Heat exchanger for bath water, and heat pump for bath water heating

Abstract

To provide a heat exchanger for bath water that can heat bath water with high efficiency, and eliminates deterioration of a heat exchanger due to dirt of bath water, and has a small manufacturing cost.SOLUTION: A heat exchanger (9) for bath water is composed of a large-diameter resin pipe (15) of a specified length, and a small-diameter metal pipe (16) inserted into the resin pipe (15). Bath water (3) from a bathtub (2) is introduced into one end part of the resin pipe (15), discharged from the other end part, and then returned to the bathtub (2). A refrigerant pumped by a compressor (7) of a heat pump (1) is introduced into the other end part of a metal pipe (16), discharged from the one end part, and then sent to the expansion valve (11).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a bath water heat exchanger for heating bath water, and a bath water heating heat pump equipped with the bath water heat exchanger. [Background technology]

[0002] In systems that use a heat pump to reheat bath water in a bathtub, the heat pump and the bath water are generally not directly exchanged, but a heat exchanger is interposed between them. The heat exchanger exchanges heat with the condenser of the heat pump, and then with the bath water in the bathtub, and the heat medium, such as water, circulates within the heat exchanger. If the heat pump and the bath water were to directly exchange heat, dirt from the bath water would adhere to the condenser of the heat pump, causing a deterioration in performance or even a breakdown, but this can be prevented. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-37963 A

[0004] Patent Document 1 describes a condenser, i.e., a heat exchanger, that can directly exchange heat between the refrigerant of a heat pump and the bath water in a bathtub. This heat exchanger is made of metal and looks like a single thick pipe, but inside it is divided by multiple inner walls, and each of the divided sections is a pipe. In other words, multiple pipes are formed by the inner walls. Of these multiple pipes, one pipe formed in the center is a relatively large-diameter pipe for bath water, through which bath water from the bathtub flows, is heated, and is returned to the bathtub. Around this pipe for bath water, multiple small-diameter pipes, i.e., hot water supply pipes, are formed surrounding the pipe for bath water, and hot water supply water, i.e., purified water, is flowed and heated. Outside these multiple hot water supply pipes, multiple small-diameter refrigerant pipes through which the refrigerant of the heat pump flows are formed. Because of this configuration, the refrigerant of the heat pump can directly heat the purified water for hot water supply, or reheat the bath water in the bathtub. Summary of the Invention [Problem to be solved by the invention]

[0005] If the heat exchanger device is interposed between the heat pump and the bathtub as in the conventional system, the bath water containing dirt does not directly enter the condenser of the heat pump, so there is no risk of dirt adhering to the condenser of the heat pump or damaging the condenser. However, since there is no direct heat exchange between the refrigerant of the heat pump and the bath water, it is not possible to increase the efficiency. Therefore, there is a problem that the cost required for heating the bath water is high. In contrast, the heat exchanger described in Patent Document 1 is highly efficient because it is designed to be filled with the refrigerant of the heat pump and the bath water from the bathtub. In other words, the cost required for heating the bath water is low. In addition, since the bath water pipe in this heat exchanger has a relatively large diameter, it is excellent in that it is less likely to be blocked even if dirt adheres to it. However, the heat exchanger described in Patent Document 1 requires the provision of multiple inner walls in the metal pipe, and the structure is complex and difficult to process. This is expected to result in high manufacturing costs. In addition, although this heat exchanger has an external appearance like a single thick pipe, the internal structure is complex, making it difficult to bend it and to make it compact, such as by making it into a convex shape. However, this also poses the problem that the heat exchanger becomes bulky and takes up a lot of installation space.

[0006] The present invention aims to solve the above problems. That is, the object is to provide a heat exchanger for bath water that can heat the bath water in a bathtub with high efficiency, does not have the risk of deterioration of the heat exchanger due to contamination of the bath water, and has low manufacturing costs. Another object is to provide a heat exchanger for bath water that can be made compact. [Means for solving the problem]

[0007] The bath water heat exchanger of the present invention is composed of a large-diameter resin pipe of a specified length and a small-diameter metal pipe inserted into the resin pipe. Bath water from the bathtub is introduced into one end of the resin pipe and discharged from the other end to be returned to the bathtub. The refrigerant pumped in by the compressor of the heat pump is introduced into the other end of the metal pipe and discharged from one end to be sent to the expansion means.

[0008] In another embodiment of the invention, the metal tube in the bath heat exchanger is a flexible stainless steel tube. In another embodiment of the invention, the bath heat exchanger is configured to be wound in a circular shape several times and stacked. Effect of the Invention

[0009] The bath water heat exchanger according to the present invention is highly efficient because it heats the bath water from the bathtub directly with the refrigerant from the heat pump. The bath water heat exchanger has a simple structure consisting of a large-diameter plastic pipe of a given length and a small-diameter metal pipe inserted into the plastic pipe. This reduces manufacturing costs. Furthermore, since the bath water from the bathtub passes through the large-diameter plastic pipe, even if dirt from the bath water adheres to the pipe, there is no risk of blockage due to the large inner diameter. In other words, there is no risk of deterioration of the heat exchanger due to dirt from the bath water.

[0010] According to yet another invention, the metal pipe is made of a flexible pipe made of stainless steel. Since it is made of stainless steel, even if dirt from the bathtub adheres to the inner wall of the resin pipe or the outer circumferential surface of the metal pipe, the dirt can be removed by flowing a relatively high concentration of hypochlorous acid through the resin pipe. This is because stainless steel is not corroded by hypochlorous acid. In addition, since it is made of a flexible pipe, it can be curved. Since the resin pipe can also be easily curved, the bathtub heat exchanger can be curved into a desired shape. This makes it possible to make the bathtub heat exchanger compact and save the installation space. According to yet another invention, the bathtub heat exchanger is in a state of being wound in a circle several times and stacked. The bathtub heat exchanger can be made even more compact. According to yet another invention, the bathtub heat exchanger is provided with a refrigerant pipe connector and is detachable from the refrigerant pipe of the heat pump. Therefore, the bathtub heat exchanger can be placed near the bathtub or a filtration device that filters the bathtub water, increasing the freedom of installation. Furthermore, if the bath water heat exchanger deteriorates, it can be easily replaced. [Brief description of the drawings]

[0011] [Figure 1]1 is a front view showing a heat pump for heating bath water according to an embodiment of the present invention and a bathtub. [Diagram 2] 1 is a perspective view showing, in partial cross section, a bathwater heat exchanger according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Bathtubs that are eligible for heat pumps for heating bath water> The present embodiment will be described below. As shown in FIG. 1, a heat pump 1 for heating bath water according to this embodiment heats bath water 3 in a bathtub 2. The bathtub 2 may be a small one for home use, but this embodiment is mainly intended for large bathtubs 2 in public baths, nursing homes, and the like. The bathtub 2 in such facilities is used while being circulated and filtered, and the bath water 3 is drained periodically, for example, once a week. The bathtub 2 is then cleaned, and new bath water is supplied from a hot water supply pipe 5. The bath water 3 supplied to the bathtub 2 is used until it is next drained, and is reheated as appropriate. The heat pump 1 for heating bath water according to this embodiment reheats the bath water 3 to maintain it at an appropriate temperature.

[0013] <Heat pump for heating bath water> The bath water heating heat pump 1 according to this embodiment includes a compressor 7 for compressing a refrigerant, a bath water heat exchanger 9 according to this embodiment, i.e., a condenser, which will be described in detail below, an expansion means, i.e., an expansion valve 11, for reducing the pressure of the refrigerant, and an evaporator 12 for absorbing heat from the outside air, which are connected by a refrigerant pipe 13. The expansion means may be a capillary tube or the like. Although the bath water heating heat pump 1 is shown as an integrated unit in FIG. 1, a heat pump main body 14 including the compressor 7 and the expansion valve 11 is provided in a machine room or the like, and the evaporator 12 is installed outside the room. As will be described next, the bath water heat exchanger 9 according to this embodiment is detachable from the refrigerant pipe 13, and can be installed in a location different from the heat pump main body 14. In this embodiment, the bath water heat exchanger 9 is set in a location close to the bathtub 2.

[0014] <Heat exchanger for bath water> As shown in Fig. 2, the bath water heat exchanger 9 according to this embodiment is roughly composed of a large-diameter resin pipe 15, a small-diameter metal pipe 16 inserted in the resin pipe 15, and connecting structures 18, 18 provided at both ends. These are several meters long, for example 5 meters, and are wound in a circular shape several times and stacked, that is, formed in a spiral shape. In other words, it is compact.

[0015] The resin pipe 15 is made of, for example, polyvinyl chloride, which is flexible and resistant to corrosion by chemicals, though the type of resin is not limited. As will be explained later, bath water 3 flows through the pipe, and dirt may adhere to the inner wall surface. Chemicals such as disinfectants and detergents may be poured to remove dirt, but the resin pipe 15 will not deteriorate. The resin pipe 15 may contain short reinforcing fibers such as glass fiber, i.e., fillers, or may have coiled thin steel wires embedded in it. Reinforcing in this way has the effect of making it less susceptible to damage by internal pressure or external forces.

[0016] In this embodiment, the metal pipe 16 is made of stainless steel and is formed into a bellows shape, so-called flexible pipe. Since it is made of stainless steel, it will not corrode even if chemicals such as cleaning agents and disinfectants flow around it. And since it is a flexible pipe, it can be easily bent. Furthermore, the flexible pipe has the effect of increasing the efficiency of heat exchange. The bath water 3 is placed in the resin pipe 15. That is, it flows through the gap between the inner wall of the resin pipe 15 and the outer circumferential surface of the metal pipe 16. Since the metal pipe 16 is a flexible pipe and has unevenness formed on the outer circumferential surface, turbulence is generated in the flow of the bath water, increasing the efficiency of heat exchange.

[0017] The connecting structures 18, 18 provided at both ends of the resin pipe 15 and the metal pipe 16 each have a bath water supply / discharge port 20, 20 for supplying / discharging the bath water 3, and a refrigerant supply / discharge port 21, 21 for supplying / discharging the refrigerant circulating in the heat pump 1 for heating the bath water. The bath water supply / discharge port 20, 20 communicates with the inside of the resin pipe 15. The bath water 3 introduced from the bath water supply / discharge port 20 of one connecting structure 18 of the bath water heat exchanger 9 flows through the resin pipe 15 and is discharged from the bath water supply / discharge port 20 of the other connecting structure 18. On the other hand, the refrigerant supply / discharge ports 21, 21 are connected to the metal pipe 16. The refrigerant introduced from the refrigerant supply / discharge port 21 of the other connecting structure 18 of the bath water heat exchanger 9 is discharged from the refrigerant supply / discharge port 21 of the one connecting structure 18. The refrigerant supply / discharge ports 21, 21 have refrigerant pipe connectors 21a, 21a at their tips, allowing them to be easily connected to and disconnected from the refrigerant pipe 13 of the heat pump 1 for heating bath water.

[0018] The bath water heat exchanger 9 according to the present embodiment, which is configured as described above, is connected to a bathtub 2 as shown in Fig. 1. That is, the bathtub 2 is formed with a bath water outlet 23 and a bath water return port 24. A pump 25 and a filtration device 26 are provided in the piping from the bath water outlet 23, and the piping is connected to a bath water supply / discharge port 20 at one end of the bath water heat exchanger 9 according to the present embodiment. The bath water supply / discharge port 20 at the other end of the bath water heat exchanger 9 is connected to the bath water return port 24. In the bath water heating heat pump 1, the refrigerant compressed in the compressor 7 is supplied from the refrigerant supply / discharge port 21 at the other end, discharged from the refrigerant supply / discharge port 21 at one end, and sent to the expansion valve 11.

[0019] Therefore, when the pump 25 and the compressor 7 are driven, the bath water 3 in the bathtub 2 is filtered by the filtration device 26 to remove dirt, and then the bath water 3 is fed into the bath water heat exchanger 9 of this embodiment through the bath water supply and discharge port 20 at one end. Meanwhile, the refrigerant is fed into the bath water heat exchanger 9 through the refrigerant supply and discharge port 21 at the opposite end. Heat is exchanged between the refrigerant and the bath water 3, and the bath water 3 is heated. The heated bath water 3 is returned to the bathtub 2, and the refrigerant that has released heat is sent to the expansion means, i.e., the expansion valve 11. The refrigerant circulates through the bath water heating heat pump 1, and the bath water 3 continues to be supplied to the bath water heat exchanger 9 of this embodiment, where it is heated and returned to the bathtub 2. This allows the bath water 3 to be maintained at an appropriate temperature.

[0020] The bath water heat exchanger 9 according to this embodiment is highly efficient because it directly exchanges heat between the bath water 3 and the refrigerant. Furthermore, compared to turning cold water into hot water, it circulates and reheats the relatively warm bath water 3. Therefore, the amount of heat exchanged is relatively small, and the compressor 7 can be driven with a relatively low output. In other words, it has the excellent feature of consuming little power. [Explanation of symbols]

[0021] 1 Heat pump for heating bath water 2 Bathtub 3 Bathtub 5 Hot water pipe 7 Compressor 9 Bath water heat exchanger 11 Expansion valve 12 Evaporator 13 Refrigerant pipe 14 Heat pump main body 15 Resin tube 16 Metal tube 18 Connection structure part 20 Bath water supply / exhaust port 21 Refrigerant supply / discharge port 23 Bath water outlet 24 Bath water return port 25 Pump 26 Filtration Equipment

Claims

1. A large diameter plastic pipe of a predetermined length; a small-diameter metal tube inserted into the resin tube; Bath water from the bathtub is poured into one end of the resin pipe and discharged from the other end and returned to the bathtub. The refrigerant pumped in by the compressor of the heat pump is introduced into the other end of the metal tube and discharged from one end thereof to be sent to the expansion means.

2. 2. The bath heat exchanger of claim 1, wherein said metal tube comprises a flexible tube made of stainless steel.

3. 3. The bath water heat exchanger according to claim 1, wherein the bath water heat exchanger is wound in a circular shape a number of times and laminated.

4. 3. The bath water heat exchanger according to claim 1, further comprising a refrigerant pipe connector, the refrigerant pipe being detachable from the refrigerant pipe of the heat pump.

5. Equipped with a bath water heat exchanger that condenses the refrigerant, The bath water heat exchanger includes a large-diameter resin pipe having a predetermined length, a small-diameter metal tube inserted into the resin tube; Bath water from the bathtub is poured into one end of the resin pipe and discharged from the other end and returned to the bathtub. The heat pump for heating bath water is configured such that the refrigerant pumped by the compressor of the heat pump is introduced from the other end of the metal tube and discharged from one end to the expansion means.

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