Heat exchange unit

Abstract

To provide a heat exchange device easy to maintain for suppressing the heat energy loss of heat-exchanged fluid as much as possible during high temperature drainage.SOLUTION: A support member has at least a right circular cylinder part, and a heat transfer medium distribution pipe is molded in a spiral shape along the outer shape of the support member while being turned around a vertical axis so as to set an inflow port of heat transfer medium on the lowermost end side and an outflow port on the uppermost end side and supported by the support member. A cover body is provided outside the heat transfer medium distribution pipe. The cover body has at least a lateral face part which is a vertical side face part provided in parallel to the right circular cylinder part of the support member, with its upper and lower bottom face opened. A space between the support member and the cover body is a guide flow passage where the heat-exchanged fluid flows down along the outer surface of the heat transfer medium distribution pipe.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat exchange unit, and to a falling film type heat exchanger in which heat exchange is performed by causing a heat medium flowing inside a heat transfer tube and a heat exchange fluid to flow down in the form of a thin film on the outer surface of the heat transfer tube. [Background technology]

[0002] The need for energy conservation has further increased with the government setting a goal of reducing carbon dioxide (CO2) emissions from energy sources, which account for the majority of greenhouse gases, to zero by 2050. When talking about energy conservation, electrical energy comes to mind, but on the other hand, although thermal energy is consumed in many processes, such as production activities at companies' factories, it does not seem to have penetrated as familiar an approach to energy conservation measures as electrical energy.

[0003] One well-known energy conservation measure from the perspective of thermal energy is the large-scale initiative undertaken by local governments and other organizations to effectively utilize the large amounts of heat (exhaust heat) generated at waste incineration facilities as electricity generation, steam, and hot water. On the other hand, even if the exhaust heat is not on such a large scale, thermal energy is consumed and exhausted in many situations in production processes. However, most of this small- and medium-scale exhaust heat is often not recognized as thermal energy that can be reused and is simply discarded (waste heat).

[0004] For example, examples of waste heat include cleaning equipment used in food factories and kitchens, and medium- to high-temperature wastewater discharged after heating food, etc. If such waste heat could be recovered and reused as thermal energy, the fuel used to generate thermal energy could be reduced, which would not only reduce costs for companies but also reduce CO2 emissions, killing two birds with one stone.

[0005] Efforts to reduce the environmental burden are a social requirement and unavoidable for companies, regardless of their size. Patent Documents 1 and 2 are extremely significant inventions that meet this need and pave the way for even small-scale waste heat to be recovered and reused as thermal energy.

[0006] Specifically, a case is provided to house the heat exchange unit, and a reservoir tank with many drip holes on the bottom surface is provided on the top of the case, and the heat exchange fluid is dripped from the drip holes toward the heat transfer medium flow pipe of the heat exchange unit, and heat exchange takes place between the heat transfer medium in the heat transfer medium flow pipe and the heat exchange fluid. The heat exchange unit is provided so as to be removable from the case. This is a common configuration in both Patent Documents 1 and 2.

[0007] Furthermore, when the fluid to be heat exchanged is, for example, warm wastewater used for cleaning, the warm wastewater is often dirty or contains impurities. Therefore, Patent Documents 1 and 2 emphasize ease of maintenance, such as removing the heat exchange unit from the case and cleaning the heat transfer medium flow pipes.

[0008] In Patent Documents 1 and 2, in order to efficiently drip the heat exchange fluid onto the heat transfer medium pipe, which is formed into a loop wound into a long and narrow oval or circular shape in plan view, a storage tank is installed above the heat exchange unit and the heat exchange fluid is temporarily stored there. The bottom of the storage tank has many small drip holes that match the shape of the heat transfer medium pipe, and the heat exchange fluid is dripped evenly from these holes onto the heat transfer medium pipe.

[0009] However, Patent Document 1 has drawbacks such as the drip hole becoming clogged or the large amount of hot water discharged overflowing from the storage tank. In such cases, the hot water not only reduces the heat exchange efficiency as a heat exchange fluid that is not subjected to heat exchange, but also overflows from the case, soiling the floor of a factory, etc.

[0010] Therefore, in Patent Document 2, an overflow pipe is provided in the storage tank, and a guide member consisting of a circular flat plate is further provided between the storage tank and the heat transfer medium flow pipe, so that the heat exchange fluid flowing out from the overflow pipe is guided to a drip path for the heat exchange fluid dripping from the drip hole in the storage tank to the heat transfer medium flow pipe.

[0011] However, Patent Document 2 does not completely solve the problem of the drip hole being clogged. When the drip hole is clogged, the heat exchange fluid passes through the overflow pipe and the guide member before finally coming into contact with the heat transfer medium pipe, during which the temperature of the heat exchange fluid drops, resulting in poor thermal efficiency. In addition, the provision of the overflow pipe and guide members makes the structure complicated, and maintenance, including cleaning, is time-consuming. [Patent Document 1] Patent Publication No. 2021-042868 [Patent Document 2] Patent No. 7138384 Summary of the Invention [Problem to be solved by the invention]

[0012] In consideration of the problems described above, the present invention has an objective of providing a heat exchange device that minimizes the loss of thermal energy from the heat exchange fluid, such as wastewater discharged from a cleaning device, and is easy to maintain. [Means for solving the problem]

[0013] The heat exchange device of the present invention is a heat exchange device in which a heat transfer medium flows inside a heat transfer medium flow pipe, and a heat exchange fluid is caused to flow down in the form of a thin film onto the outer surface of the heat transfer medium flow pipe, thereby performing heat exchange between the heat transfer medium and the heat exchange fluid, the support member has at least a right circular cylinder portion or a right angular prism portion, the heat transfer medium flow pipe is rotated about a vertical axis and molded into a spiral shape to follow the outer shape of the support member, so that the side connected to the heat transfer medium inlet is at the bottom end and the side connected to the heat transfer medium outlet is at the top end, and the heat exchange device is supported by the support member, a cover body is provided on the outside of the heat transfer medium flow pipe, the cover body has at least a side portion which is a vertical side portion arranged parallel to the right circular cylinder portion or right angular prism portion of the support member, the upper and lower bottom portions are open, and a guide flow passage is formed between the support member and the cover body, for the heat exchange fluid to flow down the outer surface of the heat transfer medium flow pipe.

[0014] Since there is no physical barrier between the heat transfer fluid and the heat transfer medium pipe, the heat transfer fluid can directly contact the heat transfer medium pipe while minimizing the loss of thermal energy of the heat transfer fluid. In addition, the cover prevents the heat transfer fluid from splashing around unnecessarily, so the heat transfer fluid adheres closely to the heat transfer medium pipe and flows down in a thin film, achieving efficient heat exchange without waste. In addition, the heat transfer medium pipe, support member, and cover are all independent parts, so they can be removed and easily cleaned.

[0015] The support member for the heat exchanger of the present invention is characterized in that the upper portion of the right circular cylinder portion or the right angular cylinder portion has a conical portion having a circular cone shape or a polygonal protrusion portion having a polygonal protrusion shape.

[0016] This makes it possible to prevent a large amount of the heat exchange fluid that flows down and hits the support member from scattering uselessly, and to efficiently guide the heat exchange fluid to the heat transfer medium flow pipe.

[0017] Furthermore, the cover body of the heat exchanger of the present invention is characterized in that the upper part of the vertical side portion has an inverted cone-shaped side portion or an inverted polygonal pyramid-shaped side portion that expands in a direction away from the cone portion or polygonal thrust portion of the support member.

[0018] As a result, even if a large amount of heat exchange fluid flows down from a cooking pot or the like, the amount of fluid that is dropped off can be minimized and the large amount of heat exchange fluid can be guided to the heat transfer medium pipe.

[0019] The heat exchanger of the present invention is characterized in that at least one notch is provided in the lower end of the vertical side surface of the cover.

[0020] This allows the heat exchange fluid that has completed heat exchange with the heat transfer medium flow pipe to flow out through the cutout, and the heat exchange device of the present invention can be placed directly in, for example, a drainage pit that is located directly below a cooking pot in the kitchen to receive high-temperature wastewater flowing out from the cooking pot.

[0021] The heat transfer medium pipe of the heat exchanger of the present invention is characterized in that it has a spiral or helical portion around a vertical axis that matches the shape of the upper part of the support member, thereby making it possible to lengthen the flow of the heat transfer medium pipe and to allow the heat exchange fluid to contact the heat transfer medium pipe at a position closer to the downstream position of the heat exchange fluid.

[0022] Furthermore, the heat transfer medium flow pipe, the cover body, and the support member of the heat exchanger of the present invention are contained in a container, and the container is provided with an outlet for discharging the heat exchange fluid overflowing from the guide flow passage and the heat exchange fluid flowing out from the notch in the cover body. By providing the container, the device can be used safely even in an environment where the heat exchange fluid does not flow directly onto the floor. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic diagram showing a heat exchange system in a kitchen as an example in which a heat exchanger according to the present invention is used; [Diagram 2]1A is a cross-sectional view, FIG. 1B is a plan view, FIG. 1C is an enlarged view of part A, and FIG. 1D is a perspective view of a cover, each of which shows a schematic diagram of an embodiment of a heat exchanger according to the present invention. [Diagram 3] 4A to 4D are diagrams showing other shapes of the heat exchange device according to the present invention, in which (a) is a cylinder, (b) is a perspective view of the cover body of (a), (c) is an ellipse, and (d) is a polygonal prism. [Figure 4] 1A and 1B are diagrams showing a state in which a heat exchanger according to the present invention is housed in a housing box, in which (a) is a perspective view and (b) is a front sectional view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals. Note that the term "right circular cylinder" refers to a shape that includes not only a circular shape in plan view, but also an ellipse in plan view, and the term "right prism" refers to a shape that includes a square or rectangle in plan view, such as a hexagon in plan view.

[0025] Reference numeral 1 in Fig. 1 is a heat exchanger according to a first embodiment of the present invention, which is a diagram showing an outline of a heat exchange system in a kitchen. The heat exchanger is installed in a drainage pit 3 provided directly below a large cooking pot 2 used in kitchens such as food service centers, and when the heat exchange fluid, which is high-medium temperature wastewater discharged from the cooking pot 2, drips under its own weight into a heat transfer medium flow pipe 4 of the heat exchanger 1, heat exchange occurs between the heat exchange fluid and the heat transfer medium flowing in the heat transfer medium flow pipe.

[0026] The water supply pipes 5 and 6 are connected to an inlet 7 and an outlet 8 of the heat transfer medium flow pipe 4, respectively, so that the heat transfer medium flowing through the heat transfer medium flow pipe 4 is heated and supplied to a hot water tank of an air conditioning boiler or the like.

[0027] 2(a) shows a schematic cross-sectional view of the heat exchanger 1. The heat transfer medium pipe 4 is formed into a spiral shape wound around a vertical axis along the outer shape of a right circular cylindrical support member 9. The upper bottom surface 9a of the support member is closed, and the heat transfer medium pipe 4 is removably supported by the support member 9. In order to make the flows of the heat exchange fluid and the heat transfer medium nearly countercurrent, the heat transfer medium pipe 4 connected to the inlet 7 connected to the water supply pipe 5 is arranged at the bottom end side of the support member 9, and the outlet 8 is arranged at the top end side of the support member 9.

[0028] The support member 9 may support the heat transfer medium pipe 4 by, for example, placing the uppermost pipe 4b on the outlet 8 side of the heat transfer medium pipe 4 on the upper bottom surface 9a of the support member 9, or may provide a flange portion (not shown) on the support member 9 and place or engage the lowermost pipe 4a on the inlet 7 side of the heat transfer medium pipe 4. Alternatively, the heat transfer medium pipe 4 may be placed on the upper bottom surface 9a of the support member 9 in a spiral shape.

[0029] The pipe 4a on the inlet 7 side and the pipe 4b on the outlet 8 side are formed so that the inlet 7 and the outlet 8 are at the same height, and are connected to the water supply pipes 5 and 6. A cover body 10 is placed on the outer periphery of the heat transfer medium flow pipe 4. The cover body 10 has a vertical side portion 10a that is shaped parallel to the support member 9, and is tubular in shape with open top and bottom portions.

[0030] 2(b) and 2(c), the fluid to be heat exchanged collides with the upper bottom surface 9a of the support member 9 and is guided to the side surface 9b. The fluid to be heat exchanged flows down in the form of a thin film through the gap between the support member 9 and the side surface 9b and along the outer surface of the heat transfer medium flow pipe 4, and the heat of vaporization is released from the liquid film surface to the outside air, and heat is exchanged with the heat transfer medium in the heat transfer medium flow pipe 4.

[0031] The cover body 10 serves to control the flow of the heat exchange fluid so that the heat exchange fluid flows evenly down the outer surface of the heat transfer medium flow pipe 4, and the area between the support member 9 and the cover body 10 forms a guide passage C through which the heat exchange fluid flows down.

[0032] A material with high thermal conductivity, specifically copper or aluminum, is used for the heat transfer medium pipe 4. On the other hand, a material with lower thermal conductivity than the material used for the heat transfer medium pipe 4, such as stainless steel, is used for the support member 9 and cover body 10. This is to concentrate the thermal energy of the heat exchange fluid to the heat transfer medium pipe 4. Furthermore, if stainless steel is used for the support member 9 and cover body 10, stainless steel is less likely to corrode and is easier to maintain, such as by cleaning.

[0033] 2(b), there may be a small gap S between the support member 9 and the heat transfer medium pipe 4, and the heat exchange fluid passes through the gap S, forming a liquid film over the entire outer surface of the heat transfer medium pipe 4, and flows down through the guide passage 11 between the support member 9 and the cover body 10. Because the support member 9 and the cover body 10 are made of stainless steel, which has high thermal insulation properties, the heat exchange fluid can come into contact with the heat transfer medium pipe 4 without losing the high temperature and thermal energy it had when it was discharged from the cooking pot 2.

[0034] The cover body 10 has one or more notches 10b at its lower end, and the heat exchange fluid that flows down inside the guide flow passage 11 flows out into the drainage pit through the notches 10b.

[0035] 3(a) of the support member 12 of the heat exchanger 11 is provided with a cone-shaped cone section 12b on the upper part of the right circular cylinder section 12a. This reduces the scattering of the heat exchange fluid when it collides with the support member 12, and allows the heat exchange fluid to be guided to the heat transfer medium flow pipe 13 more smoothly.

[0036] Furthermore, the heat transfer medium flow pipe 13 extends in a spiral shape not only around the right cylindrical portion 12a of the support member 12 but also around the conical portion 12b, allowing the heat transfer medium to flow within the heat transfer medium flow pipe 13 for a longer period of time and allowing the heat energy of the heat exchange fluid to be received at a location closer to the outlet of the cooking pot 2.

[0037] The side surface of the cover body 14 has a vertical side surface 14a parallel to the right circular cylinder portion 12a of the support member 12, and an inverted cone-shaped side surface 14b expanding in a direction away from the cone portion 12b of the support member 12, and these side surfaces are open in the vertical direction. A guide flow passage C is formed between the right circular cylinder portion 12a of the support member 12 and the vertical side surface portion 14a of the cover body 14, through which the heat exchange fluid flows downward.

[0038] Furthermore, the inverted cone-shaped side surface portion 14b can guide a large amount of the heat exchange fluid flowing out of the cooking pot 2 into the guide flow passage C without overflowing the fluid.

[0039] Furthermore, in order to maintain the inlet 17 and outlet 18 of the heat transfer medium at the same height, the heat transfer medium flow pipe 13 on the inlet 17 side runs upward from the lower end of the spiral shape inside the guide flow passage C. The cross-sectional path of the guide flow passage C formed by the vertical side surface portion 14a of the cover body 14 and the right circular cylinder portion 12a of the support member 12 is large enough to pass through at least two diameters of the heat transfer medium flow pipe 13.

[0040] The heat exchange device 21 shown in Figure 3(b) is the same as that shown in Figure 3(a) except that the shape of the support member 22 is elliptical in a plan view, with a right circular cylindrical portion and a conical portion above it, the heat transfer medium flow pipe 23 is molded into a spiral shape that matches the shape of the support member 22, and the cover body 24 also has a vertical side portion and an inverted conical side portion that match the shape of the cover body 24.

[0041] The heat exchanger 31 shown in Fig. 3(c) is the same as that shown in Fig. 3(a) except that the support member 32 has a rectangular shape in plan view, has a right-angled prism portion and a polygonal pyramid portion having a polygonal protrusion shape corresponding to the right circular cylinder portion and the cone portion in Fig. 3(a), the heat transfer medium flow pipe 33 is formed into a spiral shape that matches the shape, and the cover body 34 also has a vertical side portion and an inverted polygonal protrusion-shaped side portion that matches the shape. Note that the right-angled prism here is a concept that includes a square, a rectangular parallelepiped, and a polygon in plan view.

[0042] 4 shows an embodiment in which the heat exchanger is installed on the floor surface instead of in the drainage pit 3, and the heat exchanger 11, which receives the heat exchange fluid discharged from the drain outlet 40 of a noodle-making machine, is housed in a box-shaped storage box 41. The storage box 41 is provided with a discharge outlet 42 for the heat exchange fluid.

[0043] The shape of the container box may be appropriately sized to match the shape of the heat exchange devices 1, 21, 31, and the container box prevents the heat exchange fluid from being discharged directly onto the floor surface.

[0044] The heat exchange device according to the present invention has at least a heat transfer medium flow pipe, a support member, and a cover body, and each of these can be installed removably, so that the installation location can be freely selected. Furthermore, because they are removable, they are easy to clean and maintenance is very simple. [Explanation of symbols]

[0045] 1, 11, 21, 31 Heat exchange equipment 4, 13, 23, 33 Heat transfer medium flow pipe 9, 12, 22, 32 Support members 10, 14, 24, 34 Cover body

Claims

1. A heat exchange device in which a heat transfer medium flows through a heat transfer medium pipe, and a heat exchange fluid is caused to flow in a thin film on an outer surface of the heat transfer medium pipe, thereby exchanging heat between the heat transfer medium and the heat exchange fluid, The support member has at least a right circular cylinder portion or a right angle column portion, the heat transfer medium flow pipe is formed into a spiral shape around a vertical axis so as to follow the outer shape of the support member, with the side connected to the inlet of the heat transfer medium being the lowest end side and the side connected to the outlet being the highest end side, and is removably supported by the support member; A cover body is provided on the outside of the heat transfer medium flow pipe, the cover body has at least a side surface portion, the side surface portion being a vertical side surface portion provided so as to be parallel to the right circular cylinder portion or the right angular prism portion of the support member, and upper and lower bottom surfaces of the vertical side surface portion being open; A heat exchange device characterized in that a guide passage is formed between the support member and the cover body, through which a heat exchange fluid flows down an outer surface of the heat transfer medium pipe.

2. 2. The heat exchange device according to claim 1, wherein the upper portion of the right circular cylinder portion or the right angular column portion of the support member has a conical portion or a polygonal protrusion portion.

3. The heat exchange device according to claim 2, characterized in that the cover body has an inverted cone-shaped side portion or an inverted polygonal pyramid-shaped side portion, the upper portion of the vertical side portion expanding in a direction away from the cone portion or the polygonal projection portion of the support member.

4. 4. The heat exchange device according to claim 3, wherein at least one notch is provided in a lower end of the vertical side surface of the cover body.

5. 3. The heat exchange device according to claim 2, wherein the heat transfer medium flow pipe is formed into a spiral or helical shape around a vertical axis to match the shape of the upper part of the support member and is supported by the support member.

6. The heat exchange device according to claim 1, characterized in that the heat transfer medium flow pipe, the cover body, and the support member are contained in a storage box, and the storage box is provided with an outlet for discharging the heat exchange fluid overflowing from the guide flow passage and the heat exchange fluid flowing out from the cutout in the cover body.

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