JP2011185519A - Hot water storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage type water heater capable of carrying out boiling without problems such as stopping of the apparatus even if tapping is stopped and boiling operation is started when there is no hot water left in a hot water storage tank, and capable of supplying hot water suiting respective applications to a plurality of hot-water supply paths without wastefully leaving hot water in the hot water storage tank. <P>SOLUTION: The hot water storage type water heater includes the hot water storage tank 1, a water supply path 2 supplying water to the hot water storage tank 1, a high temperature hot-water supply path 11 directly tapping the hot water of the hot water storage tank, a high temperature side opening and closing valve 13 provided in the middle of the high temperature hot-water supply path 11, a mixing hot-water supply path 10 mixing and tapping the hot water of the hot water storage tank 1 and water supplied from the outside of the hot water storage tank 1, a mixing side opening and closing valve 12 provided in the middle of the mixing hot-water supply path 10, a tank hot water temperature detecting means 14 for detecting a temperature of the hot water in the hot water storage tank 1, and a control means 15 for respectively controlling the high temperature side opening and closing valve 13 and the mixing side opening and closing valve 12 on the basis of the tank hot water temperature. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hot water storage type water heater.

  Hot water heaters that store hot water heated by heating means such as heat pumps in hot water storage tanks, mix hot water extracted from the hot water storage tanks with water as needed, and supply them to hot water terminals such as baths and kitchens are widely used. It is used. The hot water storage tank is always filled with hot water and water, and hot water is stored in the upper layer and water is stored in the lower layer. A water supply path for supplying water from a water source such as a water supply is connected to the lower part of the hot water storage tank. In the boiling operation for heating the water in the hot water storage tank, the water taken out from the lower part of the hot water storage tank is sent to the heating means to make hot water, and the hot water is returned to the upper part of the hot water storage tank.

  In the conventional hot water storage type hot water supply equipment, an open / close means such as an electric expansion valve is provided on the water supply path for supplying water to the hot water storage tank. Normally, this open / close means is kept open, and the hot water in the hot water storage tank is gone. Is detected to shut off the water supply and stop the hot water supply (see, for example, Patent Document 1).

JP 2005-134064 A

  At the time of boiling, dissolved oxygen in the boiled water appears as bubbles due to a decrease in solubility due to an increase in water temperature. In the above-described conventional hot water storage type hot water heater, the hot water supply is stopped after closing the opening and closing means on the water supply path connected to the hot water storage tank, and then the boiling operation is started, but the water supply path is always closed during the boiling. Because it is maintained, the water source water pressure is not applied to the tank. For this reason, the state where the bubbles generated from the dissolved oxygen stay in the upper part of the tank without being successfully discharged from a relief valve or the like provided in the hot water storage tank or bubbles exist in the heating means. As a result, when the hot water supply terminal such as a faucet is opened, hot water mixed with air and water blows out from the hot water supply terminal, or a certain amount of hot water heated by the heating means does not flow, and the temperature of the hot water partially There is a problem that the temperature rises excessively and becomes an abnormally high temperature, the protection means works, and the heating means stops.

  In addition to a mixed hot water supply route that mixes hot water stored in the hot water storage tank with water from the water source and discharges the hot water, a hot water storage device that has a high temperature hot water supply route that directly discharges high temperature hot water stored in the hot water storage tank. In the case of the type hot water supply device, when the opening and closing means on the water supply path for supplying water to the hot water storage tank is closed, the hot water from both the mixed hot water supply path and the high temperature hot water supply path is stopped simultaneously. For this reason, when the timing of stopping the hot water was late, the temperature of the hot water discharged to the hot water supply terminal (for example, the dishwasher) connected to the high temperature hot water supply path was too low, or the timing of stopping the hot water was early. In some cases, the temperature of the hot water supply terminal connected to the high temperature hot water supply path is too low to be used, but there is enough hot water in the hot water storage tank (bathroom, kitchen, etc.) connected to the mixed hot water supply path. In either case, there is a usability problem.

  The present invention has been made in order to solve the above-described problems, and even when the hot water in the hot water storage tank is exhausted and the boiling operation is stopped and the boiling operation is started, there is no problem that the device stops. It is an object of the present invention to provide a hot water storage type water heater that can boil up and supply hot water having a temperature suitable for each application to a plurality of hot water supply paths without wasting hot water in a hot water storage tank. And

  A hot water storage type hot water supply apparatus according to the present invention includes a hot water storage tank for storing hot water heated by a heating means, a water supply path for supplying water to the hot water storage tank, a high temperature hot water supply path for directly discharging hot water taken out of the hot water storage tank, A hot water on-off valve provided in the middle of the hot water supply path, a mixed hot water path for mixing hot water taken out from the hot water storage tank and water supplied from outside the hot water storage tank, and provided in the middle of the mixed hot water supply path A mixing side on-off valve, a tank hot water temperature detecting means for detecting the temperature of the hot water in the hot water storage tank, and a high temperature side opening / closing valve and a mixing side on / off valve based on the hot water in the tank detected by the tank hot water temperature detecting means And control means for controlling each of the above.

  According to the present invention, even when the hot water is stopped and the boiling operation is started when the hot water in the hot water storage tank is exhausted, the boiling operation can be performed without problems such as the equipment being stopped. Moreover, hot water having a temperature suitable for each application can be supplied to a plurality of hot water supply paths without wasting hot water in the hot water storage tank.

It is a block diagram which shows Embodiment 1 of the hot water storage type water heater of this invention. It is a flowchart which shows the control action in Embodiment 1 of this invention.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing Embodiment 1 of a hot water storage type water heater of the present invention.

  As shown in FIG. 1, the hot water storage tank unit 100 includes a hot water storage tank 1 for storing hot water heated by a heating means 5 such as a heat pump. A water supply pipe 2 for supplying water from a water source such as a water supply is connected to the lower part of the hot water storage tank 1. Water is supplied into the hot water storage tank 1 through the water supply pipe 2. The hot water storage tank 1 is always kept full of upper water and lower water.

  During the boiling operation, the water in the hot water storage tank 1 passes through the incoming water pipe 3 connected to the lower part of the hot water storage tank 1 and is conveyed to the heating means 5 by the circulation pump 4 installed on the incoming water pipe 3. The water heated by the heating means 5 becomes high-temperature hot water, and is conveyed and stored in the hot water storage tank 1 through the hot water piping 6 connected to the upper part of the hot water storage tank 1 from the heating means 5. In addition, a relief valve 7 for releasing excessive pressure in the hot water storage tank 1 is installed in the upper part of the hot water storage tank 1.

  The hot water supply pipe 8 connected to the upper part of the hot water storage tank 1 and the water supply pipe 2 are connected to the mixing valve 9. A mixed hot water supply path 10 is connected to the downstream side of the mixing valve 9. The user can set a desired hot water temperature by operating an external instruction system 101 (setting means) configured by a remote controller or the like installed in a kitchen or bathroom, for example. The mixing valve 9 is configured so that the temperature of the mixed hot water obtained by mixing the hot water taken out from the hot water storage tank 1 through the hot water supply pipe 8 and the water supplied from the water supply pipe 2 becomes the hot water temperature set by the user. The mixing ratio of both is controlled so that The mixed hot water whose temperature is controlled in this way is supplied to a hot water supply terminal such as a shower in a bath or a kitchen or a washroom through a mixed hot water supply path 10. In the middle of the mixed hot water supply path 10, a mixing side open / close valve 12 configured by an electromagnetic valve or the like that can shut off the mixed hot water supply path 10 is installed.

  Further, a high temperature hot water supply path 11 is branched from the hot water supply pipe 8 upstream of the mixing valve 9, and high temperature hot water taken out from the hot water storage tank 1 can directly flow into the high temperature hot water supply path 11 as it is. Hot water passing through the hot water supply path 11 is supplied to a hot water supply terminal that requires high temperature hot water, such as a dishwasher. In the middle of the high temperature hot water supply path 11, a high temperature side opening / closing valve 13 constituted by an electromagnetic valve or the like capable of blocking the high temperature hot water supply path 11 is installed.

  On the surface of the hot water storage tank 1, a temperature sensor 14 (tank hot water temperature detecting means) for detecting the temperature of the hot water in the hot water storage tank 1 (hereinafter referred to as “tank hot water temperature”) is installed. In the illustrated configuration, a plurality of temperature sensors 14 are installed at different heights. When the hot water in the hot water storage tank 1 is consumed and the position of the boundary layer (mixed layer) between hot water and water rises, the detected temperature starts from the higher temperature (hot water temperature) in order from the lower temperature sensor 14. It switches to low temperature (water temperature). For this reason, according to the detected value of each temperature sensor 14, the amount of hot water in the hot water storage tank 1 can also be detected.

  The operation of the hot water storage type water heater of the present embodiment is controlled by the control unit 15 (control means). In particular, in the present embodiment, the control unit 15 controls the opening / closing timing of the mixing-side opening / closing valve 12 and the high-temperature side opening / closing valve 13 based on the hot water temperature in the tank detected by the temperature sensor 14.

  Next, the operation of the hot water storage type water heater configured as described above will be described based on the flowchart of FIG. FIG. 2 is a flowchart showing the control operation in the first embodiment of the present invention.

  The user can set a desired temperature T1 of hot water discharged from the mixed hot water supply path 10 (hereinafter referred to as “mixed hot water temperature”) by operating the external instruction system 101. The hot water supply terminal of the mixed hot water supply path 10 is a shower in a bath, a faucet in a kitchen or a bathroom, and the like. For this reason, the mixed hot water temperature T1 is usually set to about 40 to 60 ° C.

  Furthermore, the user can set the minimum temperature T2 of hot water discharged from the high temperature hot water supply path 11 (hereinafter referred to as “high temperature hot water temperature”) by operating the external instruction system 101. In a dishwasher as an example of a hot water supply terminal connected to the high temperature hot water supply path 11, it may be required to supply hot water of about 80 to 90 ° C. in order to ensure a predetermined cleaning ability. For this reason, when such high temperature hot water cannot be supplied, it is necessary to stop the hot water supply to the high temperature hot water supply path 11. The high temperature hot water temperature T2 is a temperature set to stop the hot water supply to the high temperature hot water supply path 11 when the hot water temperature in the tank falls below the high temperature hot water temperature T2. Therefore, the high temperature hot water temperature T2 is set to about 80 ° C., for example.

  In step S <b> 1 of FIG. 2, the temperature sensor 14 detects the hot water temperature in the tank. In step S2, the mixed hot water temperature T1 set by the user is compared with the in-tank hot water temperature T0 detected in step S1. If the hot water temperature T0 in the tank is lower than the mixed hot water temperature T1 in this step S2 (when T0 <T1), the hot water in the hot water storage tank 1 will not reach the mixed hot water temperature T1 even if the hot water is discharged as it is. Therefore, in this case, in order to stop the hot water from the mixed hot water supply path 10, the process proceeds to step S <b> 4, and the mixed side on-off valve 12 is closed to shut off the mixed hot water supply path 10. Then, it progresses to step S3.

  On the other hand, if the tank hot water temperature T0 is equal to or higher than the mixed hot water temperature T1 in step S2, it is possible to discharge hot water having the mixed hot water temperature T1, so it is necessary to stop the hot water from the mixed hot water supply path 10. There is no. Therefore, in this case, the process proceeds to step S3 as it is.

  In step S3, the hot tapping temperature T2 is compared with the tank hot water temperature T0 detected in step S1. As described above, when the temperature of the hot water supply to the high temperature hot water supply path 11 is lower than the high temperature hot water supply temperature T2, the hot water supply to the high temperature hot water supply path 11 needs to be stopped. Therefore, when the tank hot water temperature T0 is lower than the high temperature hot water temperature T2 in step S3 (when T0 <T2), the process proceeds to step S5, where the high temperature side on-off valve 13 is closed and the high temperature hot water supply path 11 is shut off. . Thereafter, the process proceeds to step S6.

  On the other hand, if the tank hot water temperature T0 is equal to or higher than the high temperature hot water temperature T2 in step S3, hot water having a temperature higher than the high temperature hot water temperature T2 can be discharged to the high temperature hot water supply path 11; There is no need to stop the hot water. Therefore, in this case, the process proceeds to step S6 as it is.

  In step S6, it is determined whether both the mixing side on-off valve 12 and the high temperature side on-off valve 13 are closed. If both are closed, the process proceeds to step S7, and either of them is closed. If not, the process from step S1 is executed again. In step S7, the boiling operation (heating operation) of the hot water storage tank 1 is started.

  Next, an outline of the boiling operation of the hot water storage type water heater of this embodiment will be described. After the mixing side opening / closing valve 12 and the high temperature side opening / closing valve 13 are closed as described above, the circulation pump 4 is driven, and the water in the hot water storage tank 1 is taken out from the lower part of the hot water storage tank 1 through the incoming water pipe 3. To the heating means 5. The hot water heated by the heating means 5 is returned to the upper part of the hot water storage tank 1 through the hot water piping 6 and stored.

  Since the water heated by the heating means 5 becomes high temperature and expands in volume, the pressure in the hot water storage tank 1 rises, but the hot water corresponding to the volume expansion is discharged from the relief valve 7 installed in the upper part of the hot water storage tank 1. . Thereby, a pressure rise is suppressed. Further, when the heating means 5 heats the water, dissolved oxygen dissolved in the water appears as bubbles and is returned from the hot water supply pipe 6 to the upper part of the hot water storage tank 1 together with the heated water. However, in the hot water storage type hot water supply apparatus of the present embodiment, the water pressure from the water supply pipe 2 always acts in the hot water storage tank 1 even during the boiling operation. With this water pressure, the bubbles in the hot water storage tank 1 are pushed out toward the relief valve 7 and are reliably discharged from the relief valve 7.

  Thus, according to the present embodiment, bubbles generated during boiling can be reliably discharged from the relief valve 7. For this reason, when hot water is supplied to a faucet or the like, it is possible to reliably prevent the hot water mixed with air and water from being blown out. In addition, since bubbles are prevented from interposing in the heating means 5 and the hot water piping 6, the water supplied to the heating means 5 flows smoothly and does not reach a high temperature. It can be done reliably without hindrance.

  Further, according to the present embodiment, the mixed-side hot water supply path 10 and the high-temperature hot water supply path 11 are respectively controlled by controlling the mixing-side open / close valve 12 and the high-temperature side open / close valve 13 based on the detected hot water temperature in the tank. Hot water can be supplied at a suitable temperature, and the hot water in the hot water storage tank 1 can be used without waste. That is, according to the present embodiment, when the temperature of the hot water in the tank falls below the high temperature hot water temperature T2 (for example, 80 ° C.), the high temperature hot water supply path 11 is shut off by the high temperature side opening / closing valve 13. For this reason, it can prevent that the low temperature hot water which is not suitable for the hot water supply terminal (such as a dishwasher) of the high temperature hot water supply path 11 is supplied. On the other hand, even if the hot water temperature in the tank falls below the high temperature hot water temperature T2, if the hot water temperature in the tank is equal to or higher than the mixed hot water temperature T1 (for example, 40 ° C.), the mixed hot water supply path 10 is not blocked. For this reason, even if the temperature of the hot water in the tank falls below the high temperature hot water temperature T2, the hot water in the hot water storage tank 1 is taken from the mixed hot water supply path 10 to the bath or kitchen until the hot water temperature in the tank falls below the mixed hot water temperature T1. Can be supplied to. For this reason, since the hot water in the hot water storage tank 1 can be used without waste, power consumption, water resources, and the like can be reduced.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described, but only differences from the above-described first embodiment will be described. Since the configuration of the hot water storage type hot water heater of the second embodiment is the same as that of the first embodiment except for the following points, the illustration is omitted.

  In Embodiment 1, the temperature of the hot water in the tank is detected by the temperature sensor 14 installed in the hot water storage tank 1, but the means for detecting the hot water in the tank is not limited to such a configuration. For example, the temperature of the hot water in the tank is detected by providing first temperature detecting means for detecting the temperature of hot water passing through the high temperature hot water supply path 11 and second temperature detecting means for detecting the temperature of hot water passing through the mixed hot water supply path 10. You may make it do. Since the temperature of the hot water passing through the high temperature hot water supply path 11 can be regarded as being equal to the hot water temperature in the tank, the hot water temperature in the tank can be detected by the first temperature detecting means. Moreover, the control part 15 controls the opening degree of the mixing valve 9 so that the temperature of the mixed hot water detected by the said 2nd temperature detection means may become equal to the mixed hot water temperature T1. For this reason, when the temperature of the hot water supplied from the hot water supply pipe 8 becomes equal to or lower than the mixed hot water temperature T1, the controller 15 controls the opening of the mixing valve 9 to fully open the hot water side. It flows to the mixed hot water supply path 10 as it is. Therefore, when the hot water temperature in the tank is lowered, the hot water temperature detected by the second temperature detecting means can be regarded as being equal to the hot water temperature in the tank, so that the hot water temperature in the tank is detected by the second temperature detecting means. be able to.

  In the second embodiment, there is provided a hot water detection means such as a flow rate sensor for detecting that the hot water has been discharged from the mixed hot water supply path 10 or the high temperature hot water supply path 11, and a predetermined time has elapsed since the hot water detection was detected by the hot water detection means. It is desirable that the temperature detected by the first temperature detection means or the second temperature detection means after the elapse of time or after a predetermined amount of hot water is regarded as the hot water temperature in the tank and to be controlled in the same manner as in the first embodiment. This is because, in the initial stage from the start of hot water supply, the hot water in the hot water storage tank 1 is not affected by the hot water in the pipe or the temperature of the pipe itself.

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Water supply piping 5 Heating means 7 Relief valve 8 Hot water supply piping 9 Mixing valve 10 Mixed hot water supply path 11 High temperature hot water supply path 12 Mixing side on-off valve 13 High temperature side on / off valve 14 Temperature sensor 15 Control part 101 External indication system

Claims (5)

A hot water storage tank for storing hot water heated by the heating means;
A water supply path for supplying water to the hot water storage tank;
A high temperature hot water supply path for directly discharging hot water taken out from the hot water storage tank;
A high temperature side opening / closing valve provided in the middle of the high temperature hot water supply path;
A mixed hot water supply path for mixing hot water taken out from the hot water storage tank and water supplied from outside the hot water storage tank,
A mixing-side on-off valve provided in the middle of the mixed hot water supply path;
Tank hot water temperature detecting means for detecting the temperature of hot water in the hot water storage tank;
Control means for controlling the high temperature side on-off valve and the mixing side on-off valve based on the tank hot water temperature detected by the tank hot water temperature detecting means,
A hot water storage type water heater characterized by comprising:   The control means shuts off the high temperature hot water supply path by closing the high temperature side on-off valve when the detected hot water temperature in the tank falls below a first predetermined value, and the detected hot water temperature in the tank 2. The hot water storage type hot water heater according to claim 1, wherein when the value falls below a second predetermined value lower than a predetermined value of 1, the mixed hot water supply path is shut off by closing the mixing-side on-off valve.   The control means, when both the high temperature side on-off valve and the mixing side on-off valve are closed, heats the water in the hot water storage tank while the water pressure from the water supply path is applied to the hot water storage tank. The hot water storage type water heater according to claim 2, wherein a heating operation for heating is started.   The hot water storage type hot water supply apparatus according to claim 2 or 3, further comprising setting means that allows a user to set the first predetermined value and the second predetermined value, respectively.   The tank hot water temperature detecting means includes first temperature detecting means for detecting the temperature of hot water passing through the high temperature hot water supply path, and second temperature detecting means for detecting the temperature of hot water passing through the mixed hot water supply path. The hot water storage type water heater according to any one of claims 1 to 4, wherein the hot water storage type water heater is configured.

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