JP2011117667A - Storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage type water heater capable of suppressing the increase of medium temperature water caused by water in a hot water storage tank stirred by hot water flowing into the hot water storage tank from a heat source machine. <P>SOLUTION: The storage type water heater is provided with: the hot water storage tank 4; a water supply pipe 6 one end of which is connected to a water source and the other end of which is connected to a lower part of the hot water storage tank 4; a boiling circuit which heats the water taken from the lower part of hot water storage tank 4 with the heat source machine and then returns it from a flow inlet, provided at an upper part of the hot water storage tank 4, to the hot water storage tank 4; a baffle plate 13 almost horizontally provided at a position opposed to the flow inlet 12a in the hot water storage tank 4 spaced from the flow inlet 12a; and a protrusion 14 which is provided on an inner surface of the hot water storage tank 4 and deflects the hot water having passed above the baffle plate 13. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Hot water storage water heaters store hot water obtained by heating water from a water source such as a water supply in a hot water storage tank, and take out the hot water from a hot water pipe connected near the top of the hot water storage tank at the request of the user. It has a function of mixing with water from a water source and supplying it to a hot water supply terminal such as a hot water tap or a bathtub. Since the entire system is applied with a predetermined pressure obtained by reducing the water pressure of the water source, the same amount of hot water used by the user is supplied from the water source to the hot water storage tank, and the hot water tank is always filled with water. It is maintained in the state filled with.

  At this time, if hot hot water flowing from the heat source machine and low temperature water supplied from the water source are mixed in the hot water storage tank to form a large amount of medium temperature water, the hot water temperature becomes unstable and the thermal efficiency decreases. . Therefore, the temperature distribution of the water in the hot water storage tank is such that the high temperature layer by hot water and the low temperature layer by water are almost separated, and the medium temperature layer by the medium temperature water formed by mixing both layers is as small as possible. It is desirable to be.

There are two main reasons for the expansion of the medium temperature water layer. One is due to heat exchange associated with natural convection generated between the intermediate temperature layer and the high temperature layer and between the intermediate temperature layer and the low temperature layer formed in the hot water storage tank, and the intermediate temperature layer expands over time. The other factor is that the water in the hot water tank is stirred by the hot water that is heated by the heat source machine and flows from the top of the hot water tank. In this case, a large amount of hot water and water are mixed. A lot of medium temperature water is generated in a short time.
Although it is difficult to suppress the medium temperature layer that expands over time due to natural convection, the medium temperature water generated by stirring the water in the hot water tank is suppressed by controlling the flow field in the hot water tank. It is possible.

  As a conventional hot water storage type water heater, a hot water supply circuit in which the lower part of the hot water storage tank, the pump, the heat source machine, and the upper part of the hot water storage tank are connected in sequence, and hot water obtained by heating the hot water source with the heat source machine is poured into the hot water storage tank. For example, there is a rectifying plate provided in the vicinity of the inlet in the hot water storage tank (see, for example, Patent Document 1). In this hot water storage type hot water heater, the hot water flowing into the hot water storage tank from the inlet at the upper part of the hot water storage tank is configured to be decelerated while the flow velocity vector is deflected from the vertically downward direction to the horizontal direction by the rectifying plate.

JP-A-6-265213

  However, in the hot water storage type hot water heater described in Patent Document 1, the hot water diffused in the horizontal direction by the baffle plate forms a flow field along the inner surface of the hot water storage tank. The flow is vertically downward along the trunk plate. As a result, when the water in the hot water storage tank is agitated, high-temperature water and medium-temperature water or low-temperature water are mixed to increase the medium-temperature water, which may cause the hot water temperature to become unstable and decrease the thermal efficiency. .

  In addition, mineral water such as calcium and magnesium is contained in tap water and groundwater that serve as the water source for hot water storage hot water heaters, and when water containing a large amount of these mineral components is heated with a heat source machine, the main component is calcium carbonate. The scale to be deposited. This scale circulates in the boiling circuit 16 including the heat source unit and the hot water storage tank by the water flow created by the pump provided in the hot water storage type hot water heater. However, when the boiling is completed and the pump operation is stopped, the scale is moved by its own weight. Deposits at the bottom of the hot water tank. As a result, there is a possibility that the pressure loss of the flow path is increased by partially closing the outlet provided in the vicinity of the bottom of the hot water storage tank for sending water to the heat source machine. Further, as the scale builds up, the outlet may be completely blocked, making boiling operation impossible.

  The present invention has been made to solve the above-described problems, and is a hot water storage type hot water heater capable of suppressing an increase in medium hot water due to stirring of the water in the hot water storage tank by the hot water flowing into the hot water storage tank from the heat source device. And to prevent the scale generated during the boiling operation from accumulating at the bottom of the hot water storage tank.

  A hot water storage type hot water supply apparatus according to the present invention includes a heat source machine that heats water to generate hot water, a cylindrical body part, and a hot water storage tank that is installed so that the axis of the body part is in a vertical direction. And a water supply pipe having one end connected to the water source and the other end connected to the lower part of the hot water storage tank, and hot water taken from the lower part of the hot water storage tank, after being heated by the heat source device, to the upper part of the hot water storage tank A boiling circuit for returning from the provided inlet into the hot water storage tank, a hot water supply pipe having one end connected to the upper part of the hot water storage tank, and the inlet at a position facing the inlet in the hot water storage tank; A baffle plate provided in a substantially horizontal direction at an interval, and a protrusion provided on the inner surface of the hot water storage tank for deflecting hot water passing over the baffle plate are provided.

  According to the present invention, the hot water heated by the heat source device, flowing into the hot water storage tank from the inlet and then diffused by the baffle plate and flowing downward along the inner surface of the hot water storage tank is provided on the inner surface of the hot water storage tank. The projection is deflected upward or horizontally by the projection and stays in the upper part of the hot water storage tank. As a result, the intermediate temperature layer formed near the center of the hot water storage tank and the low temperature layer formed at the bottom are not agitated, so that the temperature boundary layer is maintained and the increase in intermediate temperature water can be suppressed.

  In addition, the scale generated during boiling is also diffused by the baffle plate and drifts in the hot water tank along with the flow of hot water along the inner surface of the hot water tank, but most of this scale is accumulated in the protrusions and accumulated in the hot water tank. The amount of scale that accumulates at the bottom is reduced.

It is a figure which shows the whole structure of the hot water storage type water heater in embodiment of this invention. It is sectional drawing of the hot water storage tank in embodiment of this invention. It is a schematic diagram which shows the principle which suppresses that a scale accumulates in the bottom part of the hot water storage tank in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram of a hot water storage type water heater in an embodiment of the present invention. A hot water storage type water heater 1 shown in FIG. 1 includes a heat pump unit 2 that is a heat source unit, and a hot water storage tank unit 3 in which a hot water storage tank 4 that stores hot water heated by the heat pump unit 2 is accommodated. In the heat pump unit 2, a compressor 2a, a water / refrigerant heat exchanger 2b, an expansion valve 2c and an evaporator 2d are sequentially connected in an annular manner to circulate the refrigerant, and a fan 2e that blows outside air to the evaporator 2d. Is installed. On the other hand, in the hot water storage tank unit 3, a pump 5 that supplies water, which is a load medium of the refrigeration cycle, to the water-refrigerant heat exchanger 2 b, a water supply pipe 6 that supplies water as the water source to the hot water storage tank 4, and water from the water source A pressure reducing valve 7 for reducing the pressure below a predetermined pressure, a mixing valve 8 for mixing hot water in the hot water storage tank 4 and water from the water source to produce hot water at a temperature required by the user, and hot water produced by the mixing valve 8 A hot water supply pipe 10 that supplies hot water to a hot water supply terminal 9 such as a bathtub or the like is provided.

  Here, the hot water storage tank 4 has a cylindrical body portion, and is installed so that the axis of the body portion is substantially vertical.

  Then, the water refrigerant heat exchanger 2b and the hot water storage tank 4 are connected via a pump 5 by a heat source unit forward piping 11, and the water refrigerant heat exchanger 2b and the hot water storage tank 4 are connected by a heat source unit return piping 12 so that the heat pump The unit 2 and the hot water storage tank unit 3 are connected to form a boiling circuit 16.

  FIG. 2 is a cross-sectional view of the hot water storage tank 4. An inlet 12 a for pouring hot water heated by the heat pump unit 2 into the hot water storage tank 4 through the heat source return pipe 12 is provided at the upper part of the hot water storage tank 4. A baffle plate 13 is provided at a position facing the inlet 12a in the hot water storage tank 4 at a predetermined interval from the inlet 12a to deflect the flow velocity vector of hot water flowing from the heat pump unit 2 and decelerate at the same time. Yes. The material of the baffle plate 13 is stainless steel, copper, resin, or the like, and is fixed to the inner surface of the hot water storage tank 4 in a substantially horizontal direction by a method such as welding, adhesion, or caulking. In addition, in this Embodiment, although the baffle board 13 is being fixed to the inner surface of the hot water storage tank 4, you may be fixing to the heat source machine return piping 12, for example.

  A protrusion 14 is provided on the inner surface above the hot water storage tank 4. The protrusion 14 is formed in a semicircular shape in which the cross section including the axial center of the body of the hot water storage tank 4 is a curved surface convex downward, and the protrusion 14 is provided over the entire circumference of the hot water storage tank 4. It has been. Thus, by providing the protrusion 14 over the entire circumference of the hot water storage tank 4, it is possible to effectively suppress an increase in medium temperature water without the hot water storage tank 4. The protrusion 14 is preferably provided so as to protrude 10% or more of the inner diameter of the body portion of the hot water storage tank 4.

  In the present embodiment, among the three parts of the stainless steel body part constituting the hot water storage tank 4 and the pair of lid parts sealing both ends of the body part, the sheet metal member of the lid part constituting the upper wall surface of the hot water storage tank 4 However, the protrusion 14 may be provided by bending the end of a part constituting the body of the hot water storage tank 4. As described above, the protruding portion 14 can be easily formed by bending the sheet metal member constituting the body portion of the hot water storage tank 4. Alternatively, the protrusion 14 may be manufactured as a separate part and fixed to the inner surface of the hot water storage tank 4 by a method such as welding, bonding, or caulking.

  Next, the boiling operation of the hot water storage type hot water supply device 1 and the flow field in the hot water storage tank 4 during the boiling operation will be described. When the boiling operation is started, the refrigeration cycle and the boiling circuit 16 are operated. On the refrigeration cycle side, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2a is sent to the water-refrigerant heat exchanger 2b and exchanges heat with the low-temperature water sent from the hot water storage tank 4 to the water-refrigerant heat exchanger 2b. Dissipates heat and becomes a high-pressure, low-temperature refrigerant. This refrigerant is depressurized by passing through the expansion valve 2c, and enters a gas-liquid two-phase state. Then, it flows into the evaporator 2d, absorbs heat from the outside air, and is evaporated and vaporized. The low-pressure refrigerant exiting the evaporator 2d is sucked into the compressor 2a and becomes high-temperature and high-pressure gas refrigerant again, and this cycle is repeated until boiling is completed.

  On the other hand, on the boiling circuit 16 side, the low-temperature water in the hot water storage tank 4 is sent from the outlet 11a provided near the bottom by the pump 5 to the water-refrigerant heat exchanger 2b through the heat source unit forward piping 11, and the refrigerant and heat High temperature hot water is made by exchanging and heating. This hot water is returned to the hot water storage tank through an inlet 12 a provided at the upper part of the hot water storage tank 4 through the heat source unit return pipe 12. This cycle is repeated until the hot water in the hot water storage tank 4 reaches a predetermined amount, and boiling is completed.

  When hot water and cold water are mixed in the hot water storage tank 4 during the boiling operation to form intermediate temperature water, the hot water temperature becomes unstable and the thermal efficiency decreases, so the amount of intermediate temperature water is possible. As few as possible is better. Therefore, as a temperature distribution in the hot water storage tank 4 during the boiling operation, the hot water heated by the heat pump unit 2 stays at the top to form a high temperature layer, and is supplied from the water source through the water supply pipe 6 to the bottom through the water supply port 6a. Low temperature water stays to form a low temperature layer, and the intermediate temperature layer formed between the two layers is not a layer formed by stirring the water in the hot water storage tank 4 with the inflow of hot water, but the high temperature layer and the low temperature layer. It is desirable that the layer is formed only by natural convection accompanying the temperature difference. That is, by suppressing the agitation by the hot water flowing into the hot water storage tank 4 to the minimum, the medium hot water formed in the hot water storage tank 4 can be minimized.

  In the present embodiment, the hot water heated by the heat pump unit 2 first flows into the hot water storage tank 4 from the inlet 12 a provided at the upper part of the hot water storage tank 4. A baffle plate 13 is provided at a position facing the inlet 12a in order to prevent the water in the hot water storage tank 4 from being agitated by the flow velocity vector going downward of the hot water hot water storage tank 4 flowing in to form the intermediate hot water. Yes. When the hot water collides with the baffle plate 13, the flow velocity vector of the hot water is deflected from the downward direction in the horizontal direction and is simultaneously decelerated.

  The hot water deflected by the baffle plate 13 and passed over the baffle plate 13 flows out along the inner surface of the hot water storage tank 4 and finally flows downward of the hot water storage tank 4. Although the hot water at this time is decelerated from the time when it flows in from the inlet 12a, it has a downward flow velocity vector, so that stirring occurs in a wide range in the hot water storage tank 4 as it is. Therefore, the flow velocity vector of the hot water is again deflected upward or horizontally by the protrusion 14 provided on the inner surface above the hot water storage tank 4 to limit the region where the water is stirred in the hot water storage tank 4 and the hot water is stored in the hot water storage tank 4. It is restrained that intermediate temperature water is formed by making it retain in the upper part of.

  That is, by providing such a protruding portion 14, the flow velocity vector field in the hot water storage tank 4 during the boiling operation has almost no variation depending on the location, at least in the cross section of the hot water storage tank 4 below the protruding portion 14. Since it becomes a vector field which goes to the downward direction of the hot water storage tank 4 uniformly, the stirring accompanying the production | generation of a vortex is suppressed and formation of intermediate temperature water is suppressed.

  Next, the principle of suppressing the scale 15 from being deposited on the bottom of the hot water storage tank 4 by the projection 14 will be described with reference to FIG. The scale 15 generated during the boiling operation circulates in the boiling circuit 16 including the heat pump unit 2 and the hot water storage tank 4 by the water flow created by the pump 5 provided in the hot water storage type hot water heater 1. When boiling is completed and the operation of the pump 5 is stopped, the scale 15 is deposited on the bottom of the hot water storage tank 4 by its own weight, but is provided near the bottom of the hot water storage tank 4 and is an outlet for sending water to the heat pump unit 2. When 11a is partially or completely blocked by the accumulated scale 15, the boiling operation is hindered.

  In the present embodiment, the scale 15 generated during the boiling operation and flowing into the hot water storage tank 4 together with the hot water moves in the hot water storage tank 4 by the flow field described above, but is provided on the inner surface of the hot water storage tank 4. Since the cross-sectional shape of the protrusion 14 is a substantially semicircular shape that protrudes downward, the scale 15 can be positively deposited on the protrusion 14 when the flow of hot water collides with the protrusion 14 and is deflected. . As a result, since the amount of the scale 15 accumulated at the bottom of the hot water storage tank 4 can be suppressed, the possibility that the outflow port 11a provided near the bottom of the hot water storage tank 4 is blocked by the scale 15 and the boiling operation is hindered is reduced. Is done.

  In order to maximize the above effect, for example, the protrusion 14 may form an acute angle with the wall surface of the body of the hot water tank 4 depending on the flow rate of hot water flowing from the heat pump unit 2 into the hot water tank unit 3. The shape may protrude upward, or may be a box shape.

  Note that the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and developments are included within the scope of the technical idea of the present invention.

  DESCRIPTION OF SYMBOLS 1 Hot water storage type water heater, 2 Heat pump unit (heat source machine), 4 Hot water storage tank, 6 Water supply pipe, 10 Hot water supply pipe, 12a Inflow port, 13 Baffle plate, 14 Protrusion part, 16 Boiling circuit.

Claims (6)

A heat source machine that generates hot water by heating water;
A hot water storage tank having a cylindrical body, and installed so that the axis of the body is in the vertical direction;
A water supply pipe having one end connected to a water source and the other end connected to a lower portion of the hot water storage tank;
Hot water taken from the lower part of the hot water storage tank, heated by the heat source machine, and then heated to return from the inlet provided at the upper part of the hot water storage tank to the hot water storage tank;
A hot water supply pipe having one end connected to the upper part of the hot water storage tank;
A baffle plate provided in a substantially horizontal direction at a distance from the inlet at a position facing the inlet in the hot water storage tank;
A hot water storage type water heater provided with an inner surface of the hot water storage tank, and a projection that deflects hot water that has passed above the baffle plate.   The hot water storage type water heater according to claim 1, wherein the protrusion is provided over the entire circumference of the hot water storage tank.   The hot water storage type hot water supply device according to claim 1 or 2, wherein the protrusion includes a curved surface that protrudes downward in a cross section including an axis of the body portion.   The hot water storage type hot water supply apparatus according to claim 1 or 2, wherein the protruding portion protrudes upward so as to form an acute angle with a wall surface of a body portion of the hot water storage tank.   The hot water storage type hot water supply apparatus according to any one of claims 1 to 4, wherein the protruding portion protrudes by 10% or more of an inner diameter of a body portion of the hot water storage tank.   The hot water storage type hot water supply apparatus according to any one of claims 1 to 5, wherein the protrusion is configured by bending a sheet metal member constituting a wall surface of the hot water storage tank.

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