CZ2014956A3 - Enthalpic heat-exchange apparatus - Google Patents

Abstract

Countercurrent enthalpy exchanger (1) having a quadrangle-shaped central region (11) at its ends in the direction of flow through the exchanger boundary regions (12, 13) which narrow away from the central region (11) and to separate the flow of the heat transfer medium in the direction from the inner space to the outside, the vapor-permeable lamellas (10) with contouring and sealed lamellae (10) are arranged in a contoured manner with the means for generating the eddy flow, and two adjacent lamellae (10) each form a intermediate plate flow channel in the central region (11). The lamella (10) is formed as a one-piece self-supporting common molding of the central region (11) and the outer regions (12, 13), without a reinforcing support grid. Two adjacent lamellae (10) form an intermediate plate flow channel in the outermost region (12, 13), in which walls there are straight projections (121, 131) lying in the flow direction of the heat transfer medium between the central region (11) and the respective inlet or outlet of the latter. media.

Description

Enthalpy heat exchanger

Field of technology

A countercurrent enthalpy exchanger having a parallelogram-shaped central region, at the ends of which in the direction of flow through the exchanger there are end regions which taper away from the central region, and are arranged contour-like and flowing in order to separate the heat transfer medium flow from the interior to the outside. media sealed vapor-permeable lamellae with shaped means for inducing eddy flow. In this case, two adjacent lamellae in each case form one intermediate plate flow channel in the central region.

Prior art

Recuperative heat exchangers are known, through which the heat transfer medium flows in opposite directions in spaces separated from each other by heat exchange walls. An example of such a recuperation system is the device according to WO2013091099A1. The heat exchange surfaces of the exchanger itself are vapor-permeable pleated plates arranged in layers on top of each other so as to form a system of parallel mutually separated channels. A warmer fluid transferring heat and steam and a colder fluid receiving heat and steam flow through them. The inputs and outputs of the heat exchange medium are made through distribution systems connected to both sides of the exchanger. Said device is characterized by a substantially laminar flow of the heat exchange medium in the direct channels of the exchanger. This is not particularly advantageous in terms of the efficiency of the heat exchanger itself, moreover its structure of the individual layers Žf formed by connecting the heat exchange surface itself with the liquid supply and discharge system of the systems is relatively complex.

The exchanger according to the patent CZ 300 | 99 B6 comprises a frame in which layers of thin fins are arranged, in which air leaving the room and entering the room is alternately guided. Each lamella has inlet and outlet space of flowing medium in the end parts. The middle part of the lamellas is formed by channels whose task is to change the direction and speed of the air flow, because the swirling of the gaseous medium significantly increases the efficiency of heat exchange. The material of the lamella walls is a thin metal or plastic foil. Such a material has sufficient rigidity, so it does not have to be reinforced with frames and other reinforcing elements. This is advantageous in terms of achieving the largest possible effective surface area of the exchanger.

Ύ In addition to heat exchange, ie in the winter, in addition to heating the supply air with the exhaust air, the requirement imposed on the air-conditioning system for enclosed spaces is to prevent moisture leakage. With the recovery of the exhaust heat, it is necessary in this case to prevent the loss of moisture and to transfer it from the exhaust air stream to the supply air. The devices fulfilling this task are the so-called enthalpy exchangers. It is obvious that between the leaving and coming air there can be no air, resp. moisture-tight partition.

i Between two separate internal spaces of countercurrent enthalpy। In the heat exchanger through which the air flows in the opposite direction, a wall with the function of a membrane permeable to water vapor and not to air must be used. The air coming out of the heated space transfers heat and moisture at the same time through the walls of the air entering the room, which positively prevents the air in the room from drying out. The material of vapor-permeable membranes, in view of its low rigidity, requires that the membrane be reinforced by a support means to which it would be attached.

The supporting part of the lamella of the enthalpy exchanger according to the prior art are reinforcing support spacer grids, which form rigid skeletons made of plastic coated with a material fulfilling the function of a vapor-permeable membrane. Due to the fact that the membrane is glued to the frame, the frame reduces the functional area of the lamella and thus reduces the efficiency of both heat transfer and moisture transfer.

The object of the invention is to increase the efficiency of an enthalpy exchanger without increasing the external dimensions of the exchanger and without a significant increase in the cost of manufacturing its fins.

The essence of the invention

The object of the invention is achieved by an enthalpy exchanger comprising flow lamellae for two opposite medium streams, the essence of which is that the lamella is formed as a self-supporting molding of the central region and the outer regions without a reinforcing support grid, the lamella being vapor permeable. Such lamellae do not contain reinforcing elements, for example grids, which reduce the heat exchange and steam exchange area.

The outermost parts of the lamella comprise protrusions lying in the direction of flow of the heat transfer medium between the central region and the respective inlet or outlet of this medium. This reduces the resistance to flow in these areas, thus increasing the efficiency of the exchanger.

The self-supporting molding is a composite, one of its components being a supporting nonwoven layer which is connected to a vapor-permeable membrane. The material of the vapor-permeable membrane is, in a preferred embodiment, a sulfonated block copolymer, which has very good properties in terms of vapor permeability, strength and dimensional stability in both dry and wet conditions.

The connection of the carrier nonwoven layer with the vapor-permeable membrane is realized by pressing or welding or gluing or dipping. This is advantageous technologically, since they can be carried out on known coating or laminating devices.

The slats are connected to each other at least in some parts of the circumference by welding or gluing with airtight welds. Thus, it is possible to achieve a perfect separation of the input and output medium in an economical manner.

Preferably, the lamella is made by pressing from a planar blank held circumferentially between the forming plates at a temperature higher than 4CfC.

Explanation of drawings

The device according to the invention is schematically shown in the drawing, in which Fig. 1 is an oblique view of an enthalpy exchanger with working medium flow directions, Fig. 2 is a side view of the enthalpy exchanger of Fig. 1 in direction P1, Fig. 3 is a plan view; Fig. 4a is a section CC of Fig. 3, Fig. 4b shows a detail of the projection of the central region of the lamella of Fig. 3, Fig. 5 is an oblique view of a part of the exchanger containing four fins in the connected state; Fig. 5.

Examples of embodiments of the invention

An enthalpy exchanger is a device used to transfer heat and moisture from a gaseous medium emerging from an indoor service space to a gaseous medium entering from an outdoor space into an indoor space.

The basic building block of the enthalpy exchanger 1 according to the invention is a profile plate, hereinafter referred to as a fin 10. The fins 10 are stacked as layers on top of each other, the adjacent fins being joined together on part of their perimeters. Thus, alternating flow inter-plate spaces are formed between the pairs of lamellae 10 forming channels 2 for the flow of gaseous medium in the direction A from the enclosure to the outdoor space and channels a 3 for the flow of gaseous medium in the direction B from the outdoor space to the enclosure. These lamellae allow the transfer of heat from the heated and moist medium discharged, for example from an air-conditioned space, to a cold and usually dry medium supplied from an outdoor space. The lamella 10 is essentially a molding of a planar blank comprising protrusions and depressions on both sides.

The lamella assembly 10 is inserted and fixed in the housing 100 of the enthalpy exchanger 1. Both outer fins 10 '. which adjoin the side walls of the housing 100 from the inside, contribute to the desired nature of the medium flow in the two extreme flow spaces, the transfer of heat and moisture practically not taking place through them.

The scheme of the exchanger is shown in Fig. 1 and 2. On them are hatched areas between the fins 10 and 10, respectively. 102, inlet or outlet openings to the flow inter-plate spaces, the unshaded areas are closures of the flow inter-plate spaces.

The lamella 10 is two-component. The first component is a nonwoven backing layer on which a vapor permeable membrane is applied. It is preferably formed of a sulfonated block polymer. The connection of the carrier nonwoven layer with the vapor-permeable membrane is realized by pressing or gluing or dipping. The sulfonated block polymer is advantageous with respect to the degree of vapor permeability, strength and dimensional stability in both dry and wet conditions. In addition, it is also advantageous in terms of membrane production technology, which can be implemented on known coating or laminating devices. Thus, protrusions and depressions can be formed in the surface of the resulting lamella by pressing, the purpose of which is to create a swirling flow of the medium passing through the slit forming the flow channel between two adjacent lamellae 10 10 '. Eddy flow generally increases the efficiency of heat transfer and moisture passage through the lamella separating the flowing media.

The main advantage is the self-supporting construction of the lamella 10. It does not contain a reinforcing grid, which in other constructions reduces the effective area for the transfer of heat and moisture between the discharged and supplied gaseous medium.

One flow cross-section in the housing 100 of the exchanger 1 is formed by two fins 10, which have the same contour of the surface, but differ in the direction of avoidance of the circumferential recesses by which the fins are connected to each other. In the description of the shape, these two types will be further indicated by reference numerals as lamellae 10x and 10y, for reasons of distinction.

In the exemplary embodiment, the central region 11 of the lamella 10 has a substantially square or rectangular shape, which is followed in the direction of the length of the lamella by end regions 12, 13, the surface of which tapers away from the central region. In the exemplary embodiment, the surfaces of the end regions are triangular. This facilitates the arrangement of the inlet and outlet flow of the medium through the exchanger in a diagonal manner (see Fig. 1). The flow space between two adjacent lamellae 10 is not divided by any closed partition. It is, of course, possible for the shape of the central region to be a rectangle or a rhombus with adjacent, for example, non-equilateral triangles of the extreme regions 12,13.

In the exemplary embodiment according to FIG. 3, the central region 11 of the lamella 10x is shaped by longitudinal parallel corrugated projections 111. The curve of their ridges 111 'is substantially a sinusoidal Sx in the plane of the surface of the lamella 10. The distance between two adjacent ridges 11T is a spacing R. The ridges 111 'of the protrusions 111 are shown in solid line, the depressions in the middle between them form protrusions on the other side of the lamella 10. The cross-section of the central region by the plane C-C of Fig. 3 is shown in Fig. 4a. In the exemplary embodiment, the height v of the waves of the protrusions 111, i.e. the maximum thickness of the lamella 10, is 3.5 mm. The sinusoid Sx of the ridge 111 'of the protrusions 111 begins in the part »6« »adjacent to the end region 12 by the lower apex DV. In the part adjacent to the extreme region 13, the sine wave Sx ends with the upper peak HV.

In the lamella 10x of the first type, the rim 123 of the end region 12 (top left in Fig. 3) is bent upwards, the second rim 124 of the end region 12 is bent downwards. The rim 133 of the outermost triangular region 13 parallel to the rim 123 of the outermost triangular region 12 is bent upwards, the rim 134 of the extreme triangular region 13 parallel to the rim 124 of the extreme triangular region 12 is bent downwards.

In the lamella 10y of the second type, the sinusoid Sv of the ridge 111 of the protrusions H1 is shifted with respect to the position of the sinusoid Sx of the lamella 10x by half the wavelength λ of the sinusoid Sx, Sy so that it begins in the part adjacent to the end region 12 by the upper peak HV and in the part adjacent to the end region. 13 the sine wave Sv ends with the lower peak DV (FIG. 4b). In places where the sinusoids Sx and Sv intersect or touch, they also touch the adjacent ridges 11Γ, 111.

The outermost triangular areas 12, 13 are provided with pressed straight elongated intermittent projections 121.131, which have the direction of flow of the medium in this part of the flow space and which form depressions 122,132 on the opposite side of the lamella. which do not impair the flow on this opposite side of the lamella, even if they are perpendicular to this flow direction.

The height of the protrusions 121, 131 and the depressions 122,132 of the end regions 12, 13 is a maximum of 1.7 mm.

The thickness and surface dimensions of the lamella 10, the height of the protrusions 121, 131, the height in the corrugated central region 11 can vary according to the technical solution, not shown, without exceeding the scope of protection given by the protection requirements.

In the lamella 10y of the second type, the rim 123 is bent downwards by the end region 12 parallel to the projections 121, the second rim 124 is bent upwards by the end region 12. The rim 133 of the outermost triangular region 13 parallel to the rim 123 of the outermost triangular region 12 is bent downwards, the rim 134 of the extreme triangular region 13 parallel to the rim 124 of the extreme triangular region 12 is bent upwards.

a * 7 * ·

Giant. 5 and 6 show the stacking of the individual lamellae 10 and their connection. In an exemplary embodiment, the enthalpy exchanger 1 comprises twenty fins 10. Fig. 4 shows four fins, which are marked 10xi, 10ν ₂ , 10xg, 10v4 from top to bottom. A detail of the left side of the fin assembly is shown in Fig. 6.

The perimeters of the folded fins contact in the longitudinal sides 112 of the central region 11, where they are encapsulated with sealant and form opposite walls 113 of the housing 100 of the exchanger 1. Similarly, the ends of the end regions forming the narrow faces 114 of the housing 100 are encapsulated.

Adjacent lamellae 10 are alternately closed by hems 123, 124, 133, 134 according to Figs. 5 and 6. The joining of hems 123, 124, 133, 134 is made by welding or gluing.

On the left side of Fig. 5 and in Fig. 6, the edges 123 of the lamellae 10ν? Are welded. 10xg, which closes the space between these lamellas, on the contrary, between the edges 123 of the lamellas 10xi and 10ϋ2, the entrance or exit to the space between them is open. Likewise, between the edges 124 of the lamellae 10x1 and IPv4 there is also an inlet or outlet opening. Next, two welded edges 124 of lamellae 10xi and 10v? Are shown. 10xg and 10v4.

On the right side of Fig. 5 the weld of the edges 133 of the lamellae 10y ₂ and 10xg and the inlet openings between the edges 133 of the lamellae 10xi and 10ν _{ζ are} visible. 10x ₃ and IPv4. On the contrary, the invisible part of the circumference of the end region 13 comprises, analogously to the part of the circumference of the end region 12 with edges 124 (front view in Fig. 6), two welded edges 134 of lamellae 10xi and 10V2, 10xg and 10v4. Between the edges 134 slats 10v ?. 10xg is also the inlet or outlet opening.

In addition to the fundamental advantage of the self-supporting construction of the lamella 10 and thus the absence of a reinforcing grid, the enthalpy exchanger 1 retains the advantage of a relatively long path along which heat and moisture are exchanged against the medium streams. In addition to the unevenness of the lamellae 10 of the central region 11 contributing significantly to the heat and moisture exchange efficiency, a further increase in this efficiency is achieved by reducing the resistance to medium flow in the outer regions 12, 13 by the shape and especially the direction of the protrusions 121, 131 in these regions.

List of reference marks

X 100 11 111 111 '111' 112 113 114 115 12 121 122 123 124 13 131 132 133 134 2 & 3 A

B DV HV

3Í RS _x Sy V λ enthalpy heat exchanger fin (10 ', 10x, 10y, 10xi, 10x ₃ , 10y ₂ , 10 y ₄ ) heat exchanger housing middle area (slats) protrusion (middle areas of the fins) ridge of the lug (middle areas of the fins) back protrusion (middle lamella area) longitudinal side middle area housing wall (exchanger upper, lower) narrow face (exchanger housings front, rear) side wall (exchanger housing) outer area (lamellae) (straight) protrusion (in the area of the outer part) (straight ) depression (in the area of the outermost part) hem (outermost areas) rim (outermost areas) edge area (slats) (straight) protrusion (in the area of the outermost part) (straight) depression (in the area of the outermost part) rim (outermost areas) outermost areas) channel (flow in direction A) channel (flow in direction B) flow direction (from closed space outwards) flow direction (from outer space to inner space) lower peak (sine wave) upper peak (sine wave) pitch distance of ridges (protrusions middle region) sine wave sine wave protrusion wave height (middle regions) sine wave length vky S _x , S _y

Claims (6)

PATENT CLAIMS Countercurrent enthalpy exchanger (1), having a central region (11) in the shape of a rectangular quadrilateral, at the ends of which in the direction of flow through the exchanger follow end regions (12, 13) which taper away from the central region (11), of the heat transfer medium in the direction from the interior to the exterior, vapor-permeable lamellae (10) which are identical in contour and sealed in terms of flowing medium are arranged with shaped means for inducing eddy flow, two adjacent lamellae (10) in each case forming one interplate flow in the central region (11). a channel, characterized in that the lamella (10) is formed as a one-piece self-supporting molding of the central region (11) and the outer regions (12, 13) without a reinforcing support grid, each adjacent two lamellae (10) forming in the outer region (12, 13) one intermediate plate flow channel, in the walls of which straight protrusions (121, 131) are formed lying in the direction of flow of the heat transfer medium between the central region (11) and the respective inlet ne bo output of this medium. Countercurrent enthalpy exchanger (1) according to claim 1, characterized in that the self-supporting lamella molding (10) is a composite, one component of which is a supporting nonwoven layer which is connected to a vapor-permeable membrane. Countercurrent enthalpy exchanger (1) according to claim 2, characterized in that the material of the vapor-permeable membrane is a sulfonated block copolymer. Countercurrent enthalpy exchanger (1) according to Claim 2 or 3, characterized in that the connection of the carrier nonwoven layer to the vapor-permeable membrane is effected by pressing or welding or by gluing or dipping. Countercurrent enthalpy exchanger (1) according to any one of claims 1 to 4, characterized in that the fins (10) are connected to each other at least in some parts of the circuit by welding or gluing with airtight joints. Countercurrent enthalpy exchanger (1) according to any one of claims 1 to 35, characterized in that the lamella (10) is made of a planar blank by pressing between forming plates with a temperature higher than 4 (rC).