Storage tank type hot water supply device

Abstract

To solve a problem on difficulty in draining at an upstream side of a check valve 32 in a draining operation, as convection can be prevented by disposing the check valve 32 in a heating returning pipe 7 but air does not flow to the upstream side of the check valve 32.SOLUTION: A heating returning pipe 7 is provided with a check valve 32 having a valve for suppressing backflow of hot water / water from a hot water storage tank 1 to heating means, the check valve 32 has an air passing function capable of allowing the air to mutually flow in and out at an upstream side and a downstream side of the check valve 32, and the check valve 32 is disposed on a highest position of the heating returning pipe 7, so that it is possible to realize both prevention of lowering of a hot water storage temperature in the hot water storage tank 1 due to heat radiation by convection of hot water of an upper portion of the hot water storage tank 1 to the heater heating means 8 through the heating returning pipe 7, and effect of improving draining performance of the heating returning pipe 7 and the heating going pipe 5 at an upstream side with respect to the check valve 32.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a storage type hot water supply device that stores hot water heated by a heating means. [Background technology]

[0002] In a storage-type water heater that stores high-temperature hot water by connecting a hot water storage tank and a heating means having a heat exchanger by a circulation circuit and performing a boiling operation in which water taken from the bottom of the hot water storage tank is heated to a high temperature by the heating means and returned to the top of the hot water storage tank, it has been known to provide a check valve in the middle of the heating return pipe to prevent convection in the circulation circuit that occurs when a circulation pump provided in the circulation circuit is stopped and to prevent the water in the hot water storage tank from cooling down due to the convection (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-75958 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if an air vent valve is not provided at the apex, convection can be prevented by providing a check valve in the heating return pipe, but since air does not flow upstream of the check valve, there is a problem that it is difficult to drain water upstream of the check valve during the water draining operation. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention provides a hot water storage tank for storing hot water, a water supply pipe for supplying water to the hot water storage tank, and a water heater for heating the water in the hot water storage tank. First A heating means; A second heating means for heating the water in the hot water storage tank; The hot water storage tank lower portion and the Second a heating pipe connected to the upstream side of the heating means; Second A heat return pipe connecting the downstream side of the heating means and the upper part of the hot water storage tank. And In the hot water supply device, A heating branch pipe that branches off from the middle of the heating forward pipe and joins the heating return pipe via the first heating means; a circulation pump that is provided in the heating branch pipe and sends hot water in the hot water storage tank to the first heating means; and In the hot water storage tank, First A check valve that prevents backflow of hot and cold water to the heating means and The check valve has an air passage function that allows air to pass between the upstream side and the downstream side of the check valve, and the check valve is Heating branch pipe was placed at the highest position.

[0006] In addition, Heating branch pipe The water separator has an upflow pipe through which water flows upward and a downflow pipe through which water flows downward, and the length of the upflow pipe is shorter than the length of the downflow pipe.

[0007] The lower end of the downcomer pipe is First It was located at a lower position than the heating means.

[0008] In addition, Heating branch pipe The above First A thermostat is provided to prevent the heating means from overheating, The check valve is disposed upstream of the thermostat and at a higher position than the thermostat.

[0009] In addition, Heating branch pipe The horizontal pipe includes a first horizontal pipe extending in a substantially horizontal direction and a second horizontal pipe provided downstream of the first horizontal pipe, Heating branch pipe The second horizontal pipe is provided with the thermostat, and the length of the first horizontal pipe is longer than the length of the second horizontal pipe. Effect of the Invention

[0010] Thus, according to the present invention, a check valve with air passage function is provided at the highest point of the heating return pipe, which prevents the hot water at the top of the hot water storage tank from dissipating heat by convection to the heater heating means through the heating return pipe, thereby preventing a drop in the temperature of the hot water stored in the hot water storage tank, while also achieving the effect of improving the water drainage ability of the heating return pipe and the heating supply pipe, which are upstream of the check valve. [Brief description of the drawings]

[0011] [Figure 1] Schematic diagram of the hot water supply device of the present invention. [Diagram 2] Cross-sectional view of the HP unit of the hot water supply device of the present invention. [Diagram 3] Diagram of the heating branch pipe of the present invention [Figure 4] An enlarged cross-sectional view of the main part of the HP unit of the hot water supply device of the present invention. [Diagram 5] A diagram showing the configuration of the check valve of the present invention. [Figure 6] A diagram showing the configuration of the check valve of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of a hot water supply device of the present invention will be described with reference to Figs. In Figure 1, reference numeral 1 denotes a hot water storage tank that stores hot water for a storage-type hot water heater, 2 denotes a water supply pipe that supplies water to the bottom of the hot water storage tank 1, 3 denotes a hot water outlet pipe that outputs hot water from the top of the hot water storage tank 1, 4 denotes a heat pump type heat pump heating means which is a heating means for heating the water in the hot water storage tank, 5 denotes a heating supply pipe connecting the bottom of the hot water storage tank 1 and the heat pump heating means 4, 6 denotes a heat pump side circulation pump installed midway along the heating supply pipe 5, and 7 denotes a heating return pipe that connects the heat pump heating means 4 and the top of the hot water storage tank 1.

[0013] Reference numeral 8 denotes an electric heater heating means which is a heating means for heating the water in the hot water storage tank, reference numeral 9 denotes a heating branch pipe which branches off midway through the heating supply pipe 5 and joins the heating return pipe 7 via the heater heating means 8 (here, this is a heating branch pipe which is composed of a heating return pipe to the heater heating means 8 and a heating supply pipe), reference numeral 10 denotes a heater side circulation pump provided midway through the heating supply pipe 5, and reference numeral 11 denotes a thermostat which detects whether the temperature of the heat from the heater heating means 8 has reached an overheating temperature.

[0014] The heater heating means 8 is formed by bending a stainless steel pipe into a U-shape, and is configured by embedding, by die-casting, a flow piping 8a inside which a heat transfer medium flows, and an electric heater 8b consisting of a 200V, 1KW sheathed heater also bent into a U-shape, in a heat transfer metal 8c made of aluminum, with the flow piping 8a positioned on the outer periphery so as to cover the electric heater 8b.

[0015] Reference numeral 12 denotes a hot water supply side water supply bypass pipe that branches off midway through the water supply pipe 2, reference numeral 13 denotes a hot water mixing valve that mixes the hot water flowing through the hot water outlet pipe 3 and the city water flowing through the hot water supply side water supply bypass pipe 12 in an appropriate ratio to adjust the hot water temperature to the set hot water temperature, reference numeral 14 denotes a hot water pipe through which the mixed water mixed in the hot water mixing valve 13 circulates, reference numeral 15 denotes a hot water tap that supplies the mixed water from the hot water pipe 14, reference numeral 16 denotes a flow sensor installed midway through the hot water pipe 14 to detect the hot water flow rate, and reference numeral 17 denotes a hot water temperature sensor that detects the temperature of the mixed water mixed by the hot water mixing valve 13.

[0016] In addition, reference numeral 18 denotes a bath side water supply bypass pipe that is bypassed from the water supply pipe 2, reference numeral 19 denotes a bath mixing valve that mixes hot water from the hot water outlet pipe 3 with water from the bath side water supply bypass pipe 18 and controls the mixing ratio to supply hot water at the desired bath set temperature, reference numeral 20 denotes a water filling pipe for supplying the hot water mixed by the bath mixing valve 19 to the bathtub 21, reference numeral 22 denotes a flow sensor installed midway through the water filling pipe 20 to detect the bath flow rate, reference numeral 23 denotes a bath temperature sensor that detects the temperature of the mixed water mixed by the bath mixing valve 19, and reference numeral 24 denotes a bath solenoid valve that supplies the mixed water mixed by the bath mixing valve 19 to the bathtub by switching the valve.

[0017] Reference numeral 25 denotes a water supply pressure reducing valve installed in the water supply pipe 2 to reduce the pressure of city water to a constant water supply pressure, 26 denotes a water supply cut-off valve which cuts off the water supply, 27 denotes a water supply thermistor installed in the water supply pipe 2 to detect the temperature of the city water, and 28 denotes a relief valve installed in communication with the top of the hot water storage tank 1 and which can be opened and closed manually.

[0018] Reference numeral 29 denotes a drain pipe connected to the bottom of the hot water storage tank 1 and installed midway through the water supply pipe 2, and a drain valve 30 is provided midway through the drain pipe 29 so that the drain pipe 29 can be manually opened and closed.

[0019] Next, the control device 31, which is responsible for controlling the operation of the hot water supply and bath operation, adjusts the hot water supply setting flow rate so that it is equal to the value detected by the flow sensor 16, and also controls the valve opening of the hot water supply mixing valve 13 so that the hot water supply temperature is equal to the value detected by the hot water supply temperature sensor 17.

[0020] Reference numeral 32 denotes a check valve that is provided downstream of the heater heating means 8 and upstream of the thermostat 11, and prevents backflow of high-temperature hot water from the upper part of the hot water storage tank 1 due to convection.

[0021] Next, the hot water supply operation will be described. When the hot water tap 15 is opened, city water flows into the bottom of the hot water storage tank 1 from the water supply pipe 2, and high-temperature hot water is discharged from the top of the hot water storage tank 1 through the hot water outlet pipe 3, where it is mixed with water from the hot water supply side water supply bypass pipe 12 in the hot water supply mixing valve 13 and passes through the hot water supply pipe 14. The control device 31 then controls the valve opening of the hot water supply mixing valve 13 so that the value detected by the hot water supply temperature sensor 17 matches the hot water supply set temperature, thereby supplying hot water at the hot water supply set temperature. When adjusting the hot water supply flow rate, the control device 31 adjusts the flow rate so that the value detected by the flow sensor 16 matches an arbitrary hot water supply set flow rate, and supplies hot water. When the hot water tap 15 is closed, the control device 31 stops controlling the valve opening of the hot water supply mixing valve 13 and stops hot water supply.

[0022] Next, when a command to fill the bath is given via a remote control (not shown), the control device 31 opens the bath solenoid valve 24, and the cold water from the water supply pipe 2 and the hot water from the hot water outlet pipe 3 are adjusted by the bath mixing valve 19 to the bath temperature set via the remote control, and the water is filled to the bathtub 21 via the filling pipe 20 until a predetermined amount is counted by the flow sensor 22. Once the predetermined amount of water has been filled, the bath solenoid valve 24 is closed, and the filling operation ends.

[0023] Next, the boiling operation for boiling the water in the hot water storage tank 1 using the heat pump heating means 4 will be described. When it is detected that the required amount of heat does not remain in the hot water storage tank 1, the control device 31 starts the boiling operation. The control device 31 starts the operation of the compressor and the heat pump side circulation pump 6 (not shown), and the cold water supplied from the bottom of the hot water storage tank 1 via the heating circulation circuit composed of the heating supply pipe 5 and the heating return pipe 7 is boiled to a high temperature in a water-refrigerant heat exchanger (not shown), and is returned to the top of the hot water storage tank 1, and the high-temperature water is stored by stacking it in order from the top of the hot water storage tank 1. Then, when it is detected that the required amount of heat has been stored in the hot water storage tank 1, the control device 31 stops the operation of the compressor and the heat pump side circulation pump 6, and ends the boiling operation.

[0024] In addition, the boiling operation for boiling the water in the hot water storage tank 1 using the heater heating means 8 will be described. When it is detected that the required amount of heat does not remain in the hot water storage tank 1, the control device 31 starts the boiling operation. The control device 31 starts the operation of the heater heating means 8 and the heater side circulation pump 10, and the cold water supplied from the lower part of the hot water storage tank 1 through the heating circulation circuit composed of the heating forward pipe 5, the heating branch pipe 9, and the heating return pipe 7 is heated by the heater heating means 8 to a high temperature and is boiled, and returned to the upper part of the hot water storage tank 1, and the high-temperature water is stored in layers from the upper part of the hot water storage tank 1. Then, when it is detected that the required amount of heat has been stored in the hot water storage tank 1, the control device 31 stops the operation of the heater heating means 8 and the heater side circulation pump 10, and ends the boiling operation.

[0025] As methods for heating the hot water storage tank 1, heating using the heat pump heating means 4 and heating using the heater heating means 8 have been described, but heating using either one alone or driving both may be used.

[0026] Next, we will explain the water draining operation in a hot water storage type hot water supply system, in which the user opens the drain valve 30 and drains the water in the hot water storage tank 1 and each pipe when the house is left empty for a few days or just one day in winter and there is a risk of freezing. When draining water from the hot water storage tank 1 and each pipe at the user's discretion or by command from a remote control (not shown), the user first closes the water supply cut-off valve 26, opens the relief valve 28, and opens the drain valve 30 to begin draining water; after continuing to drain for a predetermined period of time, the water will be drained from the hot water storage tank 1 and each pipe.

[0027] Next, the detailed structure of the heating branch pipe 9 will be described with reference to FIGS. The heating branch pipe 9 is composed of an upstream branch pipe 9A of the piping upstream of the heater heating means 8, the heater heating means 8, and a downstream branch pipe 9B of the piping downstream of the heater heating means 8. The downstream branch pipe 9B is composed of an ascending pipe 9a through which water flows vertically upward, a first horizontal pipe 9b extending horizontally and having a check valve 32 at the top of the heating branch pipe 9, a descending pipe 9c disposed on the back side of the heater heating means 8 and through which water flows vertically downward, and a second horizontal pipe 9d having a thermostat 11 and joining the heating return pipe 7.

[0028] The length X of the upflow pipe 9a is shorter than the length Y of the downflow pipe 9c, and the downstream branch pipe 9B has an inverted S-shaped trap structure with an upward convexity.

[0029] In this way, since a check valve 32 is provided in the first horizontal pipe 9b of the heating branch pipe 9, it is possible to prevent the hot water at the top of the hot water storage tank 1 from dissipating heat by convection through the downstream branch pipe 9B to the unheated heater heating means 8, thereby preventing a drop in the temperature of the hot water stored in the hot water storage tank 1.

[0030] The check valve 32 is provided in the first horizontal pipe 9b which flows through the highest position of the heating branch pipe 9, and has an air passage function (described in detail later) which allows air to flow in and out between the upstream and downstream sides of the check valve 32.

[0031] As a result, when performing the water draining operation, the user starts the water draining operation by closing the water supply cutoff valve 26, opening the relief valve 28, and opening the drain valve 30, and water drains from the bottom of the hot water storage tank 1 and also drains from the heating circulation circuit.

[0032] At this time, the water downstream of the check valve 32 of the heating branch pipe 9 is drained from the drain pipe 29 via the heating return pipe 7. Then, when the water downstream of the check valve 32 is drained, air flows from the downstream to the upstream of the check valve 32 because the check valve 32 allows air to flow.

[0033] Then, as air flows from the downstream side of the check valve 32 to the upstream side of the check valve 32, the water in the uprising pipe 9a upstream of the check valve 32, the heater heating means 8, and the upstream branch pipe 9A is drained, and the water draining operation in the heating branch pipe 9 is completed.

[0034] In this way, air can flow while hot water or cold water can be prevented from flowing back, so that it is possible to achieve both the effect of suppressing natural convection and the effect of improving the drainage performance of the heating branch pipe 9.

[0035] In addition, the length X of the upflow pipe 9a is shorter than the length Y of the downflow pipe 9c to form an inverted S-shaped trap structure. When the heating means 8 is stopped, the hot water in the hot water storage tank 1 becomes hotter than the water in the heating branch pipe 9. However, the long downflow pipe 9c, which is oriented in the opposite direction to the direction of gravity, is configured to suppress backflow from the heating return pipe 7, thereby compensating for the decrease in the check ability of the check valve 32 caused by allowing air to flow and preventing backflow.

[0036] In addition, the length Y of the downcomer pipe 9c is set to a predetermined length such that the second horizontal pipe 9d is located at least below the heater heating means 8 from the position of the first horizontal pipe 9b, and the first horizontal pipe 9b having the check valve 32 is positioned at a higher position than the second horizontal pipe 9d having the thermostat 11.

[0037] As a result, if there is a sudden power outage due to a change in weather or the like while the heater heating means 8 is performing a boiling operation, the water that has been stagnating inside the heater heating means 8 will be boiled to a high temperature and will move inside the heating branch pipe 9 due to convection. However, since the second horizontal pipe 9d having the thermostat 11 is positioned below the heater heating means 8, it is possible to prevent the high-temperature water from moving to the thermostat 11 due to convection and the thermostat 11 from detecting an abnormally high temperature.

[0038] Furthermore, when the length of the first horizontal tube 9b is P and the length of the second horizontal tube 9d is Q, the length P of the first horizontal tube 9b is longer than the length Q of the second horizontal tube 9d.

[0039] In this way, by lengthening the length P of the first horizontal pipe 9b, when there is a sudden power outage due to a change in weather or the like during the heating operation of the heater heating means 8, the first horizontal pipe 9b serves as a heat dissipation section for the high-temperature water that has been accumulating inside the heater heating means 8, and by preventing the high-temperature water from being transmitted to the thermostat, it is possible to prevent the thermostat 11 from detecting an abnormally high temperature.

[0040] Furthermore, if the vertical length of the heater heating means 8 is Z as shown in Figures 3 and 4, the length Y of the downcomer pipe 9c is longer than the combined length of the length X of the upcomer pipe 9a and the vertical length Z of the heater heating means 8, so that the lower end of the downcomer pipe 9c is positioned lower than the heater heating means 8.

[0041] In other words, the connection portion between the second horizontal pipe 9d and the heat return pipe 7, and the thermostat 11 provided on the second horizontal pipe 9d are located at a lower position than the heater heating means 8.

[0042] In this way, by making the length Y of the downcomer pipe 9c longer than the combined length X of the upcomer pipe 9a and the vertical length Z of the heater heating means 8, the connection between the second horizontal pipe 9d and the heat return pipe 7 and the thermostat 11 provided on the second horizontal pipe 9d are arranged so as not to overlap with the heater heating means 8, and the check valve 32 and the connection between the upcomer pipe 9a and the first horizontal pipe 9b are arranged at a higher position than the heater heating means 8. Therefore, when removing parts or piping for maintenance such as a breakdown or inspection, it is not necessary to reach for the back side of the heater heating means 8. Since the heater heating means 8 does not overlap with the connection points of the parts and piping as shown in FIG. 3, a structure that does not impair maintainability can be provided.

[0043] Next, an example of the check valve 32 will be described in detail with reference to FIGS. The first horizontal pipe 9b has a check valve 32 disposed therein, and is configured by fitting a male side adaptor 33 and a female side adaptor 34 into the first horizontal pipe 9b.

[0044] In addition, 35 is a valve such as a packing, 36 is a top formed integrally with valve 35, 37 is a guide that prevents top 36 from tilting, 38 is a spring that opens valve 35 when it receives pressure equal to or greater than a predetermined pressure from a predetermined direction and closes valve 35 when the pressure is below the predetermined pressure, 39 is a housing that has valve 35, top 36, guide 37, and spring 38 inside, and 40 is an O-ring mounting groove provided on the outer periphery of the housing for positioning an O-ring.

[0045] As shown in FIG. 6, by removing the O-ring and installing the check valve 32 in the O-ring installation groove 40, a gap is created that cannot be sealed unless an elastic member such as an O-ring is fitted in.

[0046] Air flows through this gap, so that even if a check valve 32 is provided, air can flow from the downstream side of the check valve 32 to the upstream side of the check valve 32 (air passage function).

[0047] In addition, since this gap is very small and only air can pass through, water will not get in and cause a backflow. Even if water does get in, it will drain out during the water draining operation, so there is no problem. During the water draining operation, the gap can function as an air inlet on the upstream side of the check valve 32.

[0048] In this way, by arranging the check valve 32 without the O-ring, it is possible to achieve both the effect of suppressing natural convection and the effect of improving the drainage of the heating branch pipe 9 without using any special parts.

[0049] In addition, in order to suppress the decrease in check capability caused by placing the check valve 32 without the O-ring, the heating branch pipe 9 is made into an inverted S-trap, thereby making it possible to reliably suppress backflow.

[0050] The present invention is not limited to the embodiments, and modifications may be made without departing from the spirit and scope of the invention. For example, in this embodiment, two heating means are used, one of which is a heating branch pipe 9, but the heating branch pipe 9 may be divided into a heating forward pipe 5 heading toward the heating means and a heating return pipe 7 returning from the heating means.

[0051] In addition, the heating means in this embodiment uses a heat pump heating means 4 and a heater heating means 8, but is not limited to this and may be, for example, a heat pump that uses geothermal heat, a heat pump that uses solar light, or a heating means that uses a fuel cell.

[0052] Further, in this embodiment, the description is given using two heating means, but the number of heating means may be one.

[0053] In addition, in this embodiment, the check valve 32 with the O-ring removed is used as the air passage function, but this is not limited to this, and other methods are available, such as drilling a hole in the check valve 32 that only air can pass through, or making the outer dimensions of the check valve 32 slightly smaller than the inner dimensions of the female side adapter 34. [Explanation of symbols]

[0054] 1 Hot water tank 4. Heat pump heating means (heating means) 5. Heated feed pipe 6. Heat pump side circulation pump 7 Heat return pipe 8 Heater heating means (heating means) 9 Heating branch pipe 11 Thermostat 28 Relief valve 29 Drain pipe 30 Drain valve 32 Check valve 33 Male adapter 34 Female adapter 35 Valve 40 O-ring mounting groove 9A Upstream branch pipe 9B Downstream branch pipe 9a Ascending pipe 9b First horizontal pipe 9c downcomer 9d Second horizontal pipe

Claims

1. A hot water storage tank for storing hot water; A water supply pipe that supplies water to the hot water storage tank; A first heating means for heating water in the hot water storage tank; A second heating means for heating the water in the hot water storage tank; A heating pipe connecting a lower portion of the hot water storage tank and an upstream side of the second heating means; In a hot water supply device including a heat return pipe connecting a downstream side of the second heating means and an upper portion of the hot water storage tank, a heating branch pipe that branches off from the middle of the heating forward pipe and joins the heating return pipe via the first heating means; A circulation pump provided in the heating branch pipe for sending hot water in the hot water storage tank to the first heating means; a check valve having a valve for suppressing a backflow of hot water from the hot water storage tank to the first heating means is provided in the heating branch pipe; The check valve has an air passage function that allows air to pass between the upstream side and the downstream side of the check valve, A storage type hot water supply device, characterized in that the check valve is arranged at the highest position of the heating branch pipe.

2. The heating branch pipe is The device has an upflow pipe through which water flows upward and a downflow pipe through which water flows downward, 2. The storage type hot water heater according to claim 1, wherein the length of the ascending pipe is shorter than the length of the descending pipe.

3. 3. The storage type hot water supply apparatus according to claim 2, wherein a lower end of said downcomer pipe is disposed at a position lower than said first heating means.

4. the heating branch pipe is provided with a thermostat for preventing the first heating means from overheating; 4. The storage type hot water supply device according to claim 1, wherein the check valve is disposed upstream of the thermostat and at a higher position than the thermostat.

5. The heating branch pipe is A first horizontal pipe extending in a substantially horizontal direction and a second horizontal pipe provided downstream of the first horizontal pipe, The second horizontal pipe of the heating branch pipe is provided with the thermostat, 5. The storage type hot water supply device according to claim 4, wherein the length of the first horizontal pipe is longer than the length of the second horizontal pipe.

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