JPH03267632A - Instant hot water supply device - Google Patents

Abstract

PURPOSE:To make it possible to prepare for the next instant hot water supply even at the time of usage of cold water only by a method wherein a by-pass, which connects a hot water entering passage from a main hot water supply device for a hot water storage tank and a water supply passage to a faucet of a cold water source, is provided, and a thermo-valve, which switches over passages in response to a temperature of entering water from the by-pass, is provided. CONSTITUTION:At the beginning of a hot water releasing from a faucet 2, since the temperature of remaining water in a piping from a hot water supply piping 3 to a by-pass 14 is not higher than a set temperature, a thermo-valve 15 is opened to the by-pass side 14. Throw-away water until the time when remaining water in the hot water piping 3 of a main hot water supply device 1 and the main hot water supply device 1 are raised to a set temperature is divided and flows to a hot water storage tank 5 and the by-pass 14, and it is used for two purposes to push hot water in the hot water storage tank 5 and as cold water for mixing at the faucet 2. Since it is used for both hot water side and cold water side, discharging of the remaining water and throw-away water can be performed in a short period of time. Also, when an intermittent hot water releasing from the faucet 2 is done by a small quantity, a total flow rate of a flow rate for the path to reach the faucet 2 through the hot water storage tank 5 and a flow rate for the passage to reach the faucet 2 through the by-pass 14 is made to pass through a heat exchanger 3 of the main hot water supply device 1.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to hot water supply equipment, such as central water heating equipment, where faucets such as vanities and sinks are installed far away from the main water heater. The present invention relates to an instant hot water supply device for auxiliary heating that is applied.

[Conventional technology]

In hot water equipment where the faucet is located far away from the main water heater, a large amount of cold water remaining in the long piping is discharged when the faucet initially starts discharging hot water, until hot water at the desired temperature comes out. It takes time.

Additionally, if the main water heater is a once-through type, it takes time to drain the waste water. Therefore, there is a demand for adding a device that can instantly supply hot water, and there is a very high demand for instant hot water supply for bathroom vanities and the like.

Methods of instant hot water supply systems include a hot water circulation method that constantly circulates hot water through the pipes, a disposal hydraulic method that disposes of the remaining water in the pipes through a route separate from the faucet, and a small water heater installed near the terminal faucet for auxiliary heating. There are methods such as installing an electric water heater. For bathroom vanities, the main method is to install an electric water heater in view of ease of installation and equipment costs, and various companies have announced small electric water heaters for instant hot water supply.

Examples of such electric water heaters include the example shown in Gf Fig. 5 and the example shown in Fig. 6fI! There is an example shown in J.

In the example shown in FIG. 5, a hot water supply pipe 53 connecting a main water heater 51 and a faucet 52 has a hot water storage tank 55 of an electric water heater 58 in the vicinity of the faucet 52, and a branch that bypasses the hot water storage tank 55. A passage 53A is provided in the hot water supply pipe 53. The hot water storage tank 55 has an electric heater 54 built therein. The faucet 52 is a faucet that can freely mix hot and cold water, and is connected to city water through a water supply channel 59. The heating temperature of the main water heater 51 is set to 40 to 50°C, which is close to the operating temperature, and the heating temperature of the electric water heater 58 is set to about 80°C, which is higher than this.

In the case of this configuration, the high temperature hot water from the electric water heater 58 is mixed with the remaining water in the hot water supply piping 53 and supplied to the faucet 52 at the initial stage of hot water supply, so that hot water is immediately supplied.

The example in FIG. 6 shows the hot water outlet passage 57 of the hot water storage tank 55 and the
9 are merged with the branch passage 59A at a mixing valve 60, and connected to the hot water inlet side of the faucet 52. The heating temperature of the main water heater 51 is set to a high temperature of about 80°C, and the mixing valve 60 mixes the water with cold water from the water supply channel 59 to the faucet 52.
supply hot water inlet. The heating temperature of the hot water storage tank 55 is also 8
It is set to about 0'C.

In this example, at the beginning of hot water supply, the hot water supply pipe 53 of the main water heater 51
The remaining water is used to push up the hot water in the hot water storage tank 55,
High temperature hot water from the hot water storage tank 55 is supplied.

[Problem to be solved by the invention]

In the conventional example shown in FIG. 5, the temperature of hot water discharged from the hot water storage tank 55, which is set at a higher temperature than the main water heater 51, fluctuates depending on the discharge flow rate and is not constant, so the temperature of hot water discharged from the faucet 52 fluctuates. is large. Therefore, it is not convenient to use unless a thermostatic faucet is used as the faucet 52.

In the conventional example shown in FIG. 6, from the main water heater 51 to the hot water storage tank 55
The remainder of the hot water supply piping 53 up to this point and the cold water used as waste water until the main water heater 51 starts up are all supplied to the hot water inlet side of the faucet 52 via the hot water storage tank 55. Therefore, after the hot water in the small-capacity hot water storage tank 55 runs out, the faucet 5
Cold water is discharged from 2, and the temperature of the hot water drops during use, making it difficult to use. Moreover, since all of the waste water and the like flows into the hot water storage tank 55, the operating rate of the electric heater 54 becomes high and the operating cost increases.

Note that, as in the conventional example shown in FIG.
In the electric water heater of the type A, a throttle valve and an on-off valve (not shown) are provided in the water supply channel 59 and the hot water inlet of the hot water storage tank 55, respectively, and when the hot water temperature in the hot water pipe 53 is low, Branch path 5 with the throttle valve and on-off valve fully closed.
It has been proposed to open only 3A (Japanese Unexamined Patent Application Publication No. 6
1-237929). According to this, the remaining water and waste water at the initial stage of hot water discharging can be discharged somewhat quickly.

However, since the configuration is not such that the remaining water is used as cold water to be supplied to the faucet 52, but the remaining water is discharged from the hot water path side, the remaining water and waste water cannot be discharged in a sufficiently short time. Moreover, since two valves, a throttle valve and an on-off valve, are required as valves that respond to the water temperature, the structure becomes complicated.

The purpose of this invention is to drain the remaining water in the pipes and the waste water until the main water heater starts up in a short time, to minimize fluctuations in the hot water temperature, and to prepare for the next immediate hot water supply even when only water is used. An object of the present invention is to provide an instant hot water supply device with a simple structure.

[Means to solve the problem]

The present invention provides an instant hot water supply system in which hot water is stored in a hot water storage tank equipped with a heating device for an auxiliary water heater, in which a hot water inlet path from a main water heater in the hot water storage tank is connected to a water supply path to a faucet of a cold water source. A bypass path is provided, and a thermovalve is provided at the connection between the bypass path and the water supply channel to switch the flow path in response to the temperature of water entering from the bypass path.

The thermovalve is switched such that when the temperature is higher than a predetermined temperature, the upstream portion of the water supply channel is opened, and when the temperature is lower than a predetermined temperature, the bypass path is opened to the faucet side.

[For production]

At the beginning of hot water supply from the faucet, the water temperature in the hot water piping of the main water heater is low, so the thermo valve opens to the bypass path side, and the remaining water in the piping from the main water heater to the auxiliary water heater and the main water heater The water discarded until the start of operation is used both to push up the hot water in the auxiliary water heater's hot water storage tank and to produce cold water for mixing at the faucet. Since the water is discharged through these two systems, residual water, etc., can be discharged quickly.

When the main water heater starts up and the temperature of the water in the bypass passage reaches a predetermined temperature or higher, the thermovalve switches to the water supply channel side, and all hot water from the main water heater flows into the hot water storage tank.

When the water faucet is used only for water and the water in the bypass path is low temperature, the thermo valve works to drain the remaining water and waste water from the main water heater until hot water reaches the specified temperature. supplied to the stopper.

Therefore, the water in the pipes from the main water heater to the auxiliary water heater is replaced with hot water, and preparations are made for immediate hot water supply the next time the hot water is tapped.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 and 2.

The main water heater 1 is a once-through type equipped with a fin-tube heat exchanger 13 and a burner 12, and the heat exchanger 13 is connected at both ends to the city water supply pipe 11 and the hot water supply pipe 3. There is. The burner I2 is equipped with a control device (not shown) that ignites and extinguishes the burner depending on the amount of water passing through it. Main water heater 1
The outlet temperature of the hot water is adjusted to, for example, 80°C.

A faucet 2 and an instant hot water supply device A are installed on a washstand (not shown) separate from the main water heater I.

The auxiliary water heater 8 of the instant hot water supply device A has an electric heater 4, which is a heating device, built into the bottom of a hot water storage tank 5.

The electric heater 4 is turned on and off by an appropriate control means so that the temperature of the hot water in the hot water tank 5 reaches a set temperature (for example, 80° C.).

A hot water inlet passage 6 at the lower part of the hot water storage tank 5 is connected to the hot water supply pipe 3 of the main water heater l, and a hot water outlet passage 7 at the upper part is connected to the faucet 2.

The faucet 2 has two valve handles 2 for hot water supply and water supply.
A, 2B is a freely mixing hot water faucet, in which a water supply channel 9 consisting of piping connected to a cold water source such as city water and the hot water outlet path 7 are connected to the water side and hot water side inlets, respectively.

A bypass path 14 branches off from the hot water inlet path 6 of the hot water storage tank 5, and is connected to a portion of the water supply path 9 near the faucet 2 by a thermovalve 15. The thermovalve 15 is a three-way valve that switches in response to the temperature of the water entering from the bypass passage 14, and when the temperature of the water entering is higher than a predetermined temperature, the upstream portion 9A of the water supply channel 9 is switched, and when the temperature is lower than the predetermined temperature. In this state, the bypass paths 14 are respectively opened to the faucet 2 side. The predetermined temperature is set, for example, to 25 to 30°C. Thermo valve 1
5 may be a device that mechanically switches the flow direction in response to the inlet water temperature using a thermal expansion element, or a solenoid valve that switches the flow direction in response to a detection signal from a temperature detector provided in the bypass path 14. good.

The operation of the above configuration will be explained with reference to FIG.

At the initial stage of hot water discharging from the faucet 2, the temperature of the water remaining in the piping from the hot water supply piping 3 to the bypass passage 14 is below the set temperature.
It is open on the side. Therefore, the hot water supply pipe 3 of the main water heater 1
The remaining water in the tank and the waste water until the main water heater l reaches the set temperature are divided into the hot water storage tank 5 and the bypass passage 14, as shown by diagonal lines in FIG. It is used for both pushing up the hot water inside and mixing cold water for the faucet 2. In this way, since it is used for both the hot water side and the water side, the remaining water and waste water can be discharged in a short time.

Also, when discharging hot water in small amounts intermittently from the faucet 2, the total flow rate of the flow rate Q1 of the route leading to the faucet 2 via the hot water storage tank 5 and the flow rate Q2 of the route leading to the faucet 2 via the bypass path 14. Qt will pass through the heat exchanger 3 of the main water heater 1. Therefore, the number of cases in which the burner 12 of the main water heater 1 does not ignite due to insufficient flow rate is reduced. That is, the sixth
In the conventional example shown in the figure, in the case of a small amount of intermittent use, the flow rate on the hot water side is throttled and the flow rate passing through the main water heater 51 is reduced, and the main water heater 51 often does not ignite. Problems like this will be resolved.

Main water heater 1 is starting up with slightly low-temperature water (25-30℃)
) flows into the bypass passage 14, the thermovalve 15 is activated and the water is switched to the upstream portion 9A side of the water supply channel 9 (FIG. 2(B)). When the main water heater l is fully started up,
All of the hot water from the main water heater 1 flows into the hot water storage tank 5, and while mixing with the cold water in the hot water storage tank 5, the cold water is discharged from the hot water storage tank 5 via the hot water outlet path 7. The cold water that is discharged is mixed with hot water, so it reaches a certain temperature. Therefore, after the hot water stored in the hot water storage tank 5 is dispensed, the temperature of the hot water dispensed from the faucet 2 does not drop significantly. After the cold water in the hot water storage tank 5 is completely drained, the hot water temperature in the hot water storage tank 5 reaches the set temperature due to the inflow of high temperature water from the main water heater 1, so the electric heater 4 is turned off and the main water heater 1 is turned off. Only 1 is in operation.

If the discharge of cold water from the hot water storage tank 5 is insufficient, the temperature inside the hot water storage tank 5 will drop significantly, the operating rate of the electric heater 4 will increase, and the fluctuation in the hot water temperature during hot water tap will also increase. However, with this configuration, much of the remaining water and waste water flows into the bypass path 1.
4 side, the temperature drop in the hot water storage tank 5 is suppressed to a small level, and fluctuations in the outlet temperature are small. Therefore, the operation rate of the electric heater 4, which is easy to use and has a high energy cost, is reduced, and the operating cost can be reduced. For example, the heating setting temperature of the hot water storage tank 5 is 80°C, and the inlet water temperature is 10°C.
If the outlet temperature is 40° C., the flow rate ratio between the hot water storage tank 5 and the bypass path 14 is 4:6, and more than half of the waste water flows through the bypass path 14 side.

When only water is used, that is, when only the valve handle 2B on the water side of the faucet 2 is opened, unless the hot water is used immediately, the water in the bypass passage 14 is at a low temperature, so the thermo-valve 15 is not in the bypass passage. It opens on the 14th side. Therefore, as mentioned above, until the hot water comes at a slightly lower temperature,
), as shown by diagonal lines, there is residual water in the hot water supply pipe 3 and the main water heater 1.
Discarded water until the start of water is supplied to the faucet 2, and the water in the hot water supply pipe 3 is replaced with hot water dispensed from the main water heater 1. Therefore, preparations are made for instant hot water supply at the time of next hot water supply, and instant hot water supply performance is improved.

In this way, this instant hot water supply device 1 [A is the bypass path 1
4 and one thermovalve 15, the instant hot water supply performance can be improved and the hot water temperature can be stabilized. In addition, since the temperature of the water supplied to the faucet 2 is approximately constant as described above, the normal valve handle 2A,
Good usability can be obtained by using the adjustable type water faucet 2 according to 2B. Therefore, the type of faucet 2 can be freely selected.

FIG. 3 shows another embodiment of the invention. In this example, a mixing valve IO is provided that lowers the temperature of hot water in a hot water outlet path 7 of a hot water storage tank 5 with cold water in a water supply channel 9, and a bypass path I4 is connected to a portion of the water supply channel 9 for mixing by a thermovalve 15. This is what I did. The cold water inlet of the water faucet 2 is connected to a branch path 9C of the water supply channel 9. In the case of this structure as well, effects such as rapid discharge of waste water and stabilization of the hot water temperature can be obtained as in the above-mentioned embodiment.

FIG. 4 shows yet another embodiment. This example uses a single/one-handle faucet 16 equipped with a mixing valve 10. With this configuration as well, the same effects as described above can be obtained.

The combination of faucet 2 and mixing valve lO in Fig. 3, and the faucet 16 with mixing valve lO in Fig. 4, can be replaced with an electronic buzzer or thermostatic faucet, which will further improve usability. I can figure it out.

In each of the above embodiments, the case where the main water heater 1 is a once-through type has been described, but this instant hot water supply device A can also be used when the main water heater 1 is a hot water storage type boiler, a solar water heater, etc. can also be used.

Even in that case, it is effective when the hot water supply piping 3 is long. Further, the present invention can be effectively applied not only to washstands but also to kitchen sinks and the like where instant hot water supply methods such as a waste water type cannot be adopted.

〔Effect of the invention〕

The instant hot water supply device of the present invention is provided with a bypass path that connects the hot water inlet path of the hot water storage tank in the auxiliary water heater and the water supply path to the faucet, and the connection part between the bypass path and the water supply path is configured to respond to the temperature of the incoming water. Since the system is equipped with a thermo-valve that opens the bypass path when the water temperature is low, when the faucet starts discharging hot water, either the residual water in the pipes and the waste water until the main water heater starts up, or the water from the auxiliary water heater's hot water storage tank. The water flows into the bypass passage and is used both to push up the hot water in the hot water storage tank and to provide cold water for mixing at the faucet. Therefore, the remaining water and waste water can be discharged in a short time, and hot water at the set temperature can be immediately supplied.

In addition, since most of the remaining water and waste water flows through the bypass path, the drop in temperature within the hot water storage tank is kept to a small level, and fluctuations in the hot water temperature are minimized. Therefore, it is easy to use, and the operating rate of the heating device of the auxiliary water heater is reduced, reducing operating costs.

Moreover, even when only water is used, leftover water and waste water are supplied from the bypass path to the faucet, and the water in the hot water supply piping from the main water heater to the auxiliary water heater is replaced with hot water. Therefore, preparations are made for instant hot water supply the next time hot water is dispensed, and instant hot water supply performance is further improved.

Furthermore, since it is only necessary to add a bypass path and one thermovalve to the auxiliary water heater, the structure is simple.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, and FIG. 2 (A
) to (C) are diagrams for explaining the operation, FIGS. 3 and 4 are diagrams for explaining the configuration of other embodiments of the present invention, and FIGS. 5 and 6 are diagrams for explaining the configuration of the conventional example. ■...Main water heater, 2...Water faucet, 3...Hot water supply piping,
4... Electric heater (heating device), 5... Hot water storage tank,
6... Hot water inlet path, 7... Hot water outlet path, 8... Auxiliary water heater, 9... Supply channel, 9A... Upstream part, 12... Burner, 13... Heat exchanger, 14...Bypass road, 15
-・Thermo valve, 16... Faucet, A... Instant hot water supply device Fig. 1

Claims (1)

[Claims] The inlet and outlet channels of a hot water storage tank equipped with a heating device are branched from the inlet channel to an auxiliary water heater connected to a main water heater and a faucet, respectively, and a cold water source water supply channel connected to the faucet. Provided at a connection between a connected bypass path and the water supply channel of this bypass path, the upstream portion of the water supply channel responds to the temperature of the incoming water from the bypass channel, and when the temperature is higher than a predetermined temperature, the upstream portion of the water supply channel An instant hot water supply device comprising: a thermo valve that switches to a switching state in which each of the bypass paths opens to the faucet side when the temperature is low.