A cross flow heat exchange unit and compact solar heat absorber

Abstract

The application discloses a cross flow heat exchange unit and a compact solar heat absorber, and relates to the technical field of solar heat absorbers. The cross flow heat exchange unit comprises oppositely arranged hot side wall plates and non-hot side wall plates, and an intermediate transition plate is clamped and fixed between the hot side wall plates and the non-hot side wall plates. The inner side surface of the hot side wall plate is provided with a plurality of grooves and forms a plurality of discontinuous outer layer medium channels. The inner side surface of the non-hot side wall plate is provided with a plurality of grooves and forms a plurality of discontinuous inner layer medium channels. The intermediate transition plate is provided with connecting holes for connecting the inner layer medium channels and the outer layer medium channels. Any two adjacent outer layer medium channels are connected through an inner layer medium channel and two connecting holes and form a cross flow channel. One end of the cross flow channel is a medium inlet, and the other end is a medium outlet. The scheme provided by the application can make the heat distribution in the medium channels uniform, thereby prolonging the service life of the equipment.

Description

Technical Field

[0001] This invention relates to the field of solar absorber technology, and in particular to a cross-flow heat exchange unit and a compact solar absorber. Background Technology

[0002] In direct S-CO2 Brayton cycle-based solar thermal power generation systems, the S-CO2 receiver is the core component for achieving photothermal conversion. The S-CO2 receiver must effectively absorb high-density, non-uniform solar energy flow while maintaining a high-pressure operating environment (Brayton cycle: ≥20MPa), which places higher demands on its safe and efficient operation. Safe and efficient operation under high temperature and pressure conditions has become one of the major challenges in S-CO2 receiver development. To date, the main application forms of S-CO2 receivers are thick-walled tubular receivers and compact receivers based on fine-channel designs. Among them, compact receivers use fine channels as the basic heat exchange unit; their small hydraulic diameter and large specific surface area give them good pressure resistance and excellent thermal performance. Previous studies have preliminarily demonstrated that compact solar receivers have advantages such as high thermal efficiency (90%) and long life (creep life of 90,000 h and fatigue life of 100,000 cycles), making them one of the most promising S-CO2 receiver types.

[0003] Although compact receivers based on fine-channel designs and tubular receivers possess excellent heat transfer and pressure resistance, a significant temperature gradient exists within the heat exchange unit under conditions of high-density, non-uniform, periodically alternating external solar flux and unilateral heating. This is the primary cause of excessive thermal stress. When the stress exceeds the material's limits, stress failure can occur. Especially under low Reynolds number conditions, S-CO2 heat transfer is even worse, preventing heat from being carried away promptly within the heat exchange channels, leading to heat accumulation and exacerbating the risk of stress failure.

[0004] In response to the above problems, a new solution is urgently needed. Summary of the Invention

[0005] The purpose of this invention is to provide a cross-flow heat exchange unit and a compact solar absorber to solve the problems existing in the prior art, so as to make the temperature distribution inside the medium channel uniform, thereby reducing the thermal stress caused by the temperature gradient and improving the service life of the equipment.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a cross-flow heat exchange unit, comprising: hot sidewalls and non-hot sidewalls arranged opposite to each other, wherein an intermediate transition plate is sandwiched and fixed between the hot sidewalls and the non-hot sidewalls;

[0008] The inner surface of the hot sidewall is provided with multiple grooves to form multiple discontinuous outer medium channels; the inner surface of the non-hot sidewall is provided with multiple grooves to form multiple discontinuous inner medium channels; the intermediate transition plate is provided with connecting holes for connecting the inner medium channels and the outer medium channels, and any two adjacent outer medium channels are connected through one inner medium channel and two connecting holes to form a cross-flow channel, one end of which is a medium inlet and the other end is a medium outlet.

[0009] Preferably, the crossflow channel has two types: in the first type, the outer medium channel is a curved channel and the inner medium channel is a straight channel.

[0010] In the second type of crossflow channel, the outer medium channel is a straight channel, and the inner medium channel is a curved channel.

[0011] The first type of cross-flow channel and the second type of cross-flow channel are arranged opposite each other to form a dual-channel group. The straight channels in the two types of cross-flow channels are located on both sides of the width direction of the dual-channel group, and the curved channels in the two types of cross-flow channels extend towards each other.

[0012] Preferably, the curved channel is a zigzag channel or a bend channel.

[0013] Preferably, the non-heated sidewall panel includes a non-heated sidewall panel body and a channel top plate disposed inside the non-heated sidewall panel body. The channel top plate is provided with a plurality of hollowed-out flow channels, which are grooves on the inner side of the non-heated sidewall panel.

[0014] Preferably, multiple rows of the cross-flow channels are provided, with two cross-flow channels in each row, and a confluence channel is provided between the two cross-flow channels in each row. Multiple confluence ports communicating with the confluence channels are provided on the non-heated sidewall. A diversion channel is provided at both ends of each row of cross-flow channels, and multiple diversion ports communicating with the diversion channels are provided on the non-heated sidewall.

[0015] An inlet header and an outlet header are provided on the outer side of the non-heated side wall panel. The inlet header is fixedly installed on the outer side of the non-heated side wall panel and communicates with each of the branch ports. The outlet header is fixedly installed on the outer side of the non-heated side wall panel and communicates with each of the confluence ports. The inlet header is provided with a heat exchange unit inlet, and the outlet header is provided with a heat exchange unit outlet.

[0016] The present invention also provides a compact solar absorber, including a heat exchange module and a support frame, wherein the heat exchange module is fixedly mounted on the support frame and the heat exchange module includes a plurality of cross-flow heat exchange units as described above.

[0017] Preferably, the heat exchange module further includes an inlet manifold and an outlet manifold. One inlet manifold corresponds to multiple heat exchange units. The inlet manifold is connected to the inlet of the heat exchange unit on multiple inlet headers and to the main inlet of the absorber. The outlet manifold corresponds to multiple heat exchange units. The outlet manifold is connected to the outlet of the heat exchange unit on multiple outlet headers and to the main outlet of the absorber.

[0018] Preferably, the compact solar absorber is cylindrical.

[0019] The present invention achieves the following technical effects compared to the prior art:

[0020] The cross-flow heat exchange unit provided by this invention has a double-layer structure for the cross-flow channels, including an outer medium channel and an inner medium channel. This makes the temperature distribution of the inner and outer layers uniform and avoids the situation where the heat exchange medium flows only in the flow channels of the hot side wall plate, which would otherwise cause excessive local thermal stress. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the compact solar absorber provided in Embodiment 2;

[0023] Figure 2 for Figure 1 The front view;

[0024] Figure 3 This is a schematic diagram of the heat exchange module.

[0025] Figure 4 for Figure 3 A view from another direction;

[0026] Figure 5 This is a schematic diagram of the cross-flow heat exchange unit provided in Example 1;

[0027] Figure 6 for Figure 5 A view from another direction;

[0028] Figure 7 for Figure 5 Exploded view of the structure;

[0029] Figure 8 This is a structural schematic diagram of the top plate of the channel;

[0030] Figure 9 for Figure 8 Enlarged view of the middle section structure;

[0031] Figure 10 This is a schematic diagram of the intermediate transition plate.

[0032] Figure 11 for Figure 10 Enlarged view of the middle section structure;

[0033] Figure 12 This is a schematic diagram of the structure of the thermal sidewall panel;

[0034] Figure 13 for Figure 12 Enlarged view of the middle section structure;

[0035] Figure 14 This is a schematic diagram of the dual-channel assembly;

[0036] In the diagram: 1-Heat exchange module; 2-Bracket; 3-Heat absorber main inlet; 4-Heat absorber main outlet; 101-Inlet manifold; 102-Outlet manifold; 103-Heat exchange module inlet; 104-Heat exchange module outlet; 5-Heat exchange unit; 501-Inlet header; 502-Outlet header; 503-Heat exchange unit inlet; 504-Heat exchange unit outlet; 505-Non-heated side wall plate body; 506-Channel top plate; 507-Intermediate transition plate; 508-Heated side wall plate; 5071-Connecting hole; 5061-Inner medium channel in the shape of a straight channel; 5062-Inner medium channel in the shape of a curved channel; 5081-Outer medium channel in the shape of a straight channel; 5082-Outer medium channel in the shape of a curved channel; 6-Cross-flow channel; 61-Medium inlet; 62-Medium outlet. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The purpose of this invention is to provide a cross-flow heat exchange unit and a compact solar absorber to solve the problems existing in the prior art, so as to make the temperature distribution inside the medium channel uniform, thereby reducing the thermal stress caused by the temperature gradient and improving the service life of the equipment.

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] This embodiment provides a cross-flow heat exchange unit 5, such as Figures 5-13 As shown, it includes: a hot side wall plate 508 and a non-hot side wall plate arranged opposite to each other, and an intermediate transition plate 507 is sandwiched and fixed between the hot side wall plate 508 and the non-hot side wall plate.

[0042] The inner surface of the hot sidewall 508 is provided with multiple grooves to form multiple discontinuous outer medium channels; the inner surface of the non-hot sidewall is provided with multiple grooves to form multiple discontinuous inner medium channels; the intermediate transition plate 507 is provided with connecting holes 5071 for connecting the inner medium channels and the outer medium channels. Any two adjacent outer medium channels are connected through one inner medium channel and two connecting holes 5071 to form a cross-flow channel 6. One end of the cross-flow channel 6 is the medium inlet 61, and the other end is the medium outlet 62.

[0043] Among them, the hot side wall plate 508, the intermediate transition plate 507 and the non-hot side wall plate are fixedly connected in sequence, and the connection method can be welding or other methods.

[0044] During operation, the heat exchange medium flows in from the medium inlet 61 of each cross-flow channel 6, and flows sequentially through multiple cross-arranged outer and inner medium channels to achieve uniform heat distribution, and flows out from the medium outlet 62 to the confluence channel on one side of the medium outlet 62.

[0045] The heat exchange medium is S-CO2.

[0046] The cross-flow heat exchange unit 5 provided in this embodiment has a double-layer structure for the cross-flow channel 6, which includes an outer medium channel and an inner medium channel. This makes the heat distribution between the inner and outer layers uniform and avoids the situation where the heat exchange medium only flows in the flow channel of the hot side wall plate 508 layer, which would cause excessive local thermal stress.

[0047] Multiple rows of cross-flow channels 6 are provided, with two cross-flow channels 6 in each row. A confluence channel is provided between the two cross-flow channels 6 in each row. Multiple confluence ports connected to the confluence channels are provided on the non-heated side wall. A branch channel is provided at both ends of each row of cross-flow channels 6. Multiple branch ports connected to the branch channels are provided on the non-heated side wall.

[0048] An inlet header 501 and an outlet header 502 are provided on the outer side of the non-heated side wall. The inlet header 501 is fixedly installed on the outer side of the non-heated side wall and connected to each branch port. The outlet header 502 is fixedly installed on the outer side of the non-heated side wall and connected to each confluence port. A heat exchange unit inlet 503 is provided on the inlet header 501 and a heat exchange unit outlet 504 is provided on the outlet header 502.

[0049] In some embodiments, such as Figure 14 As shown, the cross-flow channel 6 has two types. In the first type, the outer medium channel is a curved channel and the inner medium channel is a straight channel.

[0050] In the second type of crossflow channel, the outer medium channel is a straight channel, and the inner medium channel is a curved channel.

[0051] The first type of cross-flow channel and the second type of cross-flow channel are arranged opposite each other to form a dual-channel group. The straight channels in the two types of cross-flow channels 6 are located on both sides of the width direction of the dual-channel group, and the curved channels in the two types of cross-flow channels 6 extend towards each other.

[0052] Among them, the curved channel is a zigzag channel or a bend channel.

[0053] The solution provided in this embodiment greatly improves the space utilization of the heated sidewall panel 508 and the non-heated sidewall panel. The two cross-flow channels 6 in the dual-channel group complement each other in terms of heat, further improving the uniformity of heat distribution.

[0054] In some embodiments, the non-heated sidewall panel includes a non-heated sidewall panel body 505 and a channel top plate 506 disposed inside the non-heated sidewall panel body 505. The channel top plate 506 is provided with a plurality of hollowed-out flow channels, which are grooves inside the non-heated sidewall panel.

[0055] In this embodiment, the non-heated sidewall panel is a separate panel; however, in other embodiments, the non-heated sidewall panel may also be a single panel.

[0056] Example 2

[0057] This embodiment provides a compact solar absorber, such as Figures 1-4 As shown, it includes a heat exchange module 1 and a support 2. The heat exchange module 1 is fixedly mounted on the support 2. The heat exchange module 1 includes multiple heat exchange units 5 as described in Embodiment 1.

[0058] The heat exchange module 1 also includes an inlet manifold 101 and an outlet manifold 102. One inlet manifold 101 corresponds to multiple heat exchange units 5. The inlet manifold 101 is connected to the inlet 503 of the heat exchange units on multiple inlet headers 501. The inlet manifold 101 is connected to the total inlet 3 of the absorber. The outlet manifold 102 corresponds to multiple heat exchange units 5. The outlet manifold 102 is connected to the outlet 504 of the heat exchange units on multiple outlet headers 502. The outlet manifold 102 is connected to the total outlet 4 of the absorber.

[0059] A heat exchange module outlet 104 is provided on the outlet manifold 102; a heat exchange module inlet 103 is provided on the inlet manifold 101.

[0060] This embodiment possesses all the advantages described in Embodiment 1, and will not be repeated here.

[0061] Working principle: Low-temperature S-CO2 enters the manifold system through the main inlet 3 of the receiver; the manifold system then distributes the S-CO2 into heat exchange module 1; in heat exchange module 1, the low-temperature S-CO2 is distributed to each heat exchange unit 5 via the inlet manifold; the inlet header of heat exchange unit 5 receives the S-CO2 from the inlet manifold; the S-CO2 in the inlet header enters the medium channel via the non-heated sidewall; the low-temperature S-CO2 is heated by the solar flux radiated from the mirror field in the medium channel; the heated high-temperature S-CO2 enters the outlet header via the non-heated sidewall; then, the outlet manifold merges the high-temperature S-CO2 from the outlet header; finally, the high-temperature S-CO2 in heat exchange module 1 is merged through the manifold system and leaves the receiver via the main outlet 4 of the receiver.

[0062] In some embodiments, the heat absorber is cylindrical.

[0063] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A cross-flow heat exchange unit, characterized in that: It includes hot sidewalls and non-hot sidewalls arranged opposite to each other, with an intermediate transition plate sandwiched and fixed between the hot sidewalls and the non-hot sidewalls; The inner surface of the hot sidewall plate is provided with multiple grooves to form multiple discontinuous outer medium channels; the inner surface of the non-hot sidewall plate is provided with multiple grooves to form multiple discontinuous inner medium channels; the intermediate transition plate is provided with connecting holes for connecting the inner medium channels and the outer medium channels. Any two adjacent outer medium channels are connected through one inner medium channel and two connecting holes to form a cross-flow channel. One end of the cross-flow channel is a medium inlet, and the other end is a medium outlet. There are two types of cross-flow channels. In the first type, the outer medium channel is a curved channel, and the inner medium channel is a straight channel. In the second type of crossflow channel, the outer medium channel is a straight channel, and the inner medium channel is a curved channel. The first type of cross-flow channel and the second type of cross-flow channel are arranged opposite each other to form a dual-channel group. The straight channels in the two types of cross-flow channels are located on both sides of the width direction of the dual-channel group, and the curved channels in the two types of cross-flow channels extend towards each other.

2. The cross-flow heat exchange unit according to claim 1, characterized in that: The curved channel is a zigzag channel or a bend channel.

3. The cross-flow heat exchange unit according to claim 1, characterized in that: The non-heated sidewall panel includes a non-heated sidewall panel body and a channel top plate disposed inside the non-heated sidewall panel body. The channel top plate is provided with a plurality of hollowed-out flow channels, which are the grooves inside the non-heated sidewall panel.

4. The cross-flow heat exchange unit according to claim 1, characterized in that: The system is provided with multiple rows of cross-flow channels, with two cross-flow channels in each row. A confluence channel is provided between the two cross-flow channels in each row. Multiple confluence ports communicating with the confluence channels are provided on the non-heated sidewall. A branch channel is provided at both ends of each row of cross-flow channels. Multiple branch ports communicating with the branch channels are provided on the non-heated sidewall. An inlet header and an outlet header are provided on the outer side of the non-heated side wall panel. The inlet header is fixedly installed on the outer side of the non-heated side wall panel and communicates with each of the branch ports. The outlet header is fixedly installed on the outer side of the non-heated side wall panel and communicates with each of the confluence ports. The inlet header is provided with a heat exchange unit inlet, and the outlet header is provided with a heat exchange unit outlet.

5. A compact solar thermal absorber, characterized in that: It includes a heat exchange module and a support, wherein the heat exchange module is fixedly mounted on the support, and the heat exchange module includes a plurality of cross-flow heat exchange units as described in claim 4.

6. The compact solar absorber according to claim 5, characterized in that: The heat exchange module further includes an inlet manifold and an outlet manifold. One inlet manifold corresponds to multiple heat exchange units. The inlet manifold is connected to the inlet of the heat exchange unit on multiple inlet headers and is connected to the main inlet of the absorber. The outlet manifold corresponds to multiple heat exchange units. The outlet manifold is connected to the outlet of the heat exchange unit on multiple outlet headers and is connected to the main outlet of the absorber.

7. The compact solar absorber according to claim 5, characterized in that: The compact solar absorber is cylindrical.

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