JP4069853B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus, and more particularly to a hot water storage type hot water supply apparatus provided with mixing means for hot water and water.

  Conventional water heaters do not supply the water side only through the hot water side of the electric hot / cold water mixing valve due to the pressure loss balance of the piping when water flow detection means such as a flow sensor cannot detect the hot water supply state. A phenomenon may occur, and the temperature of the hot water of the minute amount hot water supply is compared with a predetermined temperature set in advance, and it is determined by comparison that the temperature of the hot water of the minute amount hot water supply exceeds the predetermined temperature set in advance. In this case, the hot water side of the electric hot / cold water mixing valve is controlled to be fully closed. (For example, see Patent Document 1)

JP 2002-71209 A (page 2-8, FIG. 1)

Conventional water heater, when the water flow detecting means such as the flow rate sensor is determined to exceed the predetermined temperature where the temperature is preset Yu small amount hot water supply can not be inspected known hot water supply state, the hot water side of the electric hot and cold water mixing valve Is fully closed. Therefore, even when the faucet is closed slowly, the hot water temperature of the small amount of hot water supply exceeds the preset temperature, and the mixing ratio of the hot water and water of the electric hot water mixing valve is fully closed (water side fully open). Control. When hot water is supplied again in a short time after the hot water supply is stopped, the hot water in the mixed hot water pipe, which will be described later, is first supplied to the faucet etc., and then the water flows to the faucet etc. until the water flow detection means such as the flow sensor detects the hot water supply state. Supplied. When the water flow detection means such as a flow sensor detects the hot water supply state, the mixing ratio of hot water and water in the electric hot / cold water mixing valve is controlled, and hot water at a set temperature is supplied to the faucet or the like. Thus, the hot water supply from the faucet becomes hot water → water → hot water, and the hot water temperature falls. In particular, when the temperature of the water of the water source is low, such as in winter, there is a problem that the drop in the hot water supply temperature becomes noticeable and uncomfortable for the user.

  In addition, when the user wants to supply hot water in a very small amount, there is also a problem that only water comes out.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a hot water supply apparatus that can supply hot water of a set temperature even when a small amount of hot water is supplied. And

The hot water supply apparatus according to the present invention comprises a hot water storage tank that heats internal water by a heating means and stores the water as hot water therein, a water supply pipe that sends water from the water source, and a branch from the water supply pipe to supply water to the hot water storage tank. Hot water storage tank water supply pipe to be sent, hot water supply pipe to send hot water stored in the hot water storage tank, mixing means for mixing the water in the water supply pipe and hot water in the hot water supply pipe, and mixed hot water supply to send the mixed hot water from the mixing means A water flow detecting means for detecting the supply and stop of hot water from the presence or absence of hot water flowing through the mixed hot water pipe, a hot water temperature sensor for detecting the temperature of hot water passing through the mixed hot water pipe, and the mixing means And a control unit for controlling the mixing ratio of
When the water flow detecting means detects the supply of hot water passing through the mixed hot water supply pipe, the control section controls the mixing rate of the mixing means according to a set temperature, and the water flow detecting means When the supply stop of hot water passing through the hot water supply pipe is detected, the mixing means is stopped at the mixing ratio of hot water and water when the water flow detection means determines that hot water is not flowing into the mixed hot water supply pipe, The mixing temperature of the mixing unit is controlled according to the set temperature after the temperature sensor detects a temperature equal to or higher than a predetermined temperature .

  The hot water supply apparatus of the present invention is capable of mixing the mixing means immediately even when the detected temperature of the hot water temperature sensor for detecting the temperature of the hot water passing through the mixed hot water pipe exceeds a predetermined temperature when a small amount of hot water is being supplied. Since the mixing rate is controlled according to the set temperature without changing the rate to the hot water side fully closed (water side fully open), even when a small amount of hot water is being supplied, it is possible to supply hot water at the set temperature. Usability is improved.

Embodiment 1 FIG.
FIG. 1 is an overall configuration diagram of a hot water supply apparatus showing Embodiment 1 of the present invention, and FIG. 2 is a control flowchart in Embodiment 1 of the present invention.
In FIG. 1, a heating element 2 is provided in the lower part of a hot water tank 1 for storing water and hot water, and heats and heats the water in the hot water tank 1. The boiling temperature sensor 3 is provided on the outer periphery of the lower part of the hot water tank 1 and detects the boiling state of water in the hot water tank 1. The electric hot / cold water mixing valve 4 as a mixing means changes the mixing ratio of hot water and water by electric control to produce mixed hot water at an appropriate temperature.

On the other hand, one end of the hot water supply pipe 5 is connected to the upper part of the hot water storage tank 1, and the other end is connected to the hot water supply port of the electric hot water mixing valve 4 to supply hot water heated in the hot water storage tank 1 to the electric hot water mixing valve 4. To do. One end of the water supply pipe 6 is connected to a water source such as a water pipe, and the other end is connected to a water supply port of the electric hot / cold water mixing valve 4 to supply water from the water source to the electric hot water / water mixing valve 4. The hot water storage tank water supply pipe 7 is branched from the water supply pipe 6 and connected to the lower part of the hot water storage tank 1 to supply water in the hot water supply pipe 6 into the hot water storage tank 1. One end of the mixed hot water supply pipe 8 is connected to the mixed hot water outlet of the electric hot water mixed valve 4 and the other end is connected to a faucet or the like. The pressure reducing valve 9 is attached in the middle of the hot water tank water supply pipe 7 to reduce the water source water pressure to a predetermined pressure.
The hot water supply pipe 5 in the vicinity of the upper part of the hot water tank 1 is provided with a relief valve 10 for releasing (discharging) the hot water in the hot water tank 1 which has undergone volume expansion during boiling. The water flow detection means 11 detects the presence or absence of hot water flowing in the mixed hot water supply pipe 8 to detect hot water supply and hot water supply stop. The hot water temperature sensor 12 is attached to the mixed hot water pipe 8 and detects the temperature of the hot water flowing through the mixed hot water pipe 8 in order to correct the hot water temperature by the electric hot water mixing valve 4.

The control unit 13 that controls the entire hot water supply apparatus includes a determination unit that determines whether a temperature detected by the hot water temperature sensor 12 has reached a predetermined temperature α, which will be described later, a storage unit that stores setting values such as the predetermined temperature α, A timer function and the like are provided, and the heating element 2, the electric hot and cold water mixing valve 4 and the like are controlled based on signals from the boiling temperature sensor 3, the hot water temperature sensor 12, and the water flow detecting means 11.

The operation of the first embodiment configured as described above will be described with reference to FIG.
First, the water sent from the water source to the hot water tank water supply pipe 7 is decompressed by the pressure reducing valve 9 and flows into the hot water tank 1 to keep the hot water tank 1 always full. In this state, when the heating element 2 is energized using, for example, midnight power, the water in the hot water tank 1 is heated. When the boiling temperature sensor 3 detects the boiling temperature set by an operation panel such as a remote controller (not shown), the heating element 2 is deenergized. The hot water in the hot water tank 1 expanded by heating is discharged from the relief valve 10.
When the faucet or the like is opened to supply hot water, the hot water stored in the hot water tank 1 and the water source water pass through the hot water supply pipe 5 and the water supply pipe 6 to the electric hot water mixing valve 4, respectively, where the mixed hot water supply pipe 8 The mixing ratio of hot water and water in the electric hot / cold water mixing valve 4 is controlled so that the temperature detected by the temperature sensor 12 for hot water supply attached to the temperature becomes a set temperature set by an operation panel such as a remote controller (not shown). At this time, whether or not hot water is flowing through the mixed hot water supply pipe 8 is detected by the water flow detection means 11 attached to the mixed hot water supply pipe 8, and the water flow detection means 11 detects the flow of hot water (for example, a flow rate of 1.5 L / min or more). When detected, feedback control is started on the electric hot / cold water mixing valve 4 based on the temperature detected by the hot water supply temperature sensor 12.

Next, the above operation will be described in more detail with reference to the flowchart of FIG.
First, in step S <b> 1, the water flow detection unit 11 determines whether hot water is flowing through the mixed hot water supply pipe 8. Here, when it is determined that the faucet or the like is opened and hot water is flowing into the mixed hot water supply pipe 8, hot water at a set temperature set by an operation panel such as a remote controller (not shown) is supplied to the electric hot water mixing valve 4. The mixing ratio of hot water and water is controlled (step S2). On the other hand, if it is determined in step S1 that no hot water is flowing into the mixed hot water supply pipe 8, the mixing ratio of hot water and water in the electric hot water mixing valve 4 is fully opened and the system is on standby (step S7).

  In step S <b> 3, the water flow detection unit 11 determines whether hot water is not flowing through the mixed hot water supply pipe 8. If it is determined that hot water is flowing, the process returns to step S2. If it is determined that hot water is not flowing, the process proceeds to step S4. In step S4, the electric hot water mixing valve 4 is stopped at the mixing ratio of hot water and water when the water flow detecting means 11 determines that no hot water is flowing into the mixed hot water supply pipe 8. Here, the reason for stopping the mixing ratio of hot water and water in the electric hot water mixing valve 4 while maintaining the mixing ratio when the hot water supply stops is that once the hot water supply is stopped and the hot water is supplied again without taking time, This is so that hot water at a set temperature can be supplied immediately.

In step S5, the temperature detected by the hot water supply temperature sensor 12 attached to the mixed hot water supply pipe 8 is compared with a predetermined temperature α (for example, α = 55 ° C.) set in advance. Here, if detected temperature ≧ predetermined temperature α, hot water at a set temperature set by an operation panel such as a remote controller (not shown) is supplied by controlling the mixing ratio of hot water and water in the electric hot water mixing valve 4. (Step S6)
In the above operation, for example, when hot water is flowing at a minute flow rate at which the water flow detecting means 11 cannot detect whether hot water is flowing through the mixed hot water supply pipe 8, the mixing of hot water and water of the electric hot water mixing valve 4 is performed at step S4. Since the rate is stopped at the mixing rate when hot water supply is stopped, as described above, a phenomenon may occur in which the water side is not supplied only through the hot water side of the electric hot water mixing valve 4 due to the balance of the pressure loss of the piping. However, in such a case, since hot water having a temperature equal to or higher than the set temperature is supplied to the mixed hot water supply pipe 8, the hot water is detected by the hot water temperature sensor 12 in step S5, and the electric hot water mixing valve is used. The hot water of set temperature is supplied by controlling the mixing ratio of hot water and water. If hot water is not flowing through the mixed hot water supply pipe 8 as detected by the water flow detecting means 11, the temperature detected by the hot water temperature sensor 12 in step S5 is equal to or lower than the predetermined temperature α. Then, after the water flow detecting means 11 determines whether or not hot water is flowing into the mixed hot water supply pipe 8, the process proceeds to step S7, where the hot water and water mixing ratio of the electric hot water mixing valve 4 is fully opened and waits.

  According to the hot water supply apparatus shown in the first embodiment that operates as described above, even if the temperature detected by the hot water temperature sensor 12 exceeds a predetermined temperature α during the small amount of hot water supply, the electric hot water mixing valve 4 is immediately turned on. When the temperature detected by the hot water supply temperature sensor 12 is equal to or higher than the predetermined temperature α, the mixing rate of the electric hot / cold water mixing valve 4 is controlled according to the set temperature without the water and water mixing ratio being fully opened. Therefore, even when a very small amount of hot water is supplied, it is possible to supply hot water at a set temperature and provide an easy-to-use hot water supply device.

Embodiment 2. FIG.
In the description of Embodiment 1 above, if the detected temperature of hot water detected by the hot water temperature sensor 12 ≧ predetermined temperature α (for example, 55 ° C.), the mixing ratio of hot water and water in the electric hot water mixing valve 4 is controlled. Thus, hot water at a set temperature is supplied, but this may be performed for a predetermined time (for example, 10 minutes).

FIG. 3 is a flowchart of control in Embodiment 2 of the present invention, and the description of the same parts as those in FIG.
In step S8, the elapsed time t after the water flow detection means 11 determines that no hot water is flowing into the mixed hot water supply pipe 8 is cleared. Next, in step S9, measurement of the elapsed time t is started. In step S10, the measured elapsed time t is compared with the predetermined time T. If t ≧ T, the process proceeds to step S7. Otherwise, the process proceeds to step S5.
By the way, for example, when the faucet is not tightened due to carelessness of the user, or due to a malfunction of the faucet, the water flow detection means 11 has performed a hot water supply at a minute flow rate that cannot be determined that hot water is flowing into the mixed hot water supply pipe 8. In this case, the hot water in the hot water storage tank 1 is continuously used, and eventually the hot water runs out. However, according to the second embodiment, the water flow detection means 11 determines that no hot water is flowing into the mixed hot water supply pipe 8. The elapsed time t was measured, and when the predetermined time T passed, the faucet was not tightened by the user's carelessness by fully opening the water and water mixing ratio of the electric hot water mixing valve 4 to the water side. Even when hot water is supplied at a minute flow rate due to a case or a faucet failure, it is possible to reliably prevent hot water from running out and provide a more convenient hot water supply device.

It is a whole block diagram of the hot water supply apparatus which shows Embodiment 1 of this invention. It is a control flowchart in Embodiment 1 of the hot water supply apparatus. It is a control flowchart in Embodiment 2 of the hot water supply apparatus.

Explanation of symbols

1 Hot water tank 4 Electric hot water mixing valve (mixing means)
8 Mixed hot water supply pipe 11 Water flow detection means 12 Temperature sensor for hot water supply 13 Control unit

Claims (2)

A hot water storage tank that heats internal water by heating means and stores it as hot water, a water supply pipe that sends water from the water source, a hot water tank water supply pipe that branches from this water supply pipe and sends water to the hot water storage tank, A hot water pipe for sending hot water stored in the hot water tank, a mixing means for mixing the water in the water supply pipe and the hot water in the hot water pipe, a mixed hot water pipe for sending the mixed hot water from the mixing means, and this mixed hot water pipe Water flow detecting means for detecting supply and stop of supply of hot water from the presence or absence of flowing hot water, a temperature sensor for hot water supply for detecting the temperature of hot water passing through the mixed hot water supply pipe, and a control unit for controlling the mixing rate of the mixing means And
When the water flow detecting means detects the supply of hot water passing through the mixed hot water supply pipe, the control section controls the mixing rate of the mixing means according to a set temperature, and the water flow detecting means When the supply stop of hot water passing through the hot water supply pipe is detected, the mixing means is stopped at the mixing ratio of hot water and water when the water flow detection means determines that hot water is not flowing into the mixed hot water supply pipe, A hot water supply apparatus that controls the mixing rate of the mixing means according to a set temperature after the temperature sensor detects a temperature equal to or higher than a predetermined temperature . Control of the mixing rate of the mixing means according to a set temperature performed after the hot water temperature sensor detects a predetermined temperature or higher is performed after the water flow detecting means detects a stop of hot water passing through the mixed hot water pipe. The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus is executed only for a period of time.

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