CN201973915U - U-shaped passage combined heat pipe receiver - Google Patents

Abstract

The utility model relates to a U-shaped channel combination type heat pipe receiver, which comprises a high-temperature-resistant insulation layer, a lighting hole, a heat-absorbing section of a heat pipe group, a partition plate, a diffuse reflection cone, an aluminum alloy shell, an annular sleeve, and a heat pipe group Condensing section, annular radiation absorbing ribs, outer wall semi-enclosed air flow baffle, inner wall semi-enclosed air flow baffle, fully enclosed air flow baffle, gas inlet, gas outlet, etc. The high-temperature heat pipe group is evenly arranged in a circular shape. The heat-absorbing section and the condensation section of the heat pipe group are separated by a partition plate. The heat-absorbing section of the heat pipe is in close contact with the annular radiation absorbing rib, and forms a U-shaped heat absorption together with the diffuse reflection cone. Mouth. The condensing section of the heat pipe is covered by an annular sleeve, and a partition plate is built between adjacent heat pipes to guide the gas flow path in a serpentine shape. The utility model is suitable for dish type-Stirling solar thermal power generation systems with different power sizes, and has the advantages of more uniform heat flow distribution, higher heat transfer efficiency and more stable system than the previous indirect receivers.

Description

A U-shaped channel combined heat pipe receiver

technical field

The utility model relates to a heat pipe receiver, in particular to a U-shaped channel combined heat pipe receiver.

Background technique

Dish-Stirling solar thermal power generation is one of the highest photoelectric conversion efficiency methods in solar thermal power generation technology. It gathers solar radiation into a thermal receiver through a rotating parabolic dish concentrator, and the receiver absorbs the energy and then the The Stirling heat engine realizes the conversion of solar energy into electrical energy. Generally, the power of solar Stirling engines is relatively small, which is suitable for distributed energy utilization and has the potential for large-scale combined grid-connected power generation. In addition, they can also be designed as combined fuel and solar concentrator heating systems, which can use fossil fuels instead of sunlight to continuously generate electricity when there is no sunlight.

The dish solar thermal power generation system includes main components such as concentrators, receivers, heat engines, supports, and tracking control systems. When the system is working, the sunlight reflected from the concentrator is focused on the heat receiver, and the working medium of the heat engine flows through the receiver to absorb the heat energy converted from sunlight, so that the temperature of the medium rises, which can drive the heat engine to run and drive the generator generate electricity.

The receiver is the core component of light-to-heat conversion. There are two types of receivers in dish solar thermal power generation systems: direct receivers and indirect receivers. The existing dish-stirling thermal power generation system widely uses the direct receiver. Due to the very obvious instability of solar radiation, coupled with the problem of the concentration accuracy of the condenser itself, it often leads to serious temperature unevenness in the direct receiving heat exchange tube, which in turn leads to problems such as thermal fatigue, oxidation, service life, etc. A series of problems, while making the overall operation of the system very unstable. Indirect receivers generally use liquid metal as an intermediate medium. Through the evaporation and condensation of liquid metal, the heat is indirectly transferred to the heat exchange tube of the Stirling machine. Some foreign research reports show that the heat pipe receiver is the first 20 of the 21st century. The core breakthrough point in the development of dish-Stirling solar technology in 2008, the experimental results of applying the heat pipe absorber to the STM 4-120 Stirling machine show that the overall photothermal efficiency of the system has increased by more than 10%, and its huge potential makes People inspire. At present, the indirect receiver is still in the stage of experimental research. Although some indirect receivers of this type have been designed at home and abroad, there are some obvious defects of various kinds.

Sandia National Laboratory in the United States successively designed the first and second generation pool boiling indirect receivers in the 1990s. This pool boiling receiver has simple structure, low processing cost, strong adaptability, and is suitable for large inclination angle Operating within the range, the metal vapor is directly condensed on the heat exchange tube of the heat engine, and the efficiency is very high, but the filling amount of the working fluid is large, and the consequences of leakage will be disastrous. The German Aerospace Center designed the first-generation and second-generation heat pipe receivers respectively, but local working fluid leakage occurred after a period of use. US Patent No. 5,113,659 relates to a high-temperature heat pipe receiver capable of storing heat. The receiver is composed of a plurality of cylindrical high-temperature heat pipes, and when a problem occurs in one of the heat pipes, it will not seriously affect the others, which improves the reliability of the receiver. Domestic Nanjing University of Technology also designed a combined heat pipe receiver. The receiver uses several special-shaped high-temperature heat pipes as the heat transfer unit, which improves the operating efficiency and reliability. The light ratio is low, so there will also be the problem of uneven temperature. At the same time, the outer side of the heat pipe in the condensation section of the heat pipe adopts the form of a sleeve to transfer heat. On the one hand, the arrangement of the bushings leads to a looser arrangement of the heat pipe groups on one side of the heat-absorbing cavity, which also significantly reduces the overall heat transfer capacity.

A receiver with excellent performance should have the characteristics of uniform heat transfer, high transmission efficiency, and long service life. The performance of the thermal receiver is one of the key factors that determine whether the entire system can operate well.

Contents of the invention

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a U-shaped channel combined heat pipe receiver.

The utility model is realized through the following technical solutions:

U-shaped channel combined solar heat pipe receiver includes high temperature resistant insulation layer, daylighting hole, partition board of heat pipe group heat absorbing section, diffuse reflection cone, aluminum alloy shell, annular sleeve, heat pipe group condensation section, annular radiation absorbing ribs, outer wall Semi-enclosed air flow baffle, inner wall semi-enclosed air flow baffle, fully enclosed air flow baffle, gas inlet and gas outlet; the heat-absorbing section of the heat pipe group and the condensation section of the heat pipe group pass through the partition plate, and are evenly arranged in a ring in the center , the annular radiation absorbing rib is in contact with the heat-absorbing section of the heat pipe group, the heat-absorbing section of the heat pipe group, the annular radiation absorbing rib and the diffuse reflection cone constitute a U-shaped heat-absorbing cavity, and the diffuse reflection cone is located at the bottom of the U-shaped heat-absorbing cavity, and the diffuse reflection The back of the cone is connected with the partition plate, the condensing section of the heat pipe group is covered with an annular sleeve, and the annular sleeve is fixed on the partition plate through bolt connection. There are semi-closed airflow baffles on the outer wall and semi-closed airflow baffles on the inner wall at intervals between the heat pipes. The width of the closed airflow baffle and the semi-closed airflow baffle on the inner wall are both half of the width of the annular sleeve, and a fully enclosed airflow baffle is arranged between the two heat pipes, that is, it is connected with the inner and outer cylindrical walls, and the two fully enclosed airflow baffles A plurality of gas inlets and a plurality of gas outlets are evenly arranged on the outer wall of the side annular sleeve along the axial direction, and the outer side of the whole device is covered with a high-temperature heat-resistant insulation layer, and the outer side of the insulation layer is covered with an aluminum alloy shell for fixing.

The heat-absorbing section of the heat pipe group adopts two different absorbing coatings, the light entrance side adopts the coating with low absorption rate, and the cavity bottom side adopts the coating with high absorption rate. The material of the partition plate, annular sleeve, annular radiation absorbing rib outer wall semi-enclosed air flow baffle, inner wall semi-enclosed air flow baffle and fully enclosed air flow baffle is made of high temperature resistant alloy material 1Cr18Ni9Ti, and the lighting hole is made of high temperature resistant ceramic material .

Compared with the prior art, the utility model has the following beneficial effects:

(1) The combined cylindrical high-temperature heat pipe and arc-shaped connecting piece are used to form the heat-absorbing chamber, and the processing and manufacturing technology is very mature, which simplifies the complicated structure of the heat-absorbing end in the past. Moreover, a single heat pipe can be disassembled very conveniently, so that even if a certain heat pipe is damaged, it can be replaced quickly without greatly affecting the work of other heat pipes and the operation of the system.

(2) The heat-absorbing section of the heat pipe adopts two different absorbing coatings to avoid the problem of excessively high heat flux at the inlet section of the general U-shaped cavity absorber, effectively prolonging the service life of the system and enhancing the overall System stability.

(3) The serpentine heat exchange air passage in the cooling section of the heat pipe can effectively meet the requirements of the high-efficiency Stirling engine with small useless volume and good sealing. At the same time, the air resistance is within an acceptable range, and the heat transfer effect is better than that of the previous cooling section heat transfer method.

Description of drawings

Fig. 1 is a schematic structural diagram of a U-shaped channel combined heat pipe receiver;

Fig. 2 is the A-A sectional schematic diagram of Fig. 1;

Fig. 3 is the B-B sectional schematic diagram of Fig. 1;

In the figure: high temperature insulation layer 1, lighting hole 2, heat pipe group heat absorption section 3, partition plate 4, diffuse reflection cone 5, aluminum alloy shell 6, annular sleeve 7, heat pipe group condensation section 8, annular radiation absorption Rib 9 , outer wall semi-enclosed airflow baffle 10 , inner wall semi-enclosed airflow baffle 11 , fully enclosed airflow baffle 12 , gas inlet 13 , gas outlet 14 .

Detailed ways

The utility model will be further described with reference to the accompanying drawings.

As shown in Figure 1, Figure 2, and Figure 3, the U-shaped channel combined solar heat pipe receiver includes a high-temperature-resistant insulation layer 1, a lighting hole 2, a heat-absorbing section of the heat pipe group 3, a partition plate 4, and a diffuse reflection cone 5. Aluminum alloy shell 6, annular sleeve 7, condensation section of heat pipe group 8, annular radiation absorbing rib 9, outer wall semi-enclosed air flow baffle 10, inner wall semi-enclosed air flow baffle 11, fully enclosed air flow baffle 12, gas inlet 13 and gas outlet 14; heat pipe group heat absorbing section 3 and heat pipe group condensing section 8 pass through the partition plate, and are evenly arranged in a ring in the center, and the annular radiation absorbing rib 9 is in contact with the heat pipe group heat absorbing section 3, and the heat pipe group heat absorbing section 3. The annular radiation absorbing rib 9 and the diffuse reflection cone 5 constitute a U-shaped heat-absorbing cavity, the diffuse reflection cone 5 is located at the bottom of the U-shaped heat-absorbing cavity, the back of the diffuse reflection cone 5 is connected with the partition plate 4, and the heat pipe The condensing section of the group is covered with an annular sleeve 7, and the annular sleeve 7 is fixed on the partition plate 4 through bolt connection. There is a sealing ring between the annular sleeve 7 and the partition plate 4, and an outer wall is arranged between adjacent heat pipes. The semi-enclosed air flow baffle 10 and the inner wall semi-enclosed air flow baffle 11, the outer wall semi-enclosed air flow baffle 10 is connected with the outer ring of the annular sleeve 7, the inner wall semi-enclosed air flow baffle 11 is connected with the inner ring of the annular sleeve 7, and the outer wall is semi-enclosed The width of the airflow baffle 10 and the semi-enclosed airflow baffle 11 on the inner wall is half of the width of the annular sleeve 7, and a fully enclosed airflow baffle 12 is arranged between the two heat pipes, that is, it is connected with the inner and outer cylindrical walls, and the fully enclosed airflow A plurality of gas inlets 13 and a plurality of gas outlets 14 are evenly arranged on the outer wall of the annular sleeve 7 on both sides of the baffle plate 12 along the axial direction. The alloy shell 6 is fixed.

The heat-absorbing section 3 of the heat pipe group is axially divided into two uniform parts from the light entrance to the bottom surface of the cavity, and two different absorbing coatings are used respectively. The light entrance side adopts a coating with low absorption rate, and the cavity bottom side Use a high-absorbency coating. Annular fins are added to the condensing section 8 of the heat pipe group to enhance the heat transfer effect.

The material of the partition plate 4, the annular sleeve 7, the annular radiation absorbing rib 9 outer wall semi-enclosed air flow baffle 10, the inner wall semi-enclosed air flow baffle 11 and the fully enclosed air flow baffle 12 adopts high temperature resistant alloy material 1Cr18Ni9Ti, daylighting Hole 2 is made of high temperature resistant ceramic material.

The use of annular radiation absorbing ribs 9 has three functions: 1. The insulation layer and the separator of the cavity; 2. Absorb the light radiation between the gaps between adjacent heat pipes, and transfer heat to the heat pipes through heat conduction; 3. Reflect part of the incident light to the heat pipes , so that its radiant energy is absorbed by the heat pipe.

The daylighting hole has two main functions: 1. Focusing on the entrance of light; 2. Limiting the convective heat transfer between the cavity and the external environment to reduce heat loss.

The light inlet section of the heat-absorbing section of the heat pipe group is coated with a high-temperature resistant absorbing coating with a relatively low absorption ratio of about 0.8, and the bottom section is coated with a high-temperature resistant absorbing coating with a relatively high absorption ratio greater than 0.9 to enhance the uniformity of heat flow distribution. Ring fins are added to the condensation section of the heat pipe group to enhance the heat exchange effect.

The working process of the present utility model is as follows:

First, the sun's rays are focused by the dish-type parabolic mirror, and the theoretical focus is the center point of the lighting hole. Focused light enters the heat-absorbing cavity through the daylighting hole, most of it is incident on the heat-absorbing section of the high-temperature heat pipe group and the inner side of the annular radiation absorbing rib, and a small part is directly incident on the diffuse reflection cone. Most of the focused light energy incident on the inside of the heat pipe and the annular radiation absorbing rib is directly absorbed and converted into heat energy, and a small amount is reflected or scattered. Most of the light incident on the diffuse reflection cone at the bottom of the heat-absorbing cavity is diffusely reflected. The body has only a relatively small light hole, so most of the reflected and scattered light is reabsorbed in the cavity, and only a small amount of light leaves the cavity through the light hole. In this way, most of the light entering the lighting hole is absorbed by the heat absorbing section of the heat pipe group and converted into heat energy, and at the same time, the heat is transferred to the liquid metal sodium in the heat pipe to evaporate, and the evaporated gaseous metal sodium condenses in the condensation section of the heat pipe , so that the heat is transferred to the tube wall and fins of the condensation section, the high-pressure Stirling working fluid enters the annular sleeve from the gas inlet tube, and flows along the serpentine flow channel, through convective heat exchange with the tube wall and fins , absorb the heat in the cooling section of the heat pipe, and then flow out from the gas outlet pipe into the Stirling machine to drive it to work.

Claims (3)

1. a U-shaped channel group mould assembly solar heat pipe receivers is characterized in that comprising that high-temperature-resistant thermal-insulation layer (1), lightlng hole (2), heat pipe heat endotherm section (3), demarcation strip (4), diffuse reflection cone (5), aluminum alloy casing (6), annulus (7), heat pipe heat condensation segment (8), annular radiation absorb rib (9), the semiclosed blast fence of outer wall (10), the semiclosed blast fence of inwall (11), completely-enclosed flow baffle plate (12), gas inlet (13) and gas outlet (14); Heat pipe heat endotherm section (3) and heat pipe heat condensation segment (8) pass demarcation strip, centering is evenly arranged ringwise, the annular radiation absorbs rib (9) and contacts with heat pipe heat endotherm section (3), heat pipe heat endotherm section (3), the annular radiation absorbs rib (9) and diffuse reflection cone (5) has constituted the U-shaped heat-absorbing chamber, diffuse reflection cone (5) is positioned at U-shaped heat-absorbing chamber bottom, the back side of diffuse reflection cone (5) is connected with demarcation strip (4), the heat pipe heat condensation segment is with annulus (7) outward, annulus (7) is fastened on the demarcation strip (4) by bolt, be provided with sealing ring between annulus (7) and the demarcation strip (4), be interval with semiclosed blast fence of outer wall (10) and the semiclosed blast fence of inwall (11) between the adjacent heat pipe, the semiclosed blast fence of outer wall (10) links to each other with annulus (7) outer shroud, the semiclosed blast fence of inwall (11) links to each other with ring in the annulus (7), the width of semiclosed blast fence of outer wall (10) and the semiclosed blast fence of inwall (11) is half of annulus (7) width, wherein be provided with completely-enclosed flow baffle plate (12) between two heat pipes, promptly all link to each other with interior outside cylindrical wall, evenly be provided with a plurality of gas inlets (13) and a plurality of gas outlet (14) on completely-enclosed flow baffle plate (12) both sides annulus (7) outer wall vertically successively, the whole device outside coats high-temperature-resistant thermal-insulation layer (1), and heat-insulation layer outside metallized aluminum alloy shell (6) is fixed.

2. a kind of U-shaped channel group mould assembly hot pipe receiver according to claim 1, it is characterized in that described heat pipe heat endotherm section (3) adopts two kinds of different absorber coatings, the light inlet side adopts the low coating of absorptivity, and a side adopts the high coating of absorptivity at the bottom of the chamber.

3. a kind of U-shaped channel group mould assembly hot pipe receiver according to claim 1, it is characterized in that described demarcation strip (4), annulus (7), annular radiation absorb the material employing high-temperature alloy material 1Cr18Ni9Ti of the semiclosed blast fence of rib (9) outer wall (10), the semiclosed blast fence of inwall (11) and completely-enclosed flow baffle plate (12), lightlng hole (2) adopts high temperature ceramic material.

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