CN104197760A - Pipeline type pulse heat pipe heat exchanger - Google Patents

Abstract

The invention provides a pipeline type pulsating heat pipe heat exchanger, which is characterized in that it includes a heat medium flow pipe, and a pulsating heat pipe is respectively arranged on the front and rear sides of the heat medium flow pipe, and the pulsating heat pipe includes an evaporation section and a condensation section and an adiabatic section between the evaporating section and the condensing section, the heat medium flow pipeline includes an inlet pipeline, an outlet pipeline and an intermediate pipeline between the inlet pipeline and the outlet pipeline, wherein the pulsation The evaporation section of the heat pipe is arranged on the side of the inlet pipeline of the heat medium flow pipe, and the condensation section of the pulsating heat pipe is arranged on the side of the outlet pipeline of the heat medium flow pipeline. The pulsating heat pipe of the present invention can transfer heat efficiently, relying on the self-oscillating flow of vapor and liquid two-phase medium to transfer heat under the external condition of no power. During the whole process, no need to consume external mechanical and electric power, self-oscillation is realized under thermal drive, and it has the characteristics of easy manufacture and low cost.

Description

A pipeline type pulsating heat pipe heat exchanger

technical field

The invention relates to a device of a line type heat exchanger which utilizes a pulsating heat pipe to enhance heat exchange. Utilizing the phase change heat transfer and pulsation effect of the pulsating heat pipe, the heat exchange efficiency of the heat exchanger is effectively improved, and an efficient pulsating heat pipe heat exchanger is formed. Mainly used in ships, automobiles, aerospace, electronics, waste heat recovery, solar energy and geothermal utilization, etc. It has the characteristics of high heat exchange efficiency, less pressure loss, and not easy to scale.

Background technique

In transportation, aerospace and industrial processes, it is necessary to control or enhance the transfer of heat between equipment systems and the surrounding environment or between different parts of the same system. The heat exchanger is not only one of the key equipments necessary to ensure normal production and life, but also plays an irreplaceable role in energy saving, emission reduction and secondary utilization of energy. At present, there are many types of heat exchangers, and the technology is relatively mature, but how to improve heat exchange efficiency with high efficiency and energy saving is still a difficult problem for heat exchangers.

The pulsating heat pipe is a new type of high-efficiency heat transfer equipment, which mainly relies on the self-oscillating flow of the vapor and liquid two-phase medium to transfer heat during operation. Its working principle is: vacuumize the inside of the tube and fill it with a certain amount of working medium. Because the tube diameter is small enough, bubble columns and liquid columns will be formed in the tube, which are arranged at intervals and randomly distributed. At the evaporating end, the working fluid absorbs heat to generate bubbles, rapidly expands and boosts the pressure, and pushes the working fluid to flow to the low-temperature condensation end, where the bubbles cool, shrink and burst, and the pressure drops. In this way, due to the pressure difference between the two ends and the pressure imbalance between adjacent tubes, the working fluid oscillates and flows between the evaporation section and the condensation section, thereby realizing heat transfer. In the whole process, there is no need to consume external mechanical and electric power, and it is completely self-oscillation driven by heat. The pulsating heat pipe has the advantages of simple structure, easy manufacture and low cost, and has been successfully applied in the heat treatment of power equipment and microelectronics. The heat transfer coefficient of the pulsating heat pipe with reasonable structure is very large. The thermal conductivity of the plate-type pulsating heat pipe made of stainless steel plate is about 2000W/m·K, which is 120 times higher than that of the original stainless steel, while maintaining the original advantages of stainless steel.

Contents of the invention

The problem to be solved by the present invention is to provide a pipeline type pulsating heat pipe heat exchanger with high heat transfer performance.

In order to solve the above technical problems, the present invention provides a pipeline type pulsating heat pipe heat exchanger, which is characterized in that it includes a heat medium flow pipe, and a pulsating heat pipe is provided on the front and rear sides of the heat medium flow pipe, and the pulsating heat pipe It includes an evaporating section, a condensing section, and an adiabatic section between the evaporating section and the condensing section, and the heat medium flow pipeline includes an inlet pipeline, an outlet pipeline, and an intermediate pipeline between the inlet pipeline and the outlet pipeline, Wherein, the evaporating section of the pulsating heat pipe is arranged on the side of the inlet pipe of the heat medium flow pipe, and the condensation section of the pulsating heat pipe is arranged on the side of the outlet pipe of the heat medium flow pipe.

Preferably, an enhanced heat exchange pipe network is provided between the evaporation section of the pulsating heat pipe and the inlet pipeline of the heat medium flow pipeline, and between the condensation section of the pulsating heat pipe and the outlet pipeline of the heat medium flow pipeline.

More preferably, the enhanced heat exchange pipe network and the pulsating heat pipes are respectively arranged symmetrically on both sides of the heat medium flow pipe.

Preferably, the pulsating heat pipe is a serpentine pipe, the serpentine pipes are connected end to end to form a closed circuit pulsating heat pipe, and its cross-sectional shape is circular, and refrigerant is arranged in the serpentine pipe.

Preferably, the pulsating heat pipe is a serpentine pipe, the end of the serpentine pipe is not connected to form an open loop pulsating heat pipe, and its cross section is circular, and refrigerant is arranged in the serpentine pipe.

More preferably, the liquid filling rate of the serpentine tube is 55%, and the refrigerant is R134a, acetone, alcohol, water or ammonia water. (The working fluid can be determined based on comprehensive considerations such as actual heat transfer and cost).

Preferably, the heat medium flow pipe is a serpentine pipe.

More preferably, the elbow part of the serpentine pipe is arranged in the heat insulation box.

Preferably, the heat medium flow pipe is provided with a heat medium, and the flow rate of the heat medium is 0.02kg/s-1.5kg/s.

Preferably, the pulsating heat pipe is installed vertically, its evaporating section is located on the upper side, and the condensing section is located on the lower side, and the heat medium in the heat medium flow pipe flows from the high end to the low end.

Preferably, the pulsating heat pipe is installed horizontally, the evaporating section is located on the left or right of the adiabatic section, the condensing section is located on the right or left of the adiabatic section, and the number of bends of the pulsating heat pipe is more than 40.

Compared with prior art, the beneficial effect of the present invention is:

1. The present invention is a device for enhancing heat exchange by using the phase change of the working liquid in the pulsating heat pipe. Pulsating heat pipes can transfer heat efficiently, relying on the self-oscillating flow of vapor and liquid two-phase media to transfer heat under unpowered external conditions. During the whole process, no need to consume external mechanical and electric power, self-oscillation is realized under thermal drive, and it has the characteristics of easy manufacture and low cost.

2. The enhanced heat exchange pipe network of the present invention is installed between the heat medium flow pipe and the pulsating heat pipe, which is beneficial to the heat exchange between the heat medium fluid pipe and the pulsating heat pipe, and at the same time can make the pulsating heat pipe evenly heated, better improving Heat transfer efficiency of a pulsating heat pipe heat exchanger.

Description of drawings

Figure 1a is a schematic diagram of the structure of an open pulsating heat pipe;

Figure 1b is a schematic diagram of the structure of a closed pulsating heat pipe;

Fig. 2 is a structural schematic diagram of a heat medium flow pipeline;

Figure 3 is a schematic diagram of the structure of the enhanced heat exchange pipe network;

Figure 4a is a schematic structural diagram of a pipeline type pulsating heat pipe heat exchanger using an open pulsating heat pipe;

Figure 4b is a schematic structural diagram of a pipeline type pulsating heat pipe heat exchanger using a closed pulsating heat pipe;

Fig. 5 is a top view of the pipeline type pulsating heat pipe heat exchanger.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

A pipeline type pulsating heat pipe heat exchanger using an open pulsating heat pipe, comprising a pulsating heat pipe 1 , a heat medium flow pipe 2 , an enhanced heat exchange pipe network 3 and an adiabatic box 4 .

As shown in Figure 1a, the pulsating heat pipe 1 is a serpentine tube bent from a copper tube with an outer diameter of 4 mm and an inner diameter of 2.7 mm, and the bending radius is 8 mm. The ends of the serpentine tube are not connected to each other. The open circuit pulsating heat pipe has a circular cross-section. The serpentine tube is provided with R134a refrigerant, the liquid filling rate is 55%, and the vacuum degree reaches 10 ^-3 Pa. The working fluid can be determined based on comprehensive considerations such as actual heat transfer and cost. The pulsating heat pipe 1 includes an evaporating section 11 , a condensing section 13 and an adiabatic section 12 between the evaporating section 11 and the condensing section 13 . The length and number of bends of the evaporating section 11 and the condensing section 13 can be determined according to actual needs.

As shown in Figure 2, the heat medium flow pipe 2 is made of a material with high heat transfer performance of copper (copper is a good heat conduction material, on the basis of considering the production cost and heat transfer performance, it is recommended to choose purple The copper tube is bent as the heat medium flow pipe), and the pipe is serpentine, which increases the heat dissipation area of the heat medium and facilitates heat exchange. Intermediate pipeline 23 between pipelines 22 . The elbow part of the serpentine pipe is arranged in the heat insulation box 4, and the heat insulation box 4 covers the elbow part of the heat medium flow pipe 2, so as to reduce heat loss. A heat medium is arranged in the heat medium flowing pipeline, and the flow rate of the heat medium is 0.02kg/s-1.5kg/s. There is no special requirement for the pipe diameter, which can be determined according to the flow rate of the heat medium.

As shown in Figure 3, the enhanced heat exchange pipe network is braided by copper wires with a diameter of 1 mm, and the copper wires are interwoven horizontally and vertically to form a network structure. The purpose is to increase the contact area and use materials with high thermal conductivity. Can enhance heat transfer. The shape and size of the enhanced heat exchange pipe network are determined according to the length of the hot and cold sections of the pulsating heat pipe, and the material can be determined according to actual needs. Its size just covers the condensation section or evaporation section of the pulsating heat pipe, and it is installed between the heat medium flow pipe and the pulsating heat pipe. It is good to improve the heat exchange efficiency of the pulsating heat pipe heat exchanger.

As shown in FIG. 4 a , a pulsating heat pipe 1 is provided on the front and rear sides of the heat medium flow pipe 2 , and the heat medium flow pipe 2 and the pulsation heat pipe 1 are vertically arranged. Wherein, the evaporation section 11 of the pulsating heat pipe 1 is arranged on the side of the inlet pipeline 21 of the heat medium flow pipeline 2, and the condensation section 13 of the pulsating heat pipe 1 is arranged on the side of the outlet pipeline 22 of the heat medium flow pipeline 2. side. Between the evaporation section 11 of the pulsating heat pipe 1 and the inlet pipeline 21 of the heat medium flow pipeline 2 and between the condensation section 13 of the pulsating heat pipe 1 and the outlet pipeline 22 of the heat medium flow pipeline 2, reinforcement Heat exchange pipe network 3. As shown in FIG. 5 , the enhanced heat exchange pipe network 3 and the pulsating heat pipe 1 are symmetrically arranged on both sides of the heat medium flow pipe 2 . The heat medium enters the pipe through the entrance, and flows in an S shape in the pipe, which strengthens the heat exchange area of the heat medium. Heat medium flow pipes can be arranged according to actual needs. During installation, fix the heat medium flow pipe 2 first, and arrange the enhanced heat exchange pipe network 3 at both ends of the heat medium flow pipe 2, so as to minimize the gap between the enhanced heat exchange pipe network 3 and the heat medium flow pipe 2, so that Compactly installed between the pulsating heat pipe 1 and the heat medium flow pipe 2; the heat insulation box 4 is installed at the elbow of the heat medium flow pipe 2 to reduce the heat loss of the heat medium at the elbow and improve the performance of the pipeline type pulsating heat pipe. heat transfer efficiency of the heat exchanger.

The length and structural form of the parts of the pipeline type pulsating heat pipe heat exchanger involved in the present invention can be determined according to actual conditions. The pipeline type pulsating heat pipe heat exchanger can be installed vertically or horizontally. As shown in Figure 4a, when the pulsating heat pipe 1 is installed vertically, the evaporation section is located on the upper side, the condensation section is located on the lower side, the heat medium inlet is set at a high place, and the heat medium in the heat medium flow pipe 2 flows from the high end to the low end . The number of elbows of the pulsating heat pipe has no specific requirements. When the pulsating heat pipe 1 is installed horizontally, the evaporating section is located on the left or right side of the adiabatic section, the condensing section is located on the right or left side of the adiabatic section, and the heat medium flow inlet can be set at any end. A large number of experiments have proved that in the following When water is the heat medium at 100°C and R134a is the refrigerant of the pulsating heat pipe, the heat transfer efficiency increases from 75% to 90% as the number of elbows of the pulsating heat pipe increases. Generally, the number of elbows meets more than 40. The heat exchanging efficiency of the heater has obvious promoting effect, and at the same time, it can get rid of the limitation of vertical installation and horizontal installation of the pulsating heat pipe.

When in use, the high-temperature heat medium passes through the enhanced heat exchange pipe network to supply energy to the evaporation section of the pulsating heat pipe, the pulsating heat pipe starts, and through the phase change heat transfer and pulsation effect of the pulsating heat pipe, the heat is transferred to the condensation section. The low-temperature water passes through the condensation section, which strengthens the heat exchange in the condensation section, so that the heat can be dissipated quickly, and the purpose of strengthening the heat exchange is achieved.

Example 2

As shown in Figure 4b, it is a schematic structural diagram of a pipeline-type pulsating heat pipe heat exchanger using a closed-type pulsating heat pipe. The structure of the pipeline-type pulsating heat-pipe heat exchanger using a closed-type pulsating heat pipe is similar to that of Example 1, the difference is that , the structure of the pulsating heat pipe 1 is different. The pulsating heat pipe 1 is a serpentine pipe. A refrigerant is provided in the tube.

Claims (10)

1. A pipeline type pulsating heat pipe heat exchanger is characterized in that it comprises a heat medium flow pipe (2), and a pulsating heat pipe (1) is respectively provided on the front and rear sides of the heat medium flow pipe (2), and the pulsating heat pipe (1) The heat pipe (1) includes an evaporation section (11), a condensation section (13) and an adiabatic section (12) between the evaporation section (11) and the condensation section (13), and the heat medium flow pipe (2) includes an inlet pipeline (21), outlet pipeline (22) and an intermediate pipeline (23) between the inlet pipeline (21) and the outlet pipeline (22), wherein the evaporation section of the pulsating heat pipe (1) (11) is arranged on the side of the inlet pipeline (21) of the heat medium flow pipeline (2), and the condensation section (13) of the pulsating heat pipe (1) is arranged on the outlet pipeline of the heat medium flow pipeline (2) ( 22) side. the 2. The pipeline type pulsating heat pipe heat exchanger according to claim 1, characterized in that, the evaporation section (11) of the pulsating heat pipe (1) and the inlet pipe (21) of the heat medium flow pipe (2) An enhanced heat exchange pipe network (3) is arranged between the condensing section (13) of the pulsating heat pipe (1) and the outlet pipe (22) of the heat medium flow pipe (2). the 3. The pipeline type pulsating heat pipe heat exchanger according to claim 2, characterized in that, the enhanced heat exchange pipe network (3) and the pulsating heat pipe (1) are respectively symmetrically arranged on the heat medium flow pipe (2) on both sides. the 4. The pipeline type pulsating heat pipe heat exchanger according to claim 1, characterized in that, the pulsating heat pipe (1) is a serpentine tube, and the end-to-end connection of the serpentine tubes forms a closed loop pulsating heat pipe, Its section shape is circular, and refrigerant is arranged in the serpentine tube. the 5. The pipeline type pulsating heat pipe heat exchanger according to claim 1, characterized in that, the pulsating heat pipe (1) is a serpentine tube, and the ends of the serpentine tubes are not connected to form an open circuit pulsating heat pipe , its cross-sectional shape is circular, and refrigerant is arranged in the serpentine tube. the 6. The pipeline type pulsating heat pipe heat exchanger according to claim 1, wherein the heat medium flow pipe is a coiled pipe. the 7. The pipeline type pulsating heat pipe heat exchanger according to claim 6, characterized in that, the elbow part of the serpentine pipe is arranged in the heat insulation box (4). the 8 . The pipeline type pulsating heat pipe heat exchanger according to claim 1 , wherein a heat medium is arranged in the heat medium flow pipe, and the flow rate of the heat medium is 0.02kg/s-1.5kg/s. the 9. The pipeline type pulsating heat pipe heat exchanger according to claim 1, wherein the pulsating heat pipe (1) is installed vertically, the evaporating section is located on the upper side, the condensing section is located on the lower side, and the heat medium flow pipe (2) The heat medium flows from the high end to the low end. the 10. The pipeline type pulsating heat pipe heat exchanger according to claim 1, wherein the pulsating heat pipe (1) is installed horizontally, the evaporating section is located on the left or right side of the adiabatic section, and the condensing section is located in the adiabatic section The right or left side of the pulsating heat pipe (1) has more than 40 elbows. the