Back-spraying type heat collecting tube
By using a return-spray type heat collector tube with internal circulation design, the problems of heat loss due to external circulation of heat transfer medium and tube bending and bursting of inner tubes are solved, achieving efficient heat utilization and cost reduction.
Patent Information
- Application Number
- CN202422556379.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-15
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-10-15
AI Technical Summary
The heat transfer medium of existing biaxial concentrating medium- and high-temperature solar collector tubes suffers from large heat loss and high cost when circulating externally. Furthermore, the poor flow of the heat transfer medium within the collector tube at the same inlet and outlet end can easily lead to the inner tube bending and bursting.
The heat transfer medium is circulated within the heat collection tube by a return-spray type heat collection tube design. The flow is accelerated and evenly distributed through the spray cavity or spray pipe structure to avoid dead zones. Vacuum jacket and sealed connection are used to reduce heat dissipation and ensure smooth flow.
This technology enables the heat transfer medium to circulate within the heat collection tube, reducing heat loss and costs while improving heat utilization. It also avoids the risk of the inner tube bending and bursting, ensuring safety and reliability.
Smart Images
Figure CN223623139U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of medium and high temperature solar energy utilization with dual-axis solar radiation. Background Technology
[0002] In current dual-axis and solar concentrating high-temperature solar energy applications, the collector tubes are generally straight-through. The medium in multiple collector tubes needs to be connected and heated in a relay-like flow. This requires connecting the collector tubes with insulation pipes, which means external circulation. This results in significant heat loss in the air, and the external connecting pipes need to be insulated, leading to higher costs.
[0003] To address the issue of having the inlet and outlet at the same end, allowing the heat transfer medium to circulate within the collector tube, while also preventing heat loss from external pipes and reducing costs, a common problem with collector tubes having the inlet and outlet at the same end has been the occurrence of inner tube bending and glass shattering due to poor flow within the tube. To ensure smooth flow of the working medium back towards the outlet, preventing localized stagnation of the heat transfer medium in the inner tube that could cause bending and glass breakage, and to ensure equal opportunities for liquid flow outlets in each layer of the heat-absorbing inner tube, a return-spray core tube and distributed outlet pipes were invented and installed within the inner tube. Utility Model Content
[0004] The present invention aims to invent a recirculating internal circulation heat collector tube that allows the heat transfer medium to circulate and heat the heat inside the heat collector tube instead of circulating and dissipating heat outside the heat collector tube. This tube allows for smooth flow and equal opportunities for each layer of liquid to flow out, avoiding local stagnation that could cause the inner tube to bend and break the glass cover. It is safe, reliable, and can improve heat utilization and reduce pipeline costs.
[0005] This utility model is implemented using the following solution:
[0006] 1. A type of return-spray solar collector tube, comprising a cover tube, an inner tube, a return-spray core tube, and a liquid outlet tube, characterized in that:
[0007] A. The return spray core tube is either a spray cavity type or a spray pipe type. The spray cavity type core tube consists of a spray cavity and an inlet pipe, both located inside the inner tube. The inlet pipe is L-shaped and consists of a long pipe and a short pipe that are perpendicular to each other and connected. The open end of the long pipe is inserted into the spray cavity and fixedly connected to each other. There is a sealed fixed connection between the short pipe and the inner tube, and its port is exposed outside the inner tube, which is the inlet interface of the external working fluid. The spray cavity consists of a spray cavity body and a back cover plate that are fixedly connected and sealed to each other. The back cover plate is fixedly connected to the support pile, and the support pile is fixedly connected to the adjustment plate welded to the inner tube wall.
[0008] B. The nozzle-type core tube is composed of an inlet pipe and a nozzle. The inlet pipe is formed by a long pipe and a short pipe that are perpendicularly connected and communicate with each other. It extends from the side wall of the inner tube head to the short pipe opening outside the inner tube, forming the medium inlet interface. The long pipe end located at the tail of the inner tube is sealed with a plug plate and fixedly connected to the adjusting plate. The adjusting plate is connected to the inner tube. The peripheral wall of the long pipe end and one opening of multiple "L"-shaped nozzles are fixedly connected and communicate with each other. The other opening of each "L"-shaped nozzle points to the head of the inner tube. The plug plate may have individual small holes or no individual small holes.
[0009] C. At least one section of the inner tube is contained within the cover tube, and the interlayer of this section is a vacuum. The outer surface of the inner tube section contained within the cover tube is coated with a heat-absorbing coating, and the cover tube is transparent. The inner tube may have one end exposed outside the cover tube, and this type of heat collector tube is called a single-exposed return-spray heat collector tube; or both ends may be exposed outside the cover tube, and this type of heat collector tube is called a double-exposed return-spray heat collector tube.
[0010] D. The exposed section of the inner tube of the single-exposed return-spray type heat collector tube has a sealed connection with the cover tube. This port of the inner tube is welded with a cover plate for sealing. The interlayer between the cover tube and the inner tube is a vacuum. The short pipe of the inlet pipe is located in the exposed section of the inner tube. Its port extends from one side of the inner tube, i.e., the circumferential surface. The outlet pipe is located on the other side of the exposed section of the inner tube and communicates with the inner tube. It is perpendicular to the inner tube and has a sealed connection. The outer port of the outlet pipe extends outside the inner tube and is the outlet interface of the heated working fluid. The outlet pipe may be distributed or it may be a single external interface rather than distributed. Along the length of the generatrix of the distributed outlet pipe in the inner tube, there are one or more layers of inlet holes that allow the medium to enter the outlet pipe. Each layer of inlet holes is located on the circumferential surface of the distributed outlet pipe. The end of the heat collector tube that connects the inlet interface and the outlet interface is called the head of the heat collector tube. The other end of the inner tube is also closed and located inside the cover tube. This end of the heat collector tube is called the tail of the heat collector tube.
[0011] E. The inner tube of the double-exposed, back-spraying heat collector tube has both ends exposed outside the cover tube, and the ends of the inner tube and the cover tube are sealed and fixedly connected, or both ends are sealed and fixedly connected through Kovar alloy rings and bellows. This is called a double-exposed, double-sealed back-spraying heat collector tube. Alternatively, one end is sealed and fixedly connected through Kovar alloy rings and bellows, while the other end is sealed and welded through Kovar alloy rings but without bellows. This type of heat collector tube is called a double-exposed, single-sealed back-spraying heat collector tube. There is a vacuum between its cover tube and inner tube.
[0012] One end of the inner tube of the double-dew-return-spray collector tube is connected to the inlet port of the inlet pipe and the outlet port of the outlet pipe. This end is the head of the double-dew-return-spray collector tube. The other end of the inner tube is the tail of the double-dew-return-spray collector tube. The long end of the inlet pipe installed in the inner tube is either fixedly connected to the spray chamber or fixedly connected to the spray pipe. The outlet pipe is either distributed or has only one outlet port. The portion of the distributed outlet pipe is enclosed in the inner tube. One or more small holes are opened on the circumferential surface along its generatrix direction. Both ends of the inner tube are sealed with cover plates.
[0013] 2. The inner tube end of the single-exposed return-spray type heat collector tube, which is enclosed in the cover tube, is connected to the cover tube by an elastic bracket. The elastic bracket and the inner tube are welded together, and the elastic bracket and the transparent cover tube are movably connected.
[0014] 3. On the spray cavity body of the spray cavity type core tube, there are small holes for spraying liquid on one side facing the heat collection tube head, called spray holes.
[0015] 4. The back cover plate of the spray chamber may have a back cover hole that is much smaller than the spray hole, or it may have no back cover hole. Attached Figure Description
[0016] 1. Figure 1 This is a front sectional view of a single-exposed return-jet collector tube with a spray cavity core.
[0017] 2. Figure 2 yes Figure 1 KK section view
[0018] 3. Figure 3 yes Figure 1 QQ cross-section view
[0019] 4. Figure 4 This is a front sectional view of a double-exposed, double-sealed, return-jet solar collector tube.
[0020] 5. Figure 5 yes Figure 4 G-G section view
[0021] 6. Figure 6 This is a front sectional view of a double-exposed, single-sealed, return-spray type solar collector tube.
[0022] 7. Figure 7 yes Figure 6 G-G section view
[0023] 8. Figure 8 This is a front sectional view of a single-exposed return-jet collector tube with a nozzle-type core tube.
[0024] 9. Figure 9 yes Figure 8 KK section view
[0025] 10. Figure 10 yes Figure 8 G-G section view Detailed Implementation
[0026] Figure 1 This is a front sectional view of a single-exposed return-spray type solar collector tube with a spray cavity core tube. Figure 1 In this design, 1 is the short inlet pipe, which is fixedly connected to the exposed section of the inner pipe 6. Its port is the inlet interface for the working fluid, protruding outside the inner pipe 6. 2 is the distributed outlet pipe, with one end protruding outside the inner pipe 6 as the outlet interface for the working fluid. This end is fixedly and sealed to the inner pipe 6 nearby. The other end is enclosed within the inner pipe. It has two or more layers of small holes along its generatrix direction, such as... Figure 1 As shown, these small holes are the inlets of the liquid outlet pipe, ensuring that the working liquid from each layer flows out of the inner tube equally and without dead zones, thus guaranteeing uniform temperature across the entire circumference of the heat-absorbing inner tube and preventing it from bending or contacting the cover glass at high temperatures, thus avoiding tube breakage. 3 is the head cover plate of the inner tube 6, and 4 is a Kovar alloy ring with a thermal expansion coefficient very close to that of the cover glass 9, which is welded to the glass. This Kovar alloy ring is welded to the steel inner tube 6 via the corrugated pipe 14 to ensure that the interlayer between the cover tube 9 and the inner tube 6 is a vacuum 13.
[0027] exist Figure 1 In the diagram, 5 is the long inlet pipe, whose right end is inserted into the spray chamber 12 and welded together. The spray chamber 12 can also represent the spray chamber. 6 is a steel heat-absorbing inner tube with a heat-absorbing coating on its outer surface that can absorb solar heat. 7 is the back cover plate of the spray chamber 12. The back cover plate 7 and the spray chamber 12 are connected in a sealed manner. It is best to make a small hole on the back cover plate, much smaller than the spray nozzle, called a back cover hole. Figure 1 The K-hole in the middle facilitates the flow of liquid behind the spray chamber. The back cover plate 7 and its support pile 10 are fixedly connected. 8 is an adjusting plate, a thin plate that can tilt forward or backward to adjust when there is a difference in thermal expansion between the inlet pipe 5 and the inner pipe 6, preventing the inner pipe from bending. 9 is a transparent cover pipe, and 10 is a support pile for the spray chamber body 12, which is fixedly connected to the adjusting plate 8. 11 is an elastic support, one end of which is welded to the inner pipe 6, and the side in contact with the glass cover pipe can slide along the glass, making it a movable connection. 12 is the spray chamber body, which can also represent the spray chamber. 13 is the vacuum layer, and 14 is a corrugated pipe.
[0028] Figure 2 This is a KK cross-sectional view of a return-jet collector tube, showing the part numbers and... Figure 1 Those that are the same in Chinese have the same meaning.
[0029] Figure 3 yes Figure 1 The cross-sectional view is taken in the QQ direction; 15 in the figure is the spray nozzle. The remaining part numbers and... Figure 1 Those that are the same in Chinese have the same meaning.
[0030] Figure 4 This is a front view of a double-exposed, double-sealed, return-spray type solar collector tube. Both ends of its inner tube are exposed outside the cover tube. Near the ends, the inner tube and the glass cover tube are connected to each other with a corrugated pipe and Kovar alloy ring for mutual sealing, so that the interlayer between the two is a vacuum 13.
[0031] exist Figure 4 In this system, 1 is the short inlet pipe, welded to the inner pipe 6. 2 is the distributed outlet pipe, with two or more layers of small holes on its circumferential surface along its generatrix length; one end is inside the inner pipe 6, and the other end is outside the inner pipe 6. 3 is the head cover plate of the inner pipe 6, welded to the end of the inner pipe. 4 is a Kovar alloy sealing ring. 5 is the long inlet pipe, its right end inserted into the spray chamber 8. 6 is the heat-absorbing inner pipe, the outer surface of the section inside the cover pipe has a solar spectrum selective heat-absorbing layer. 7 is the spray hole. 8 is the spray chamber, welded to the long inlet pipe. 9 is the back cover plate of the spray chamber, which may or may not have individual small holes. 10 is the adjusting plate. 11 is the tail cover plate of the inner pipe, welded to the inner pipe. 12 is the glass cover pipe. 13 is the vacuum. 14 is the bellows.
[0032] Figure 5 yes Figure 4 The GG sectional view. All part numbers in this drawing are... Figure 4 Since the corresponding part numbers are the same, their meanings are also the same, so they will not be repeated.
[0033] Figure 6 This is a front sectional view of a double-exposed, single-sealed, return-spray type solar collector tube, and Figure 4 The difference is that the cover tube and the inner tube at its tail end are directly welded together by Kovar alloy rings, eliminating the need for a bellows. Figure 6 and Figure 4 All part numbers correspond one-to-one and are identical, so their meanings also correspond one-to-one and are identical, and there is no need to describe them repeatedly.
[0034] Figure 7 yes Figure 6 The GG direction sectional view. Parts with the same part number have the same meaning. It and Figure 5 The only difference is that the bellows has been removed; otherwise, they are identical.
[0035] Figure 8This is a front sectional view of a single-exposed return-spray collector tube containing a nozzle-type core tube. In the figure, 1 is the short inlet tube, which is sealed to the inner tube 6, and its port is the external inlet interface. 2 is the sealing cover plate of the inner tube head. 3 is the non-distributed liquid outlet tube, i.e., the external outlet interface, which is sealed to the inner tube 6. 4 is a Kovar alloy ring. 5 is the long inlet tube, whose port is sealed by a plug plate 8. The plug plate may have individual small holes or no individual small holes. The end of the long tube 5 is welded to and connected to multiple "L"-shaped nozzles 7. The long tube 6 on the right side of the nozzle is connected perpendicularly to the adjusting plate 9. The adjusting plate 9 is welded to the inner wall of the inner tube 6. 10 is an elastic support, which has a fixed weld to the inner tube 6. It is located between the inner tube and the cover tube and is movably connected to the cover tube. 11 is a transparent cover tube. The interlayer 12 between the cover tube 10 and the inner tube 6 is a vacuum. 13 is a bellows, which has a sealed connection at one end to the Kovar alloy ring and a sealed connection at the other end to the inner tube 6.
[0036] Appendix Figure 9 yes Figure 8 The KK direction sectional view, the part numbers in the figure are as follows: Figure 8 Those with the same name in China have the same meaning.
[0037] Appendix Figure 10 yes Figure 8 The cross-sectional view in the GG direction, with each part number in the figure. Figure 8 Those with the same name in China have the same meaning.
[0038] Advantages of this utility model
[0039] 1. This utility model can overcome the heat loss in the external circulation pipeline that must be used in the metal glass straight-through collector tube used in medium and high temperature solar thermal utilization, and eliminate the need for external circulation insulation connection pipe, thereby reducing costs.
[0040] 2. In applications where the inlet and outlet are located at the same end (i.e., a same-end collector tube for internal circulation), the heat transfer medium, heat transfer oil or molten salt, flows while being heated in the circuit. If the flow is not smooth or there are dead zones, the glass cover tube may shatter due to the bending of the inner metal tube causing it to come into contact with the high temperature. Therefore, this novel return-spray collector tube can convert the pressure energy from the pump in the inlet tube into kinetic energy through the spray chamber or nozzle to accelerate the return flow. The liquid flow in each layer, distributed along the cross-section of the collector tube, flows evenly into the distributed outlet tube, eliminating dead zones and ensuring safety.
[0041] 3. The heat transfer medium of this utility model circulates inside the heat collection tube, which can improve the utilization rate of solar heat and reduce the cost by reducing the heat insulation pipeline.
Claims
1. A return-spray type solar collector tube, comprising a cover tube, an inner tube, a return-spray core tube, and a liquid outlet tube, characterized in that: A. The return spray core tube is either a spray cavity type or a spray pipe type. The spray cavity type core tube consists of a spray cavity and an inlet pipe, both located inside the inner tube. The inlet pipe is L-shaped and consists of a long pipe and a short pipe that are perpendicular to each other and connected. The open end of the long pipe is inserted into the spray cavity and fixedly connected to each other. There is a sealed fixed connection between the short pipe and the inner tube, and its port is exposed outside the inner tube, which is the inlet interface of the external working fluid. The spray cavity consists of a spray cavity body and a back cover plate that are fixedly connected and sealed to each other. The back cover plate is fixedly connected to the support pile, and the support pile is fixedly connected to the adjustment plate welded to the inner tube wall. B. The nozzle-type core tube is composed of an inlet pipe and a nozzle. The inlet pipe is formed by a long pipe and a short pipe that are perpendicularly connected and communicate with each other. The short pipe extends from the side wall of the inner pipe head to the outside of the inner pipe, forming the medium inlet interface. The long pipe end located at the tail of the inner pipe is sealed with a plug plate and fixedly connected to the adjusting plate. The adjusting plate is connected to the inner pipe. The peripheral wall of the long pipe end and one opening of multiple "L"-shaped nozzles are fixedly connected and communicate with each other. The other opening of each "L"-shaped nozzle points to the head of the inner pipe. The plug plate may have individual small holes or no individual small holes. C. At least one section of the inner tube is contained within the cover tube, and the interlayer of this section is a vacuum. The outer surface of the inner tube section contained within the cover tube is coated with a heat-absorbing coating, and the cover tube is transparent. The inner tube may have one end exposed outside the cover tube, and this type of heat collector tube is called a single-exposed return-spray heat collector tube; or both ends may be exposed outside the cover tube, and this type of heat collector tube is called a double-exposed return-spray heat collector tube. D. The exposed section of the inner tube of the single-exposed return-spray type heat collector tube has a sealed connection with the cover tube. This port of the inner tube is welded with a cover plate for sealing. The interlayer between the cover tube and the inner tube is a vacuum. The short pipe of the inlet pipe is located in the exposed section of the inner tube. Its port extends from one side of the inner tube, i.e., the circumferential surface. The outlet pipe is located on the other side of the exposed section of the inner tube and communicates with the inner tube. It is perpendicular to the inner tube and has a sealed connection. The outer port of the outlet pipe extends outside the inner tube and is the outlet interface of the heated working fluid. The outlet pipe may be distributed or it may be a single external interface rather than distributed. Along the length of the generatrix of the distributed outlet pipe in the inner tube, there are one or more layers of inlet holes that allow the medium to enter the outlet pipe. Each layer of inlet holes is located on the circumferential surface of the distributed outlet pipe. The end of the heat collector tube that connects the inlet interface and the outlet interface is called the head of the heat collector tube. The other end of the inner tube is also closed and located inside the cover tube. This end of the heat collector tube is called the tail of the heat collector tube. E. The inner tube of the double-exposed, back-spraying heat collector tube has both ends exposed outside the cover tube, and the ends of the inner tube and the cover tube are sealed and fixedly connected, or both ends are sealed and fixedly connected through Kovar alloy rings and bellows. This is called a double-exposed, double-sealed back-spraying heat collector tube. Alternatively, one end is sealed and fixedly connected through Kovar alloy rings and bellows, while the other end is sealed and welded through Kovar alloy rings but without bellows. This type of heat collector tube is called a double-exposed, single-sealed back-spraying heat collector tube. There is a vacuum between its cover tube and inner tube. One end of the inner tube of the double-dew-return-spray collector tube is connected to the inlet port of the inlet pipe and the outlet port of the outlet pipe. This end is the head of the double-dew-return-spray collector tube. The other end of the inner tube is the tail of the double-dew-return-spray collector tube. The long end of the inlet pipe installed in the inner tube is either fixedly connected to the spray chamber or fixedly connected to the spray pipe. The outlet pipe is either distributed or has only one outlet port. The portion of the distributed outlet pipe is enclosed in the inner tube. One or more small holes are opened on the circumferential surface along its generatrix direction. Both ends of the inner tube are sealed with cover plates.
2. The return-jet type solar collector tube according to claim 1, characterized in that: The inner tube end of the single-exposed return-spray type heat collector tube, which is enclosed in the cover tube, is connected to the cover tube by an elastic bracket. The elastic bracket and the inner tube are welded together, and the elastic bracket and the transparent cover tube are movably connected.
3. The return-jet type solar collector tube according to claim 1, characterized in that: On the spray cavity body of the spray cavity type core tube, there are small holes for spraying liquid on one side facing the heat collection tube head, called spray holes.
4. The return-jet type solar collector tube according to claim 1, characterized in that: The back cover plate of the spray chamber may have a back cover hole that is much smaller than the spray hole, or it may have no back cover hole.