JPH08121799A - Water heater with instantaneous heating function - Google Patents

Abstract

PURPOSE: To eliminate unnecessary circulation of water by the decrease of the temperature of the water in a circulation water channel in a water heater body by the influence of a fan and the low atmospheric temperature even if the water temperature of a circulation water channel near a hot water supply port is sufficiently high. CONSTITUTION: If a fan is operated for a predetermined time in the state that the water of a circulating water channel is not circulated, or if the difference between the atmospheric temperature and the set hot water supply temperature is larger than a predetermined value, in the step S35, there are steps S36, S38, S39 of increasing a reference value a corresponding to the difference between a criterion temperature difference set hot water supply temperature Ts for circulating to heat the circulating water channel and a water temperature Tr in the water channel detected in a water heater body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply device having an immediate hot water function.

[0002]

2. Description of the Related Art As shown in FIG. 6 (a), a water heater 50
In the case where the pipe 52 from the hot water outlet 51 to the hot water outlet 51 is provided in only one direction, the temperature of the hot water in the pipe 52 from the hot water supply device 50 to the hot water outlet 51 decreases after a long time has passed after the hot water is discharged, and then the hot water is discharged next. At this time, low-temperature hot water is discharged by the amount of staying in the pipe 52. Therefore, as shown in FIG. 6 (b), the heat exchanger 56 should be located as close to the outlet 51 as possible.
There has already been devised a hot water supply device with an immediate hot water function in which a circulating water passage 57 is provided and the hot water temperature in the circulating water passage 57 is always close to a set temperature.

An outline of the immediate hot water function will be described below. Figure 6
As shown in (b), the circulating water passage 57 has an immediate hot water pump 58.
And a circulating water temperature sensor 59 for detecting the water temperature Tr in the water channel 57. As shown in FIG. 7, when the instant hot water switch for enabling the instant hot water function is turned on, first, the instant hot water pump 58 is turned on (step S51). The instant hot water pump 58 is turned off when the water temperature Tr detected by the sensor 59 becomes equal to or higher than the set hot water supply temperature Ts (steps S52 → S53). Even after the instant hot water pump 58 is turned off, the water temperature Tr of the circulating water passage 57 is constantly checked, and the instant hot water pump 58 is activated when the temperature Tr falls below the set hot water supply temperature Ts by a predetermined temperature α (for example, about 3 ° C.). (Step S54 → S51). When water flows in the circulating water channel 57, it is detected by a water flow sensor (not shown), the burner 60 is ignited, and the water temperature in the circulating water channel 57 is raised.
As a result, the hot water in the circulating water passage 57 is always maintained at a temperature between (Ts-α) and Ts, and hot water close to the set temperature Ts is promptly supplied from the hot water outlet 51.

[0004]

Normally, the piping of the circulating water passage 57 outside the hot water supply apparatus 50 is covered with a heat insulating material, whereas the piping inside the hot water supply apparatus 50 is not covered with such a coating. . Therefore, as shown in FIG.
The hot water temperature Tr in the inner circulating water passage decreases faster than the hot water temperature Tp in the outer circulating water passage 57. Further, in the hot water supply device 50, the fan 61 is rotated at the same time as the burner 60 is ignited during hot water supply or reheating, so that the hot air in the circulating water passage in the hot water supply device 50 is more easily cooled by the wind of the fan 61. (Tr 'in the figure) In these cases, the hot water pump 58 and the burner 60 are wastefully used even though it is not necessary to circulate.
There is a problem that is activated.

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 apparatus with an immediate hot water function which does not perform unnecessary circulation.

[0006]

Means for Solving the Problems and Actions The present invention, which has been made to solve the above problems, comprises: a) a heat exchanger provided in the body of a hot water supply device, the heat exchanger having a burner and a fan; A circulating water channel that connects the exchanger to a hot water outlet provided outside the hot water supply device body, c) a circulating water temperature sensor that detects the temperature of the water in the circulating water channel in the hot water supply device body, and d) the circulating water channel. When the difference between the temperature detected by the circulating water temperature sensor and the specified set temperature exceeds a specified reference value, the immediate hot water pump is activated and the burner of the heat exchanger is activated. In a hot water supply apparatus with an immediate hot water function, comprising:
Further, f) a reference value changing means for increasing the reference value when the fan is operated for a predetermined time in a state where the water in the circulating water channel is not circulating, is provided.

If the fan is operated for a predetermined time or longer in a state where the water in the circulating water channel is not circulating, the temperature of the hot water in the circulating water channel outside the apparatus body does not decrease so much, but the temperature in the circulating water channel inside the apparatus body does not increase. Only the hot water temperature drops rapidly, and the difference between the hot water temperature in the circulating water passage near the tap hole and the hot water temperature detected by the circulating water temperature sensor becomes larger than usual. Therefore, in such a case, the reference value is increased to prevent unnecessary circulation and heating.

Further, the water supply pipe is connected to a position before the circulation water passage enters the heat exchanger, and the hot water outlet is opened to form a water flow from the water supply pipe to the hot water outlet via the heat exchanger. In the hot water supply apparatus provided with hot water supply control means for detecting the above and operating the burner and the fan, the immediate hot water control means may be a mechanism for stopping the immediate hot water pump in such a case. In this case, while the hot water is supplied from the hot water outlet, the fan is operated and the hot water pump is stopped, so that the condition of the reference value changing means is satisfied and the reference value is changed in the larger direction.

Incidentally, a water channel other than the circulating water channel is provided in the main body of the hot water supply apparatus, and the fan may be operated when the water in the other water channel is heated. Also in this case,
The condition of the reference value changing means is satisfied, and the reference value is changed in the larger direction.

In the above, the water temperature drop in the circulating water channel in the main body of the water heater by the operation of the fan is targeted, but in the circulating water channel in the main body of the water heater, which is often arranged outdoors due to the decrease of the outside temperature. The water temperature is often placed indoors, and is more likely to drop as compared to the circulating water channel near the outlet that is covered with a heat insulating material. Therefore, in this case, it is preferable to provide an outside air temperature sensor and increase the reference value when the difference between the outside air temperature and the set temperature becomes a predetermined value or more.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a one-can two-channel water heater with an immediate hot water function will be described with reference to FIG. Since this hot water supply device is a one-can, two-water channel type, two heat absorption parts, that is, the hot water supply side heat absorption part 13 and the additional heating side heat absorption part 14 are provided for one burner 25 and the heat exchanger 12. Of these, the hot water circulating water passage 1 that circulates between the hot water supply side heat absorption part 13 and the hot water outlet 17
6, and the reheating side water absorption part 14 is connected to a reheating circulation water channel 20 that circulates between the bathtub 19. A water supply passage 15 is connected to the immediate hot water circulation water passage 16 inside the water heater main body 11, and water is supplied to the circulation water passage 16 in front of the heat exchanger 12. Immediate water pump 1 in the immediate hot water circulation channel 16
8, a flow sensor 33, a hot water temperature sensor 32, and a circulating water temperature sensor 35 are provided, and a water supply temperature sensor 31 is provided in the water supply passage 15. On the other hand, the circulation water passage 20 on the additional heating side is provided with an additional heating pump 21, a bath temperature sensor 34, and a water flow switch 22.

An open / close valve 27 and a proportional valve 28 are provided in the fuel pipe 26 of the burner 25. The proportional valve 28 is a flow control valve that adjusts the flow rate of fuel according to a signal from the outside. A fan 29 is provided in the vicinity of the burner 25 and supplies the air required for combustion of the burner 25. Water heater main body 1
An outside air temperature sensor 44 for detecting the outside air temperature Tk
Is provided.

Each of these sensors 31, 32, 33, 34,
Temperature and flow rate signals Tc, Th, Q, T from 35 and 44
The ON / OFF signals of f, Tr, Tk and the water flow switch 22 are input to the control unit 49. In addition, the control unit 49 includes an immediate hot water switch 40, an additional heating switch 41, and a hot water temperature setting unit 42.
Further, the bath temperature setting unit 43 is connected, and the signals of the immediate hot water function ON / OFF, the additional heating ON / OFF, the set hot water supply temperature Ts, and the set bath temperature Tfs are input from the respective units. Then, from the control unit 49, the hot water pump 18 and the reheating pump 2
1, a pump operation signal is sent to the opening / closing valve 27, a valve opening / closing signal is sent to the proportional valve 28, a valve opening signal is sent to the fan 29, and a fan operation signal is sent to the fan 29.

The control unit 49 is composed of a computer having a ROM and a RAM, and performs the following control according to a program stored in the ROM in advance. Less than,
Various controls performed by the control unit 49 will be described with reference to the flowcharts of FIGS.

First, the hot water supply control will be described with reference to FIG. When the hot water outlet 17 is opened, the water in the water supply passage 15 enters the hot water circulation water passage 16 and the water flows toward the hot water outlet 17. This water flow is detected by the flow rate sensor 33, and the flow rate signal Q is sent to the control unit 49. The control unit 49 determines whether or not Q is equal to or higher than a predetermined ignition flow rate Q0 (step S1). If Q> Q0, then Q is multiplied by (Ts-Tc) (necessary heating number). number)
Is greater than the minimum ignition number (step S2). If Q> Q0 and the required heating number is larger than the minimum ignition number, the process proceeds to step S3, the on-off valve 27 is opened to ignite the burner 25, and the temperature detected by the hot water temperature sensor 32 is detected. The opening of the proportional valve 28 is adjusted so that Th becomes the set hot water supply temperature Ts. At this time, the control unit 49 operates the fan 29 to supply air to the burner 25, but the control unit 49 counts the operation time of this fan.

When it is determined in step S1 that Q is smaller than the ignition flow rate Q0, or when it is determined in step S2 that the required heating number is smaller than the minimum ignition number, the process proceeds to step S4 and the burner 25 is operated. Extinguish the fire. At this time, the fan 29 is also stopped, and the operation time and the operation stop time of the fan 29 until then are determined by the control unit 4.
9 is stored in the RAM.

Next, the additional heating control will be described with reference to FIG. When the additional heating switch 41 is turned on, the control unit 49 operates the additional heating pump 21 (step S11). Additional heating pump 2
When 1 is activated, water flows in the reheating circulation channel 20 and the water flow switch 22 is turned on. As shown in FIG. 4B, when the control unit 49 receives an ON signal from the water flow switch 22 (step S21), it ignites the burner 25 and operates the fan 29 (step S22).

Returning to FIG. 4A, the bath temperature Tf is lower than the set bath temperature Tfs by a predetermined value β (Tfs-
β) or more is determined (step S12), T
When f ≧ (Tfs−β), the process proceeds to step S14 and the reheating pump 21 is stopped. When the additional heating pump 21 is stopped, the water flow switch 22 is turned off, so the control unit 49 extinguishes the burner 25 as shown in FIG.
9 is stopped (step S23). At this time as well, similarly to the above, the operating time and the stop time of the fan 29 are stored in the RAM. After that, after waiting for a predetermined time for pump protection to elapse (step S15), step S15
Returning to 11, the additional heating pump 21 is started.

In step S12 of FIG. 4A, Tf
If <(Tfs-β), the process proceeds to step S13, and the operation of the reheating pump 21 is continued until the bath temperature Tf becomes equal to or higher than the set bath temperature Tfs (step S13). And Tf
When ≧ Tfs, the process proceeds to step S14 to stop the reheating pump 21. The above is the content of the additional heating control.

Next, the control of the immediate hot water function will be described with reference to FIG. When the instant hot water switch 40 is turned on, the control unit 49 first activates the instant hot water pump 18, ignites the burner 25, and activates the fan 29 (step S31). Then, the water temperature Tr in the hot water circulation water passage 16 is set to the set hot water supply temperature Ts.
Until the above, the ignition of the burner 25 and the operation of the instant hot water pump 18 are continued (step S32), and they are stopped when Tr ≧ Ts (step S33).

Next, the temperature correction values a and b are initialized to 0 (step S34), and it is determined whether or not the fan cooling condition is satisfied (step S35). The fan cooling conditions are (1) the fan 2 before a predetermined time (for example, 3 minutes) from the present time.
Was 9 working? (2) During that time, was water flowing in the circulating water channel 16? 2 conditions, and when both the requirements (1) and (2) are satisfied, it is assumed that the fan cooling condition is satisfied. The requirement (1) can be determined from the fan operating time and the stop time stored in the RAM in steps S3 and S23. The requirement (2) can be determined from the operation record of the hot water pump 18 stored in the control unit 49 itself. When the fan cooling condition is satisfied, a predetermined value a0 (for example, 2 ° C.) is substituted for the temperature correction value a (step S36). When the fan cooling condition is not satisfied, the temperature correction value a remains the initial value 0.

Next, the difference between the outside air temperature Tk detected by the outside air temperature sensor 44 and the set hot water supply temperature Ts is a predetermined value C (for example, 40).
(° C.) or higher (step S37).
When the difference (Ts-Tk) between the outside air temperature and the set hot water supply temperature is equal to or greater than the predetermined value C, another temperature correction value b is set to the predetermined value b0.
(For example, 1 ° C.) is substituted (step S38). When the difference between the two temperatures is C or less, the temperature correction value b remains at the initial value 0.

After determining the correction values a and b in this way, this time, the water temperature T in the hot water circulating water passage 16 in the main body of the water heater is increased.
It is determined whether or not r is equal to or lower than a temperature (Ts-α-a-b) lower than the set hot water supply temperature Ts by (α + a + b) (step S39). When Tr ≧ (Ts−α−a−b), there is a possibility that the temperature has not yet dropped in the external immediate hot water circulation channel 16, so the determination in step S39 is repeated. When Tr becomes (Ts-α-a-b) or less, the immediate hot water circulation channel 1 near the hot water outlet 17 outside the water heater main body.
Because the water temperature may have dropped within 6,
Returning to step S31, the hot water pump 18 is operated to perform heating.

[0024]

In the conventional hot water supply apparatus with quick hot water function, the fan is operated when the water in the circulating water channel is not circulated, so that the water temperature in the external circulating water channel is not lowered, but the hot water supply apparatus is operated. Only the water temperature in the circulating water channel inside the body may drop significantly. In this case, conventionally, it has been determined whether or not circulation is necessary based on the water temperature in the circulating water channel in the water heater body. In the hot water supply apparatus with an immediate hot water function according to the present invention, in such a case, the temperature difference serving as the criterion for starting circulation is increased to prevent wasteful circulation and wasteful heating. Also, because the outside temperature is low,
When there is a possibility that the temperature of the circulating water channel in the water heater main body that is not covered with the heat insulating material may greatly decrease, useless circulation and heating are similarly prevented.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a one-can two-channel hot water supply device with an immediate hot water function according to an embodiment of the present invention.

FIG. 2 is a graph showing changes in hot water temperature in the hot water circulation passage.

FIG. 3 is a flowchart of hot water supply processing in the hot water supply device according to the embodiment.

FIG. 4 is a flowchart of additional heating processing in the hot water supply device according to the embodiment.

FIG. 5 is a flowchart of instant hot water function processing in the hot water supply device according to the embodiment.

FIG. 6 is an explanatory diagram of a one-way system and a circulation system in hot water supply.

FIG. 7 is a flowchart of an immediate hot water function process of a conventional hot water supply device.

[Explanation of symbols]

 11 ... Hot water supply device main body 12 ... Heat exchanger 13 ... Hot water supply side heat absorption part 14 ... Heating side heat absorption part 15 ... Water supply channel 16 ... Immediate hot water circulation water channel 17 ... Hot water outlet 18 ... Immediate hot water pump 19 ... Bathtub 20 ... Additional heating circulation Water channel 21 ... Reheating pump 22 ... Water flow switch 25 ... Burner 26 ... Fuel pipe 27 ... Open / close valve 28 ... Proportional valve 29 ... Fan

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Kunihiko Ishizaka 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi Japan Yupuro Co., Ltd. (72) Inventor Mikio Ochi 43-1, Uozakihama-cho, Higashinada-ku, Kobe Within Pro Co., Ltd.

Claims (4)

[Claims] 1. A circulating water channel for connecting a) a heat exchanger provided in the main body of the hot water supply device and equipped with a burner and a fan, and b) the heat exchanger and a hot water outlet provided outside the main body of the hot water supply device. And c) a circulating water temperature sensor that detects the temperature of the water in the circulating water channel in the body of the hot water supply device, d) an instant hot water pump provided in the circulating water channel, and e) a temperature detected by the circulating water temperature sensor. In a hot water supply apparatus with an immediate hot water function, which includes an immediate hot water control means for operating the immediate hot water pump and burning the burner of the heat exchanger when the difference from the predetermined set temperature is equal to or higher than a predetermined reference value,
Further, f) a hot water supply apparatus with an immediate hot water function, which is provided with reference value changing means for increasing the above reference value when the fan is operated for a predetermined time in a state where water in the circulating water channel is not circulating. 2. A water supply pipe is connected to a position before the circulation water channel enters the heat exchanger, and a hot water outlet is opened to form a water flow from the water supply pipe to the hot water outlet via the heat exchanger. 2. A hot water supply apparatus with an immediate hot water function according to claim 1, further comprising hot water supply control means for detecting this and operating the burner and the fan, wherein the immediate hot water control means stops the immediate hot water pump in this case. 3. The hot water supply system with instant hot water supply function according to claim 1, wherein the hot water supply device main body is provided with a water passage other than the circulating water passage, and the fan is operated even when water in the other water passage is heated. apparatus. 4. A circulating water channel for connecting a) a heat exchanger provided in the main body of the hot water supply device and equipped with a burner and a fan, and b) the heat exchanger and a hot water outlet provided outside the main body of the hot water supply device. And c) a circulating water temperature sensor that detects the temperature of the water in the circulating water channel in the body of the hot water supply device, d) an instant hot water pump provided in the circulating water channel, and e) a temperature detected by the circulating water temperature sensor. In a hot water supply apparatus with an immediate hot water function, which comprises an immediate hot water control means for operating the instant hot water pump and burning the burner of the heat exchanger when the difference from the predetermined set temperature is equal to or higher than a predetermined reference value,
Furthermore, f) an outside air temperature sensor for detecting the temperature of outside air, and g) a reference value changing means for increasing the above reference value when the difference between the outside air temperature and the set temperature is a predetermined value or more. A hot water supply device with an instant hot water function.