JPH11159873A - Water heater with heat reserving function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability, safety and heat reserving performance of a water heater by accomplishing heat reserving combustion at a proper timing. SOLUTION: This water heater A enables heat reserving combustion even when a water quantity sensor 10 does not detect a flow rate. In this case, a boiling body temperature sensor 13 is provided and a control part 14 is provided. A control is performed to start heat reserving combustion when the temperature of a boiling body detected by the boiling body temperature sensor 13 is below the heat reserving combustion start temperature or to stop the heat reserving combustion when the temperature is above the heat reserving combustion stopping temperature while the heat reserving combustion start temperature is variably controlled in response to changes in the water intake temperature as detected by a water intake temperature sensor 9 so that the interval of the heat reserving combustion is made longer when the water intake temperature is high and it is made shorter when the temperature is low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater with a heat retaining function that can perform hot water heating and combustion even when a flow rate sensor does not detect a flow rate.

[0002]

2. Description of the Related Art Conventional hot water heaters such as instantaneous hot water heaters are provided with means for improving the tapping performance by maintaining the temperature and burning even when the flow rate sensor does not detect the flow rate. The one with the function (warm-up combustion function) that has been used is available. A conventional water heater provided with this warm combustion function will be described with reference to FIG.

FIG. 5 is a configuration diagram of a conventional water heater of this type. The water heater has at least a water inlet pipe 20 and a hot water pipe 21
And a can body 22 disposed between these pipes 20 and 21
(Comprising a heat exchanger 23, a burner mechanism 24, a fan 25, etc.) and a hot water supply pipe 2 from the water input pipe 20 without passing through the can 22.
1 and a bypass pipe 26 directly leading to
And a water proportional valve 27 disposed in the water supply port. The water inlet temperature sensor 28 and the water amount sensor 2
9 is provided.
0, a tapping temperature sensor 31 and a temperature sensor 32 are provided. Reference numeral 33 denotes a control unit for causing the hot water heater to operate as a heat-retaining combustion function and for controlling other parts of the apparatus.

[0004] The warming and burning function of the above-described conventional water heater has a function of burning the water in the can body in advance during cold start and while waiting for tapping by raising the water temperature in the can according to the procedure of software incorporated in the control unit 33. At the time of rising and re-watering, the temperature is controlled so as to quickly reach the set temperature.

[0005]

However, unlike the hot water function provided by the forced circulation circuit, the heat-retaining combustion function of the above-mentioned conventional water heater has repeated durability, because instantaneous combustion is repeated many times. It is necessary to consider safety,
If the interval of heat retention combustion is set long to ensure durability and safety, there is a problem that heat retention performance (usability) deteriorates. Conversely, if the interval of the heat-retention combustion is set short, there is a problem that the durability and the safety are deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a heat retaining function which can improve durability, safety and heat retaining performance by performing thermal combustion at an appropriate timing in the thermal combustion function. It is an object to provide a water heater.

[0007]

Means for Solving the Problems To achieve the above object, a water heater with a heat retaining function of the present invention comprises at least a water inlet pipe, a hot water pipe, and a heat exchanger disposed between these pipes. A heat retaining function having a can body having a vessel, and an inlet water temperature sensor and a water amount sensor provided in the water inlet line, and configured to perform heat insulation combustion even when the water amount sensor does not detect a flow rate. A water heater with a can body temperature sensor for detecting the temperature in the heat exchanger,
If the can body temperature detected by the can body temperature sensor is lower than the insulated combustion start temperature, the insulated combustion is started. After the insulated combustion is started, the insulated combustion is stopped if the can body temperature exceeds the insulated combustion stop temperature. At the same time, the warming combustion start temperature is controlled so as to be variable in response to a change in the incoming water temperature detected by the incoming water temperature sensor, and when the incoming water temperature is high, the warming combustion interval is controlled to be long, The first feature is that a control unit that controls so that the warming combustion interval is shortened when the incoming water temperature is low is provided. In addition, the water heater with a heat retaining function of the present invention is provided at least in the water inlet pipe, the tap water pipe, a can body having a heat exchanger disposed between these pipes, and the water inlet pipe. A water heater having a heat retaining function, comprising a water input temperature sensor and a water amount sensor, and configured to be capable of performing heat insulation combustion even when the water amount sensor does not detect the flow rate, wherein the temperature in the heat exchanger is controlled. Along with a can body temperature sensor for detecting, an outside air temperature sensor for detecting an outside air temperature is provided, and if the can body temperature detected by the can body temperature sensor is lower than the insulated combustion start temperature, the insulated combustion is started, After the start of the insulated combustion, if the can body temperature exceeds the insulated combustion stop temperature, control is performed to stop the insulated combustion, and the insulated combustion start temperature is variable according to a change in the outside air temperature detected by the outside air temperature sensor. Be able to Controlling controls so kept burning interval becomes longer when the outside air temperature is high,
A second feature is that a control unit is provided for controlling so as to shorten the warming combustion interval when the outside air temperature is low.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a water heater with a heat retaining function of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a water heater with a heat retaining function according to a first embodiment of the present invention, and FIG. 2 explains the conditions for starting warm combustion in the water heater with a heat retaining function according to the first embodiment of the present invention. FIG. 3 is a configuration diagram of a water heater with a heat retaining function according to a second embodiment of the present invention, and FIG. 4 is a diagram showing the start of heat retaining combustion in a water heater with a heat retaining function according to the second embodiment of the present invention. It is a graph for explaining conditions.

First, the configuration of a water heater A with a heat retaining function according to a first embodiment of the present invention will be described with reference to FIG. A water heater A with a heat retaining function includes a water inlet line 1, a hot water outlet line 2, and a can body 3 disposed between these water lines 1 and 2.
(Consists of heat exchanger 4, burner mechanism 5, fan 6, etc.)
A bypass pipe 7 directly from the water inlet pipe 1 to the tapping pipe 2 without passing through the can body 3, a bypass servo 8 disposed in the bypass pipe 7, and a water inlet temperature provided in the water inlet pipe 1. A heat exchanger such as a sensor 9 and a water amount sensor 10, an overflow servo 11 and a tapping temperature sensor 12 provided in the tapping line 2, and bend portions on both sides of a heat exchange pipe constituting the heat exchanger 4. A can body temperature sensor 13 for detecting the temperature of water in the heat exchanger 4 is provided near the heat exchanger 4. Also one
Reference numeral 4 denotes a control unit for setting conditions for keeping warm combustion, etc.
It controls each part of the device.

When the temperature of the can detected by the can temperature sensor 13 is lower than the temperature at which the insulated combustion is started, the control unit 14 starts the insulated combustion. After the insulated combustion is started, the insulated temperature is changed to the insulated combustion stop temperature. Is maintained so that the warming combustion is stopped, and the warming start temperature is controlled so as to be variable in response to a change in the incoming water temperature detected by the incoming water temperature sensor 9. Software for controlling the combustion interval so as to be longer and the warming combustion interval to be shorter when the incoming water temperature is low is built in. Here, the above-mentioned warm combustion start temperature obtained by Equation 1 is used.

[0011]

[Formula 1] Insulated combustion start temperature = Ts + a / T + b α = a / T + b Ts: set temperature T: incoming water temperature a, b: coefficient

The grounds for setting the conditions for starting and keeping warm combustion in the water heater with the function of keeping warm according to the first embodiment are as follows. As shown in FIG. 2, the above-mentioned can body temperature sensor 1 is used in summer when the incoming water temperature is high.
When the can body temperature detected in 1 falls with time from the warming stop temperature “set temperature Ts + β”, which is the warming end condition, and reaches the warming start temperature “set temperature Ts + α”, which is the warming start condition. Then, the warm combustion is started again.
At this time, the time from the warming start temperature to the warming stop temperature, that is, the warming interval H1 becomes longer. On the other hand, in winter when the incoming water temperature is low, the can body temperature detected by the can body temperature sensor 11 falls with time from the set temperature + β, which is the insulated combustion stop temperature, and the set temperature, which is the insulated start temperature in winter. When the temperature has reached “temperature + α ′”, the warm combustion is started again. At this time, the time from the warming combustion start temperature to the warming combustion stop temperature, that is, the warming interval H2 is shortened. In short, it is not necessary to frequently perform heat insulation combustion because the water temperature is high in summer and the water inside the can is difficult to cool (the heat insulation interval is long). Conversely, the water temperature is low and the water in the can easily cools in winter. For this reason, the required can body temperature cannot be obtained unless the heat insulation combustion is performed frequently (the heat insulation interval is short). In the above, β
> Α ′> α.

In the water heater with the heat retention function of the first embodiment configured as described above, each component basically performs a predetermined function as in a normal water heater. However, during the operation of the heat retaining function, a unique operation is performed according to the procedure of the software built in the control unit 14. That is,
When operated in accordance with the software procedure incorporated in the control unit 14, the temperature of the warm-burning start can be varied within a certain range according to the incoming water temperature and set with good timing. There is no need to repeat the operation, and unnecessary heat retention combustion can be eliminated, so that durability and safety can be improved. Also, in a low temperature period such as winter, the temperature can be kept at an appropriate timing, and the heat retention is improved. Furthermore, unnecessary heat retention combustion can be reduced as much as possible, and energy can be saved. The can body temperature sensor 13
Is conventionally disposed after the heat exchanger outlet separated from the can body (or heat exchanger), but in the above configuration, the can body temperature sensor 13 is attached to the bend portion of the heat exchanger 4. Since it is arranged, the temperature inside the can can be detected more accurately, and the above-described condition for keeping warm combustion can be set more accurately.

Next, the configuration of a water heater B with a heat retaining function according to a second embodiment of the present invention will be described with reference to FIG. The basic configuration is the same as that of the first embodiment, and only the differences will be described. The water heater B with the heat retention function newly adds the outside air temperature sensor 15 to the configuration of the water heater A with the heat retention function shown in FIG. Factors. Also, in the case of the software built in the control unit 14 in the case of the second embodiment, unlike the case of the first embodiment, the can body temperature detected by the can body temperature sensor 13 is the same as that of the insulated combustion. If the temperature is lower than the start temperature, the insulated combustion is started, and after the insulated combustion is started, the insulated combustion is controlled to be stopped when the can body temperature exceeds the insulated combustion stop temperature. The software was controlled so as to be variable in response to the change in the outside air temperature detected in the above. The software used was such that the warm combustion interval was long when the outside air temperature was high, and the warm combustion interval was short when the outside air temperature was low. Here, the above-mentioned warm combustion start temperature obtained by Equation 2 is used.

[0015]

## EQU2 ## Insulation combustion start temperature = Ts + a / T + b α = a / T + b Ts: set temperature T: outside air temperature a, b: coefficient

The grounds for setting the warming combustion start condition and the warming combustion ending condition in the water heater with the warming function according to the second embodiment are as follows. That is, as shown in FIG. 4, in summer when the outside air temperature is high, the can body temperature detected by the can body temperature sensor 11 falls with time from the insulated combustion stop temperature “set temperature + β” which is the insulated combustion end condition. When the temperature reaches the warming start temperature “set temperature + α”, which is the warming start condition in summer, the warming combustion is started again. At this time, the time from the warming combustion start temperature to the warming combustion stop temperature, that is, the warming interval H3 becomes longer. On the other hand, in winter when the outside air temperature is low, the can body temperature detected by the can body temperature sensor 13 falls with time from the insulated combustion stop temperature “set temperature + β” which is the insulated combustion end condition,
When the temperature reaches the warming start temperature “set temperature + α ′” which is the warming start condition in winter, the warming restarts again.
At this time, the time from the warming start temperature to the warming stop temperature, that is, the warming interval H4 is shortened. In short, in the summer, the outside air temperature is high and the water inside the can is difficult to cool, so there is no need to perform frequent thermal insulation combustion (long heat retention interval). Conversely, in the winter, the outside air temperature is low and the water inside the can is easily cooled For this reason, the required can body temperature cannot be obtained unless the heat insulation combustion is performed frequently (the heat insulation interval is short). In the above, it is assumed that β> α ′> α.

According to the water heater with a heat retaining function according to the second embodiment of the above construction, each component basically performs a predetermined operation similarly to a normal water heater, and when the heat retaining function is activated, It performs a unique operation according to the procedure of software built in the control unit 14. In other words, if the operation is performed according to the procedure of the software built in the control unit 14, the temperature for keeping warm combustion can be varied within a certain range according to the outside air temperature and set with good timing. There is no need to repeat the combustion, and wasteful heat retention combustion can be eliminated, so that durability and safety can be improved. Also, in a low temperature period such as winter, the temperature can be kept at an appropriate timing, and the heat retention is improved. As a result, unnecessary heat retention combustion can be reduced as much as possible, resulting in energy saving. Since the can body temperature sensor 13 is disposed near the heat exchanger 4 such as bends on both sides of a heat exchange pipe constituting the heat exchanger 4 as in the case of the first embodiment, The temperature inside the body can be detected more accurately, and the above-described warming combustion start temperature can be set more accurately.

In the first and second embodiments of the present invention, α, α 'and β are, for example, α = −2 ° C., α ′
= -1 ° C, β = 4 ° C, etc., an appropriate value can be determined in advance by experiment or the like as a constant value. In the above, in summer and winter, for example, an appropriate temperature between 15 ° C and 20 ° C can be selected as the boundary condition.

[0019]

According to the present invention, a water heater having a heat retaining function according to the first aspect of the present invention has the above-described structure and operation.
At least a water inlet pipe, a tap water pipe, a can body having a heat exchanger disposed between these pipes, and a water inlet temperature sensor and a water amount sensor provided in the water inlet pipe, A water heater with a heat retention function configured to be able to perform heat insulation combustion even when the water amount sensor does not detect a flow rate, provided with a can body temperature sensor for detecting the temperature in the heat exchanger, If the can body temperature detected by the can body temperature sensor is lower than the insulated combustion start temperature, the insulated combustion is started. After the insulated combustion is started, the insulated combustion is stopped if the can body temperature exceeds the insulated combustion stop temperature. At the same time, the warming combustion start temperature is controlled so as to be variable in response to a change in the incoming water temperature detected by the incoming water temperature sensor, and when the incoming water temperature is high, the warming combustion interval is controlled to be long, Incoming water temperature Since the provided control unit for controlling the heat insulating combustion interval is shortened when low, it is possible to improve the durability by preventing unnecessary thermal insulation for high temperature period such as summer. In a low-temperature period such as winter, the temperature can be kept at an appropriate timing, and there is an effect that the heat retention is improved. Therefore, unnecessary heat retention combustion can be reduced as much as possible, and energy can be saved. Moreover, according to the water heater with a heat retention function of claim 2, at least a water inlet pipe, a hot water pipe,
A can body having a heat exchanger disposed between these pipes, and a water inlet temperature sensor and a water quantity sensor provided in the water inlet pipe, when the water quantity sensor does not detect the flow rate A water heater with a heat retention function configured to be able to perform heat retention combustion, further comprising a can body temperature sensor for detecting a temperature in the heat exchanger, and an outside air temperature sensor for detecting an outside air temperature. The insulated combustion is started when the can body temperature detected by the can body temperature sensor is lower than the insulated combustion start temperature, and the insulated combustion is stopped when the insulated body temperature exceeds the insulated combustion stop temperature after the insulated combustion is started. Control so that the warming start temperature can be varied in response to a change in the outside air temperature detected by the outside air temperature sensor. When the outside air temperature is high, the warming combustion interval becomes longer. Controlled, since when the outside air temperature is low is provided a control unit for controlling the heat insulating combustion interval is shortened, thereby improving the durability by preventing unnecessary thermal insulation for high temperature period such as summer. In a low-temperature period such as winter, the temperature can be kept at an appropriate timing, and there is an effect that the heat retention is improved. Therefore, unnecessary heat retention combustion can be reduced as much as possible, and energy can be saved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a water heater with a heat retaining function according to a first embodiment of the present invention.

FIG. 2 is a graph for explaining a warming start temperature in the water heater with a warming function according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a water heater with a heat retention function according to a second embodiment of the present invention.

FIG. 4 is a graph for explaining a warming combustion start temperature in a water heater having a warming function according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a conventional water heater with a heat retaining function.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inlet line 2 Outlet line 3 Can 4 Heat exchanger 9 Inlet temperature sensor 10 Water quantity sensor 13 Can temperature sensor 14 Control part 15 Outside temperature sensor A, B Water heater with heat retention function

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Eiichi Tsuji 93, Edocho, Chuo-ku, Kobe-shi, Hyogo Pref.

Claims (2)

[Claims] 1. A can body having at least a water inlet pipe, a tap water pipe, and a heat exchanger disposed between these pipes,
A water heater with a heat retaining function, comprising a water temperature sensor and a water amount sensor provided in the water inlet line, and configured to be capable of performing heat insulation combustion even when the water amount sensor does not detect a flow rate, A can body temperature sensor for detecting the temperature in the heat exchanger is provided, and if the can body temperature detected by the can body temperature sensor is lower than the insulated combustion start temperature, the insulated combustion is started. When the can body temperature is higher than the insulated combustion stop temperature, the insulated combustion is controlled to be stopped, and the insulated combustion start temperature is controlled so as to be variable in response to a change in the incoming water temperature detected by the incoming water temperature sensor. A control unit is provided that controls so that the warming combustion interval is long when the incoming water temperature is high, and that the warming combustion interval is short when the incoming water temperature is low. Thermal insulation function with the water heater to be. 2. A can body having at least a water inlet line, a tapping line, and a heat exchanger disposed between these lines,
A water heater with a heat retaining function, comprising a water temperature sensor and a water amount sensor provided in the water inlet line, and configured to be capable of performing heat insulation combustion even when the water amount sensor does not detect a flow rate, A can body temperature sensor for detecting the temperature in the heat exchanger is provided, and an outside air temperature sensor for detecting an outside air temperature is provided, and the can body temperature detected by the can body temperature sensor is a warming combustion start temperature. If the temperature falls below the temperature, the insulated combustion is started.After the insulated combustion is started, the insulated combustion is controlled to be stopped if the can body temperature exceeds the insulated combustion stop temperature. It is controlled so that it can be changed in response to a change in temperature. When the outside air temperature is high, it is controlled so that the warm combustion interval becomes long. Thermal insulation function water heater, characterized in that Le is provided with a control unit for controlling to be shorter.