Instant water heater

Abstract

To provide an instant water heater which has a joint between piping 16 and hot water outlet piping 12 such that a hot water inlet pipe 2 and a hot water outlet pipe 3 are integrally manufactured at a joint part of a manual flow regulator 1, where the surrounding area is covered with a material that has elasticity, insulation and low thermal conductivity such as rubber and joined watertightly to an opening of a vacuum-insulated double-walled tank 4, with a heater 5 and a temperature sensor 13 embedded therein.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an instant hot water supply device in a single-pipe water heater. [Background technology]

[0002] In single-pipe water heaters, if the piping is long, when hot water supply is stopped for a while, the water cools down inside the piping, and when hot water supply is restarted, cold water comes out for a while. There are methods to keep the piping warm using ribbon heaters, but this has the problem of consuming a lot of power.

[0003] Traditionally, a method of attaching an instant hot water heater that diverts water from the hot water inlet pipe to the hot water outlet pipe near the faucet at the pipe outlet of a single-pipe hot water heater has been researched in JP 2016-176666 and elsewhere.

[0004] In JP 2016-176666, a switching valve was used to switch between a first path from the water source to the hot water storage tank and a second path from the water heater to the hot water storage tank.

[0005] However, in recent years, single-pipe water heaters can be easily turned on and off using a remote control device, so they can be operated only when used continuously and turned off when used for short periods of time, which may not require a switching valve.

[0006] In the present invention, a method was implemented in which the hot water inlet pipe from the single-pipe hot water heater is branched off with a manual flow rate regulator and mixed at the outlet pipe, and the table in Figure 2 was obtained. The calculation formula in the table in Figure 2 is an approximation, but it generally agreed with the experimental results.

[0007] ▲1▼ is the case where the flow rate of temperature A inside the vacuum insulated double tank flowing out to the outlet pipe and the flow rate of temperature B branched off from the inlet pipe by a manual flow regulator and flowing out to the outlet pipe are ▲1▼1:1, ▲2▼1:0.6, and ▲3▼1:1.5. These results roughly match the experimental results, but when the temperature was 90℃-80℃, the outlet piping was cold so the outlet water dropped in temperature by 5℃-10℃.

[0008] As a result, it was found that when the inlet water temperature is 10°C, the outlet water temperature is most stable when the ratio of the flow rate flowing out of the vacuum insulated double tank at a maximum temperature of 90°C and the flow rate of the inlet water mixed into the outlet pipe via the manual flow regulator is 1:1.

[0009] However, it is believed that the hot water flowing into the vacuum insulated double tank is subjected to hydrodynamic losses due to internal agitation, and when the manual flow regulator was fully open, a temperature change like that shown in ▲3▼ occurred.

[0010] Since the temperature in the piping from the single-pipe water heater to the instant hot water heater changes from 5℃ to 30℃ depending on the air temperature, it was concluded from the results of ▲1▼, ▲2▼, ▲3▼, ▲4▼, ▲5▼, and ▲6▼ that in a method of branching and mixing the hot water from the inlet pipe to the outlet pipe, attaching a manual flow regulator to adjust the temperature of the outlet pipe is one method.

[0011] TIFF2025003908000002.tif8153, manual flow regulator attached, piping length 10m, single pipe water heater temperature 40℃, water temperature inside the piping 10℃. The maximum temperature inside the vacuum insulated double tank was 90℃, and a water faucet was attached to the piping to avoid the influence of water pressure, and the hot water outlet pipe was 1m long.

[0012] Because the instant hot water heater works as an electric storage water heater, hot water can be supplied for a while even if the single-pipe water heater is switched off. When using the water temporarily, such as for washing hands, the single-pipe water heater can be switched off, and only when using continuously, the single-pipe water heater can be switched on.

[0013] In addition, it can be used as a temporary hot water heater by connecting the water pipe to the hot water supply pipe of a faucet such as a toilet that does not have a hot water supply pipe, and can be easily connected to an existing faucet. If the faucet is not a mixer faucet, the temperature in the vacuum insulated double tank may be adjusted with a temperature controller. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] JP 2016-176666 A Summary of the Invention [Problem to be solved by the invention]

[0015] The problem to be solved by the present invention is to supply hot water only during continuous use by turning on the remote control switch 10 of the single-pipe water heater 7, and to supply hot water by using the hot water in the vacuum insulated double tank 4 by turning off the remote control switch 10 of the single-pipe water heater 7 during normal intermittent use, thereby saving fuel for the single-pipe water heater 7, reducing the load on the single-pipe water heater 7, and to easily produce a device that quickly produces hot water both during continuous use and intermittent use in order to supply hot water at an appropriate temperature according to the type of faucet 8 and the length of the piping 16. A manual flow regulator 1 is placed in the path that branches from the hot water inlet pipe 2 to the hot water outlet pipe 3 to adjust the branched flow rate, and the hot water in the vacuum insulated double tank 4 is kept warm and heated by the action of the heater 5, temperature sensor 13, and temperature controller 9, and appropriate hot water is supplied depending on the type of faucet 8. In addition, the vacuum insulated double tank 4 is intended to improve heat retention. [Means for solving the problem]

[0016] Any valve that can adjust the flow rate appropriately will do, but for example, a manual flow regulator 1 such as a needle valve is connected to a joint where the hot water inlet pipe 2 and hot water outlet pipe 3 are manufactured, and a joint between the piping 16 and the hot water outlet pipe 12 is created. The surrounding area is covered with a stretchy, insulating material with low thermal conductivity such as rubber, and this is joined to the opening of the vacuum insulated double tank 4 so as to be watertight, and a lid unit 11 with a heater 5 and temperature sensor 13 embedded is manufactured.

[0017] The heater 5 and temperature sensor 13 are wired to a temperature controller 9, equipped with a power switch, and connected to an electrical outlet.

[0018] Water pipe 17 may pass through single-pipe water heater 7 and be connected to hot water inlet pipe 2 via pipe 16, or may be connected directly to hot water inlet pipe 2. Hot water discharged from hot water outlet pipe 3 may be passed through hot water outlet pipe 12 to a faucet 8 such as a mixer faucet, or a faucet 8 may be installed on piping 16.

[0019] In order to absorb volume changes caused by expansion and contraction due to temperature changes in the vacuum insulated double tank 4, a hollow body 6 made of an elastic material is placed in the vacuum insulated double tank 4. Effect of the Invention

[0020] The table in Figure 2 shows that the outlet hot water temperature changes depending on the mixing ratio of the hot water branched off from the hot water inlet pipe 2 and the hot water discharged from the vacuum insulated double tank 4, due to the adjustment action of the manual flow regulator 1 in this invention.

[0021] If a thermostatic mixer faucet is used as faucet 8, since the mixer faucet has a temperature adjustment function, the manual flow regulator 1 can be adjusted by decreasing the mixing ratio as shown in ▲2▼ in the table. If a lever-type mixer faucet used in a washroom or kitchen is used as faucet 8, and some temperature drop can be tolerated, a larger mixing ratio can be used as shown in ▲3▼ to increase the amount of hot water. Also, if the piping 16 is short, the mixing ratio can be increased as shown in ▲1▼~▲3▼, and the set temperature of the vacuum insulated double tank 4 can be adjusted with the temperature controller 9.

[0022] In places where there is no piping 16, such as in a bathroom washbasin, the water supply pipe 17 can be connected to the hot water inlet pipe 2 and used as a hot water heater immediately. In this case, even if the faucet 8 is not a mixer faucet, the mixing ratio can be adjusted to ▲1▼~▲3▼. In addition, the temperature can be adjusted to the appropriate level using a temperature controller 9 or the like.

[0023] Measurements were taken under conditions of a set temperature of 40°C for the single pipe water heater 7, an initial temperature of 10°C inside the pipe 16, and a temperature setting of 90°C inside the vacuum insulated double tank 4. Figure 2 is a table showing the measurements and calculations of the temperature inside the pipe 16, the terminal outlet temperature of the hot water outlet pipe 12, and the temperature inside the vacuum insulated double tank 4. By adjusting the flow rate with the manual flow regulator 1, the measurement results were almost consistent with the approximation formula in Figure 2. However, when the vacuum insulated double tank 4 was at 90°C-80°C, the hot water outlet pipe 12 was cold, resulting in a temperature drop of 5°C-10°C compared to the approximation formula.

[0024] In order to avoid the influence of water pressure on the vacuum insulated double tank 4, the water faucet 8 is installed on the hot water supply pipe 2 side and the vacuum is cut off. TIFF2025003908000003.tif8150

[0025] For example, in the formula, A+B, A represents the amount of hot water discharged at the temperature inside the vacuum insulated double tank 4 at temperature A, and B represents the amount of hot water entering the hot water outlet pipe 3 from the manual flow regulator 1 at the temperature of the hot water inlet pipe 2 at temperature B. These are approximate formulas measured with ▲1▼1:1, ▲2▼1:0.6, and ▲3▼1:1.5.

[0026] By adjusting the manual flow regulator 1 and the temperature controller 9, appropriate hot water can be provided in response to the characteristics of the type of faucet 8, changes in use, changes in the length of the piping 16, changes in hot water temperature due to seasonal changes, etc. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is an explanatory diagram of the present invention. [Diagram 2] FIG. 2 is a table showing temperature changes according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] This instant hot water heater is characterized in that the manual flow regulator 1 is integrally made of resin or metal at the joints between the hot water inlet pipe 2, the hot water outlet pipe 3, the piping 16, and the hot water outlet piping 12, and is covered with a stretchy, insulating material with low thermal conductivity such as rubber, and is treated to be watertight with the opening of the vacuum insulated double tank 4, and a heater 5, a temperature sensor 13, or a heater with a temperature sensor, etc. are attached in an insulated state to form a lid unit 11. EXAMPLES

[0029] Fig. 1 is an explanatory diagram of one embodiment of the present invention, showing an example in which a mixer faucet is attached as a water faucet 8 to the top of the hot water outlet pipe 3. The manual flow regulator 1, hot water inlet pipe 2, and hot water outlet pipe 3 are integrally molded, the heater 5 and the power source for the temperature sensor 13 are embedded in silicon rubber around them, and the opening of the vacuum insulated double tank 4 is made watertight to form a lid unit 11.

[0030] The lid unit 11 can be used with vacuum insulated double tanks 4 of different capacities as long as the openings of the vacuum insulated double tanks 4 are the same. Also, when the water faucet 8 is installed on the hot water outlet pipe 12, the inner bottle 14 and the lid unit 11 must be able to withstand the water pressure, but this is not the case for the outer bottle 15.

[0031] From the table in Figure 2 and the measurement results, it can be seen that when A the maximum set temperature inside the vacuum insulated double tank 1 is 90°C, B the temperature inside the pipe 16 is 10°C, and the set temperature of the single-pipe water heater 7 is 40°C, a flow rate ratio of 1:1 is most stable, so there is no need to finely adjust the manual flow regulator 1, but depending on the type of faucet 8, the purpose, the length of the pipe 16, and the temperature inside the pipe 16, it may be better to adjust the temperature using the flow rate ratio of the manual flow regulator 1 or the temperature controller 9, but if the faucet 8 is a thermostatic mixing faucet, it is only necessary to set the appropriate value once.

[0032] When using hot water for hand washing etc. with faucet 8 without a mixer faucet, it is possible to expose only the temperature controller 9 and set the manual flow regulator 1 to an appropriate value and bury it together with the hot water heater. When faucet 8 is a thermostatic mixer faucet such as a bath faucet, the mixer faucet itself has a temperature adjustment mechanism, so the manual flow regulator 1 and temperature controller 9 can be set to appropriate values ​​and buried.

[0033] The piping connected to the hot water inlet pipe 2 can be a pipe 16 connected to a single-pipe water heater 7 as well as a water supply pipe 17, allowing it to be used temporarily.

[0034] The results of Tables ▲1▼ and ▲2▼ in Figure 2 show that when hot water from the single-pipe water heater 7 reaches the hot water inlet pipe 2, even if the circuit of the vacuum insulated double tank 4 where the hot water is mixed in the hot water outlet pipe 3 by the hot water inlet pipe 2 and the manual flow regulator 1 is not closed, there will be no drop in temperature as long as the amount of hot water in the vacuum insulated double tank 4 is greater than the amount of cold and hot water in the piping 16.

[0035] Therefore, if the length of the piping 16 is long, the problem can be solved by increasing the capacity of the vacuum insulated double tank 4 or by using two or more hot water heaters in series.

[0036] When the water faucet 8 is placed on the hot water outlet pipe 12, water pressure is applied when the faucet is closed, and at the same time, volume changes due to temperature changes occur in the vacuum insulated double tank 4 and the hot water outlet pipe 12, etc., so an elastic hollow body 6 is placed in the vacuum insulated double tank 4 to absorb this volume change. [Explanation of symbols]

[0037] 1 Manual flow regulator 2. Hot water pipe 3. Hot water pipe 4. Vacuum insulated double tank 5. Heater 6 hollow body 7 Single-pipe water heater 8 Faucet 9 Temperature Controller 10 Remote control device 11 Lid unit 12 Hot water outlet piping 13 Temperature Sensor 14 Inner bottle 15 Outer bottle 16 Piping 17 Water piping

Claims

1. In a method of attaching an instantaneous hot water heater to the pipe 16 of a single-pipe hot water heater 7, the joint of the manual flow regulator 1 attached to the path branching from the hot water inlet pipe 2 to the hot water outlet pipe 3 is manufactured as an integral structure with the hot water inlet pipe 2 and the hot water outlet pipe 3, processed to have a joint between the pipe 16 and the hot water outlet pipe 12, and covered with a material having elasticity and low thermal conductivity so as to be watertight with the opening of the vacuum insulated double tank 4, and a heater 5 and a temperature sensor 13 or a heater with a temperature sensor are attached to the covering body,

2. 2. An instant hot water heater according to claim 1, wherein an expandable hollow body is installed in a vacuum insulated double tank.

Images