in the hot water storage tank 2 are attached at predetermined intervals. The hot water circulation circuit 6 is provided with a hot water inlet temperature sensor 15a for detecting the hot water inlet temperature to the heat exchanger 7 and a hot water outlet temperature sensor 15b for detecting the hot water outlet temperature from the heat exchanger 7. ing. Further, the bathtub water circulation circuit 11 includes a bathtub water inlet temperature sensor 15c for detecting a bathtub water inlet temperature to the heat exchanger 7, and a bathtub water outlet temperature sensor 15d for detecting a bathtub water outlet temperature from the heat exchanger 7. Installed. The control unit 50 reads the detection values of the temperature sensors 14a, 14b, 15a, 15b, 15c, 15d, and controls the heating element 4, the circulation pumps 8, 12, and the circulation flow rate adjustment valve 9 based on the settings of the operation unit 60. I do.
[0013]
Here, depending on the adjustment of the circulation flow rate adjusting valve 9, the circulation amount of the hot water circulation circuit 6 increases or decreases, and the heating capacity of the bathtub 10 changes. When the circulation flow rate regulating valve 9 is fully opened, the heating capacity is maximum, and when the circulation amount of the hot water circulation circuit 6 is reduced, the heating capacity decreases, but the temperature of the hot water returning to the bathtub 10 can also be lowered.
The operating temperature of the over-temperature prevention device 17 is set to operate when the temperature detected by the temperature sensor 15c is equal to or higher than a predetermined temperature which is higher than the abnormality determination temperature at which the controller 50 stops the operation of the circulation pumps 8 and 12. In this example, the temperature is set to 60 ° C. so as not to cause instantaneous burns in the bathtub water in the bathtub 10.
[0014]
FIG. 2 shows the electric circuit of the power supply 19, the overheat prevention device 17, and the circulation pumps 8 and 12. When the excessive temperature rise prevention device 17 operates, the electric circuits of the circulation pumps 8 and 12 are cut off, the operation of the circulation pumps 8 and 12 is forcibly stopped regardless of the control unit 50, and the reheating operation is forcibly stopped. It is configured as follows.
[0015]
Next, the operation of the hot water supply type water heater in the first embodiment will be described.
First, water supplied from the water supply pipe 3 is reduced to a predetermined pressure by the pressure reducing valve 3 and supplied to the hot water storage tank 2. The hot water is heated to the temperature set by the operation unit 60 by the heating element 4 attached to the hot water storage tank 2. The expansion water in the hot water storage tank 2 at the time of boiling is discharged from the relief valve 5a.
When hot water is supplied to a general faucet or the like, the faucet is opened, hot water is supplied through the hot water supply pipe 5 by the power of the water source water pressure, and water is supplied to the lower part of the hot water storage tank 2.
[0016]
Next, the reheating operation of the bathtub water will be described.
When the operation unit 60 receives an instruction to start the additional heating of the bathtub 10, the additional heating operation is started. When the additional heating operation is started, first, the circulation pump 12 is operated, and hot water in the bathtub 10 is taken out to the bathtub water circulation circuit 11 and returned into the bathtub 10 through the heat exchanger 7. On the other hand, the circulation pump 8 is also operated to draw hot water from the upper part of the hot water storage tank 2 to the hot water storage circuit 6 and return to the lower part of the hot water storage tank 2 through the heat exchanger 7. At this time, the heat exchanger 7 heat-exchanges (heat-transfers) the high-temperature hot water stored in the hot-water storage tank 2 to the low-temperature bath water to heat the bath water to a temperature suitable for bathing. be able to.
[0017]
In the vicinity of the heat exchanger 7, there are provided a hot water inlet temperature sensor 15a, a hot water outlet temperature sensor 15b, a bath water inlet temperature sensor 15c, and a hot water outlet temperature sensor 15d. The temperature is detected, and the recirculation flow control valve 9 is adjusted based on the detected temperature to perform additional heating control.
[0018]
Here, for the following description, the input value which is the detected temperature of the storage water inlet temperature sensor 15a of the heat exchanger 7 is Thi, the input value which is the detected temperature of the storage water outlet temperature sensor 15b is Th, and the bathtub water inlet temperature. The input value as the detected temperature of the sensor 15c is defined as Tci, and the input value as the detected temperature of the bathtub water outlet temperature sensor 15d is defined as Tco.
It is confirmed whether or not the input value Tci of the bathtub water inlet temperature sensor 15c of the heat exchanger 7 is equal to or higher than a preset bathtub temperature set by the operation unit 60 or the like. If Tci is equal to or higher than the set temperature, the circulation pump 8 is turned off and the circulation pump 12 is turned off, and the reheating in the bathtub 10 is completed. If Tci is lower than the set temperature, the reheating is continued.
[0019]
Here, since the circulation flow rate adjusting valve 9 is adjusted to restrict the flow rate of the hot water circulation circuit 6, the additional heating capacity is limited, Tco can be suppressed to a certain temperature or less, and high-temperature water is supplied to the bathtub 10. In the case of no supply, furthermore, when the bathtub water inlet temperature sensor 15c of the heat exchanger 7 fails and Tci cannot be detected accurately, or when the microcomputer of the control unit 50 has a malfunction, the additional heating operation is performed. Does not stop, and even if the temperature of the bathtub water in the bathtub 10 rises above the temperature set by the operation unit 60, the reheating operation can be stopped by the overheat prevention device 17.
[0020]
As described above, according to the first embodiment, the operation is performed when the temperature detected by the temperature sensor 15c is equal to or higher than the predetermined temperature which is higher than the abnormality determination temperature at which the operation of the circulation pumps 8 and 12 is stopped by the control unit 50. By attaching the set overheat prevention device 17 to the bathtub water circulation circuit 11a, even if the reheating operation of the bath cannot be controlled due to a malfunction of the temperature sensor 15c or runaway of the control unit 50, the reheating operation is performed. Can be forcibly stopped.
In the first embodiment, bath water is described as an example of the external liquid in the first embodiment. However, the external liquid may be hot water such as a hot water heater.
[0021]
【The invention's effect】
As described above, according to the hot water supply type water heater according to the present invention, even when the temperature detecting means for detecting the temperature of the external liquid fails, or when the microcomputer of the control unit runs out of control and becomes uncontrollable. When the temperature becomes equal to or higher than the predetermined temperature which is higher than the abnormality determination temperature at which the operation of the circulation pump is stopped by the control unit, the safety control device operates to reliably stop the reheating operation.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a hot-water storage type water heater according to a first embodiment of the present invention.
FIG. 2 is an electric circuit diagram of main components according to the first embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hot water supply main body 2 Hot water storage tank 6 Bath water circulation circuit 7 Heat exchanger 8 Circulation pump 10 Bath tub (external heat load)
11 Bath water (external liquid) circulation circuit 11a Bath water (external liquid) going circulation circuit 11b Bath water (external liquid) return circulation circuit 12 Circulation pump 15a Hot water inlet temperature sensor 15b Hot water outlet temperature sensor 15c Bath water (external liquid) ) Inlet temperature sensor 15d Bath tub water (external liquid) outlet temperature sensor 17 Overheat prevention device (safety control device)
18a Bathtub water (external liquid) going pipe port 18b Bathtub water (external liquid) return pipe port 19 Power supply 50 Control unit 60 Operation unit

Claims (4)

A hot water storage tank supplied with water from a lower part and discharged from the upper part, a hot water storage circuit for heating the hot water by heating means to the hot water storage tank and returning the hot water taken out from the upper part of the hot water storage tank to the hot water storage tank; A circulation pump that circulates the hot water taken out of the hot water tank into the water circulation circuit, a heat exchanger that exchanges heat between the hot water taken out of the hot water tank and the external liquid, and an external liquid circulation circuit that circulates the external liquid. A circulation pump that circulates the external liquid through the external liquid circulation circuit, a temperature detection unit that detects the temperature of the external liquid, and controls the operation of each of the circulation pumps according to the external liquid temperature detected by the temperature detection unit. A controller, when the temperature of the external liquid detected by the temperature detector is equal to or higher than a predetermined temperature higher than an abnormality determination temperature at which the controller stops the operation of the circulation pump, Hot water storage type water heater, characterized in that a safety control device for forcibly stopping the operation of the independent circulation pump and control unit. The hot water supply type water heater according to claim 1, wherein the safety control device is attached to the external liquid circulation circuit away from the heat exchanger in the external liquid circulation circuit. The hot water supply type water heater according to claim 1 or 2, wherein the safety control device cuts off an electric circuit of the circulation pump and forcibly stops the operation of the circulation pump when the safety control device is operated. The hot-water storage type water heater according to claim 1, wherein the safety control device operates when the temperature of the external liquid becomes 60 ° C or higher.

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