JPS61268995A - Connecting structure of heat exchanging element - Google Patents

Abstract

PURPOSE:To permit to form a heat exchanging body having various sizes, shapes and performances by a method wherein the plate type body, made of ceramics, and the heat exchanging element, consisting of a tube, are connected to the through-hole of a frame body through an elastic body of rubber. CONSTITUTION:In the heat exchanging element 11, a plurality of tubes 21, made of ceramics, is penetrated through the plate-like body or a fin 31, made of ceramics, and both of them are fixed mutually by each other. According to this method, heat conductivity is large and high fin efficiency is obtained while the dew-point corrosion by sulfuric acid may be avoided. The frame body 41 is bored with the through-holes 45 at the same position as the tube 21 and a gap between the frame body 41 and the outer diameter of the end 22 of tube is fitted with the elastic body 51 of rubber. Further, the tube end 22 of a different heat exchanging element 11 is fitted into the elastic body 51 and, thus, a plurality of heat exchanging elements 11 are connected with each other. Accordingly, the outflow leakage of fluid may be prevented and shock vibration may be absorbed. On the other hand, thermal deformation may be absorbed even when a multitude of elements 11 is connected and the assembling work may be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a connection structure for heat exchange elements, and particularly to a connection structure for gas-liquid type heat exchange elements useful for recovering heat from gases at low corrosion temperatures. Regarding.

[Prior art] In a heat exchanger using tubes, when a liquid such as water is allowed to flow inside the tube and a gas is allowed to flow outside the tube, heat exchange can be performed effectively by providing fins on the outside of the tube. This is well known, and it has been widely put into practical use to wrap metal fins around a metal tube to make a fin tube.

However, when flowing fuel combustion gas containing impurities such as sulfur outside the tube, low-temperature corrosion of the fins and outer surface of the tube becomes a problem.1 If ordinary metal is used, the life of the heat exchanger is short. was there.

On the other hand, heat exchangers made of ceramic monolith bodies that are resistant to low-temperature corrosion are also known (Japanese Patent Application Laid-Open No. 80-80 JE1
098. 57-129398, etc.), but most of these are suitable for "air-air type heat exchange" in which both the heated and non-heated fluids are gases, and the heat transfer coefficients on both sides of the heat transfer wall are approximately the same. However, if the heat transfer coefficients on both sides of the heat transfer wall are significantly different, such as combustion gas and water, the heat transfer area on the gas side is insufficient, and the heat transfer on the water side is The area becomes excessive, resulting in poor heat balance and reduced heat exchange efficiency.

In order to solve these problems, the present inventors previously proposed in Japanese Patent Application No. 59-203089 that a ceramic honeycomb body is connected to a plurality of parallel ceramic tubes that are inserted through and fixed to the honeycomb body. proposed a heat exchanger. This heat exchanger has a heat transfer coefficient that is smaller than the heat transfer area on the source side, which has a high heat transfer coefficient, by passing a liquid such as wood inside the tube and passing a gas such as combustion gas through the ventilation channels of the honeycomb body. By increasing the heat transfer area on the low air side, it is possible to improve heat balance and improve heat exchange efficiency.

[Problems to be Solved by the Invention] Incidentally, such heat exchange bodies are generally made of thin-walled ceramics, and there are limits to the dimensions and shapes that can be mass-produced. Therefore, it is difficult to manufacture large products suitable for heat recovery from large flow rates of gas, and even if the product is made of fat, it is difficult to manufacture heat exchangers of various sizes for a wide variety of uses. The process becomes extremely complicated, and the manufacturing cost increases significantly, making it impractical.

Therefore, we came up with the idea of configuring such a heat exchange body by connecting smaller standardized heat exchange elements, but in the connection structure of such heat exchange elements, fluid seals It is required that the heat exchange element be able to absorb heat deformation, vibration, and shock so that the heat exchange element will not be damaged, be easy to manufacture and assemble, and be able to reliably support the weight of a large number of heat exchange elements.

An object of the present invention is to provide a connection structure for heat exchange elements that solves these problems.

Problem E, Minor Solution, Means for Solving] The present invention consists of a plurality of parallel ceramic tubes that are inserted into and fixed to a plate-shaped body so that the tube ends protrude, and the plate-shaped body. In the connection structure of the heat exchange element, one end surface of a frame body is provided with through holes having an inner diameter larger than the outer diameter of the tube end on both end surfaces at the same pitch as the tube end. The tube end is inserted into the through hole with a rubber-like elastic body interposed between the outer periphery and the inner periphery of the through hole, and the heat exchange element is attached to the other end surface of the frame body. This is a heat exchange element connection structure characterized in that another heat exchange element is attached to the heat exchange element.

According to the present invention, since the two heat exchange elements are connected facing each other via the frame, by repeating this connection structure one after another in the axial direction of the tube, heat exchange can be performed to any desired length. A heat exchanger in which elements are connected in series is obtained. Further, each of the tubes of the heat exchange element is communicated with each of the tubes of the other heat exchange element via a through hole, and.

Since the tube end and the through hole are connected through a rubber-like elastic body, the fluid flowing inside the tube is sufficiently sealed from the outside of the system, and thermal deformation, vibration, shock, etc. are also absorbed. Furthermore, since both the frame and the rubber-like elastic body have simple shapes, this connection structure is easy to manufacture and assemble, and furthermore, the weight of the heat exchange element can be reliably supported by the frame.

In a preferred embodiment of the present invention, a plurality of heat exchange elements are attached in parallel to one end face of the frame, and also to the other end face of the frame.

Another plurality of heat exchange elements are installed in parallel opposite the first plurality of heat exchange elements.

Thereby, a heat exchange body in which any desired number of heat exchange elements are arranged in parallel can be obtained. When arranging them in parallel, they may be in the form of flat plates arranged in one direction such as vertically or horizontally along the end face of the frame, but they may be arranged in the form of 14 parallel plates at the same time in both the vertical and horizontal directions. This is particularly preferable because a well-balanced and compact heat exchanger can be obtained as a whole.

In another preferred embodiment of the invention, at least two parallel frames are fixed to a support frame perpendicular to the frames. This fixes the position of the frame phase JF and prevents excessive load from being applied to the heat exchange element.
Rigidity can be imparted to the structure of the heat exchanger as a whole. Further, when the support frame is adopted in this way, the frame material can be made of a material with a low Young's modulus such as plastic.

In yet another preferred embodiment of the present invention, the tubes and plates of the heat exchange element are made of silicon carbide ceramics. As a result, both the tube and the plate-like body have high corrosion resistance, high heat resistance, and high thermal conductivity, making it possible to provide a lightweight and highly functional heat exchanger. Furthermore, since the tube and the plate-like body are of the same quality, it is possible to provide a lightweight and highly functional heat exchanger. Resistant to thermal shock.

In yet another preferred embodiment r)m of the present invention, the plate-like body is a cell wall of a honeycomb body or a plurality of parallel fins, particularly a large number of parallel fins.

As a result, when using this heat exchange element for gas-liquid type heat exchange, the heat transfer area on the gas side is greatly increased compared to the heat transfer area on the liquid side, and the heat transfer between the gas and liquid is balanced. is significantly improved. Furthermore, when multiple parallel fins are used, the gas flow direction can be set arbitrarily in a plane parallel to the fins, and when a non-uniform cell wall is used, the strength of the heat exchange element can be adjusted. can be made larger.

However, the present invention is not necessarily limited to application to heat exchange elements for such uses, for example, heat exchange elements between gas/gas or liquid/liquid, where the heating fluid side and the heated fluid side are connected. It can also be applied when there is not a large difference in heat transfer coefficient. In such a case, the plate-shaped body is not required to have a fin function so much, and therefore, it is preferable to have a sufficient number of plate-shaped bodies to hold and fix the plurality of tubes in a predetermined position.

As mentioned above, the tube is preferably made of silicon carbide ceramics, but various other ceramics may be used instead. These ceramics include silicon nitride, sialon, mullite, alumina, zirconia,
Examples include aluminum titanate, cordierite, carbon, etc., and may be reinforced with appropriate inorganic materials or whiskers, if necessary.

The same material as the tube can be selected for the plate-shaped body. In particular, using the same material as the tube not only simplifies the manufacturing process but also prevents cracks caused by thermal expansion differences at the joint between the tube and the plate-shaped body. This is preferable because it is less likely to occur, but depending on the conditions of use, the plate-shaped body may not necessarily be made of ceramics.

The frame is a strength member that supports the load of the heat exchange element, and it is better to make a large number of heat exchange elements out of a material with more toughness than the tube material, especially when the fluid to be heated is water etc. Since water flows through the through-holes of the frame, even if the heating fluid is a high-temperature gas of 200°C or higher, it will be sufficiently cooled. Therefore, the material of the frame may be carbon steel, aluminum, etc. Even if the high-temperature gas has sulfuric acid dew point corrosivity, there is no need to use corrosion-resistant steel as long as the wall is thick enough to allow for corrosion. Of course, enamel, enamel, fluorine resin, fluorine rubber, etc. Metal materials subjected to surface coating anticorrosion treatment are also preferred.

When the temperature of the heated fluid is 200° C. or lower, organic materials such as plastics and wood can be preferably used because of their durability against sulfuric acid dew point corrosion. Among plastics, fluororesins are preferred because they can withstand higher temperatures and more severe corrosion.

The frame may be solid, or may be hollow 7 to reduce weight, and if it is hollow, it may have different through holes communicating with each other.

The through-hole may have the same diameter between both end faces of the frame, but may also have a stepped portion in the middle, which makes it easier to insert the tube end of the heat exchange element to a predetermined depth.

The rubber-like elastic body is tightly filled in the gap between the outer periphery of the tube end and the inner periphery of the through hole, sealing the fluid in this gap, absorbing thermal deformation, shock, etc., and adjusting the tube pitch and the through hole pitch. If there is an error between the two, this error will also be absorbed. A rubber-like elastic body previously formed into a cylindrical shape may be used, or a liquid or paste-like rubber-like elastic body raw material may be applied to the outer periphery of the tube end and/or the inner periphery of the through hole, and the tube end is penetrated. It may be formed by hardening after being inserted into the hole, or it may be formed by inserting the end of the tube into the through hole, pouring a liquid or paste rubber-like elastic material into the gap, and then hardening. ! The material of this rubber-like elastic body can be selected as appropriate, such as ethylene propylene rubber, depending on the operating temperature range and operating atmosphere. Fluororubber is particularly suitable.

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

In FIG. 1, each of the heat exchange elements 11 includes a plurality of parallel reaction-sintered silicon carbide ceramic tubes 21 and mutually parallel reaction-sintered silicon carbide tubes 21 provided perpendicularly to the axis of the tubes 21. The fin 31 is a plate-shaped body made of high-quality ceramic. The tube 21 is inserted through the fins 31, and both are fixed to each other. Tube 21 and fin 31 as necessary
Appropriate adhesive material is applied to the joints.

The tube end 22 also projects from the fins 31 of the wound. As can be seen from FIG. 2, the tubes 21 are arranged in a grid pattern, but they may be arranged in any other suitable arrangement such as a staggered pattern.

A through hole 45 having an inner diameter larger than the outer diameter of the tube end 22 is bored in each of the frame bodies 41 at a position having the same pitch as the tube 21 .

A rubber-like elastic body 51 made of ethylene propylene rubber and preformed into a cylindrical shape is inserted into each through-hole 45 so as to fill the gap between the outer diameter of the tube end 22 and the inner diameter of the through-hole 45 . Furthermore, the respective tube ends 22 of further heat exchange elements 11 are fitted into the rubber-like elastic body 51 from both sides of the through-hole 45 . Thus, the plurality of heat exchange elements 11 are interconnected by the frame 41 and the rubber-like elastic body 51.

A large heat exchange body formed by connecting a plurality of heat exchange elements 11 in this way is preferably used for heat exchange between gas and liquid.
The combustion gas as a heating fluid is caused to flow from the top to the bottom of the page in FIG. 1, or from the front side to the back side. Sensible heat of the combustion gas is transferred from the fins 31 to the water via the tubes 21. Since the fins 31 and the chews 321 are made of silicon carbide ceramics, they have high thermal conductivity, can maintain extremely high fin efficiency, and function as a lightweight, high-performance heat exchanger. Furthermore, since the fluid to be heated is water and the fins 3I and tubes 21 are made of a material with high thermal conductivity, even if the combustion gas is high temperature, the fins 31
, the outer surface temperature of the tube 21 is approximately 100°C.

Therefore, fin 31. If the tube 21 were made of metal or the like, a problem of sulfuric acid dew point corrosion would occur, but in the present invention, since it is made of ceramics, such problems can be avoided.

A tube 21 is provided in the gap between the tube end 22 and the through hole 45.
Since the rubber-like elastic body 51 having a smaller Young's modulus is filled, leakage and injection of water, combustion gas, etc. from this gap is not only prevented.

Mechanical shocks and vibrations are also absorbed by this rubber-like elastic body 51. Moreover, when connecting a large number of such heat exchange elements (11) to increase the capacity.

There is a risk that the thermal deformation occurring in each heat exchange element will accumulate and result in a large amount of deformation for the five elements, but according to the present invention, such thermal deformation is absorbed by the individual rubber-like elastic bodies 51, and the overall deformation is In addition, when connecting a large number of heat exchange elements, it is possible to assemble them by simply fitting the tube ends 22 into the holes of the rubber-like elastic body 51, which simplifies the assembly work and shortens the process. Contribute.

In the embodiment shown in FIG. 3, the plastic frame 4
On both sides of 2, there are multiple heat exchange elmmen) 11
is attached. Therefore each heat exchange element)
Even if 11 is small, a large heat exchanger is constructed as a whole.

The frame body 42 has a through hole 4B provided with a stepped portion 4B. In this embodiment, a rubber-like elastic body 51 is fitted into the through hole 48 in advance, and then the tube end 22 whose outer periphery and end face are coated with paste-like silicone rubber sealant is inserted to a depth where it abuts the stepped portion 48. be done. In this way, the silicone rubber layer acts as a lubricant during insertion.

In the embodiment shown in FIG. 4, a hollow frame 43 manufactured by pressing a steel plate is employed. Each through hole 47
includes a tapered portion 44 and a step portion 43, and the plurality of through holes 47 communicate with each other via a hollow portion. Moreover, in each heat exchanger fin 12, the plate-like body consists of flat plate-like fins 32 and corrugated plate-like fins 33, and the flat plate-like fins 32 and corrugated plate-like fins 33 are alternately stacked to form the cell walls of the honeycomb body. are doing. In this heat exchange element, the heating fluid flows in a direction perpendicular to the plane of the paper. In the case where the plate-like body is a cell wall of a honeycomb body, the cell shape is not limited to that shown in FIG. In the embodiment shown in FIG. 4, after the tube end 22 is inserted into the first through hole 47, a fluid silicone rubber sealant is poured into the gap and is cured to form a rubber-like elastic body 51.

A heat exchanger connected using a frame 40 and a support frame 39 is shown. In this heat exchanger, heat exchange elements 11 are arranged and connected in 11 stages vertically in series, 12 rows horizontally, and further in 10 to 20 columns perpendicular to the plane of the paper. The 12 rows of heat exchange elements 11 are connected to the frame 40 in four rows each, and each frame 4o is fixed to the support frame 39. A ladder 81 is provided at the bottom of the lowest heat exchange element to the inlet of the fluid to be heated such as water, and an outlet header B2 is similarly provided at the top.
is provided. A heating fluid such as combustion gas is flowed perpendicularly to the plane of the paper, and the fluid to be heated enters the inlet from the ladder 61, is heated while passing through the tubes of each heat exchanger 11, and exits from the outlet header 82. Note that the frame body 40 and the support frame 38
Appropriate means such as welding, adhesion, and fitting are used for joining.

[Effect of the Invention J] As described above, according to the present invention, a small heat exchange element equipped with a ceramic tube can be easily connected, and a large heat exchange body can be configured to meet the requirements of a heat exchange body. This can be handled by combining and connecting heat exchange elements that are standardized, can therefore be mass-produced, and can be kept as standard stock, and have great utility value in the 1M industry.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention. FIG. 2 is a view taken along the line X-X&l in FIG. 1. Third
4 and 4 are cross-sectional views of different embodiments of the present invention. FIG. 5 is a front view of yet another embodiment of the invention. 11th l ll: Fist 6 Onna Ki Committee 1 [Mumen] 4h
Honsen [4i (31! Fin 2nd figure 4 causes 3rd figure

Claims (6)

[Claims] (1) A connection structure of a heat exchange element consisting of a plurality of parallel ceramic tubes inserted and fixed through a plate-like body so that the tube ends protrude, and the plate-like body, in which both end faces On one end surface of the frame body, in which through-holes having an inner diameter larger than the outer diameter of the tube end are provided at the same pitch as the tube, a rubber-like elastic material is provided in the gap between the outer periphery of the tube end and the inner periphery of the through-hole. The tube end is inserted into the through hole with a body interposed therebetween, and the heat exchange element is attached, and another heat exchange element is similarly attached to the other end surface of the frame. A heat exchange element connection structure featuring: (2) A plurality of heat exchange elements are attached to one end surface of the frame in a row, and also to the other end surface of the frame.
2. The connection structure according to claim 1, wherein a plurality of other heat exchange elements are mounted in parallel to face the plurality of heat exchange elements. (3) The connection structure according to claim 1 or 2, wherein at least two parallel frames are fixed to a support frame perpendicular to the frames. (4) The connection structure according to any one of claims 1 to 3, wherein the tube and the plate-like body are made of silicon carbide ceramics. (5) The connection structure according to any one of claims 1 to 4, wherein the plate-shaped body is a cell wall of a honeycomb body. (6) The connection structure according to any one of claims 1 to 4, wherein the plate-shaped body is a plurality of parallel fins.