Disclosure of Invention
The invention provides a novel loop heat pipe heat exchanger, which solves the technical problems by utilizing the performance of an antigravity heat pipe and the expanded heat exchange area.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a loop heat pipe heat exchanger comprises a shell, a fluid inlet, a fluid outlet, a gas inlet channel, a gas outlet channel, a loop heat pipe and a gas chamber, wherein the fluid inlet and the fluid outlet are respectively arranged on the shell; the gas cavity is arranged in the shell, the loop heat pipe is an antigravity heat pipe, an outlet of the gas inlet channel and an inlet of the gas outlet channel are communicated with the gas cavity, the gas exchanges heat with the evaporation end in the process of being introduced into the gas cavity from the gas inlet channel, the condensation end conducts the heat to fluid in the shell, and the shell is internally provided with an electric heater for auxiliary heating.
Preferably, a first valve is arranged on the gas inlet channel and used for controlling the flow of gas entering the heat exchanger, and the first valve is in data connection with the central controller; a first temperature sensor is arranged on the gas inlet channel and used for measuring the temperature of the gas; the first temperature sensor is disposed upstream of the first valve; the first temperature sensor is in data connection with the central controller;
the heat exchanger is further provided with a bypass pipeline connected with the inlet channel, the connecting position of the bypass pipeline and the inlet channel is located at the upstream of the first valve, and the bypass pipeline is provided with a second valve. The second valve is in data connection with the central controller;
a second temperature sensor is arranged in the heat exchanger and used for detecting the temperature of fluid in the heat exchanger; the second temperature sensor is in data connection with the central controller, and the central controller automatically controls the opening and closing of the first valve and the second valve and the heating of the electric heater according to the temperatures detected by the first temperature sensor and the second temperature sensor.
Preferably, if the temperature detected by the first temperature sensor is lower than the temperature detected by the second temperature sensor, the central controller controls the first valve to be closed and the second valve to be opened, and simultaneously controls the electric heater to heat; if the temperature detected by the first temperature sensor is higher than that detected by the second temperature sensor, the central controller controls the first valve to be opened and the second valve to be closed, and simultaneously stops the electric heater from heating.
Preferably, the condensing end is an annular tube wrapped around the outer wall of the gas chamber.
Preferably, a part or the whole of the capillary wick is arranged at the evaporation end.
Preferably, the gas inlet channel is connected to the inlet tube of the gas chamber, and the gas outlet channel is provided in the inlet tube of the gas chamber and protrudes from the inlet tube side of the gas chamber.
Preferably, the evaporation end comprises a riser, and at least one part of the riser is provided with a capillary core, so that the function of a counter-gravity heat pipe is realized; a pipeline with a condensing end flowing to an evaporating end is arranged in the center of the capillary core, and a longitudinal vertical fin is arranged on the outer wall surface of the evaporating end in a surrounding manner; the air outlet channel is arranged between and in contact with two adjacent vertical fins; the descending tube of the heat pipe is arranged between and contacted with the two adjacent vertical fins; at least a portion of the upleg and downleg are disposed within the air inlet passage.
Preferably, the fluid inlet is located on the lower side of the housing and the fluid outlet is located on the upper side of the housing.
Preferably, a portion of the inlet duct of the gas chamber extends into the housing, the cross-sectional area of the gas chamber within the housing tapering downwardly in the height direction.
Preferably, the bottom of the gas chamber is of planar configuration.
Preferably, a plurality of gas chambers are arranged in the shell, and gas inlet channels of the plurality of gas chambers are in a parallel structure.
Preferably, the evaporation end is arranged on the inlet pipe of the gas chamber, at least one part of the evaporation end is filled with the capillary core, the center of the capillary core is provided with a pipeline from the condensation end to the evaporation end, and the outer wall surface of the evaporation end is provided with longitudinal vertical fins in a surrounding mode.
Preferably, the gas outlet channel is disposed between and in contact with two adjacent vertical fins.
Preferably, the condensation end pipeline flowing to the evaporation end is arranged between and in contact with two adjacent vertical fins.
The pipeline is a plurality of, the gas outlet passageway is a plurality of, the pipeline equals with gas outlet passageway's quantity.
Further preferably, the lines are arranged between adjacent gas outlet channels, the gas outlet channels 4 flowing between adjacent evaporation end to condensation end lines 9.
Further preferably, the distance between the center of the evaporation end pipeline 9 flowing to the condensation end pipeline and the center of the adjacent gas outlet channel 4 is the same; the distance between the center of the gas outlet channel 4 and the center of the pipeline 9 from the adjacent gas evaporation end to the condensation end is the same.
Preferably, the radius of the gas outlet channel 4 is R, the radius of the pipeline 9 from the evaporation end to the condensation end is R, and the included angle between adjacent fins is a, so that the following requirements are met:
Sin(A)=a*(r/R)-b*(r/R)2-c;
a, b, c are parameters,
wherein 1.23< a <1.24,0.225< b <0.235, 0.0185< c < 0.0195;
14°<A<30°;
0.24<r/R<0.5;
further preferably, 0.26< R/R < 0.38.
Compared with the prior art, the invention has the following advantages:
1) the invention controls the opening and closing of the valve through the detected temperature, and can realize the automatic heat exchange of the heat exchanger. Because the temperature of the high-temperature gas is lower than the temperature of the fluid in the heat exchanger in the research and development and experiment processes, the heat exchange is impossible under the condition, and the heat of the heat exchanger can be taken away, so that the electric heater is required to heat and exchange the heat to meet the working requirement. Therefore, the opening and closing of the valve are intelligently controlled according to the detected temperature, so that the heat exchange of the heat exchanger is intelligently controlled.
1) The invention provides a heat exchanger with a novel structure, which utilizes an antigravity heat pipe to exchange heat, transfers heat in gas to a cold source in the heat exchanger and improves the heat utilization.
2) The condensing end of the antigravity heat pipe is wound on the outer wall of the gas cavity, and the area of the gas cavity is enlarged, so that the heat exchange area is increased, and the heat exchange effect is improved.
3) The invention improves and designs the structure of the loop heat pipe evaporation end, and further improves the heat exchange coefficient.
4) According to the invention, through a large number of numerical simulation and experiments, included angles between the pipeline 9 of the gas outlet channel and the evaporating end of the loop heat pipe flowing to the condensing end and the adjacent fins are optimized, and the heat exchange efficiency is further improved.
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings.
In this document, "/" denotes division and "×", "denotes multiplication, referring to formulas, if not specifically stated.
The following detailed description of embodiments of the invention refers to the accompanying drawings.
An antigravity loop heat pipe, as shown in fig. 5, comprises an evaporation end 6 and a condensation end 8, wherein the evaporation end 6 is located above the condensation end 8, a part of the evaporation end 6 is arranged in a fluid rising section, and a capillary wick 13 is arranged at least in a part of the evaporation end of the fluid rising section, as shown in fig. 7.
Preferably, the evaporation end comprises two parts, namely an evaporation end flow direction condensation end pipeline (descending section) 9 and an ascending section. Preferably, a condensation end flow to the evaporation end line 10 is arranged in the rising section.
As shown in fig. 1, a loop heat pipe heat exchanger includes a housing 1, a fluid inlet 2, a fluid outlet 3, a gas inlet channel 5, a gas outlet channel 4, a loop heat pipe, and a gas chamber 7, where the fluid inlet 2 and the fluid outlet 3 are respectively disposed on the housing 1, the heat pipe includes an evaporation end 6 and a condensation end 8, the evaporation end 6 is located on the upper portion of the condensation end 8, a capillary wick 13 is disposed in a pipeline of the condensation end 8 leading to the evaporation end 6, and the condensation end 8 is disposed on an outer wall of the gas chamber 7; the gas chamber 7 is arranged in the housing 1, the loop heat pipe is an antigravity heat pipe as shown in fig. 5, the outlet 5 of the gas inlet channel and the inlet of the gas outlet channel 4 are communicated with the gas chamber 7, the gas exchanges heat with the evaporation end 6 in the process of being introduced into the gas chamber 7 from the gas inlet channel 5, and the condensation end 8 conducts heat to the fluid in the housing 1.
The invention provides the heat exchanger of the loop heat pipe with the novel structure, and the loop heat pipe is used as a high-efficiency heat transfer tool, so that the heat exchanger is simple in principle and compact in structure, and the cooling efficiency is obviously improved.
Preferably, at least a portion of the evaporator end 6 of the loop heat pipe is mounted at the inlet of the gas chamber 7.
Preferably, at least a portion of said gas inlet channel 5 is provided in a gas chamber 7 inlet pipe, at least a portion of the gas chamber 7 inlet pipe being provided in the housing 1. Through such setting, can make the gas in the gas inlet passage 5 directly participate in the heat transfer of the fluid in casing 1, make gas under the combined action of fluid and loop heat pipe, further cool, improve the heat transfer effect.
Preferably, the gas chamber 7 is made of a heat conducting material, preferably a metal, such as copper, aluminum. Through the material of the gas cavity, the heat of the gas can be transferred outwards through the cavity, so that a heat exchange mode is added, and the heat of the gas is transferred to external fluid through the loop heat pipe and the gas cavity.
Preferably, an electric heater for auxiliary heating is arranged in the housing 1. When the heat is insufficient, the heating is supplemented by the electric heater.
Further preferably, the electric heaters are symmetrically distributed along the central axis of the housing 1.
Preferably, the electric heater is provided in plurality, and the heating power of the electric heater 14 becomes lower as the electric heater is closer to the gas chamber 7. Further alternatively, the lower the heating power of the electric heater 14, the larger and the closer to the gas chamber 7. Mainly because the closer to the gas chamber 7, the higher the temperature, and by setting the electric heating power variation, the uniform heating of the whole fluid can be achieved.
The heating of the electrical heating may be controlled by a central controller 14.
Preferably, the fluid in the housing 1 is a medical fluid. The heat exchanger is a heat exchanger with a function of heating liquid medicine, and the liquid medicine is used for fumigating and washing wounds.
Preferably, as shown in fig. 8, a first valve 15 is disposed on the gas inlet channel 5 for controlling the gas flow entering the heat exchanger, and the first valve 15 is in data connection with the central controller 14. A temperature sensor 16 is arranged on the gas inlet channel 5, and the first temperature sensor 16 is used for measuring the temperature of the gas. The first temperature sensor 16 is arranged upstream of the first valve 15. The first temperature sensor 16 is in data connection with the central controller 14.
The system is also provided with a bypass pipeline connected with the inlet channel 5, the connecting position of the bypass pipeline and the inlet channel 5 is positioned at the upstream of the first valve 15, and the bypass pipeline is provided with a second valve 17. The second valve 17 is in data connection with the central control unit 14. The opening and closing of the second valve 17 ensures that gas passes through the bypass line.
Preferably, the first valve is open and the second valve is closed.
Controlling the opening and closing of the valve according to the gas flow
Preferably, a gas sensor is arranged in the gas inlet channel 5 upstream of said first valve 15, the gas sensor being adapted to detect whether gas is flowing through the flue. The gas sensor is in data connection with a central controller, and the central controller controls the opening and closing of the first valve 15 and the second valve 17 according to the data detected by the gas sensor and controls the electric heater to heat.
When the central controller detects that gas passes through the gas inlet channel 5, for example, when the fan starts to operate, high-temperature gas is conveyed, the central controller controls the first valve to be opened, the second valve is closed, the gas can enter the heat exchanger, and the gas is discharged from the gas outlet channel after heat exchange is completed. When the central controller detects that no gas passes through the inlet channel 5, for example, when the fan stops running or heat cannot be used for heat exchange, the central controller controls the first valve to be closed and the second valve to be opened, and controls the electric heater to heat. Through the operation, the excessive heat can be stored in the heat exchanger 2 when gas exists, and the electric heater is used for heat exchange under the condition that no gas exists, so that the actual working requirement of the heat exchanger is met. Therefore, the heat of the gas can be fully utilized, and the actual working requirement can be met.
(II) controlling the valve to open or close according to the temperature detection
Preferably, a second temperature sensor is arranged in the heat exchanger and used for detecting the temperature of fluid in the heat exchanger. The second temperature sensor is in data connection with the central controller 14. The central controller 14 automatically controls the opening and closing of the first valve and the second valve according to the temperatures detected by the first temperature sensor and the second temperature sensor.
If the temperature detected by the first temperature sensor is lower than the temperature detected by the second temperature sensor, the central controller 14 controls the first valve to be closed and the second valve to be opened. If the temperature detected by the first temperature sensor is higher than the temperature detected by the second temperature sensor, the central controller 14 controls the first valve to be opened and the second valve to be closed.
The opening and closing of the valve are controlled through the detected temperature, and the independent heat exchange of the heat exchanger can be realized. Since it is found in the development and experiment process that the temperature of the high-temperature gas is lower than that of the fluid in the heat exchanger, the heat exchange is impossible in such a situation, and the heat of the heat exchanger can be taken away. Therefore, the opening and closing of the valve are intelligently controlled according to the detected temperature, so that the heat exchange of the heat exchanger is intelligently controlled.
(III) controlling the heating of the electric heater according to the temperature detection
The central controller 14 automatically controls the electric heater to heat according to the temperature detected by the first temperature sensor.
The central controller 14 controls the electric heater to heat if the temperature detected by the first temperature sensor is lower than a certain value, and the central controller 14 stops the electric heater to heat if the temperature detected by the first temperature sensor is higher than a certain value. Through controlling electric heater according to entry gas temperature and heating, can satisfy the heat transfer demand of reality, avoid because the heat transfer that the air temperature is low to lead to is not enough.
(IV) controlling the electric heater to heat according to the temperature of the heat exchange material
Preferably, a second temperature sensor is arranged in the heat exchanger and used for detecting the temperature of fluid in the heat exchanger. The second temperature sensor is in data connection with the central controller 14.
The central controller 14 controls the electric heater to heat if the temperature detected by the second temperature sensor is lower than a certain value, and the central controller 14 stops the electric heater to heat if the temperature detected by the second temperature sensor is higher than a certain value. Through controlling electric heater according to the fluid and heating, can satisfy the heat transfer demand of reality, avoid can't satisfy the actual work demand because the heat transfer is not enough.
(V) controlling the opening and closing of the valve and the heating of the electric heater according to the temperature detection
Preferably, a second temperature sensor is arranged in the heat exchanger and used for detecting the temperature of fluid in the heat exchanger. The second temperature sensor is in data connection with the central controller 14. The central controller 14 automatically controls the opening and closing of the first valve and the second valve and the heating of the electric heater according to the temperatures detected by the first temperature sensor and the second temperature sensor.
If the temperature detected by the first temperature sensor is lower than the temperature detected by the second temperature sensor, the central controller 14 controls the first valve to be closed and the second valve to be opened, and controls the electric heater to perform heating. If the temperature detected by the first temperature sensor is higher than the temperature detected by the second temperature sensor, the central controller 14 controls the first valve to be opened and the second valve to be closed while the electric heater is stopped from heating.
The opening and closing of the valve are controlled through the detected temperature, and the independent heat exchange of the heat exchanger can be realized. Because the temperature of the high-temperature gas is lower than the temperature of the fluid in the heat exchanger in the research and development and experiment processes, the heat exchange is impossible under the condition, and the heat of the heat exchanger can be taken away, so that the electric heater is required to heat and exchange the heat to meet the working requirement. Therefore, the opening and closing of the valve are intelligently controlled according to the detected temperature, so that the heat exchange of the heat exchanger is intelligently controlled.
Sixthly, detecting and controlling the opening of the valve and heating the electric heater according to the temperature of the fluid
Preferably, the central controller 14 automatically controls the opening of the first valve and the heating of the electric heater according to the temperatures detected by the first temperature sensor and the second temperature sensor.
If the temperature detected by the second temperature sensor decreases, the central controller 14 controls the first valve opening to increase the amount of gas entering the heat exchanger to increase the amount of heat exchange, and if the temperature detected by the second temperature sensor increases, the central controller 14 controls the first valve opening to decrease the amount of gas entering the heat exchanger to decrease the amount of heat exchange.
Preferably, the central controller 14 controls the electric heater heating power to increase while the central controller 14 controls the first valve opening to increase, and the central controller 14 controls the electric heater heating power to decrease while the central controller 14 controls the first valve opening to decrease.
Preferably, the temperature sensed by the first temperature sensor is higher than the temperature sensed by the second temperature sensor, otherwise not the gas heats the fluid, but the fluid heats the gas.
The opening of the valve and the change of the heating power of the electric heater are controlled by the detected temperature, so that the output temperature of the fluid of the heat exchanger can be kept constant. And the intelligent degree of the system is improved.
Preferably, the gas is exhaust gas or hot air.
Further preferably, the inlet pipe of the gas chamber 7 is connected to the gas inlet channel.
Preferably, as shown in fig. 3, the gas chamber 7 has a diameter gradually increasing from a position where the inlet pipe is connected downward, and then gradually decreasing to a predetermined position. The gas circulation is completed, and the heat exchange efficiency between the gas and the wall of the gas chamber is increased.
Preferably, as shown in figure 1, a portion of the inlet pipe of the gas chamber 7 extends into the housing, the cross-sectional area of the gas chamber 7 being greater than the cross-sectional area of the inlet pipe 11. The cross-sectional area of the gas chamber within the housing tapers downwardly in the height direction.
Preferably, the average cross-sectional area of the gas chamber 7 is 15-30 times the cross-sectional area of the inlet pipe 11.
Through the structural design, the heat exchange area of the gas cavity is greatly increased, the length of the heat pipe condensation end 8 wound on the outer wall of the gas cavity is also greatly increased, the heat exchange area is increased, and the heat exchange effect is further improved.
In the research, it is found that the heat source fluid in the heat exchanger can only be gas, because if the heat source fluid is liquid, the liquid can be completely accumulated in the chamber 7 and is difficult to discharge, and because the cross-sectional area of the chamber 7 is much larger than that of the inlet pipeline, the existence of excessive liquid can cause that the chamber 7 cannot be well fixed on the shell due to gravity, and the fixing difficulty is increased, so that the heat source in the heat exchanger can only be gas.
Preferably, as shown in fig. 1, the bottom and top of the gas chamber 7 are planar structures.
Preferably, a plurality of gas chambers 7 are arranged in the housing 1, and the gas inlet channels 5 of the plurality of gas chambers are in a parallel structure.
Preferably, the gas outlet channels 5 of the plurality of gas chambers are in a parallel configuration.
Preferably, the gas chamber 7 is suspended in the housing 1, and the bottom of the gas chamber is spaced from the bottom of the housing 1. Through the design, the bottom and the fluid can be fully subjected to heat exchange. By the suspended structure, it is also shown that the heat source cannot be a liquid but only a gas.
Preferably, the evaporation end 6 of the loop heat pipe is installed on the gas chamber inlet pipe, and the condensation end 8 of the loop heat pipe is wound outside the gas chamber and is in direct contact with the external fluid. The loop heat pipe condenser is wound outside the gas chamber and fully contacts with external fluid, so that the heat dissipation of gas at the evaporation end of the heat pipe is increased, and the cooling efficiency is improved.
The condensing end is an annular tube wrapped around the outer wall of the gas chamber.
Preferably, the condensing end 8 of the loop heat pipe is wound more and more densely on the outer wall of the gas chamber 6 from the upper portion to the lower portion in the height direction (the spacing between the loop pipes is smaller and larger). The main reason is to concentrate the heat as far as possible in the lower part and carry out the heat transfer, and lower part heat transfer volume is bigger and bigger moreover, then can make the water upflow of heating, promotes the abundant convection current of water, reinforcing heat transfer effect. Experiments show that the heat exchange effect can be further improved by about 15% by the structure.
Further preferably, the winding density of the condensation end 8 of the loop heat pipe on the outer wall of the gas chamber 6 is increased more and more from the upper part to the lower part along the height direction. Experiments show that the heat exchange effect can be further improved by about 7 percent through the structure.
Preferably, at least one part of the evaporation end 6 is provided with a capillary core 13, the capillary force of the capillary core provides power for the working medium to flow back and circulate, and meanwhile, the amount of the flowing back working medium meets the requirement of heat transfer, so that the effect of the antigravity heat pipe is realized.
By arranging the capillary core 13, the capillary core 13 is arranged at the evaporation end, so that the ascending section 6 of the evaporation end naturally generates flow resistance, and the steam generated at the evaporation end naturally flows to the evaporation end with low resistance and flows to the condensation end pipeline 9, thereby forming the antigravity heat pipe.
Preferably, the capillary wick 13 is only arranged in the rising section of the evaporation end, preferably in a part of the rising section. Such as shown in fig. 3 and 7.
Preferably, at least a part of the gas outlet channel 4 is arranged in the inlet pipe of the gas chamber, the cold gas of the gas outlet pre-cooling the hot gas of the gas inlet. Through the heat exchange of outlet gas and inlet gas, further realize the heat transfer effect, increase the condensation efficiency of water.
Preferably, as shown in fig. 4, the evaporation end is disposed at the inlet tube of the gas chamber, the rising section of the evaporation end is filled with the capillary wick 13 to provide a sufficient capillary force, the center of the capillary wick 13 is provided with the pipeline 10 from the condensation end to the evaporation end, by disposing the pipeline 10 (without the capillary wick), the fluid resistance of the pipeline can be reduced, the working medium flows back more smoothly, the heat transfer capability in the anti-gravity state is improved, and the outer wall surface of the rising section of the evaporation end is provided with the longitudinal vertical fins 12 in a surrounding manner, so that the heat exchange area is increased, and the heat exchange efficiency with the gas is improved.
The pipeline 10 is a gas or liquid pipeline, and realizes flexible arrangement, namely the pipe diameter is small and the pipe is easy to bend. The principle of the loop heat pipe is that if the evaporator side and the pipeline 10 are steam pipelines, the principle is that the evaporator is heated and internal working media are evaporated, steam enters the pipeline 10 along the upper outlet of the evaporator and then flows to the pipeline surrounding the lower part to be contacted with fluid to start condensation, and after the steam is completely condensed, the steam returns to the evaporator under the capillary force of the capillary core of the evaporator, so that the circulation of the working media is realized.
Preferably, the tube 10 communicates with the capillary wick 13. Through the communication, the fluid communication between the capillary wick 13 and the pipeline 10 can be realized, so that if a large pressure is generated due to heat absorption during the liquid ascending through the capillary wick, for example, even bubbles can occur, the pressure of the evaporation section can be equalized through the pipeline 10, and thus the equalization of the pressure is ensured.
Further preferably, the capillary wick 13 extends to the condensation end so as to directly suck up the liquid at the condensation end. Further improving the circulation capacity of the antigravity heat pipe.
Preferably, the capillary wick is distributed along the height direction, as shown in fig. 3. Further preferably, the capillary force of the capillary wick is gradually increased along the height decreasing direction. The closer to the condensation end, the greater the capillary force. Experiments show that the suction force to the liquid can be further improved by adopting the mode, and the suction force can be improved by more than 20% at the same cost, so that the heat exchange effect is improved.
By further analysis, the primary reason may be that as the capillary force near the condensation end becomes larger, the liquid at the condensation end can be rapidly absorbed into the capillary wick, and the liquid continuously flows towards the evaporation end. In the flowing process, the liquid absorbs heat continuously, the temperature is increased due to heat absorption, the density is reduced, the required capillary force is obviously reduced due to density change, and the liquid can be easily sucked upwards under the condition of small capillary force. The reason for this is that the present inventors have conducted extensive experiments and studies, and are not common knowledge in the art.
Further preferably, the capillary force of the capillary wick increases gradually in the height decreasing direction to a larger and larger extent. Experiments show that the suction to liquid can be further improved by adopting the mode, and the suction about 8 percent can be further improved at the same cost, so that the heat exchange effect is improved.
Preferably, the pipeline is formed by a through hole formed in the middle of the capillary core.
Preferably, as shown in fig. 7, the pipe diameter of the heat pipe position where the capillary wick is provided is larger than the pipe diameter of the heat pipe position where the capillary wick is not provided.
Further preferably, as shown in fig. 7, the change in the tube diameter between the tube at the position of the heat pipe where the capillary wick is disposed and the tube at the position of the heat pipe where the capillary wick is not disposed is a continuous change. Further preferably a straight line variation. The pipe at the large pipe diameter position and the pipe through which the small pipe passes are connected at the joint by a contraction member. The change in the tube diameter of the constriction is a linear change.
Preferably, the gas outlet channel 4 is arranged between and in contact with two adjacent vertical fins 12. Through so setting up, can reduce the mechanism that sets up independent support gas outlet passage 4 for compact structure, outlet passage's cold gas accessible pipeline and fin heat transfer keep the degree of coldness of fin, reinforcing heat transfer effect.
Preferably, the evaporation end flow direction condensation end flow direction evaporation end flow direction condensation end pipe 9 is arranged between and in contact with two adjacent vertical fins. Through so setting up, can reduce the mechanism that sets up independent support gas outlet passage 4 for compact structure, the steam accessible pipeline in the pipeline is short for a short time a small amount of heat transfer to the fin, reduces the whole thermal resistance of system, avoids producing in the evaporimeter overheated under the antigravity condition on ground, slows down the temperature shock phenomenon in the heat pipe start-up process.
Further preferably, the evaporation end flow direction condensation end pipeline 9 is closer to the outer wall of the evaporation end pipeline than the gas outlet channel 4, so that the two heat transfer processes can be simultaneously realized, and the corresponding effects are achieved.
Further preferably, the diameter of the evaporation end to condensation end pipe 9 is smaller than the gas outlet channel 4.
Preferably, the evaporation end flows to the condensation end pipeline 9 along the condensation end where a plurality of evaporation end flows can be arranged, as shown in fig. 4 and 6. Through setting up a plurality of evaporating ends flow direction condensing end pipeline 9, can make the steam that the evaporating end endotherm produced flow to condensing end pipeline 9 through a plurality of evaporating ends and get into the condensing end, further strengthen heat transfer, because the fluid endotherm evaporation in the heat pipe leads to the volume to increase moreover, flows to condensing end pipeline 9 through setting up a plurality of evaporating ends, can further alleviate pressure, improves heat transfer effect.
Further preferably, the vertical fin extends through the center of the inlet pipe of the gas chamber, and the evaporation end rising section pipeline and the inlet pipe of the gas chamber have the same center.
Preferably, the number of the evaporation end flow direction condensation end pipelines 9 is multiple, and the distance between the circle center of the multiple evaporation end flow direction condensation end pipelines 9 and the pipeline at the ascending section of the evaporation end is the same.
Further preferably, an evaporation end flow direction condensation end pipeline 9 is arranged between every two adjacent vertical fins 12. The pipeline 9 from the evaporation end to the condensation end is of a parallel structure.
Preferably, the number of the gas outlet channels 4 is multiple, and the distance between the circle center of the plurality of gas outlet channels 4 and the pipeline at the ascending section of the evaporation end is the same, so that the temperature distribution among the fins is more uniform, and the heat exchange effect is more obvious. It is further preferred that one gas outlet channel 4 is provided between each adjacent two of the vertical fins 12. The gas outlet channels 4 are of a parallel configuration.
Preferably, the number of the evaporation end flow direction condensation end pipelines 9 is multiple, the number of the gas outlet channels 4 is multiple, and the number of the evaporation end flow direction condensation end pipelines 9 is equal to that of the gas outlet channels 4.
Further preferably, the evaporation end flow direction condensation end pipe 9 is arranged between adjacent gas outlet channels 4, and the gas outlet channels 4 flow between the adjacent evaporation end flow direction condensation end pipe 9. Further preferably, the distance between the center of the evaporation end pipeline 9 flowing to the condensation end pipeline and the center of the adjacent gas outlet channel 4 is the same; the distance between the center of the gas outlet channel 4 and the center of the pipeline 9 from the adjacent gas evaporation end to the condensation end is the same. I.e. the evaporation end flow to condensation end pipe 9 is arranged in the middle of the adjacent gas outlet channel 4, and the gas outlet channel 4 flows in the middle of the adjacent evaporation end flow to condensation end pipe 9. That is, as shown in fig. 4, a first connection line is formed between the center of the circle where the evaporation end flows to the condensation end pipeline 9 and the center of the circle of the evaporation end 6, a first connection line and a third connection line are formed between the centers of the circles of the adjacent gas outlet channels 4 and the center of the circle of the evaporation end 6, and a first included angle formed between the first connection line and the second connection line is equal to a second included angle formed between the first connection line and the third connection line. Similarly, a fourth connecting line between the center of the circle of the gas outlet channel 4 and the center of the circle of the evaporation end 6, a fifth connecting line and a sixth connecting line are formed between the centers of the circles of the pipelines 9 flowing to the condensation end and the centers of the circles of the evaporation ends 6 of the adjacent evaporation ends, and a third included angle formed between the fourth connecting line and the fifth connecting line is equal to a fourth included angle formed between the fourth connecting line and the sixth connecting line. I.e. in the circumferential direction, the evaporation end flow to the condensation end line 9 and the outlet channel 4 are evenly distributed.
Through the arrangement, the evaporation end can be ensured to flow to the condensation end pipeline 9 and the gas outlet channel 4 to absorb heat uniformly to the inlet gas, and local heating unevenness is avoided. The gas outlet channel 4 can continuously participate in heat exchange after absorbing heat, and the heat is transferred to the evaporation end through the fins.
In numerical simulation and experiments, it is found that the difference between the pipe diameters of the gas outlet channel 4 and the evaporation end flowing to the condensation end pipeline 9 cannot be too large or too small, and if the difference is too large, the distance between the gas outlet channel 4 and the evaporation end flowing to the condensation end pipeline 9 is too far, so that the gas heat exchange between the channel 4 and the evaporation end flowing to the condensation end pipeline 9 is poor, the overall heat exchange is not uniform, and if the difference is too small, the distance between the gas outlet channel 4 and the evaporation end flowing to the condensation end pipeline 9 is too close, so that the gas near the outer wall of the inlet pipe 11 and/or the gas near the outer wall of the evaporation end 6 are poor, and the gas heat exchange in the overall inlet pipe 11 is not uniform; the same reason, the contained angle between adjacent fin 12 can not be too big, can lead to the distribution fin few too big, the heat transfer effect is too good, lead to gas outlet passageway 4 and evaporating end flow direction condensing end pipeline 9 quantity of distribution too little simultaneously, lead to the heat transfer inhomogeneous and the heat transfer effect is not good, on the same principle, the contained angle between adjacent fin 12 can not be too little, lead to the fin distribution too closely too little, the flow resistance greatly increases, and gas outlet passageway 4 and evaporating end flow direction condensing end pipeline 9's pipe diameter differs not greatly, but their heat transfer capacity of equal area is very different, therefore the heat transfer is inhomogeneous under this kind of condition, lead to the heat transfer effect not good. It is therefore necessary to determine the optimum dimensional relationship by extensive numerical simulations and experiments thereof.
The radius of the gas outlet channel 4 is R, the radius of the evaporating end flowing to the condensing end pipeline 9 is R, the included angle between adjacent fins is A, and the following requirements are met:
Sin(A)=a*(r/R)-b*(r/R)2-c;
a, b, c are parameters,
wherein 1.23< a <1.24,0.225< b <0.235, 0.0185< c < 0.0195;
14°<A<30°;
0.24< R/R < 0.5; further preferably, 0.26< R/R < 0.38.
The above empirical formula is obtained through a large number of numerical simulations and experiments, and has higher accuracy than the previous logarithmic function, and the error is basically within 2.4 after experimental verification.
Further preferably, a =1.235, b =0.231, and c = 0.0190.
Preferably, said 3< R <10 mm; 1.5< r <4.0 mm;
further preferably, the pipe diameter of the heat pipe at the position where the capillary core is arranged is 30-40mm, and further preferably 32 mm;
further preferably, the pipe diameter of the heat pipe without the capillary core is 5.0-6.4 mm;
further preferably, the pipe diameter of the pipeline from the condensation end to the evaporation end is 5.0-6.4 mm;
further preferably, the pipe diameter of the inlet pipe 11 is 80-200mm, preferably, 120-150 mm;
further preferably, the length of the fins in the vertical direction is 780-1500mm, preferably 1200 mm; the length of the longitudinal extension of the fins is 95% of the difference between the outer diameter of the evaporation end 6 and the inner diameter of the gas outlet channel 4. The overall heat exchange capacity of the fin is remarkably improved under the length, the heat exchange coefficient is also in a proper range, and the influence on the damage effect of the boundary layer and the fluid flow effect is relatively small
After the gas is filtered, the filtered gas is sucked into the gas cavity through the induced draft fan. The external hot gas exchanges heat with the relative low-temperature gas which is discharged outdoors in the air outlet channel in the air inlet channel 5, the heat of the low-temperature gas after heat exchange is transferred to the evaporation end through the fins, the low-temperature gas and the metal outer wall of the fluid have a heat conduction function, and the heat exchange of the gas is completed under the combined action of the heat and the metal outer wall of the fluid. After the gas begins to enter the gas chamber, hotter gas slowly passes through the fin channel of the loop heat pipe evaporator to exchange heat with the medium in the loop heat pipe, and the temperature of the hotter gas is obviously reduced. The residual gas goes deep into the gas chamber 7, exchanges heat with the external fluid through the metal outer wall of the cavity, and along with the further heat exchange of the gas, the main cold source is provided by the loop heat pipe at the moment. The evaporation end 6 of the loop heat pipe absorbs the heat of the hot gas, the liquid working medium is evaporated into a gas state, then the heat is conducted to external fluid through the loop heat pipe condensation end 8 wound outside the gas chamber, the gas working medium is condensed into a liquid state, and the antigravity loop heat pipe has the characteristic of enabling the liquid to flow back.
Preferably, the loop heat pipe capillary wick is prepared by using a powder metallurgy method. Before starting, the capillary core, the supplement cavity and the liquid conveying pipe of the evaporator of the loop heat pipe are filled with working medium, and the steam channel, the condenser and the steam pipe are in two-phase states.
The cooling chamber part adopts a cooperative heat exchange mode of taking fluid cooling as an auxiliary and taking an antigravity loop heat pipe as a main, so that the gas cooling speed can be greatly improved, and the heat exchange quantity is improved.
Preferably, the condensation end of the loop heat pipe is wound outside the gas chamber, so that the heat dissipation area is increased.
Although the present invention has been described with reference to the preferred embodiments, it is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.