JP5040529B2 - Heat pump type water heater - Google Patents

Description

The present invention relates to a heat pump type water heater using a heat storage body used to the heat storage heat in the heat storage tank.

  Conventionally, as a device for supplying a fluid such as hot water supply or low-pressure steam, a configuration in which a heat storage tank is provided to increase thermal efficiency has been provided. As a heat storage type, there are a heat storage tank type, a capsule type heat storage type, and a distributed heat storage type.

  In the heat storage tank type, there is a shell and tube type in which a metal fin tube is arranged in the heat storage tank, a supply fluid is circulated in the heat storage tank, and a heat storage material is filled in the metal fin tube (for example, Patent Document 1). ). In some cases, a supply fluid is caused to flow in a metal fin tube, and a heat storage material is filled in the heat storage tank. A metal fin tube is one in which a large number of fins (blades) are provided around a metal tube to increase the heat exchange rate inside and outside the tube. As another configuration of the heat storage tank type, there is a metal plate heat exchanger type in which a flow path of a heat storage material and a supply fluid is alternately provided between plates. This increases the heat exchange efficiency by increasing the area where the supply fluid and the heat storage material are adjacent to each other.

  The capsule-type heat storage type is a configuration in which a metal or resin capsule is filled with a heat storage material and stored in a heat storage tank (for example, Patent Document 2). The heat storage tank does not require a special structure and has an advantage that maintenance such as cleaning is easy.

Examples of the dispersion type heat storage type include an emulsion type and a microcapsule type (for example, Patent Document 3) in which a heat storage material is dispersed in water using a surfactant, and the like. The distributed heat storage type has the advantage of high heat exchange efficiency because the heat storage material is fine.
JP 2001-031957 A JP 2003-329383 A JP 2006-046773 A

  There are various heat storage methods as described above, but heat storage materials generally have low thermal conductivity, change in volume during the phase change between condensation and melting, and want to increase heat exchange efficiency. There is a problem.

  In the heat storage tank type, in order to increase the heat transfer area in order to increase the heat exchange efficiency, it is necessary to lengthen the entire length of the metal fin tube or to increase the number of fins. When using a plate, it is necessary to increase the area of the plate. In these cases, since the weight of the entire heat storage tank becomes heavy, a strength member is required, and the cost tends to increase. In addition, since there is a high possibility that the heat storage tank and the heat exchanger are damaged due to the volume change at the time of phase change, a complicated mechanism for providing expandability such as using a flexible tube is necessary.

  In the capsule-type heat storage type, in order to withstand the pressure due to expansion accompanying the phase change of the heat storage material, the heat storage capsule is formed in a spherical shape and a gap is left inside. However, since the heat conductivity of the heat storage material is low, the heat stored in the capsule center (back) cannot be used, and the heat storage efficiency has deteriorated.

  In the distributed heat storage type, since it is necessary to flow the dispersed heat storage material, the filling rate of the heat storage material is limited, and the heat storage density is low. Further, in order to increase the heat storage density, the heat storage material is mixed with the supply fluid, and therefore, a configuration for separation using evaporation, levitation, or the like is necessary. Further, since the particles are dispersed, the probability of canceling the supercooling of individual particles is lowered and the degree of supercooling is increased.

  Further, in a water heater, unlike a heater or the like, water as a supply fluid is directly put into a human mouth (oral). Therefore, there is a problem that the supply fluid must be circulated in a clean and safe state.

Accordingly, an object of the present invention is to provide a heat pump type water heater using a heat storage body that has high heat exchange efficiency and can store heat in a safe state even when it is introduced into an orally supplied fluid.

In order to solve the above problems, a typical configuration of a heat pump type water heater according to the present invention includes an air heat exchanger that performs heat exchange between a heat medium and outside air, a compressor that compresses and heats the heat medium, and a heat A water heat exchanger that performs heat exchange between the medium and water, an expansion valve that expands and cools the heat medium, a heat storage tank that stores water heated by the heat medium, and a heat storage body that is housed in the heat storage tank The heat storage body includes a plurality of tubular bodies arranged in parallel, a collection portion of box-shaped bodies communicating with the plurality of tubular bodies, and a heat storage material filled in the tubular body and the collection portion. The part is flexible and can be deformed according to the volume change of the heat storage material, and the tubular body and the assembly part are joined by press-fitting a heated wedge into the tubular body and heat-welding It is characterized by .

The configuration of the heat storage body is a capsule-type heat storage type. Since the surface area of the tubular body is increased, the heat exchange efficiency is increased. And since each tubular body is connected by the gathering part, when solidification nuclei occur in any tubular body, the condensation propagates to other tubular bodies, and quickly and reliably solidifies to effectively use latent heat. Can do. Furthermore, since at least a part of the aggregate portion can be deformed, volume change due to phase change can be absorbed.

A plurality of tubular bodies are arranged in parallel . As a result, the strength as a whole can be improved, and the effect of the propagation of condensation due to the communication of the tubular bodies and the deformation of the aggregate portion with respect to the volume change can be obtained more effectively.

The assembly portion is a box-shaped body having a rectangular outer shape and a hollow inside, and a plurality of tubular bodies are joined to one surface of the box-like body, and a surface facing the joined surface is flexible. to a variant can be der to. As a result, the distance from the plurality of arranged tubular bodies to the flexible surface becomes substantially equal, so that even if the heat storage material in the tubular body and a part of the gathering portion solidifies first, the remaining The same effect can be obtained in the tubular body. As a specific configuration for imparting flexibility, for example, it is conceivable to form a box-shaped body with resin and to reduce the thickness of the opposing surface. Moreover, it becomes possible to accumulate | store a thermal storage body and to accommodate in a thermal storage tank by making the external shape of a gathering part into a rectangle.

The tubular body and the collecting part it is joined by thermal welding. When it is assumed that the supply fluid is orally used, it is not preferable to use an adhesive. However, according to the above configuration, since the tubular body or the material of the gathering portion is used for the joining, it can be directly injected into an oral fluid.
In particular, when a heated wedge is press-fitted into the opening end of the tubular body and heat-welded, the end portion of the tubular body is in a state of spreading as close as possible. Then, the thickness of the joined portion between the tubular body and the gathering portion is increased, and the joined portion can be made strong while being able to be bonded very firmly. Therefore, in the heat storage body in which expansion and contraction are repeated, the joint portion can be prevented from rupturing, and the durability can be dramatically improved.

  It is preferable that the tubular body and the aggregate portion are formed of polypropylene. Polypropylene is relatively resistant to heat and has very little elution at a temperature of 100 degrees or less, which is the target of a water heater (cannot be detected). Therefore, it can also be directly injected into an orally fluid. In addition to polypropylene, polycarbonate and polyvinylidene chloride can be used in the same manner.

  When using a heat storage material insoluble in water, it is preferable to add salt to the heat storage material filled in the tubular body and the gathering portion. In the water heater using the above heat storage body, when it is configured to detect leakage of the heat storage material using conductivity, it is difficult to ionize depending on the material of the heat storage material, and the change in conductivity cannot be detected There is. Therefore, as described above, if salt is added to the heat storage material, which has little effect on the human body even if it is taken orally, the salt will also elute if the heat storage material leaks, and the salt will be well ionized to detect changes in conductivity. It is possible to detect the leakage of the heat storage material safely and reliably.

By using the heat storage body having the above-described configuration , it is possible to provide a heat pump type water heater with extremely high heat exchange efficiency. In particular, since the heat storage material often has a freezing point around 60 ° C., it is more suitable to use CFC rather than CO2 as the heat medium.

  It is preferable that the water flow path including the heat storage tank is provided with a conductivity detection unit for detecting leakage of the heat storage material filled in the heat storage body. Thereby, it becomes possible to detect the leakage of the heat storage material quickly.

ADVANTAGE OF THE INVENTION According to this invention, the heat pump type hot water heater using the heat storage body which has high heat exchange efficiency, absorbs the volume change of the heat storage material, and can store heat in a safe state even if it is put into an oral supply fluid Can be provided.

(Heat storage)
An embodiment of a heat storage body and a heat pump type water heater according to the present embodiment will be described. Note that dimensions, materials, and other specific numerical values shown in the following examples are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified.

  FIG. 1 is a diagram illustrating the configuration of a heat storage body according to the present embodiment. A heat storage body 1 shown in FIG. 1 includes a plurality of tubular bodies 10, a collection portion 20 communicating with the plurality of tubular bodies 10, and a heat storage material 30 filled in the tubular body and the collection portion (see FIG. 2D described later). ). As will be described later, the tubular body 10 is directly charged into a supply fluid such as water stored in a heat storage tank. The tubular bodies 10 are arranged in parallel, and aggregate portions 20 are arranged at both ends thereof. As will be described later, a diaphragm 22 (diaphragm) that can be deformed according to a change in the volume of the heat storage material is provided in a part of the collecting portion 20.

  FIG. 2 is a front view and a cross-sectional view for explaining the structure of the heat storage body. 2 (a) is a front view of the heat storage body 1, FIG. 2 (b) is a cross-sectional view taken along the line AA of the joint portion between the tubular body and the gathering portion, and FIG. 2 (c) is the gathering portion. BB sectional view seen from the 20 side, FIG.2 (d) is sectional drawing of the junction part of a tubular body and a gathering part. FIG. 3 is a diagram illustrating the joining of the tubular body and the gathering portion.

  The tubular body 10 is a thin cylindrical member made of resin. Since the supply fluid needs to flow between the tubular bodies 10, the tubular bodies 10 are arranged with a predetermined interval as shown in FIG. In the present embodiment, they are arranged in a staggered state in order to increase the density while having a constant interval.

  The joint portion of the aggregate portion 20 of the tubular body 10 is joined by thermal welding. When it is assumed that the supply fluid is orally used, it is not preferable to use an organic adhesive. However, according to the above configuration, since the tubular body or the material of the gathering portion is used for the joining, it can be directly injected into an oral fluid.

  As a specific example of heat welding, as shown in FIG. 3A, a hole 20a into which the tubular body 10 can be inserted is provided in the assembly portion 20 in advance. Then, by pressing the heated wedge 8 (wedge) as shown in FIG. 3 (b), heat welding can be performed as shown in FIG. 3 (c). Thereby, as shown in FIG.2 (d), when a junction part is seen from the gathering part 20 side, the tubular body edge part 10a has spread so that it closely_contact | adhered.

  The gathering portion 20 is a box-shaped body having an outer shape of a rectangle (a rectangular parallelepiped) and a hollow inside. Moreover, as shown in FIG.2 (d), the surface which opposes the surface which joined the tubular body 10 of the gathering part 20 has flexibility, and the diaphragm 22 (it can deform | transform according to the volume change of a thermal storage material ( Diaphragm) is provided. The diaphragm 22 is made of the same material as that of the other surface of the aggregate portion 20, but is made flexible by being made of a material thinner than the other surfaces. The diaphragm end portion 22a is thermally welded to the assembly portion 20 similarly to the tubular body end portion 10a.

  The heat storage material 30 sealed as described above is filled with a heat storage material 30. The heat storage material 30 can be used as long as it undergoes a phase change in the use temperature range, but in this embodiment, since it is intended for oral water as a supply fluid, the food additive sodium acetate trihydrate, Threitol, erythritol (artificial sweetener), and paraffin can be used. Among them, sodium acetate trihydrate has a freezing point at about 60 ° C., so that not only sensible heat but also latent heat can be used in hot water, and a high heat storage amount is obtained by using the phase change between solidification and melting. be able to.

  According to the heat storage body 1 having the above-described configuration, heat exchange with water that is a supply fluid is performed around the small-diameter tubular body 10. Therefore, compared with the spherical heat storage capsule, the heat transfer area is extremely wide and the distance from the surface of the tubular body 10 to the inside thereof is short, so that the temperature gradient is increased and the heat exchange efficiency can be increased.

  FIG. 4 is a diagram for explaining propagation of coagulation. When the heat storage material 30 is solidified, since the heat storage material 30 is sealed, the probability of occurrence of solidification nuclei is not high. For this reason, overcooling is caused, sensible heat is obtained but latent heat cannot be obtained, and the ability as a heat storage material may be reduced. In particular, when the probability of nucleation of the heat storage material 30 is low, overcooling is likely to occur. One solution to this problem is to incorporate a supercooling release agent, but there is a high possibility that the generation of solidification nuclei will be delayed inside the small-diameter tubular body 10.

  However, when the respective tubular bodies 10 are communicated with each other through the aggregate portion 20 as described above, when solidification nuclei are generated in any of the tubular bodies 10 as shown in FIG. Coagulation propagates to other tubular bodies 10 as well. Therefore, it is possible to solidify quickly and reliably and to effectively use latent heat.

  FIG. 5 is a diagram for explaining the response to the volume change accompanying the phase change of solidification or melting. First, since the tubular body 10 has a small diameter, the strength of the structure can be increased (if the wall thickness is the same, the thinner the diameter, the stronger the buckling), and it can withstand volume expansion during melting. . For example, when the heat storage material 30 at both ends of the tubular body 10 is solidified and its middle part is melted, a portion (in a slurry form) where the melted heat storage material 30 is solidified is pushed out to the collecting part 20. The tubular body 10 is not damaged. The expanded volume of the heat storage material flows out to the collecting portion 20, but as shown in FIG. 5 (a), the diaphragm 22 is deformed in the bulging direction without damaging the increasing volume change. Can be absorbed.

  On the other hand, the volume shrinks when solidifying, but as the diaphragm 22 is deformed in the direction in which it is sucked as shown in FIG. .

  Here, the tubular body 10 is preferably thin because it is necessary to increase the heat exchange efficiency and ensure the strength as a structure, and can be, for example, 6 mmφ. The thinner the tubular body 10 is, the better. However, considering the balance with the strength, it can be set to 0.2 mm, for example. The length of the tubular body 10 is limited to 200 mm or less, more preferably 150 mm or less, considering the balance with strength, because there is a limit in the distance for solidification propagation.

  In addition, by arrange | positioning the aggregation part 20 at the both ends of the tubular body 10, the intensity | strength as a whole can be improved. Further, the effect of propagation of condensation due to the communication of the tubular body 10 can be obtained on both sides of the tubular body 10, and the length of the tubular body 10 is made longer than the case where the collecting portion 20 is provided only on one side. can do.

  There is no restriction | limiting about the dimension or volume of the gathering part 20, and each tubular body 10 should just be connected. The aggregate portion 20 can be thickened so as not to be deformed by the volume change of the heat storage material 30, and the diaphragm 22 can be formed with a thickness of, for example, 1.5 mm so as to have flexibility.

  Further, the plurality of tubular bodies 10 are arranged in parallel, and the diaphragm 22 is provided on the surface opposite to the surface to which the tubular bodies 10 are connected, so that the distance from the plurality of arranged tubular bodies 10 to the diaphragm 22 is substantially equal. Become. Thereby, even if it is a case where a part of tubular body 10 and gathering part 20 solidifies previously, the same operation can be acquired in remaining tubular bodies 10.

  The tubular body 10 and the gathering portion 20 are preferably formed of polypropylene. Polypropylene has a characteristic that it is relatively resistant to heat and has very little elution at a temperature of 100 degrees or less, which is a target of a water heater (a level that cannot be detected by a measuring device). Therefore, it can be directly added to water (feed fluid) to be orally administered. In addition to polypropylene, polycarbonate and polyvinylidene chloride can be used in the same manner.

(Heat pump type water heater)
Next, the heat pump type water heater according to the present embodiment will be described with reference to FIG. The heat pump type water heater 50 includes an air heat exchanger 52 that performs heat exchange between the heat medium and the outside air, a compressor 54 that compresses and heats the heat medium, and a water heat exchanger 56 that performs heat exchange between the heat medium and water. And an expansion valve 58 for expanding and cooling the heat medium. Furthermore, the heat storage tank 60 for storing the water heated by the water heat exchanger 56, the water storage tank 62, the water supply valve 64 for supplying water to the water storage tank 62, and the water heat exchanger 56 from the heat storage tank 60 through the water storage tank 62. A pump 66 that circulates water and a mixing valve 68 that supplies hot water by mixing hot water from the heat storage tank 60 and the water supply valve 64 are provided.

  The heat storage body 1 is accommodated in the heat storage tank 60. A plurality of 1s are accommodated in the heat storage tank 60, and the heat of water (hot water) supplied from the water heat exchanger 56 is accumulated. Thereby, it becomes possible to hold | maintain the heat | fever in the heat storage tank 60 effectively (heat storage). In addition, since the outer shape of the assembly portion 20 is rectangular, the heat storage bodies 1 can be stacked in an orderly manner and accommodated in the heat storage tank 60.

According to the above configuration, it is possible to provide a heat pump type water heater with extremely high heat exchange efficiency. In particular, since the heat storage material often has a freezing point around 60 ° C., it is suitable for a floor heating combined use type water heater. In addition, it is more suitable for the heat pump to use CFCs that increase the enthalpy increment with respect to the pressure at a temperature of 60 ° C. or lower than CO _{2 in} which the pressure and enthalpy always change uniformly in the supercritical state. ing.

  Further, the water flow path including the heat storage tank 60 is provided with a conductivity detecting unit 70 for detecting leakage of the heat storage material 30 filled in the heat storage body 1. Thereby, it becomes possible to detect the leakage of the heat storage material quickly.

  However, depending on the material (type) of the heat storage material 30, it is difficult to ionize. For example, when paraffin is used as the heat storage material 30, a change in conductivity may not be detected even if it leaks. For this reason, it is preferable to add salt to the heat storage material 30. Even if the salt is orally administered, the human body is not affected, and the salt can be well ionized to detect the change in conductivity, so that the leakage of the heat storage material can be detected safely and reliably.

  Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

The present invention can be utilized as a heat pump type water heater using a heat storage body used to the heat storage heat in the heat storage tank.

It is a figure explaining the structure of a thermal storage body. It is the front view and sectional drawing for demonstrating the structure of a thermal storage body. It is a figure explaining joining of a tubular body and a gathering part. It is a figure explaining propagation of coagulation. It is a figure explaining the response | compatibility to the volume change accompanying the phase change of solidification or melting. It is a figure explaining a heat pump type water heater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Thermal storage body 8 ... Wedge 10 ... Tubular body 10a ... Tubular body end part 20 ... Collecting part 20a ... Hole 22 ... Diaphragm 22a ... Diaphragm end part 30 ... Thermal storage material 50 ... Heat pump type hot water heater 52 ... Air heat exchanger 54 ... Compressor 56 ... water heat exchanger 58 ... expansion valve 60 ... heat storage tank 62 ... water storage tank 64 ... water supply valve 66 ... pump 68 ... mixing valve 70 ... conductivity detector

Claims (4)

  An air heat exchanger for exchanging heat between the heat medium and outside air;
  A compressor for compressing and heating the heat medium;
  A water heat exchanger for exchanging heat between the heat medium and water;
  An expansion valve for expanding and cooling the heat medium;
  A heat storage tank for accumulating water heated by a heat medium;
  A heat storage body housed inside the heat storage tank,
  The heat storage body is
  A plurality of tubular bodies arranged in parallel;
  An assembly of box-shaped bodies communicating with the plurality of tubular bodies;
  The tubular body and a heat storage material filled in the gathering part,
  The gathering portion has flexibility and can be deformed according to the volume change of the heat storage material,
  The heat pump type hot water heater, wherein the tubular body and the collecting portion are joined by press-fitting a heated wedge into the tubular body and heat-welding.   The heat pump type water heater according to claim 1, wherein the tubular body and the gathering portion are made of polypropylene.   The heat pump type hot water heater according to claim 1 or 2, wherein salt is added to the heat storage material filled in the tubular body and the collecting portion. The electrical conductivity detection part for detecting the leakage of the thermal storage material with which the said thermal storage body was filled was provided in the flow path of the water containing the said thermal storage tank, The any one of Claims 1-3 characterized by the above-mentioned. 2. A heat pump type water heater according to item 1 .

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