US2846195A - Heat exchangers - Google Patents

Description

l 958' J. F. ALcock 2 HEAT EXCHANGERS- 2 Sheets -Sheet 1 Original Filed Jan. 27. 1947 Fig.

J. F. ALcocK' HEAT EXCHANGERS Aug. 5, 195.8

' 2 Sheets-She et 2 Original Filed-Jan. 27, 1947 United States Patent M 2,846,195 rmAT EXCHANGERS John Foster Alcock, North Lancing, England, assignor to Power Jets (Research and Development) 'Limited, London, England, a Britishcompany Continuation of abandoned application Serial No. 724,686, January 27, 1947. This application August 4, 1952, Serial No. 302,532

Claims priority, application Great Britain February 4, .1946

6 Claims. (Cl. 257-6) This application is a continuation of the co-pending application Serial No. 724,686 filed on January 27, 1947, now abandoned, by the present applicant and another and assigned to the same assignee.

This invention relates to a rotary regenerator type of ample, in gas turbine heat exchangers wherein the com pressor delivery is pre-heatedby the turbine exhaust gases, the relatively colder air leaving 'the' compressor has a substantially higher pressure than the relatively hotter exhaust gases leaving the turbine.

Such a heat-exchanger usually comprises a casing, fluid-tight partitioning therein dividing the whole interior of the casing into separate high-pressure-fluid and lowpressure-fluid passageways, a member constituting the regenerator matrix, driving means for etfecting relative rotation of the matrix and at least some part ofthe partitioning, the matrix passing through the partitioning from one of said passageways to the other, and a seal incorporated in said partitioning, bearing against the matrix for sealing oif the one passageway from the' other.

The matrix is usually of cellular construction. At any one instant some of the cellsof the matrix are in communication with the high-pressure fluid, some'are'in communication withthe low-pressure fluid, and of the remainder-i. e. two groups which are passing under the seal-one group is on the point of ceasing'to communicate with the high-pressure fluid and about to enter into communication with the low-pressure fluid, while. the

other is passing in the opposite way. One of said groups will subsequently discharge its high-pressure fluid content into the low-pressure path, this involving a loss of the power expended in compressing this fluid, and'the other group will require filling up to raise the'fluid pressure therein to that of the high pressure fluid, .thus involving a further loss.

This loss is obviated according to the invention by the provision of means whereby a cell which has just been cut off from the high pressure fluid isput in communication with a cell which is about to be connected tothe high-pressure fluid at a moment when both cells are'cut off from the high pressure and the low pressureregions.

This equalizes the pressure in the two cells toa value' intermediate of the high pressure and lowpressure values and substantially decreases the above mentioned loss of power.

The invention is applicable to all known types of rotary regenerator. Such heat exchangers arewell known and examples are shown in United States Patents 1,939,153;

2,8 3,195 Fatented Aug. 5, lQE

2 1,586,817 and in British patent specification 543,il93 and 645,417 the latter corresponding to application Serial N 0. 63,757 of Paul-Kolb, now Patent No. 2,598,182 granted May 27, 1952.

The invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 shows an exploded perspective view of one form of the regenerative heat exchanger with rotatable heat exchange mass,

Figure 2 is an end View showing only the matrix'and the sealing partition (shown as of arcuate'form),v

Figure 3 shows a perspective view of a regenerative heat exchanger with a hinged sealing partition,

Figure 3ashows a perspective view of the hinge'of the partition of Figure 3 in detail,

Figure 3b is afragmentary view in detail taken'from the viewpoint of the arrow 3b in Figure 3, and

Figure 4 shows a perspective view of a regenerative heat exchanger with a hinged sealing partition and automatic means to move the hinged parts to varythe area of the heat exchanger mass exposed to the two fluids.

In Figure 1 a cylindrical hollow rotor 1, secured by one of its end faces to a disc 6 carried bya shaft 2 about which it is rotatable, carries as a rim, the'fluid permeable matrix 3 divided into segmental cells d-by radial walls 5. The casing 8, enveloping the rotor, having parts 24 in fluid-tight engagement with the peripheral surface and front wall 18 engaging the endface of rotor 1 opposite to the -disc 6, is enlarged, around the rotor periphery, into parts 9 and 10 which extend from the rotor in radially opposite directions; the larger part 9 is the'entry duct-forlow pressure gas e. g. hot turbine exhaust gases and smaller part 10 is the exit duct for high pressure gase. g. the compressor delivery air in gas-turbine plant. The hot gas which constitutes the low pressure phase enters through the duct 9 and is exhaustedthrou'gh duct 9a while the cold, high pressure phase enters through duct 10a and leaves through duct 10. Wall 18 carries'a tubular extension 18a leading into the rotor 'interior, and divided asymmetrically'by fluid-tight partition 7-shown for clearness in ,Figure 1 as chordal but ac tually curved as in Figure 2into the gas outletpassage 9a and the smaller gas inlet passage'ltla. The continuation 7a of partition 7, extending up to the disc 6and'con' stituting a seal faces 11 ateach end rubbing against the inner periphery of the matrix, divides the rotor interior into separate passages 22 and 23, each open at one end and closed at the-other.

The-structureso far described is an example of a rotary regenerative heat exchanger to which the invention can be applied, the heat exchange being efiected by the rela' tive rotation of the rotor 1 (with its matrix 3) and the partitioning 7"7a. As rotor 1 turns about the'commo'n axis of rotor and casing the matrix passes through the partitioning from one passageway, wherein it is heated by the hotter fluid, to the other wherein it gives up heat to the cooler fluid. The inventive feature can be seen clearly from Figure 2, from which, for clearness, all

parts except the matrix 3 and the seal 7a are omitted.

The latter is here shown as of arcuate'form, with its convex wall facing the low pressure chamber 22, but it will be understood that this shape is not essential to the invention; it thickens towards its ends which have wide sealing faces 11 curved to conform with the inner wall of the matrix.

According to the invention, the seal 7a of Figures 1 and 2 has an internal passage 12 so arranged that a matrix cell 13 which has just left and been cut off from thehigh pressure chamber 23 is put in communication with a cell 14 which is about to move into that chamber while both cells 13, 14 are cutoif by the sealing partition 7a from both chambers, thus reducing the power less as cells 14 move into the colder stream, by about one half.

If as shown in Figure 2 each end 11 of the partition 7a seals two cells simultaneously, two passages 12 of the kind above mentioned may be provided and this will reduce the power loss by about two thirds. If desired more than two passages may be used to effect a more complete recovery of the loss of power.

In the modification shown in Figures 3 and 3a the partition 7 with its sealing portion 7a of Figures 1 and 2 is replaced within the matrix 3 by a partition formed of two parts, 15 and 16 hinged together along the axis of the rotary member 1. Part 16 is fixed to the casing end wall 18 and has an extension which, together with its limb 16a, is fixed into the extension 18a to divide the latter into passages 9a and 10a. The part is angularly movable by being fixed to the hinge pin 17. Variation in the angle between the parts 15 and 16 causes a variation in the proportions in which the matrix flow area is divided, and such variation may be eifected manually by a movable lever 25 which lies outside the rear wall of casing 8 and is secured to the hinge-pin 17 which is rigid with the partition member 15. A movable seal plate 26 between the casing 8 and the member 1 is secured to the partition part 15 to move therewith. A membrane arrangement 27, for example of sheet metal, serves to seal around the hinge pin 17.

The partition parts 15 and 16' are formed each with a passage 12 therethrough, as already described with reference to the partition 7 of Figures 1 and 2.

The hinge pin 17 with the movable partition part 15 secured thereto and the double walled membrane 27 can be seen in Figure 3 but are shown more clearly in the larger scale detailed view of which Figure 3a is a semi-perspective view. The inner wall 40 of the membrane arrangement 27 is of cylindrical form concentrically around the hinge pin 17 and is secured to the pin and the partition part 15 so that it moves angularly with them. The outer wall 41 of the membrane arrangement 27 is also of cylindrical form arranged concentrically around the inner wall 40 and secured to the number 16 so as to be stationary. The outer wall 41 of the membrane is an incomplete cylinder so that a gap 41a is provided through which the partition part 15 projects to enable it to be angularly moved. To insure sealing against escape of gas, the inner wall 46 of the membrane arrangement is a good sliding fit in theouter wall 41; The inner wall 40 is perforated at 42 in the neighborhood of the partition part 16 to enable a cell 13 to be put in communication with a cell 14 through the passage or passages 12 in the partition parts 15 and 16 and the interior of the double walled sealing membrane 27. The sealing plate 26 where it covers the end of the membrane arrangement 27 is shown cut away in Figures 3 and 3a and removed entirely in Figure 3b to expose the end of the membrane walls 40 and 41 and of the hinge pin 17.

The movement of member 15 by means of radial partitions 17a may also be effected automatically according to the variation of one or more selected operational conditions. In the example of Figure 4 the condition selected is the ratio between the pressures of the two fluids in the parts 9, 141 of casing 8. From these parts lead pipes 28, 29 respectively to a chamber 30 in which is arranged a flexible diaphragm 31 linked by a lever system 32 to the rotatable arm 33 of a variable resistance 34 connected in an electrical circuit including two electricfl power sources 35, 36 and an electric motor shaft 37 linked by a chain 38 to pin 17 outside the casing end wall 18. The electrical circuit is such that when the pressure ratio of the fluids in parts 9 and 10 varies in one direction the arm 33, shaft 37 and pin 17 rotate in one sense and when the pressure varies in the opposite direction, arm 33, shaft 27 and pin 17 rotate in the opposite sense.

I claim:

1. In a rotary regenerative type heat exchanger, which is a device comprising a fluid-permeable means constituting a cellular matrix affording paths through the cells thereof for a high pressure and a low pressure fluid, means completely separating these paths, one of said means being rotatable with respect to the other, the cells of said matrix thus each constituting part of one of said paths and then part of the other in succession by virtue of said rotatability, and sealing means engaging the relatively rotatable means to seal said paths from one another, the improvement which comprises the provision of a communicating passageway between a point of engagement of the sealing means with the matrix in a region of the matrix which is in transition from the high-pressure path to the low-pressure path and another such point in a region which is in transition from the low pressure path to the high pressure path.

2. In a rotary regenerative type heat exchanger comprising in combination a casing, a cellular fluid-permeable heat storage element in the casing constituting the regenerator matrix fluid-tight partitioning in the casing co-operating with the casing and the matrix to define two separate passageways through the cells of the matrix for high-pressure and low-pressure fluids respectively, the matrix extending through the partitioning from one of said passageways to the other, means relatively to rotate the matrix and at least some part of the partitioning, and a seal incorporated in said partitioning, engaging the matrix for sealing oil the one passageway from the other, the improvement which consists in providing the seal with at least one pressure-equalising passage forming a communication from a cell of the matrix which is passing the seal from the high pressure passageway to the low pressure passageway with a cell which is passing from the low pressure passageway to the high pressure passageway.

3. A rotary regenerative type heat exchanger comprising in combination a casing constituting a duct for the flow of fluid, a hollow cylindrical rotor coaxially mounted within said duct for rotation about their common axis, a cellular fluid-permeable heat storage rim on said rotor constituting the cellular matrix of the regenerator, fluidtight partitioning within said duct defining with said matrix two wholly separate fluid passages through the cells of said matrix and a seal constituting part of said partitioning inside said duct, dividing its interior into the said passages, said seal having sealing faces engaging the peripheral wall of said matrix in two circumferentially separated regions and having also at least one pressure-equalising fluid passage extending from a point on said sealing faces in one said region to a similar point in the other said region.

4. A rotary regenerative type heat exchanger comprising in combination an annular heat-storage matrix divided radially into fluid-permeable cells, a casing enclosing said matrix and engaging two different parts of the external periphery of the matrix, continuations of said casing constituting a first duct portion concentric with said matrix, leadinginto the interior of said matrix, and second and third duct portions extending in radially opposite directions from the external periphery of said matrix, the said second duct portion being smaller than and having a smaller arc of the external periphery of said annular matrix exposed thereto than the said third duct portion, partitioning unsymmetrically disposed in said first duct portion extending through the interior of said matrix to divide said first duct portion and the interior of the matrix into two wholly separate unequal passageways for the passage of a hot fluid and a cooler fluid at different pressures, each of said passageways within said matrix being open at one end and closed at the other end by said partitioning and each having exposed thereto an arc of the internal periphery of said matrix coextensive with the arc of the external periphery exposed to the corresponding one of said radial duct portions, means mounting said matrix in said casing for rotation around its axis to bring each part thereof successively across the high-pressure passageway, through the partitioning into and across the low-pressure passageway and thence through the partitioning back to the high-pressure passageway, and end portions 011 the part of said partitioning inside the duct having sealing faces in rubbing and sealing contact with the internal periphery of said matrix, the said part of said partitioning having at least one pressure-equalising passage extending from a point on one of said sealing faces engaging a cell of the matrix which has just left the high-pressure passageway to a point on the other of said sealing faces engaging a cell of the matrix which is just about to enter the high-pressure passageway.

5. A rotary regenerative type heat exchanger comprising in combination an annular heat-storage matrix divided radially into fluid-permeable cells, a casing en closing said matrix and engaging two different parts of the external periphery of the matrix, continuations of said casing constituting a first duct portion concentric with said matrix, leading into the interior of said matrix, and second and third duct portions extending in radially opposite directions from the external periphery of said matrix, the said second duct portion being smaller than said third duct portion, two radial partitions, at an acute angle to each other, disposed in said first duct portion and extending through the interior of said matrix into two wholly separate unequal passageways for the passage of a hot fluid and a cooler fluid at different pressures, each of said passageways within said matrix being open at one end and closed at the other, means pivotably connecting together at least the parts of said partitions inside said matrix, means for effecting relative angular movement of said parts of said partitions to vary the relative arcs of the matrix exposed to said passageways and to said radial duct portions, means mounting said matrix in said casing for rotation around its axis to bring each part thereof successively across the high-pressure passageway, through the partitioning into and across the lowpressure passageway and thence through the partitioning back to the high-pressure passageway, and an end portion on each of said pivotally connected parts having sealing faces in rubbing and sealing contact with said matrix, said pivotally connecting parts each having at least one pressure-equalising passage extending from a point on one of said sealing faces engaging a cell of the matrix which has just left the high-pressure passageway to a point on the other of said sealing faces engaging a cell ofthe matrix which is just about to enter the highpressure passageway.

6. In a rotary regenerative heat exchanger, being a device comprising a fluid-permeable matrix affording two separate fluid-flow paths therethrough, fluid-tight means defining separate paths for the flow of high and of low pressure fluid to one side of said matrix and from the other side thereof, means relatively to rotate said matrix and flowpath-defining means and a seal constituting a part of said fiowpath-defining means and engaging said matrix in a region of transition from the high-pressure to the low-pressure path and in a region of transition from the low-pressure to the high-pressure path, the improvement that the seal has a fluid-flow passageway therethrough from the one said region to the other.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Nov. 26,

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