High pressure counterflow heat exchanger

Abstract

A heat exchanger including a plurality of heat exchanger plates in a stacked arrangement. At least two counterflow sections are positioned adjacent each other. The counterflow sections comprise an intermediate section of each heat exchanger plate. The heat exchanger plates configured to transfer heat between a first fluid and a second fluid flowing in an opposite directions from the first fluid through a respective heat exchanger plate. At least one tent section is positioned on each end of each counterflow section. The tent sections are configured to angle the flow direction of the first and second fluids in the tent sections relative to the flow direction in the counterflow sections.

Claims

1. A heat exchanger, comprising: a plurality of heat exchanger plates in a stacked arrangement; at least two counterflow sections positioned adjacent each other, the at least two counterflow sections comprising an intermediate section of each heat exchanger plate of the heat exchanger plates, the heat exchanger plates configured to transfer heat between a first fluid and a second fluid flowing in opposite directions from each other through a heat exchanger plate of the plurality of heat exchanger plates; at least one tent section on each end of each counterflow section of the at least two counterflow sections, each of the tent sections of the at least one tent section directing inlet flow and outlet flow of the first fluid parallel to each other and at equally oblique angle relative to a flow direction in the at least two counterflow sections and the at least one tent section directing inlet flow and outlet flow of the second fluid parallel to each other and at equally oblique angle relative to the flow direction in the counterflow sections; at least a first pair of inlet ports configured to allow the first fluid to enter the heat exchanger and at least a first pair of outlet ports configured to allow the first fluid to exit the heat exchanger, each inlet port of the at least a first pair of inlet ports and each outlet port of the at least a first pair of outlet ports positioned through a tent section of the at least one tent section; at least a second pair of inlet ports configured to allow the second fluid to enter the heat exchanger and at least a second pair of outlet ports configured to allow the second fluid to exit the heat exchanger, each inlet port of the at least a second pair of inlet ports and each outlet port of the at least a second pair of outlet ports positioned through a tent section of the at least one tent section; a first pair of headers, wherein each of the headers of the first pair are joined by a shared wall positioned between the first pair of headers and which continues adjacent along a length of the at least two counterflow sections; and a second pair of headers not in contact with each other and not in direct contact with the shared wall.

2. The heat exchanger of claim 1, wherein the at least a first pair of inlet ports are on an opposing end of the at least a second pair of inlet ports and wherein the at least a first pair of outlet ports are on an opposing end of the at least a second pair of outlet ports.

3. The heat exchanger of claim 2, wherein the first fluid includes a cooling fluid and the second fluid is configured to transfer heat to the first fluid within the at least two counterflow sections.

4. The heat exchanger of claim 3, wherein the heat exchanger plates are comprised of a first layer for the first fluid and a second layer for the second fluid to flow therethrough, the first and second layers being positioned adjacent within the stacked arrangement of the heat exchanger.

5. The heat exchanger of claim 1, wherein each of the second pair of headers has a curve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to certain figures, wherein:

(2) FIG. 1a is a cross-sectional view of a heat exchanger plate of the prior art, showing a hot layer with angled tent sections.

(3) FIG. 1b is a cross-sectional view of a heat exchanger plate of the prior art, showing a cold layer with angled tent sections.

(4) FIG. 2 is a perspective view of an exemplary embodiment of a heat exchanger constructed in accordance with the present disclosure, showing heat exchanger plates in a stacked arrangement with inlet and outlet ports;

(5) FIG. 3a is a cross-sectional view of a second layer plate of FIG. 2, having multiple angled tent sections on both ends of a cold layer of a counterflow core section;

(6) FIG. 3b is a cross-sectional view of a first layer plate of FIG. 2, having multiple angled tent sections on both ends of a hot layer of a counterflow core section;

(7) FIG. 4 is an alternate embodiment of a single first or second hot and cold layer of a heat exchanger constructed in accordance with the present disclosure, with a tent section on each end of each core section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a partial view of an exemplary embodiment of a counterflow heat exchanger in accordance with the disclosure is shown in FIG. 2 and is designated generally by reference character 100. Other embodiments of the counterflow heat exchanger in accordance with the disclosure, or aspects thereof, are provided in FIGS. 3a-4, as will be described.

(9) Counterflow heat exchanger designs require tents at an angle relative to the counterflow core section to allow the flow to enter and exit the counterflow core section of the heat exchanger. The hot and cold layers of prior art design are shown in FIGS. 1a and 1b. Prior art counterflow heat exchangers include hot and cold layers 12, 14 attached to a parting sheet (not shown) that separates the hot and cold fluids. The heat exchanger is comprised of a cold layer including cold fins, a hot layer including hot fins and a parting sheet therebetween. This assembly is stacked one atop another to form a core with headers 16 attached to the core and arranged such that a cooling fluid enters at one end while a hot fluid enters on an opposing end, while allowing the hot and cooling fluids to flow in opposing directions to one another over a substantial portion of the core. This method of getting flow into and out of a counterflow heat exchanger optimizes heat transfer for a given amount of heat transfer surface area by ensuring that all fluid flow paths have essentially the same length, achieving essentially uniform flow through each flow passage of the heat exchanger. As shown in FIGS. 1a and 1b the prior art consists of a single counterflow section 20 with one tent section 24 at each end of the counterflow section 20. The tent sections 24 are comprised of multiple tent flow channels.

(10) With reference to FIGS. 2-3b, the present disclosure includes a heat exchanger 100 having smaller diameter headers 116 containing the highest pressure fluid to minimize header thickness (not shown), reducing heat exchanger weight and simplifying the design from a structural standpoint. High pressure heat exchangers often must have a minimum number of fins (not shown) per unit flow width to contain the high pressures, and this minimum fin density must exist throughout the heat exchanger, i.e., in both the core 117 and tent sections 124 of the heat exchanger.

(11) To maintain practical duct sizes to channel fluid to and from the heat exchanger 100, a narrow tent section width 125 is desirable; however, because a minimum distance between fins (not shown) must be maintained throughout the core 117 and tent sections 124 for structural reasons, pressure drop through the tent sections 24 of prior art counterflow heat exchangers 10 is often high, resulting in an undesirably large heat exchanger volume and weight. The reduced flow length of multiple tent sections 124 in a heat exchanger plate 111 as well as the reduction in the amount of total fluid flow passing through each tent section 124 results in reduced pressure drop in the tent sections 124 relative to the pressure drop in the tent sections 24 of prior art heat exchangers 10.

(12) With continued reference to FIG. 2 a perspective view of the heat exchanger 100 of the present disclosure is shown. The heat exchanger 100 includes a plurality of heat exchanger plates 111 in a stacked arrangement. Each heat exchanger plate 111 includes a first layer 114 (i.e, a cold layer) (see FIG. 3a) with cold fluid flowing therethrough and a second layer 112 (i.e., a hot layer) (see FIG. 3b) with a hot fluid flowing therethrough. The plates 112, 14 are stacked to form a core 117 of the heat exchanger 100. The hot and cold layers are physically separated by a parting sheet (not shown). The fluid flow passages in the hot and cold layers 112, 114 are arranged such that the hot fluid flowing through the hot layer is configured to exchange heat between the cooling fluid flowing through the cold layer. As shown in FIGS. 3a-3b, counterflow sections 120 comprise an intermediate portion 121 of heat exchange plates 111 where the heat exchange occurs. In contrast to the prior art design shown in FIGS. 1a and 1b, each layer 112, 114 of the heat exchanger 100 includes multiple counterflow sections 120 positioned adjacent each other with multiple tent sections 124 on each end. The tents sections 124 of heat exchanger 100 are relatively shorter in length than those shown in prior art 10 which reduces pressure drop for a given rate of fluid flow through the tent sections 124. The tent sections 124 are configured to angle 131 the flow direction of the first and second fluids in the tent sections 124 relative to the flow direction in the counterflow sections 120. With continued references to FIGS. 3a-3b, on one end 140 of each layer 112, 114 the tent sections 124 share a header 116 and on an opposing end 142 each tent section 124 has an individual header section 116. When the plates 111 are stacked into a core 117, the individual headers 116 combine to form continuous flow paths to channel hot and cooling fluid to and from the heat exchanger core 117. Two tent sections 124 sharing a single header 116 reduces the number of headers 116 needed and therefore reduces weight and cost of the heat exchanger 100 relative to the prior art. A solid wall 130 is positioned between the tent sections 124 and continues adjacent the counterflow core sections 120 for each layer 112, 114.

(13) Each of the layers 112, 114 includes inlet ports 132a, 132b within respective tent sections 124 configured to allow the respective fluid to enter the counterflow section 120 and two outlet ports 134a, 134b within respective tent sections 124 configured to allow the respective fluid to exit the counterflow section 120. As shown in FIG. 3a, the cold layer 114 includes two inlet ports 132a and 132b at one end 142 (i.e. a first end) where the inlet ports 132a, 132b are positioned along a surface of the respective tent 124. The cooling fluid enters and flows through the counterflow section 120 and then exits outlet ports 134a and 134b at the opposing end 140 (i.e. a second end) along a surface of the respective tent 124. As shown in FIG. 3b, the hot layer 112 includes two inlet ports 132a and 132b through respective tents 124 and header 116 at the second end 140. The hot fluid flows through the counterflow section 120, in the opposite direction of the cold fluid, and exits outlet ports 134a and 134b at the first end 142 through respective tents 124 and headers 116. It will be understood by those skilled in the art that while the flow directions are shown in a specific configuration in FIGS. 3a, 3b and 4 the flow directions can be changed between the hot and cold layers without departing from the scope of the present disclosure.

(14) The inlet and outlet ports 132a, 132b, 134a, 134b are aligned facing away from each other and directing the respective fluid into the respective counterflow sections 120. The wall 130 is continuous along the entire counterflow sections 120 (in the direction of the stacked layers) to hold the high pressure headers 116 on the heat exchanger 100. The wall 130 provides a load path by allowing the pressure forces acting on high pressure headers 116 on one end (e.g., second end 140) to react against the forces on high pressure headers 116 on the other end (e.g., first end 142). This allows for the hoop stress to be met with reduced thickness and weight.

(15) FIG. 4, illustrates a further embodiment of a counterflow heat exchanger. FIG. 4 shows a hot layer 212 but it will be understood that a cold layer will include similar structure in keeping with the disclosure. As shown in FIG. 4, four counterflow sections 220 are positioned adjacent each other. With the combination of additional counterflow sections 220, an additional header 216 combines two tents 224. Three walls 230 are positioned between each of the counterflow sections 220. As the number of counterflow sections increases, the tents 124 of heat exchanger decrease in length and are relatively shorter in length than as in the embodiment of FIGS. 3a and 3b. As described above, this also reduces flow through the tents which reduces the pressure drop of the tents relative to the pressure drop of the tents of a prior art device with only one tent section on each end of the counterflow section.

(16) The methods and systems of the present disclosure, as described above and shown in the drawings, provide for counterflow heat exchanger with superior properties including reducing tent length and fin density. While the apparatus and methods of the subject disclosure have been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.