JPH02225942A - Instantaneous hot-water heater - Google Patents

Abstract

PURPOSE:To raise hot-water temperature in a short time in a water flowing system passing through a heat exchanger of a hot-water heater by providing a variable volume insulated hot-water storing part on the downstream side of the heat exchanger, and providing an electric heater to the insulated hot-water storing part. CONSTITUTION:In a flowing water system 2 passing through a heat exchanger 1 of a hot-water heater, a variable volume insulated hot-water storing part 3 is constructed on the downstream side of the heat exchanger 1. The part 3 is increased in volume against returning means 4 owing to the rise of the pressure of the hot-water stored therein while being reduced in volume by the returning means 4 upon the lowering of the pressure of the hot-water therein. Additionally, an electric heater 5 is provided on the insulated hot-water storing part 3. Herein, desired temperature hot-water is available is a short period of time after the supply of the hot-water is started.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an instantaneous water heater.

(Prior art) For example, in a conventional ordinary instantaneous water heater as shown in Fig. 5, water is started to flow by opening the faucet at outlet a, and the water flow is started by opening the faucet at outlet a. When the water flow switch or flow rate sensor C detects water flow above a predetermined level, the burner d starts combustion and heats the heat exchanger (weapon e). After that, it reaches outlet a,
The hot spring water comes from here. Note that symbols f and M are temperature detection means such as thermistors, g is a check valve, and h is a flow rate regulating valve.

(Problem B to be solved by the invention) In this way, in the conventional instantaneous water heater, after water flow is started and a flow of water exceeding a predetermined level is detected, the burner d starts combustion and heat exchanger e is heated. Immediately after the start of water flow, residual water in the water flow system that has not been heated at all is discharged, and then gradually heated hot water is discharged. Therefore, as shown by the broken line in FIG. 4, it takes a relatively long time, such as a predetermined time tI, for example, several IO seconds, from the start of water flow until hot water at the desired operating temperature is obtained.

The present invention aims to solve this problem.

(Means for Solving the Problems) The configuration of the present invention will be explained with reference to FIGS. 1 to 4 corresponding to embodiments. In the water flow system 2 passing through the heat exchanger 1, a volume-variable thermal hot water storage section 3 is configured downstream of the heat exchanger 1.
has a structure in which the volume increases against the return means 4 as the pressure of the internal hot water rises, and the volume is decreased by the return means 4 when the pressure of the internal hot water decreases, and an electric heater 5 is installed in the hot water storage section 3. It has been established.

(Actions and Examples) Next, the operation of the present invention will be explained with reference to illustrated embodiments.

First, as shown in the construction drawing Cb), when hot water is being supplied, the volume of the hot water storage section 3 is reduced as will be described later, and hot water cannot be supplied in the same way as a conventional instantaneous water heater. can. In this state, when hot water supply is stopped by closing the hot water outlet 6, water pressure from a water supply or the like connected to the water supply lower is applied to the hot water storage section 3, and the pressure increases. Due to this pressure increase, the volume of the heat-retaining hot water storage section 3 increases against the return means 4, and hot water from the upstream side flows into the hot water storage section 3. In this way, a predetermined amount of hot water can be stored in the heated hot water storage section 3 whose volume has been increased as shown in FIG. The temperature can be raised to a desired degree, and thus hot water heated to a predetermined temperature can be stored without cooling the hot water in the hot water storage section 3.

In this state, when the hot water outlet 6 is opened to start tapping, the water remaining in the piping on the downstream side of the hot water storage section 3 is first discharged from the hot water outlet 6, and then the water is discharged into the hot water storage section 3. The stored hot water is discharged.

At the same time as the hot water is discharged, residual water in the piping on the upstream side flows into the hot water storage section 3 and mixes with the hot water inside. On the other hand, when a water flow switch (not shown) installed at an appropriate location detects water flowing through the water system 2 due to the start of hot water dispensing, the burner 8
starts combustion, the temperature in the heat exchanger 1 starts to rise, and the temperature in the heat exchanger 1 starts to rise.

As described above, in the present invention, when the hot water outlet 6 is opened to start tapping, the residual water in the piping on the downstream side of the thermal hot water storage section 3 is first discharged for a short time, but after that, the water remaining in the piping on the downstream side of the thermal hot water storage section 3 is discharged. 3
Since the hot water stored inside is discharged, hot water at a predetermined temperature or a temperature close to it can be used within a short time t, as shown in FIG. As mentioned above, until the burner 8 starts combustion and heats the heat exchanger 1 and hot water at a predetermined temperature is obtained in the heat exchanger 1, there is no water in the hot water storage section 3. Residual water in the piping on the upstream side flows in, but this residual water mixes with the hot water in the hot water storage section 3 and is not discharged as is. Since a large amount of hot water can be stored, although the temperature of the hot water coming out from the hot water outlet 6 decreases slightly, the hot water continues to come out at a temperature close to the predetermined temperature.

As described above (when the hot water outlet 6 is opened and hot water is tapped), the pressure of the hot water in the hot water storage section 3 decreases to the back pressure, so the volume of the hot water storage section 3 is As shown in FIG. 3, the amount of hot water in the thermal hot water storage section 3 is gradually reduced by the returning means 4 as the hot water starts to be dispensed, and the amount of hot water in the thermal hot water storage section 3 becomes the minimum.Therefore, in this hot water supply state, the set value of the hot water outlet temperature is changed by the hot water temperature setting device. When the combustion amount of the bath 8 is adjusted by adjusting the combustion amount of the bath 8, the amount of hot water that has been heated to the temperature after the setting change is discharged from the hot water outlet 6 is small, and the responsiveness of the hot water storage section 3 is deteriorated. Extremely small.

Next, a specific example of the control related to the above will be described. First, the control of the burner 8, etc. can be performed appropriately as in the conventional case.

For example, in the water flow system 2, the temperature sensor 9, 10 such as a thermistor provided on the upstream side and the downstream side of the heat exchanger 1, a flow rate sensor 11, a hot water temperature setting device (not shown), etc. The supply of fuel to the burner 8 can be adjusted by feedforward control or feedback control to obtain hot water at a desired set temperature.

Next, on the condition that hot water is not being supplied, the electric heater 5 can be controlled to bring the hot water in the hot water storage section 3 to the set temperature, and can also be controlled as appropriate.

Next, a specific example of the hot water storage section 3 will be described.

First, the thermal hot water storage section 3 shown schematically in FIG. 1 and in detail in FIG. be. The rubber container 12 has a mouthpiece 13 formed by insert molding or the like, and a pipe 15 of the water system 2 is connected to the mouthpiece 13 through a mounting plate 14, and an electric heater 5 is fixed thereto. Although the lower side of the heat-retaining hot water storage section 3 is omitted in the figure, a mouthpiece is also provided on the lower side, thus forming an inflow section and an outflow section for hot water.

Further, the rubber container 12 is housed in a casing 17 in which an air vent hole 16 is formed, and this casing 17 limits expansion of the container 12.

In the above configuration, when water pressure from the water supply is applied when hot water supply is stopped, the rubber container 12 deforms elastically as shown by the solid line in FIG. increase Furthermore, at a pressure comparable to the back pressure during hot water supply, the tube contracts due to its own elasticity and its volume decreases, as shown by the two-dot chain line in FIG.

Even when the rubber container 12 is used in this way, the container 1
2 is not housed in the casing 17, but its own elasticity can be used to balance water pressure and prevent unlimited expansion of the volume. Further, the specific shape of the rubber container 1'2, the method of connection with the piping 15, the configuration of the hot water inlet and outlet, etc., may be determined as appropriate. Also, elastically expandable container 2
can be constructed using bellows in addition to a rubber bag.

As another embodiment of the hot water storage section 3, the one shown in FIG. 3 is constructed of a container 12 provided with a movable partition 18. In the one shown in FIG. 3 (31), the movable partition 18 is a piston, which is biased by a spring 9 to constitute the return means 4. In the one shown in FIG. is a part of a rubber bag, a pressurizing gas such as nitrogen gas is sealed in a chamber 20 constituted by the rubber bag, and the pressure of the pressurizing gas is used as a means 4 for returning the pressure. In place of the spring 19 in Figure 3(a), the piston is biased by the pressure of pressurizing gas, or the rubber bag in Figure 3('h) is replaced with a bellows, etc., so that the hot water storage unit 3 can have the above-mentioned functions. As long as it does, it can be configured as appropriate,
Further, an appropriate method can be applied to keep the heat insulated, such as surrounding it with a heat insulating material.

In the configuration shown in FIG. 1, reference numeral 21 denotes a check valve, and 22 denotes a flow rate adjustment valve to give priority to the set temperature and tap the hot water at a reduced flow rate when the hot water supply load exceeds the capacity of the burner 8. Including these, the specific configuration of the water flow system 2 is appropriate.

(Effects of the Invention) As described above, the present invention configures a heat-retaining hot water storage section with a variable volume on the downstream side of the heat exchanger in a water flow system that passes through a heat exchanger of a water heater, so that when hot water supply is stopped, Since the volume of the thermal hot water storage section is increased and hot water is stored therein, hot water at or close to the desired temperature can be used within a short time after opening the hot water outlet and starting hot water supply. There is an effect.

In addition, the present invention has an electric heater installed in the thermal hot water storage section to raise the temperature of hot water as needed, so that hot water at a sufficient temperature can always be stored even at night in winter. be. Furthermore, since the present invention reduces the volume of the hot water storage section during hot water supply, the deterioration of responsiveness when changing the hot water temperature setting is extremely small, and such changes in the volume of the hot water storage section are caused by changes in water pressure. Since this is done automatically in response to changes, it has the effect of not complicating the control of the water heater as a whole.

[Brief explanation of the drawing]

FIGS. 1(a) and 3(b) are system explanatory diagrams showing the overall configuration and operation of the embodiment of the present invention, and FIGS. 2 and 3(a)
. fbl is an explanatory sectional view showing an example of the specific configuration of the hot water storage unit, FIG. 4 is an explanatory view showing the hot water output characteristics of the present invention and the conventional example, and FIG. 5 is an explanatory diagram of the system of the conventional example. . Code l... Heat exchanger, 2... Water flow system, 3... Hot water storage unit, 4... Return means, 5... Electric heater, 6
... Hot water outlet, 7... Water supply port, 8... Burner, 9,
10...Temperature sensor, 11...Flow rate sensor, 12.
... Container, 13 ... Mouth part, 14 ... Mounting plate, 15
...Piping, 16...Air vent hole, 17...Casing, 18...Movable partition, 19...Spring, 20...
- Chamber, 21... Check valve, 22... Flow 1ffl regulating valve. Figure 2 Figure 3 ((1) Figure 3 (b) Figure 1 ((1) Figure 1 (b,) Figure 4 Figure 5

Claims (6)

[Claims] (1) In a water flow system that passes through a heat exchanger of a water heater, a variable-capacity thermal hot water storage section is configured on the downstream side of the heat exchanger, and the thermal hot water storage section is heated by increasing the pressure of the hot water inside. An instantaneous water heater, characterized in that the volume is increased against the return means, and the volume is decreased by the return means when the pressure of the internal hot water decreases, and an electric heater is provided in the hot water storage section. (2) The instantaneous water heater according to item 1, wherein the hot water storage section is constituted by an elastically expandable container, and the instantaneous water heater uses its own elasticity as a return means. (3) In the instantaneous water heater described in paragraph 1, the hot water storage section is constituted by an elastically expandable container, and uses its own elasticity as a return means, and also limits the expansion of the container. An instantaneous water heater characterized by being housed in a casing. (4) An instantaneous water heater characterized in that the container described in paragraph 2 or 3 is a rubber container. (5) In the instantaneous water heater described in paragraph 1, the hot water storage section is constituted by a container provided with a movable partition, and the movable partition is biased by a spring, and the biasing force of the spring is returned to the container. An instantaneous water heater that is characterized by (6) In the instantaneous water heater described in paragraph 1, the hot water storage section is constituted by one chamber of a container provided with a movable partition, and the other chamber is filled with pressurizing gas, and the pressure of the pressurizing gas is An instantaneous water heater characterized by using as a return means