Disclosure of Invention
The invention aims to provide a loop heat pipe with a novel structure, and the loop heat pipe with the novel structure can realize uneven heating in the condition of heating the loop heat pipe. The heating efficiency is low.
In order to achieve the purpose, the technical scheme of the invention is as follows:
an electric heating loop heat pipe comprises an evaporation part, a condensation part, a rising part and a falling part, wherein liquid absorbs heat and evaporates in the evaporation part, enters the condensation part through the rising part to release heat, and then returns to the evaporation part through the falling part, the evaporation part comprises an electric heating part, and the electric heating loop heat pipe is characterized in that the evaporation part comprises an evaporation pipe and a fluid flowing heating part arranged in the evaporation pipe, and the fluid flowing heating part extends in the extending direction of the evaporation pipe; the fluid flow heating part comprises a shell and a main body part in the shell, wherein the main body part consists of a diamond through hole and a regular octagon through hole, the side length of the diamond through hole is equal to that of the regular octagon through hole, four sides of the diamond through hole are respectively sides of four different regular octagon through holes, and four sides of the regular octagon through hole which are not connected with each other are respectively sides of four different diamond through holes; the electric heating part is arranged in the rhombic through hole.
Preferably, the electrical heating element is a resistance heater.
Preferably, the resistive heater fills the entire square channel.
Preferably, the evaporation tube is externally provided with an insulating layer.
Preferably, a capillary structure is provided in the depressed portion.
Preferably, the liquid is ammonia, methanol, acetone or heptane.
The utility model provides a loop heat pipe, includes evaporation portion, condensing part, ascending portion and decline portion, liquid is at the evaporation portion heat absorption evaporation, gets into the condensing part through ascending portion and releases heat, then gets back to the evaporation portion through the decline portion, the evaporation portion includes electric heating component, its characterized in that, fluid flow heater block sets up a plurality ofly in the direction that the evaporating pipe extends, sets up electric heating element among the fluid flow heater block, sets up a plurality of fluid flow heater blocks in the evaporating pipe, along the fluidic flow direction in the evaporating pipe, and the interval between the fluid flow heater block is more and more littleer.
The utility model provides a loop heat pipe, includes evaporation portion, condensing part, ascending portion and decline portion, liquid is at the evaporation portion heat absorption evaporation, gets into the condensing part through ascending portion and releases heat, then gets back to the evaporation portion through the decline portion, the evaporation portion includes electric heating part, its characterized in that, the fluid flow heater block sets up a plurality ofly in the direction that the evaporating pipe extends, sets up electric heating element in the fluid flow heater block, from the entry of evaporating pipe to the export of evaporating pipe, the heating power of the electric heating element who arranges in every positive quadrangle of different fluid flow heater blocks increases gradually.
The utility model provides a loop heat pipe, includes evaporation portion, condensing part, ascending portion and decline portion, liquid is at the heat absorption evaporation of evaporation portion, gets into the condensing part through ascending portion and releases heat, then gets back to the evaporation portion through decline portion, the evaporation portion includes electric heating component, its characterized in that, fluid flow heating component sets up a plurality ofly in the direction that the evaporating pipe extends, from the entry of evaporating pipe to the export of evaporating pipe, and the length of a side of regular quadrangle is more and more littleer.
Compared with the prior art, the invention has the following advantages:
1) the invention designs the loop heat pipe of the fluid flow heating part with a novel structure, and the electric heating element is arranged in the fluid flow heating part of the loop heat pipe.
2) The invention further improves the heating uniformity and the heating efficiency by arranging the electric heating element in the evaporation tube to change the heating power along the flowing direction of the fluid in the evaporation tube.
3) The invention designs the regular distribution of the fluid flow heating parts in the evaporation tube along the direction of fluid flow at intervals, and can further improve the heating efficiency.
4) The invention designs the change of the heating power of different electric heating elements in the evaporating pipe along the length direction of the evaporating pipe, and can further improve the safety performance and the heating performance of the device.
5) The invention determines the optimal proportional relation of the electric heating powers of different layers through numerical simulation and a large number of experiments, further improves the heating uniformity and the heating efficiency, and also provides an optimal reference basis for the design of the evaporation tube with the structure.
6) The invention determines the optimal relation of each size of the fluid flow heating part through numerical simulation and a large number of experiments, and further improves the heating uniformity and the heating efficiency.
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.
A loop heat pipe as shown in fig. 1, the loop heat pipe includes an evaporation portion 1, a condensation portion 3, a rising portion 2 and a falling portion 4, the liquid absorbs heat and evaporates in the evaporation portion 1, enters the condensation portion 3 through the rising portion 2 to release heat, and then returns to the evaporation portion 1 through the falling portion 4, the evaporation portion 1 includes an electric heating member 7, the evaporation portion includes an evaporation tube 6 and a fluid flow heating member 5 disposed in the evaporation tube, the fluid flow heating member 5 extends in a direction in which the evaporation tube 6 extends; the fluid flow heating component 5 comprises a shell 61 and a main body component 62 in the shell, wherein the main body component 62 consists of a diamond-shaped through hole 51 and a regular octagonal through hole 52, the side length of the diamond-shaped through hole 51 is equal to that of the regular octagonal through hole 52, four sides of the diamond-shaped through hole 51 are respectively sides of four different regular octagonal through holes 52, and four sides 53 of the regular octagonal through hole 52, which are not connected with each other, are respectively sides of four different diamond-shaped through holes; the electric heating part 7 is disposed in the diamond-shaped through hole 51. The four included angles of the rhombic through holes are all 90 degrees, namely the rhombus is a regular quadrangle.
According to the loop heat pipe with the novel electric heating structure, the electric heating elements are uniformly distributed around the regular octagonal channels by the heating structure, so that fluid enters the regular octagonal channels and can be uniformly heated by the electric heating elements.
Preferably, the evaporation tubes 6 are arranged in a horizontal direction.
Preferably, the outer tube of the evaporation tube is the outer wall surface of the fluid flow heating element. Preferably, the evaporator tube is integrally manufactured with the fluid flow heating element.
Preferably, the cross section of the evaporation tube 6 is a regular quadrangle.
Preferably, the electrical heating element is a resistance heater.
Preferably, the evaporation tube 1 is provided with an insulating layer on the outside.
Preferably, a capillary structure is provided in the depressed portion 4. By arranging the capillary structure, the liquid is promoted to enter the evaporation part as soon as possible.
Preferably, the liquid is ammonia, methanol, acetone or heptane.
Preferably, the condensing unit is provided in a case, and the case is provided with a chemical liquid, for example, a chemical liquid for fumigation. Is used for heating the liquid medicine for fumigation.
Preferably, the inner wall of the evaporation tube 6 is provided with a groove, and the outer wall of the fluid flow heating part 5 is arranged in the groove. By such an arrangement, the mounting robustness of the fluid flow heating element can be further improved.
Preferably, the evaporation tube 6 is formed by welding a multi-stage structure, and the fluid flow heating member 5 is provided at the joint of the multi-stage structure. Through such setting, can be so that processing is convenient, save the cost.
Preferably, the electric heating element 7 is a resistance heater.
Preferably, the resistive heater 7 fills the entire square channel. Through so setting up can guarantee the wall contact of electric heating element and regular quadrangle passageway, further improve heating efficiency.
Preferably, the farther the center of the diamond-shaped through-hole is from the center of the fluid flow heating member 5, the greater the heating power of the resistance heater per unit length in the extending direction of the evaporation tube. For example, in fig. 3, the heating power of the first layer is smaller than that of the second layer, but the heating power of the second layer is also different, specifically, the heating power of the four corners is larger than that of the non-corners. It was found by vertical simulations and experiments that the further away from the center, the more heating power is required because the heating involves a larger area, especially in the outermost layer, and because the liquid outside the evaporator tube is also heated, the more heating power per unit length in the extension direction of the evaporator tube is required. The invention further improves the heating uniformity and the heating efficiency by arranging the change of the heating power of the electric heating element in the evaporation tube away from the center of the fluid flowing heating part.
Preferably, the heating power of the resistance heater per unit length in the extending direction of the evaporation tube is increased more and more as the center of the diamond-shaped through hole is farther from the center of the fluid flow heating member 5. The above-mentioned variation of the heating amplitude is also obtained through a large number of numerical simulations and experiments, and is not common knowledge in the art. Through the change of above-mentioned range, can further improve heating efficiency and heating degree of consistency.
Preferably, the fluid flow heating member 5 is a regular octagonal central fluid flow heating member, with a regular octagonal through hole in the center of the fluid flow heating member. As shown in fig. 3.
Preferably, the center of the fluid flow heating part 5 is a regular octagonal channel, the regular quadrilateral channel is of a two-layer structure surrounding the fluid flow heating part, the outermost layer is the regular octagonal channel, and the side length of the outer tube is 8 times that of the regular octagonal through hole.
Through a large number of numerical simulations and experiments, the purpose that the heating power of the electric heating elements on different layers can be required to be different to achieve uniform heating can be achieved, and the longer the side length of the regular quadrangle is, the larger the volume to be heated is, the larger the external space is, and the larger the heating power ratio of the inner layer to the outer layer is; and the longer the length of the fluid flow heating part in the extending direction of the evaporating pipe is, the larger the heating area on the whole length is, the more uniform the heating distribution is, and therefore, the heating power ratio requirement of the inner layer and the outer layer is smaller. Therefore, the invention carries out a great deal of research on the heating power of each layer, the side length and the height thereof through a great deal of vertical simulation and experiments to obtain the optimal heating power relation. For the above-described configuration of fig. 3, the ratio of the heating power of the outermost layer to the heating power of the innermost layer satisfies the following requirements:
preferably, the heating power of each element of the first layer is P1, the heating power of each element of the second layer is P2, the fluid flow heating element has a length of K1, and the side length of the regular quadrilateral channel is K2, so that the following requirements are met:
P2/P1= a-b LN (K1/K2); wherein a, b are parameters, 3.25< a <3.30,0.92< b < 0.93;
1.3<P2/P1<1.8;5.0<K1/K2<8.5;
the total heating power of the first layer and the second layer of the single evaporation tube is M, and 1500W < M < 3500W.
Preferably, a =3.28 and b = 0.923.
Preferably, 1.5< P2/P1< 1.7; 7.0< K1/K2< 7.5;
120<B2<280mm;
8<K2<30mm;
the first and second layers are inner and outer layers, respectively.
Preferably, as K1/K2 increases, a gradually decreases and b gradually increases. Through so setting up can further make the heating even, improve heating efficiency.
Preferably, the diameter of the evaporation tube 6 is continuously increased along the direction of the flow of the fluid inside the evaporation tube. The main reasons are as follows: 1) by increasing the diameter of the evaporation tube 6, the resistance to the flow of fluid in the evaporation tube can be reduced, so that the fluid heated in the evaporation tube 6 continuously moves towards the direction of increasing the diameter of the tube, thereby further promoting the flow of the fluid. 2) Because the liquid is heated and evaporated continuously in the evaporating pipe 6 along with the continuous flowing of the fluid, the volume of the fluid is larger and larger, and the pressure is larger and larger, the change of the volume and the pressure of the gas which are increased continuously is met by increasing the pipe diameter, and the pressure is distributed uniformly on the whole.
Preferably, the diameter of the evaporating tube 6 increases more and more in the direction of the flow of the fluid in the evaporating tube. The amplitude change of the pipe diameter is a result obtained by a large number of experiments and numerical simulation of the applicant, and through the arrangement, the flow of the fluid can be further promoted, and the pressure is integrally uniform.
Preferably, a plurality of fluid flow heating members 5 are provided in the evaporation tube 6, and the plurality of fluid flow heating members 5 are provided at intervals. By arranging the fluid flowing heating parts 5 at intervals, the fluid is heated in the fluid flowing heating parts and then enters the non-fluid flowing heating part area for mixing, so that the heating uniformity is ensured. After mixing, the mixture enters a fluid flow heating part for heating.
Preferably, a plurality of fluid flow heating members 5 are provided in the evaporation tube 6, and the intervals between the fluid flow heating members 5 are gradually decreased from the inlet of the evaporation tube 6 to the outlet of the evaporation tube 6. Let K1 be the distance from the entrance of the evaporation tube 6, and S be the distance between the adjacent fluid flow heating parts, S = T1(K1) I.e. S is a function of the distance K1 as a variable, and S' is the first derivative of S, satisfying the following requirements:
S’<0;
the main reason is to further enhance heat transfer. By the arrangement, the heating power along the flowing direction of the fluid can be increased, which is similar to the countercurrent movement of the loop heat pipe, so that the heating temperature at the outlet of the pipeline is increased. The temperature of the heat source, like the outlet of the pipe, is higher and higher, so that the liquid is heated sufficiently.
Through the experiment, the heating is kept uniform to the greatest extent by the arrangement, and the heating effect can be improved.
It is further preferred that the distance between adjacent fluid flow heating elements increases in increasing magnitude from the inlet of the evaporating tube 6 to the outlet of the evaporating tube 6. I.e. S "is the second derivative of S, the following requirements are met:
S”>0;
through experimental discovery, through so setting up, can further improve the heating effect. It should be noted that the above rule is a rule obtained by a large number of experiments and numerical simulations, and is not common knowledge or conventional means in the field.
Preferably, a plurality of fluid flow heating means are provided in the evaporation tube 6, each of the different fluid flow heating means being a regular quadrangle from the inlet of the evaporation tube 6 to the outlet of the evaporation tube 6The heating power of the internally arranged electric heating elements is gradually increased. Assuming that the distance from the inlet of the evaporation tube 6 is K1, the power of the electric heating element arranged in each regular quadrangle of the adjacent fluid flow heating parts is W, S = T3(K1) I.e. W is a function of the distance K1 as a variable, W' is the first derivative of W, satisfying the following requirements:
W’>0;
the main reason is to further enhance heat transfer. By the arrangement, the heating power along the flowing direction of the fluid can be increased, which is similar to the countercurrent movement of the loop heat pipe, so that the heating temperature at the outlet of the pipeline is increased. The temperature of the heat source, like the outlet of the pipe, is higher and higher, so that the liquid is heated sufficiently.
Through the experiment, the heating is kept uniform to the greatest extent by the arrangement, and the heating effect can be improved.
Further preferably, the electric heating elements arranged in each of the regular quadrangles of the adjacent fluid flow heating parts become increasingly smaller in power from the inlet of the evaporation tube 6 to the outlet of the evaporation tube 6. I.e., W "is the second derivative of S, the following requirement is satisfied:
W”>0;
through the experiment discovery, through so setting up, can further keep the whole even of heating, can improve the heating effect simultaneously. It should be noted that the above rule is a rule obtained by a large number of experiments and numerical simulations, and is not common knowledge or conventional means in the field.
Preferably, a plurality of fluid flow heating means are provided in the evaporation tube 6, and the side length of the regular quadrangle is gradually reduced from the inlet of the evaporation tube 6 to the outlet of the evaporation tube 6. The distance from the inlet of the evaporation tube 6 is K1, the side length of the regular quadrangle is C, and C = T2(K1) And C' is the first derivative of C, and meets the following requirements:
C’<0;
the main reason is because the smaller the side length of the regular quadrilateral, the more difficult the manufacture, but the better the uniformity of the overall heating. Because the liquid is heated uniformly on the whole beyond the outlet of the evaporation tube, partial dry burning caused by nonuniform heating is avoided. Through the arrangement, the cost can be saved, and the best heating uniformity and hot fluid output efficiency are achieved.
Further preferably, the length of the side of the regular quadrangle is gradually increased from the inlet of the evaporation tube 6 to the outlet of the evaporation tube 6. C' is the second derivative of C, and meets the following requirements:
C”>0。
preferably, the distance between adjacent fluid flow heating members is maintained constant.
Through the experiment discovery, through so setting up, can further keep the whole even of heating, can improve the heating effect simultaneously. It should be noted that the above rule is a rule obtained by a large number of experiments and numerical simulations, and is not common knowledge or conventional means in the field.
Preferably, the farther the center of the diamond-shaped through hole is from the center of the fluid flow heating member, the greater the heating power of the resistance heater per unit length in the extending direction of the evaporation tube.
Since it can be seen through experimentation and numerical simulations that the more outward the larger the volume to be heated, especially the outermost side, the liquid in the inner tube needs to be heated. The invention further improves the heating uniformity and the heating efficiency by arranging the change of the heating power of the electric heating element in the evaporation tube away from the center of the fluid flowing heating part.
Preferably, the heating power of the resistance heater per unit length in the extending direction of the evaporation tube is increased more and more as the diamond-shaped through hole is farther from the center of the fluid flow heating member. Through such rule setting, heating degree of consistency and heating efficiency have further been improved.
Preferably, the heating power per unit length of the electric heating element 16 is continuously increased along the direction of fluid flow within the evaporation tube. The main reason is to further enhance heat transfer. By the arrangement, the heating power along the flowing direction of the fluid can be increased, which is similar to the countercurrent movement of the loop heat pipe, so that the heating temperature at the outlet of the pipeline is increased. The temperature of the heat source, like the outlet of the pipe, is higher and higher, so that the liquid is heated sufficiently. Through a large amount of experiments and numerical simulation, the heating efficiency can be further improved by about 10% through the change of the heating power of the evaporation tube, and the heating time is saved.
Preferably, the magnitude of the continuous decrease in the heating power per unit length of the electric heating rod 16 is continuously increased along the height direction.
Through a large amount of experiments and numerical simulation, the heating efficiency can be further improved by 5% through the change of the heating power amplitude of the electric heating rod 16, and the heating time is further saved.
Preferably, the same electrical heating rod 16 in the same fluid flow heating means is divided into a plurality of sections, and the heating power per unit length of the different sections is different along the direction of fluid flow in the evaporating tube. Wherein the heating power per unit length of the different sections is continuously increased along the direction of the fluid flow in the evaporation tube. Further preferably, the magnitude of the increase is continuously increased.
Preferably, the length of each segment is the same.
Preferably, the heating power per unit length of each segment is the same.
The specific reason is as described above.
By providing the segments, manufacturing can be further facilitated.
Through analysis and experiment learn, the interval between the evaporating pipe extending direction fluid flow heater block can not be too big, and too big the effect that leads to the hot-fluid to produce is not good, simultaneously also can not the undersize, and the undersize leads to the interior intraductal easy of burning dry, and on the same hand, the length of a side of regular quadrangle also can not be too big or the undersize, and too big heating that leads to is inhomogeneous, and the undersize leads to regular quadrangle and octagon to distribute too densely, causes flow resistance to increase and the processing cost increases. Therefore, the resistance is optimized through a large number of experiments under the condition that the hot fluid steam outlet amount is preferentially met, and the optimal relation of each parameter is arranged.
Preferably, the distance between adjacent fluid flow heating members is S1, the side length of the regular quadrangle is K2, the fluid flow heating member has a regular quadrangle cross section, and the side length of the regular quadrangle cross section of the fluid flow heating member is B2, which satisfies the following requirements:
S1/B2=a-b*(10*K2/B2);
wherein a, b are parameters, wherein 0.735< a <0.740,2.67< b < 2.68;
180<B2<360mm;
12<K2<45mm;
45<S1<170mm。
further preferably, a =0.734, b =2.675;
further preferably, a is larger and B is smaller as K2/B2 is increased.
Preferably, the side length K2 of the rhombic shape of the through-hole is an average value of the inner side length and the outer side length of the rhombic shape of the through-hole, and the side length B2 of the rectangular cross section of the fluid flow heating member is an average value of the inner side length and the outer side length of the rectangular cross section of the fluid flow heating member.
The distance between adjacent fluid flow heating elements is S1, which is the distance between the opposing faces of adjacent fluid flow heating elements. Such as the distance between the left end face of the right fluid flow heating member and the right end face of the left fluid flow heating member.
Preferably, as B2 increases, K2 also increases. However, as B2 increases, the increasing amplitude of K2 becomes smaller and smaller. The change of the rule is obtained through a large amount of numerical simulation and experiments, and the heat exchange effect and the noise are further improved and reduced through the change of the rule.
Preferably, S1 decreases as B2 increases. However, as B2 increases, the magnitude of the decrease of S1 becomes smaller and smaller. The change of the rule is obtained through a large amount of numerical simulation and experiments, and the heat exchange effect and the noise are further improved and reduced through the change of the rule.
Preferably, the length of the side of the regular quadrilateral cross section of the fluid flow heating member is equal to the length of the inner wall surface of the evaporation tube.
The fluid flow heating means length K1 is preferably 50-300 mm, more preferably 100-150 mm.
Preferably, the length of the evaporation tube is between 3000-3500 mm. More preferably, 3200-.
By optimizing the optimal geometric dimension of the formula, the optimal effect of shock absorption and noise reduction can be achieved under the condition of meeting the normal flow resistance.
For other parameters, such as the wall thickness of the pipe and the wall thickness of the shell, the parameters are set according to normal standards.
For other parameters, such as the wall thickness of the pipe and the wall thickness of the shell, the parameters are set according to normal standards.
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.