A cooler and supercritical carbon dioxide Brayton cycle power generation system

Abstract

The present invention discloses a cooler and a supercritical carbon dioxide Brayton cycle power generation system. The system comprises a plurality of heat transfer members arranged in a cooler body opposite to a partition wall surface, and the heat transfer members are arranged to penetrate a liquid cooling channel and the forced air cooling channel; the air cooling section and at least a part of the liquid cooling section of the heat transfer member are covered with a liquid wick; during cooling, the coolant provided by the coolant supply unit enters the liquid cooling channel, enters the liquid cooling section of the air cooling section under the action of the capillary force of the liquid wick of the liquid cooling section, and evaporates the coolant under the action of forced air cooling, thereby reducing the temperature of the heat transfer member to the dew point temperature, and the heat transfer member transfers the cold to the partition wall surface in the supercritical carbon dioxide channel to cool the supercritical carbon dioxide working medium. The supercritical carbon dioxide working medium can be cooled to the dew point temperature without the need for a water pump to consume power, thereby reducing the inlet temperature of the compressor in the supercritical carbon dioxide power generation system and improving the power generation efficiency of the supercritical carbon dioxide power generation system.

Description

Technical Field

[0001] The invention belongs to the technical field of power generation, and in particular relates to a cooler and a supercritical carbon dioxide Brayton cycle power generation system. Background Art

[0002] The supercritical carbon dioxide Brayton cycle power generation system is generally regarded as the next generation revolutionary power generation technology due to its advantages such as high power generation efficiency and environmental protection. In the area above 600°C, it has obvious advantages over the existing steam cycle power generation technology.

[0003] The power generation efficiency of supercritical carbon dioxide increases as the inlet temperature of the compressor decreases. This is mainly because as the inlet temperature of the compressor decreases, the density will also decrease, thereby reducing the power consumption of the compressor.

[0004] The reduction of compressor inlet temperature depends on the cooling capacity of the cooler, and the current cooler is mainly air cooling technology, the cooling capacity of air cooling is limited by the ambient temperature, and air cooling technology can only cool supercritical carbon dioxide to ambient temperature at most. This greatly limits the improvement of supercritical carbon dioxide power generation efficiency.

[0005] If circulating coolant is used to cool supercritical carbon dioxide, firstly, the power consumption of the circulating water pump needs to be deducted. Secondly, this type of power generation system is usually built in arid areas such as Qinghai, where liquid cooling technology is not allowed. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a cooler for solving the problem that the existing supercritical carbon dioxide Brayton cycle power generation system is difficult to further improve the power generation efficiency under the condition of relatively low energy consumption.

[0007] A cooler of the present invention is used for cooling supercritical carbon dioxide working medium, comprising:

[0008] A cooler body is provided with a supercritical carbon dioxide flow channel, a liquid cooling flow channel and a forced air cooling flow channel which are adjacent to each other in sequence; and a plurality of partition walls are provided in the supercritical carbon dioxide flow channel along the flow direction of the fluid.

[0009] A plurality of heat transfer members, each of which corresponds to the partition wall surface one by one and is arranged in the cooler body, and each of which is provided through the liquid cooling channel and the forced air cooling channel; wherein the portions of the heat transfer members located in the liquid cooling channel and the forced air cooling channel are the liquid cooling section and the air cooling section respectively;

[0010] A plurality of liquid wicks, wherein the liquid wicks are respectively coated on the corresponding air cooling section and the liquid cooling section;

[0011] A cooling liquid supply part, wherein an output end of the cooling liquid supply part is connected to the liquid cooling channel.

[0012] The cooler of the present invention has an air-cooling partition and a liquid-cooling partition in the cooler body;

[0013] The liquid cooling baffle is arranged in the cooler body along the fluid flow direction, and cooperates with the inner cavity of the cooler body to form the supercritical carbon dioxide flow channel;

[0014] The air-cooling baffle is arranged in the cooler body along the fluid flow direction, and cooperates with the liquid-cooling baffle and the inner cavity of the cooler body to form the liquid-cooling flow channel, and cooperates with the inner cavity of the cooler body to form the forced air-cooling flow channel.

[0015] In the cooler of the present invention, the air-cooling baffle is horizontally arranged in the cooler body along the fluid flow direction;

[0016] The liquid cooling baffle comprises two sub-baffles, the first sides of the two sub-baffles are connected to each other, and the second sides of the two sub-baffles are respectively connected to two sides of the inner cavity of the cooler body in the lateral direction along the fluid flow direction;

[0017] Wherein, along the direction from the second side to the first side of the sub-partition, the vertical distance between the sub-partition and the air-cooling partition gradually increases.

[0018] The cooler of the present invention, the cooling liquid supply part includes two liquid supply units;

[0019] The output ends of the two liquid supply units are respectively connected to two sides of the liquid cooling channel that are located in the lateral direction along the fluid flow direction.

[0020] In the cooler of the present invention, the liquid supply unit is a water pipe, and the two water pipes are respectively installed on the two sides of the cooler body in the lateral direction along the fluid flow direction, and the cooler body is provided with a liquid inlet channel connected to the inner cavity of the water pipe.

[0021] In the cooler of the present invention, a plurality of liquid cooling sections arranged at intervals divide the liquid cooling flow channel into a plurality of liquid cooling sub-flow channels;

[0022] The liquid cooling section is provided with at least one communication channel communicating with adjacent liquid cooling sub-channels.

[0023] In the cooler of the present invention, the liquid absorbing core is coated on the liquid cooling section, and the first end of the liquid absorbing core extends to a side of the partition wall surface close to the liquid cooling channel.

[0024] The cooler of the present invention further comprises an air supply portion, the output end of which is connected to one end of the forced air cooling channel.

[0025] In the cooler of the present invention, the cooling liquid is water.

[0026] A supercritical carbon dioxide Brayton cycle power generation system of the present invention comprises any one of the coolers described above.

[0027] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0028] 1. In one embodiment of the present invention, a plurality of heat transfer elements are arranged in the cooler body opposite to the partition wall surface, and the heat transfer elements are arranged to penetrate the liquid cooling channel and the forced air cooling channel; the air cooling section and at least part of the liquid cooling section of the heat transfer element are covered with a liquid wick; the liquid cooling channel is arranged to be provided with cooling liquid by a cooling liquid supply unit; during cooling, the cooling liquid provided by the cooling liquid supply unit enters the liquid cooling channel, enters the liquid wick of the air cooling section under the action of the capillary force of the liquid wick of the liquid cooling section, and evaporates the cooling liquid under the action of forced air cooling, thereby reducing the temperature of the heat transfer element to the dew point temperature, and the heat transfer element transfers the cold to the partition wall surface in the supercritical carbon dioxide channel to cool the supercritical carbon dioxide working medium;

[0029] 2. In one embodiment of the present invention, the coolant in the liquid wick is forced to evaporate by air cooling, and the coolant in the liquid cooling channel continuously flows under the action of the capillary force of the liquid wick. The coolant in the liquid cooling channel exchanges heat with the supercritical carbon dioxide flow in the supercritical carbon dioxide flow channel to achieve a liquid cooling effect. At the same time, the temperature of the heat transfer element is as low as the dew point temperature, which reduces the temperature of the coolant in the liquid cooling channel, increases the heat exchange temperature difference between the supercritical carbon dioxide and the coolant, and enhances the cooling effect of the liquid cooling.

[0030] Therefore, the supercritical carbon dioxide working fluid can be stably and effectively cooled to the dew point temperature without consuming power of the liquid pump, thereby reducing the inlet temperature of the compressor in the supercritical carbon dioxide power generation system and improving the power generation efficiency of the supercritical carbon dioxide power generation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of a cooler of the present invention;

[0032] Figure 2 Another schematic diagram of the cooler of the present invention.

[0033] Explanation of the accompanying drawings: 1: cooler body; 101: supercritical carbon dioxide flow channel; 102: liquid cooling flow channel; 103: forced air cooling flow channel; 2: partition wall; 3: heat transfer element; 301: liquid cooling section; 302: air cooling section; 303: connecting channel; 4: cooling liquid supply part; 5: liquid absorption core; 6: air cooling partition; 7: liquid cooling partition; 701: sub-partition. DETAILED DESCRIPTION

[0034] The following is a further detailed description of a cooler and a supercritical carbon dioxide Brayton cycle power generation system proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0035] Embodiment 1

[0036] See also Figure 1 and Figure 2 In one embodiment, a cooler is used to cool supercritical carbon dioxide working medium, including a cooler body 1, a plurality of heat transfer elements 3, a plurality of liquid wicks 5 and a cooling liquid supply part 4.

[0037] The cooler body 1 is provided with a supercritical carbon dioxide flow channel 101, a liquid cooling flow channel 102 and a forced air cooling flow channel 103 which are adjacent to each other in sequence. The supercritical carbon dioxide flow channel 101 is provided with a plurality of partition walls 2 arranged along the flow direction of the fluid. The output end of the coolant supply part 4 is connected to the liquid cooling flow channel 102 for supplying coolant.

[0038] The heat transfer elements 3 correspond to the partition walls 2 one by one and are arranged in the cooler body 1, and the heat transfer elements 3 are all arranged in the liquid cooling channel 102 and the forced air cooling channel 103. The parts of the heat transfer elements 3 located in the liquid cooling channel 102 and the forced air cooling channel 103 are the liquid cooling section 301 and the air cooling section 302 respectively.

[0039] The liquid wick 5 is configured to cover the corresponding air cooling section 302 and liquid cooling section 301 respectively.

[0040] In this embodiment, a plurality of heat transfer members 3 are arranged in the cooler body 1 opposite to the partition wall 2, and the heat transfer members 3 are arranged to penetrate the liquid cooling channel 102 and the forced air cooling channel 103. The air cooling section 302 and at least part of the liquid cooling section 301 of the heat transfer member 3 are covered with the liquid wick 5. The liquid cooling channel 102 is arranged to be provided with cooling liquid by the cooling liquid supply part 4. During cooling, the cooling liquid provided by the cooling liquid supply part 4 enters the liquid cooling channel 102, and enters the liquid wick 5 of the air cooling section 302 under the action of the capillary force of the liquid wick 5 of the liquid cooling section 301, and evaporates the cooling liquid under the action of forced air cooling, thereby reducing the temperature of the heat transfer member 3 to the dew point temperature, and the heat transfer member 3 transfers the cold to the partition wall 2 in the supercritical carbon dioxide channel 101 to cool the supercritical carbon dioxide working medium. In this way, the supercritical carbon dioxide working medium can be cooled to the dew point temperature without the need for the liquid pump to consume power, thereby reducing the inlet temperature of the compressor in the supercritical carbon dioxide power generation system and improving the power generation efficiency of the supercritical carbon dioxide power generation system.

[0041] At the same time, in the embodiment, the coolant in the liquid wick 5 is forced to evaporate by air cooling, and the coolant in the liquid cooling channel 102 continuously flows under the action of the capillary force of the liquid wick 5. The coolant in the liquid cooling channel 102 exchanges heat with the supercritical carbon dioxide flow in the supercritical carbon dioxide channel 101 to achieve the effect of liquid cooling. At the same time, the temperature of the heat transfer element 3 is as low as the dew point temperature, which reduces the temperature of the coolant in the liquid cooling channel 102, increases the heat exchange temperature difference between the supercritical carbon dioxide and the coolant, and enhances the cooling effect of the liquid cooling.

[0042] The specific structure of the cooler of this embodiment is further described below:

[0043] In this embodiment, an air-cooling partition 6 and a liquid-cooling partition 7 may be provided in the cooler body 1 .

[0044] The liquid cooling baffle 7 is arranged in the cooler body 1 along the fluid flow direction, and cooperates with the inner cavity of the cooler body 1 to form a supercritical carbon dioxide flow channel 101. The air cooling baffle 6 is arranged in the cooler body 1 along the fluid flow direction, and cooperates with the liquid cooling baffle 7 and the inner cavity of the cooler body 1 to form a liquid cooling flow channel 102, and cooperates with the inner cavity of the cooler body 1 to form a forced air cooling flow channel 103. (That is, the air cooling baffle 6 and the liquid cooling baffle 7 are respectively arranged in the inner cavity of the cooler body 1 at intervals, and the inner cavity is divided into three chambers, namely the supercritical carbon dioxide flow channel 101, the liquid cooling flow channel 102 and the forced air cooling flow channel 103)

[0045] like Figure 1 It should be noted that the number of air-cooled partitions 6 and liquid-cooled partitions 7 needs to be set according to the number of partition walls 2, and an air-cooled partition 6 located above and a liquid-cooled partition 7 located below are respectively set between two adjacent partition walls 2 and the corresponding heat transfer components 3, thereby forming the required supercritical carbon dioxide flow channel 101, liquid-cooled flow channel 102 and forced air-cooled flow channel 103.

[0046] Since the coolant in the liquid cooling section 301 flows to the air cooling section 301 through the capillary force of the liquid wick 5, the liquid wick 5 needs to be continuously coated on the air cooling section 302 and the liquid cooling section 301 (the liquid wick 5 located in the air cooling section 302 is at least partially connected to the liquid wick 5 located in the liquid cooling section 301), that is, there is a gap between the air cooling baffle 6 and the heat transfer elements 3 on both sides for the liquid wick to pass through. The specific installation method of the air cooling baffle 6 can be achieved by connecting the two ends of the baffle with the cooler body 1. If the length of the air cooling baffle 6 is long, a number of connection points can be arranged at intervals in the length direction thereof, and the air cooling baffle 6 is fixedly connected to the corresponding heat transfer elements 3 at these connection points.

[0047] Similarly, if the wick 5 needs to be further extended to the supercritical carbon dioxide flow channel 101, the liquid cooling baffle 7 can be arranged in the same manner as the above-mentioned air cooling baffle 6. Of course, after the gap between the liquid cooling baffle 7 and the heat transfer elements 3 on both sides is filled with the wick, it is necessary to ensure that the coolant does not flow into the supercritical carbon dioxide flow channel 101 or flows as little as possible.

[0048] In this embodiment, the air-cooling baffle 6 can be arranged horizontally in the cooler body 1 along the fluid flow direction.

[0049] The liquid cooling partition 7 may include two sub-partitions 701. The first sides of the two sub-partitions 701 are connected to each other and can also be regarded as passing through the heat transfer element 3. The second sides of the two sub-partitions 701 are respectively connected to the two sides of the inner cavity of the cooler body 1 in the horizontal direction along the fluid flow direction.

[0050] Among them, along the direction from the second side to the first side of the sub-partition 701, the vertical spacing between the sub-partition 701 and the air-cooled partition 6 gradually increases. That is, the first sides of the two sub-partitions 701 are connected to each other in the middle position of the inner cavity of the cooler body 1, and the second sides of the two sub-partitions 701 are connected to the wall surfaces on both sides of the inner cavity of the cooler body 1; the above-mentioned vertical spacing gradually increases, that is, the two sub-partitions 701 are inclined relative to the horizontal direction, and the first sides of the two sub-partitions 701 are below the second side. Such a setting can make the cross-sectional area of ​​the liquid cooling channel 102 larger as it is closer to the middle; due to the different cross-sectional areas of each flow channel of supercritical carbon dioxide, as the coolant flows to the cross-sectional area, the cross-sectional area gradually decreases, mainly considering that the cross-sectional area decreases, the heat transfer coefficient is higher, and when the coolant flows from the second side to the first side by gravity, the water temperature will rise, so in order to ensure the temperature uniformity between each flow channel, the cross-sectional area of ​​the liquid cooling channel 102 is set to be larger and larger in this embodiment.

[0051] At the same time, setting the two sub-partitions 701 to be inclined can also ensure that the coolant can flow to the middle position of the liquid cooling channel, so that the liquid absorbent core 5 located in the middle position can absorb the coolant.

[0052] In this embodiment, based on the above-mentioned arrangement of the two sub-partitions 701, the cooling liquid supply part 4 can also be arranged as two liquid supply units. The output ends of the two liquid supply units are respectively connected to the two sides of the liquid cooling channel 102 in the lateral direction along the fluid flow direction, that is, the liquid cooling channel 102 is supplied with liquid from both sides, and the cooling liquid enters the liquid cooling channel 102 from both sides of the cooler body 1 and gradually flows to the middle position of the liquid cooling channel 102.

[0053] In this embodiment, the coolant may be water, and therefore, the liquid supply unit may be a water pipe. The two water pipes are respectively installed on the cooler body 1 on both sides in the horizontal direction along the fluid flow direction, and the cooler body 1 is provided with a liquid inlet channel connected to the inner cavity of the water pipe. Water can directly enter the liquid cooling channel 102 from the water pipe through the liquid inlet channel.

[0054] In this embodiment, a plurality of liquid cooling segments 301 arranged at intervals divide the liquid cooling channel 102 into a plurality of liquid cooling sub-channels. The liquid cooling segment 301 is provided with at least one connecting channel 303 connecting adjacent liquid cooling sub-channels, so that the cooling liquid can flow to each liquid cooling sub-channel.

[0055] The heat transfer element 3 may be a rib plate. For example, the number of rib plates may be an odd number, for example, nine rib plates, which are arranged vertically in the inner cavity of the cooler body 1 in sequence and at intervals, so that the liquid cooling channel 102 and the forced air cooling channel 103 can be divided into eight liquid cooling sub-channels and eight forced air cooling sub-channels. The rib plate in the middle is located at the connection of the first side of the two sub-partition plates 701, and the two rib plates located on the outermost sides can also be located at the two sides of the inner cavity of the cooler body 1 along the fluid flow direction, that is, at the connection of the second side of the two sub-partition plates 701.

[0056] Furthermore, the ribs and the partition wall 2 may be integrated into one body, the main purpose of which is to reduce the contact thermal resistance between the ribs and the surface of the supercritical carbon dioxide flow channel 101 .

[0057] In this embodiment, the above-mentioned liquid wick 5 can be configured to partially cover the air cooling section 302 and the liquid cooling section 301, or can be configured to completely cover the air cooling section 302 and the liquid cooling section 301. It can be configured according to needs and is not specifically limited here. Further, the first end of the liquid wick 5 can extend to the side of the partition wall 2 close to the liquid cooling channel 102 to ensure the capillary force on the coolant.

[0058] In this embodiment, the cooler may further include an air supply unit, the output end of which is connected to one end of the forced air cooling channel 103, for providing the air volume required by the forced air cooling channel 103. Of course, if there is an air supply device or air supply pipeline that meets the requirements in the power generation system, the air supply unit may not be additionally provided.

[0059] Embodiment 2

[0060] This embodiment provides a supercritical carbon dioxide Brayton cycle power generation system, including the cooler in the above-mentioned embodiment 1. A plurality of heat transfer members 3 are arranged in the cooler body 1 opposite to the partition wall 2, and the heat transfer member 3 is arranged to penetrate the liquid cooling channel 102 and the forced air cooling channel 103. The air cooling section 302 and at least part of the liquid cooling section 301 of the heat transfer member 3 are covered with the liquid wick 5. The liquid cooling channel 102 is arranged to be provided with cooling liquid by the cooling liquid supply part 4. During cooling, the cooling liquid provided by the cooling liquid supply part 4 enters the liquid cooling channel 102, enters the liquid cooling section 301 of the air cooling section 302 under the action of the capillary force of the liquid wick 5 of the liquid cooling section 301, and evaporates the cooling liquid under the action of forced air cooling, thereby reducing the temperature of the heat transfer member 3 to the dew point temperature, and the heat transfer member 3 transfers the cold to the partition wall 2 in the supercritical carbon dioxide channel 101 to cool the supercritical carbon dioxide working medium. In this way, the supercritical carbon dioxide working fluid can be cooled to the dew point temperature without consuming power of the liquid pump, thereby reducing the inlet temperature of the compressor in the supercritical carbon dioxide power generation system and improving the power generation efficiency of the supercritical carbon dioxide power generation system.

[0061] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A cooler for cooling supercritical carbon dioxide working medium, characterized in that: include: A cooler body, wherein the cooler body is provided with a supercritical carbon dioxide flow channel, a liquid cooling flow channel and a forced air cooling flow channel which are adjacent to each other in sequence; the supercritical carbon dioxide flow channel is provided with a plurality of partition walls arranged along the flow direction of the fluid; A plurality of heat transfer members, each of which corresponds to the partition wall surface one by one and is arranged in the cooler body, and each of which is provided through the liquid cooling channel and the forced air cooling channel; wherein the portions of the heat transfer members located in the liquid cooling channel and the forced air cooling channel are the liquid cooling section and the air cooling section respectively; A plurality of liquid wicks, wherein the liquid wicks are respectively coated on the corresponding air cooling section and the liquid cooling section; A cooling liquid supply part, wherein an output end of the cooling liquid supply part is connected to the liquid cooling channel.

2. The cooler according to claim 1, characterized in that The cooler body is provided with an air-cooling baffle and a liquid-cooling baffle; The liquid cooling baffle is arranged in the cooler body along the fluid flow direction, and cooperates with the inner cavity of the cooler body to form the supercritical carbon dioxide flow channel; The air-cooling baffle is arranged in the cooler body along the fluid flow direction, and cooperates with the liquid-cooling baffle and the inner cavity of the cooler body to form the liquid-cooling flow channel, and cooperates with the inner cavity of the cooler body to form the forced air-cooling flow channel.

3. The cooler according to claim 2, characterized in that The air-cooling baffle is horizontally arranged in the cooler body along the fluid flow direction; The liquid cooling baffle comprises two sub-baffles, the first sides of the two sub-baffles are connected to each other, and the second sides of the two sub-baffles are respectively connected to two sides of the inner cavity of the cooler body in the lateral direction along the fluid flow direction; Wherein, along the direction from the second side to the first side of the sub-partition, the vertical distance between the sub-partition and the air-cooling partition gradually increases.

4. The cooler according to claim 3, characterized in that The cooling liquid supply unit includes two liquid supply units; The output ends of the two liquid supply units are respectively connected to two sides of the liquid cooling channel that are located in the lateral direction along the fluid flow direction.

5. The cooler according to claim 4, characterized in that The liquid supply unit is a water pipe, and two of the water pipes are respectively installed on both sides of the cooler body in the lateral direction along the fluid flow direction, and the cooler body is provided with a liquid inlet channel connected to the inner cavity of the water pipe.

6. The cooler according to claim 1, characterized in that The liquid cooling sections arranged at intervals divide the liquid cooling channel into a plurality of liquid cooling sub-channels; The liquid cooling section is provided with at least one communication channel communicating with adjacent liquid cooling sub-channels.

7. The cooler according to claim 1, characterized in that The liquid absorbing core is coated on the liquid cooling section, and the first end of the liquid absorbing core extends to a side of the partition wall surface close to the liquid cooling channel.

8. The cooler according to claim 1, characterized in that It also includes an air supply part, the output end of which is connected to one end of the forced air cooling channel.

9. The cooler according to claim 1, characterized in that The coolant is water.

10. A supercritical carbon dioxide Brayton cycle power generation system, characterized in that: Comprising a cooler as claimed in any one of claims 1 to 9.

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