CN110617634B

CN110617634B - Distribution structure of capillary parts and solar heat collector thereof

Info

Publication number: CN110617634B
Application number: CN201910194677.6A
Authority: CN
Inventors: 郭春生; 马军; 张茜卓; 徐怡平; 郭斯琪; 赵熙; 李鸿路; 刘欣怡; 咸保昊
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2019-03-14
Filing date: 2019-03-14
Publication date: 2021-01-29
Anticipated expiration: 2039-03-14
Also published as: CN112833564B; CN112833564A; CN110617634A; CN112833563B; CN112833563A

Abstract

The invention provides a distribution structure of capillary parts and a solar heat collector thereof, which comprise a circular supporting plate, wherein through holes are formed in the supporting plate, the capillary parts are arranged in the through holes, and the through holes comprise circle center through holes arranged at the circle center of the supporting plate and annular through holes annularly arranged around the circle center, so that a central capillary part at the circle center of the circle and peripheral capillary parts arranged around the circle center are formed. According to the invention, a novel distribution structure of the capillary component in the heater is designed, an optimal capillary force optimization result in the optimal distribution structure is obtained through multiple tests and numerical simulation, and the test verifies, so that the accuracy of the result is proved.

Description

Distribution structure of capillary parts and solar heat collector thereof

Technical Field

The invention belongs to the field of solar energy, and particularly relates to a solar heat collector system.

Background

With the rapid development of modern socioeconomic, the demand of human beings on energy is increasing. However, the continuous decrease and shortage of traditional energy reserves such as coal, oil, natural gas and the like causes the continuous increase of price, and the environmental pollution problem caused by the conventional fossil fuel is more serious, which greatly limits the development of society and the improvement of the life quality of human beings. Energy problems have become one of the most prominent problems in the modern world. Therefore, the search for new energy sources, especially clean energy sources without pollution, has become a hot spot of research.

Solar energy is inexhaustible cleaning energyThe source and the resource amount are huge, and the total amount of solar radiation energy collected per year on the surface of the earth is 1 multiplied by 10¹⁸kW.h, which is ten thousand times of the total energy consumed in the world year. The utilization of solar energy has been taken as an important item for the development of new energy in all countries in the world, and the active development of new energy has been clearly proposed in the work report of China, wherein the utilization of solar energy particularly occupies a prominent position. However, the solar radiation has a small energy density (about one kilowatt per square meter) and is discontinuous, which brings certain difficulties for large-scale exploitation and utilization. Therefore, in order to widely use solar energy, not only the technical problems should be solved, but also it is necessary to be economically competitive with conventional energy sources.

Solar energy absorbed by a solar heat collector obtains energy by heating water, a loop heat pipe is also adopted as a heat energy utilization device in the solar energy at present, an evaporation end is used as a heat collector, but the structure is adopted to heat the whole water in the loop heat pipe heat collector, a key area cannot be effectively heated, and the cost of the loop heat pipe solar energy is generally higher due to the fact that a capillary structure part is generally arranged in the heat collector of the loop heat pipe, but the cost of the capillary structure part is high.

Disclosure of Invention

The invention aims to provide a novel loop heat pipe solar collector system which can effectively heat key areas and reduce the cost, thereby effectively utilizing solar energy.

In order to achieve the purpose, the technical scheme of the invention is as follows: a distribution structure of capillary components comprises a circular supporting plate, wherein through holes are formed in the supporting plate, the capillary components are arranged in the through holes, and the through holes comprise circle center through holes arranged in the circle center of the supporting plate and annular through holes annularly arranged around the circle center, so that a central capillary component in the circle center and peripheral capillary components arranged around the circle center are formed.

Preferably, the capillary force of the central capillary element is greater than the capillary force of the surrounding capillary elements.

Preferably, the peripheral capillary components are of a one-layer structure, the radius of the inner wall of the heat collection region is K, the center of the central capillary component is arranged at the center of the heat collection region, the distance between the center of the peripheral capillary component and the center of the heat collection region is M, the centers of adjacent peripheral capillary components are respectively connected with the center of the heat collection region, an included angle formed by the two connecting lines is a, the capillary force of a single peripheral capillary component is F1, and the capillary force of a single central capillary component is F2, so that the following requirements are met:

L2/L1 ═ a-b ═ Ln (K/M); ln is a logarithmic function;

a, b are coefficients, wherein 1.5599< a <1.5605,0.4358< b < 0.4364;

1.23<K/M<2.05；

1.2<F2/F1<1.5。

wherein 40 ° < a <100 °.

Preferably, the number of surrounding capillary elements is 4-8.

Preferably, K is 1500-; m is 756 and 1260 mm.

Preferably, a is 1.5602 and b is 0.4361.

A solar heat collector comprises a loop heat pipe, wherein the loop heat pipe comprises an evaporation end and a condensation end, the evaporation end absorbs solar energy to form a solar heat collector, the evaporation end is of a flat plate structure and comprises a heat collection area, the heat collection area comprises a transparent cover plate, a support plate, a capillary component, a first space and a second space, the transparent cover plate is arranged on the upper portion, the second space is arranged on the upper portion, the first space is arranged on the lower portion, and a separation component of the first space and the second space is of the structure.

The transparent cover plate corresponding to the through hole is provided with a lens, and the through hole is positioned on the focus of the lens.

Preferably, the through holes are provided in a plurality, each through hole is provided with a lens on the corresponding transparent cover plate, and the through holes are located at the focus of the corresponding lens.

Preferably, the evaporation end further comprises a liquid storage area, the liquid storage area is of a flat plate structure, the bottom of the liquid storage area is communicated with the liquid channel, and the height of the upper wall surface of the liquid storage area is higher than that of the capillary component.

Preferably, the heat collecting region has a circular cross-section, and the capillary members include a central capillary member disposed at a center of the circle and a peripheral capillary member disposed around the center.

Preferably, the wall surface of the lower part of the heat collection area is provided with an auxiliary heating device, a flow meter is arranged on a pipeline of the evaporation end flowing to the condensation end to test the steam flow, and the auxiliary heating device adjusts the electric heating device to heat according to the tested steam flow.

Preferably, the auxiliary heating device automatically starts heating if the tested flow rate is lower than a certain value, and stops heating if the tested flow rate is higher than a certain value.

A performance experiment device of a loop heat pipe solar heat collector comprises a loop heat pipe, wherein the loop heat pipe comprises a heat collector experiment area unit and a collection measurement unit, and water is evaporated in the heat collector experiment area unit and then condensed in the collection measurement unit; the device also comprises a water supply unit, a blowing unit, a vacuumizing unit and a PLC system installation unit, wherein the water supply unit is connected with the heat collector experiment area unit and supplies water to the heat collector experiment area unit, and the vacuumizing unit is connected with the heat collector experiment area unit and is used for vacuumizing the heat collector experiment area unit; the blowing unit is arranged on a pipeline of the heat collector experiment area unit flowing to the collecting and measuring unit and is used for condensing steam into water; the collecting and measuring unit collects and measures mass flow of the condensed water and collects the condensed water.

Compared with the prior art, the invention has the following advantages:

1) according to the invention, a novel distribution structure of the capillary component in the heater is designed, an optimal capillary force optimization result in the optimal distribution structure is obtained through multiple tests and numerical simulation, and the test verifies, so that the accuracy of the result is proved.

2) The invention is provided with the auxiliary heating device which is arranged on the tube wall below the capillary component, and the liquid in the liquid channel is heated, so that on one hand, the heat absorption capacity of the capillary can be improved, and on the other hand, the situation that the solar heat collection capacity is insufficient under special conditions (such as at night or low illumination intensity) can be avoided.

3) According to the invention, the capillary components are arranged at selective partial positions in the heat collection area, and heat collection is carried out through the corresponding lenses, so that the area where important liquid appears is selectively selected for heating, the cost of the capillary structure is reduced, the cost is integrally reduced, and the utilization rate of heat energy is improved.

4) According to the invention, the liquid storage area is arranged in the heat collector, the liquid storage area is communicated with the liquid channel of the heat collection area, and the water level is obviously higher than the height of the capillary component of the heat collection area, so that the liquid absorption capacity of the capillary component can be increased, and the drying of the heat collector can be avoided.

5) The invention designs a novel experimental platform for detecting the heat collection capacity of a solar heat collector.

Drawings

FIG. 1 is a schematic diagram of a loop heat pipe solar collector system

FIG. 2 is a schematic view of a loop heat pipe solar collector in a top view

FIG. 3 is a schematic cross-sectional view of the solar collector of FIG. 2

FIG. 4 is a schematic structural diagram of an experimental apparatus according to the present invention;

FIG. 5 is a schematic external view of the experimental apparatus according to the present invention;

FIG. 6 is a schematic sectional view of an experimental unit of the experimental apparatus according to the present invention;

FIG. 7 is a schematic structural view of a water supply unit of the experimental apparatus of the present invention;

FIG. 8 is a schematic view of the structure of a collecting and measuring unit of the experimental apparatus of the present invention.

Fig. 9 is a schematic diagram of a capillary element distribution structure according to the present invention.

The reference numbers are as follows:

solar collector system reference numerals: an evaporation end 101, a condensation end 102, a heat collection area 1011, a transparent cover plate 21, a support plate 103, a capillary component 24, a first space 104, a second space 105, a through hole 106, a lens 107, a flowmeter 108,

pressure gauges

109 and 110

Experimental setup reference numerals: 1. experimental area, 2, first pressure sensor, 3, pressure vacuum sensor, 4, second solenoid valve, 5, drying tube, 6, third solenoid valve, 7, fifth solenoid valve, 8, second pressure sensor, 9, first solenoid valve, 10, sixth solenoid valve, 11, pressure water tank, 12, condenser, 13, seventh solenoid valve, 14, second VCR joint, 15, activated carbon collecting device, 16, first VCR joint, 17, mass flow meter, 18, fourth solenoid valve, 19, water supply unit water inlet, 20, gland, 21, high transmittance quartz glass plate, 22, working unit water outlet, 23, heating module, 24, capillary component, 25, filter paper and film, 26, shell, 27, working unit water inlet, 28, liquid storage area, 29, opaque quartz glass filter paper press, 30, measuring unit water inlet, 31, measuring unit water outlet, 32. case, 33. control system touch screen

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

As shown in fig. 1, a loop heat pipe solar collector system comprises a loop heat pipe, the loop heat pipe comprises an evaporation end 101 and a condensation end 102, the evaporation end 101 absorbs solar energy to form a solar collector 101, as shown in fig. 2 and 3, the evaporation end 101 is a flat plate structure and comprises a heat collection area 1011, the heat collection area 1011 comprises a transparent cover plate 21, a support plate 103, a capillary component 24, a first space 104 and a second space 105, the transparent cover plate 21 is arranged on the upper portion, the first space 104 is formed between the support member 103 and the lower wall surface of the evaporation end 101, the support member 103 is preferably a support plate, the second space 105 is formed between the support member 103 and the transparent cover plate 21, a through hole 106 communicating the first space 104 and the second space 105 is arranged on the support member 103, the capillary component 24 is arranged in the through hole 106, the first space 105 is a liquid space, the transparent cover plate 21 corresponding to the through hole 106 is provided with a lens 107, and the through hole 106 is positioned at the focus of the lens 107.

According to the invention, the capillary parts are arranged at selective partial positions in the heat collection area, namely, the capillary parts are arranged at the heat collection part and heat collection is carried out through the corresponding lenses arranged on the transparent cover plate, so that the area where important liquid appears is selectively selected for heating, the area of the capillary parts arranged in the structure is small, the cost of the capillary structure is reduced, the cost is integrally reduced, and the utilization rate of heat energy is improved.

The support structure can play a role of supporting the capillary component, and can avoid the capillary component from sinking and keep good liquid absorption capacity compared with the situation that only the capillary component is arranged.

Preferably, the capillary members occupy 60-80% of the cross-sectional area of the heat collecting region 1011.

Preferably, the capillary member is a porous material.

Preferably, as shown in fig. 2 to 3, the through holes 106 are provided in a plurality, each through hole 106 is provided with a lens 107 on the corresponding transparent cover plate 21, and the through hole 106 is located at the focal point of the corresponding lens 107. By providing a plurality of capillary members and corresponding lenses, multipoint heating can be performed, and the heating capability can be further improved.

Preferably, as shown in fig. 3, the evaporation end further includes a liquid storage area 28, the liquid storage area 28 is a flat plate structure, the bottom of the liquid storage area 28 is communicated with the liquid space 105, and the height of the upper wall surface of the liquid storage area 28 is higher than the height of the capillary component 24.

Preferably, the height of the upper wall surface of the liquid storage region 28 is 5mm or more higher than that of the capillary member.

Preferably, the water is driven into the liquid storage area by a power plant.

The liquid storage area is arranged in the heat collector, the liquid storage area is communicated with the liquid channel of the heat collection area, and the water level is obviously higher than the height of the capillary component of the heat collection area, so that the water level is obviously higher than the upper part of the capillary component, the liquid absorption capacity of the capillary component can be increased through the pressure difference of the water level height, and the drying of the heat collector can be avoided.

The liquid storage area is connected with the condensation area of the loop heat pipe. Indicating that the reservoir is part of a loop heat pipe.

Preferably, the cross-section of the heat collecting region 1011 is circular, and the capillary member 24 includes a central capillary member disposed at the center of the circle and a peripheral capillary member disposed around the center. The invention designs a novel distribution structure of the capillary component in the heater, can further promote the liquid absorption capacity of the capillary component, avoids the defect of the liquid absorption capacity of the capillary at different positions, and aims at the targeted arrangement and reasonable layout of the capillary component at different positions.

Preferably, the capillary force of the central capillary element is greater than the capillary force of the surrounding capillary elements. Because the central fluid is distributed towards the periphery, the influence range is wide, the peripheral capillary components only radiate the periphery, and the overall radiation cannot be realized, so that the absorbed liquid can flow towards the periphery through the middle part by arranging the central capillary component with large capillary capacity, the uneven distribution of the fluid is ensured, meanwhile, the central heat collection capacity is large under normal conditions, the liquid heating capacity is strong, the heat collection capacity is ensured, and the solar energy is fully utilized.

Preferably, in the second space, the fluid is heated uniformly to avoid uneven distribution of heat exchange, which leads to drying of partial areas, because the central fluid radiates to the periphery, which can affect the whole situation, while the peripheral fluid affects only the peripheral areas. It is therefore desirable to achieve uniform distribution of internal heat transfer by reasonably distributing the amount of capillary capacity of the different capillary members. Through experiments, the capillary capacity of the central capillary element and the peripheral capillary elements is related to two key factors, wherein one factor is related to the distance between the peripheral capillary elements and the circle center of the heat collecting area and the diameter of the heat collecting area. The invention thus optimizes the optimal proportional distribution of capillary forces according to a large number of numerical simulations and experiments.

F2/F1 ═ a-b ═ Ln (K/M); ln is a logarithmic function;

a, b are coefficients, wherein 1.5599< a <1.5605,0.4358< b < 0.4364;

preferably, 1.23< K/M < 2.05;

preferably, 1.2< F2/F1< 1.5.

Wherein 40 ° < a <100 °.

Preferably, the number of the four sides is 4-8; preferably 4-5.

Preferably, K is 1500-; m is 756-1260 mm, preferably 800 mm.

More preferably, a is 1.5602 and b is 0.4361.

Preferably, the auxiliary heating device 23 is arranged on the lower wall surface of the heat collecting region, the flow meter 108 is arranged on the pipeline of the evaporation end flowing to the condensation end to test the steam flow, and the auxiliary heating device adjusts the auxiliary heating device to heat according to the tested steam flow. Through setting up auxiliary heating device, set up it on capillary part below pipe wall, the liquid in the liquid heating channel, can improve capillary heat absorption ability on the one hand, on the other hand also can avoid the not enough condition of solar energy collection ability under the special circumstances (for example evening or illumination intensity is little).

Preferably, the heating means is activated to heat when the wicking capacity of the capillary element is insufficient, for example, the capillary liquid has a working capacity exceeding a rated working life, or in the case of sufficient sunlight, the vapor flow is significantly insufficient.

The working capacity of the capillary element can be indirectly improved by heating so that the temperature of the liquid in the liquid space is increased.

Preferably, the condensation end is disposed in the water tank.

Preferably, the inlet and the outlet of the heat collector are provided with pressure sensors for detecting the pressure of the inlet and the pressure of the outlet.

Preferably, the upper wall of the liquid storage region and the support member are of an integral structure, as shown in fig. 3.

The invention also provides an experimental device for testing and researching the experimental capacity of the loop heat pipe solar thermal collector, which can be used by the invention, as shown in fig. 4-7. The experimental device comprises a loop heat pipe, the loop heat pipe comprises a heat collector experimental area unit (namely an evaporation end) and a collection measuring unit (a measuring and condensing end), the water is evaporated in the heat collector experimental area unit, and then the steam flow is measured and condensed in the collection measuring unit; the device also comprises a water supply unit, a blowing unit, a vacuumizing unit and a PLC unit, wherein the water supply unit is connected with the heat collector experiment area unit and supplies water to the heat collector experiment area unit, and the vacuumizing unit is connected with the whole system pipeline and is used for vacuumizing the interior of the experiment device pipeline; the collecting and measuring unit collects and measures the mass flow of the steam, condenses and collects condensed water; under the action of the blowing unit, residual water vapor in the pipeline is fully liquefied and collected by the collecting and measuring unit; and the PLC unit acquires and outputs mass flow data.

The experimental setup is further described below:

as shown in fig. 4, the inside of the thin film evaporation tester is formed by connecting seven parts of an experimental area unit (evaporation end), a water supply unit, a collection measurement unit, an air blowing unit, a vacuumizing unit, a PLC system installation unit and an auxiliary system and pipelines, wherein the pipeline is preferably 1/4 inches, an inlet of the experimental area unit is connected with the water supply unit, the vacuumizing unit is connected with the water supply unit, an outlet of the experimental area unit is connected with the air blowing unit through a three-way pipe between a third electromagnetic valve 6 and a fifth electromagnetic valve 7, one side of the outlet is connected with the air blowing unit, the other side of the outlet is connected with the collection measurement unit, the PLC system installation unit is located inside a box body 32, and the auxiliary system is composed. The experiment area unit provides the test condition for the film, and the water supply unit provides stable water supply for the experiment area unit, collects the accurate test steam mass flow of measuring unit and condenses and collect liquid water, and the evacuation unit provides the vacuum environment, and PLC system installation unit installation PLC control system, each unit of auxiliary system fixing provides independent experimental space.

In the experimental process, deionized water is conveyed to the experimental area unit through the water supply unit, the energy absorbed on the surface of the film is converted into a gas state from a liquid state, the gas state is liquefied and collected after the mass flow is measured through the collection test unit, and the residual water vapor in the pipeline is fully liquefied and collected after the mass flow is measured under the action of the air blowing unit connected with the vacuumizing unit and is collected by the collection test unit. And after the experiment is finished, comparing and collecting the data of the measuring unit and obtaining a test result.

As shown in fig. 4, the present embodiment is an overall structure of the apparatus. In the embodiment, an experimental area 1 is arranged at the upper part of a box body, a first pressure sensor 2 is arranged at one side of the experimental area, a second pressure sensor 8 is arranged at the other side of the experimental area, a first electromagnetic valve 9 is arranged on a connecting pipeline between a water inlet 19 and a pressure water tank 11, a sixth electromagnetic valve 10 and the second pressure sensor 8 are sequentially arranged on the connecting pipeline between the pressure water tank 11 and the experimental area 1, the water inlet 19, the first electromagnetic valve 9, the pressure water tank 11, the sixth electromagnetic valve 10, the second pressure sensor 8 and the first pressure sensor 2 form a water supply unit, the first pressure sensor 2 is arranged at the other side of the experimental area 1 and is connected with an air blowing unit through a three-way pipe between a pressure vacuum sensor 3 and a fifth electromagnetic valve 7, an external vacuum pump is connected with a device through a three-way pipe between the fourth electromagnetic valve 18 and the fifth electromagnetic valve 7, a pressure vacuum sensor 3 is arranged on a pipeline between a second electromagnetic valve 4 and a fifth electromagnetic valve 7, the pressure vacuum sensor 3, a third electromagnetic valve 6 and the fifth electromagnetic valve 7 form a vacuum pumping unit, one side of a drying pipe 5 is connected with an external blower, the other side of the drying pipe is connected with a pipeline at the side of the pressure vacuum sensor 3, the second electromagnetic valve 4 is arranged between the second electromagnetic valve 4 and the pressure vacuum sensor 3, the drying pipe 5 and the second electromagnetic valve 4 form a blowing unit, a fourth electromagnetic valve 18 and a mass flow meter 17 are sequentially arranged on a pipeline between a three-way pipe between the fifth electromagnetic valve 7 and the third electromagnetic valve 6 and a condenser 12, one side of an active carbon collecting device 15 is connected with the condenser 12 through a first VCR joint 16, the other side of the active carbon collecting device is connected with the outside through a second VCR joint 14, a seventh electromagnetic valve 13 is arranged on a pipeline connected with the outside through the second, The mass flow meter 17, the condenser 12, the first VCR joint 16, the activated carbon collecting device 15, the second VCR joint 14 and the seventh solenoid valve 13 constitute a collecting and measuring unit. Wherein, the first pressure sensor 2 measures the pressure at the water outlet of the experimental area 1, the second pressure sensor 8 measures the pressure at the water inlet of the experimental area 1, the first electromagnetic valve 9 controls the water supply unit to supply water, the pressure water tank 11 stores deionized water and ensures the stable water supply of the experimental area 1, the sixth electromagnetic valve 10 controls the water supply of the experimental area, the fifth electromagnetic valve 7 controls the communication between the experimental area 1 and the blowing unit, the second electromagnetic valve 4 controls the start and stop of the blowing unit, the drying tube 5 ensures the dryness of the blowing gas, the third electromagnetic valve 6 controls the start and stop of the vacuumizing unit, the pressure vacuum sensor 3 measures and outputs the internal vacuum degree of the pipeline, the fourth electromagnetic valve 18 controls the communication between the collecting and measuring unit and the experimental area 1, the mass flow meter 17 measures and outputs the mass flow of water vapor, the condenser 12 realizes the liquefaction of the water vapor, the first VCR joint 16 and the second VCR joint 14 realize, the activated carbon collecting device 15 collects liquid water.

Deionized water is introduced from the water inlet 19, flows through the first electromagnetic valve 9, the pressure water tank 11, the sixth electromagnetic valve 10 and the second pressure sensor 8, is evaporated into steam in the experimental area 1, and then is cooled and liquefied at the condenser 12 through the first pressure sensor 2, the fifth pressure sensor 7, the fourth electromagnetic valve 18 and the mass flow meter 17, and is collected at the activated carbon collecting device 15 through the first VCR connector 16, so that the process from evaporation to liquefaction of water is realized.

Moreover, by collecting real-time data of the gas mass flowmeter 17 in the measurement unit and a high-speed camera (optional, not shown) arranged above the experimental area 1, the system can monitor and output the evaporation rate change condition of the whole heating process and the evaporation characteristics of water above the film 25 in real time, thereby improving the test efficiency and facilitating subsequent analysis and treatment, and making it possible to accurately analyze the evaporation characteristic curve.

In addition, the outer wall of the pipeline sequentially connected with the experimental area 1, the first pressure sensor 2, the fifth electromagnetic valve 7, the fourth electromagnetic valve 18, the mass flow meter 17 and the condenser 12 is attached with a heat insulation layer, so that the temperature in the pipeline is kept above the liquefaction temperature of the water vapor, and the influence on the data accuracy caused by the premature cold liquefaction of the water vapor in the experimental area 1 before the water vapor passes through the mass flow meter 17 is prevented.

As shown in fig. 4, the experimental unit 1 is composed of a cover 20, a transparent cover 21, preferably a high-transmittance quartz glass plate, a heating module 23, a capillary member 24, filter paper and a membrane 25, and a housing 26. The shell 26 is formed by welding after being processed into two parts, a circular thin film 25 placing area and a semi-cylindrical liquid storage area 28 are formed, a hole is formed in the shell 26 below the thin film 25 and communicated with the liquid storage area 28, and the shell 26 is fastened on the upper surface of the box body 32 through bolts; the module is fixed with a glass cover component, the cavity of the module is composed of a shell 26 and a gland 20, the cavity of the module contains an opaque quartz glass filter paper pressing piece 29 for fixing a film 25, and the top of the module is a high-light-transmittance glass plate 21 fastened by a sunk screw for transmitting light and observing the evaporation condition of water vapor in real time; the round heating module 23 is installed at the bottom of the experimental zone 1 and fixed together with the housing 26.

In addition, the evaporation performance of the capillary parts under different film surface areas, different illumination conditions and different temperature conditions can be tested by changing the number of the capillary parts 24 in the experimental area, the power of the solar simulator (external) and the power of the heating module 23, and the testable data range is expanded.

As shown in fig. 6, the water supply unit is composed of, in order: the device consists of a water inlet pipe connector 19, a first electromagnetic valve 9, a pressure water tank 11, a sixth electromagnetic valve 10, a second pressure sensor 8 and a first pressure sensor 2 which are led to the outside of a box body from outside, wherein the front five parts are connected by 1/4-inch water inlet pipelines in pairs, the rear two parts are respectively arranged on pipelines at two sides of an experimental area 1, and all joint joints adopt 1/4-inch high-purity gas joints. First solenoid valve 9 control pressure water tank 11 and water inlet 19's pipeline UNICOM, sixth solenoid valve control pressure water tank 11 and the pipeline UNICOM of experiment area 1, first pressure sensor 2 detects 1 both sides pipeline pressure in experiment area respectively with second pressure sensor 8, the pressure data transmission to control system that second pressure sensor 8 will collect simultaneously, and then control pressure water tank 11's the function of supplying water, the pressure data transmission to the display interface that first pressure sensor 2 will collect, thereby carry out real-time supervision to the experimental conditions.

As shown in fig. 7, the collection and measurement unit is composed of a fourth electromagnetic valve 18, a mass flow meter 17, a condenser 12 and an activated carbon collection device 15 in sequence, the whole is connected through an 1/4-inch pipeline, and all joints adopt 1/4-inch high-purity gas joints. The fourth electromagnetic valve 18 is arranged on a pipeline between a water inlet 30 of the measuring unit and the mass flow meter 17, the mass flow meter is communicated with the condenser 12 and is responsible for detecting the mass flow of gas flowing through the pipeline, a cooling module main pipeline contained in the condenser 12 is spirally arranged in a cylinder of the condenser 12, and cooling water enters and exits from the condenser to ensure that the gas is fully liquefied; first VCR connects 16 and connects active carbon collection device 15 and condenser 12, and second VCR connects 13 and connects active carbon collection device 15 and seventh solenoid valve 13, adopts the VCR to connect and can guarantee the inside seal of pipeline, keeps apart the influence of external environment to pipeline experimental environment, and the input pipeline of active carbon collection device 15 lets in from the device bottom, guarantees the abundant absorption of active carbon to liquid water, and output pipeline leads out from the device top, and external seventh solenoid valve 13 that is used for carminative.

The procedure for performing the thin film evaporation test was as follows: the activated carbon absorption device 15 connected through the first VCR joint 16 and the second VCR joint 14 is detached, weighed, recorded in weight and reinstalled to ensure reliability of the comparison data; arranging a film 25 in an experimental area 1, arranging the film on filter paper 25, arranging a temperature-resistant water-absorbing capillary part 24 below the filter paper 25, continuously and stably supplying water to the film 25 through the temperature-resistant water-absorbing capillary part 24 and the filter paper 25 in a liquid storage area 28, covering a filter paper pressing part 29 on the filter paper 25, covering a stainless steel cover with a high-light-transmittance quartz glass plate 21 (used for observing the evaporation condition of water vapor in real time) and fastening the stainless steel cover by using countersunk screws, closing all electromagnetic valves, and installing an external solar simulator and a high-speed camera (optional) above the quartz glass plate 21; opening the second electromagnetic valve 4 and the fourth electromagnetic valve 18, starting a vacuum pump (external), continuously vacuumizing the pipeline and the activated carbon absorption device 15 for 10 minutes, then closing the fourth electromagnetic valve 18, opening the sixth electromagnetic valve 10, continuously vacuumizing the experiment area 1 and the water replenishing area 28 for 15 minutes, then opening the fifth electromagnetic valve 7, continuously vacuumizing the pressure water tank 11 for 30 minutes, closing the fifth electromagnetic valve 7 until the reading of the pressure vacuum sensor 3 is less than 1Pa, closing all the electromagnetic valves, and closing the vacuum pump; connecting a water inlet 19 with a deionized water tank (external), starting a first electromagnetic valve 9, enabling deionized water to enter a pressure water tank 11 (the capacity is 1L) by utilizing pressure difference, starting a sixth electromagnetic valve 10, intermittently delivering water to a water replenishing area 28 and an experimental area 1 at a time interval of 2 seconds, intermittently starting the sixth electromagnetic valve 10, observing the water level of the experimental area 1 once the sixth electromagnetic valve is started until the water level just wets a film 25, and stopping; connecting the water inlet 19 with the compressor; starting a constant-temperature water bath (external), and cooling the condenser 12; the solar simulator and the bottom heating module 23 are started to heat the film 25 (a thermocouple is arranged in an experimental area to monitor the temperature), when steam appears above the film 25, the fifth electromagnetic valve 7, the sixth electromagnetic valve 10 and the fourth electromagnetic valve 18 are sequentially started, the touch screen 33 is clicked, the time is set, the experiment is started, and the PLC records the experiment starting time; the PLC is used for controlling the start and stop of the compressor (external), so that the pressure difference between the first pressure sensor 2 and the second pressure sensor 8 is ensured to be stabilized at a proper value; after the system is stable, namely the reading of the gas mass flowmeter 17 is relatively stable, the steady evaporation rate of the film 25 can be measured; after the experiment is stopped, the PLC records the experiment stop time, closes the sixth electromagnetic valve 10, opens the third electromagnetic valve 6 and the seventh electromagnetic valve 13, connects the air compressor (external) with the drying pipe 5, opens the air compressor (external) to blow dry air into the pipeline, and makes the water in the pipeline fully absorbed by the activated carbon absorption device 15; the activated carbon absorption device 15 is detached and weighed again to obtain the evaporated water volume of the whole experiment, and the evaporated water volume is subjected to auxiliary comparison analysis with the data obtained by the mass flow meter 17 to increase the reliability of the data.

Preferably, the membrane may be eliminated and the capillary member 24 tested for performance without the membrane.

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.

Claims

1. A solar heat collector comprises a loop heat pipe, wherein the loop heat pipe comprises an evaporation end and a condensation end, the evaporation end absorbs solar energy to form the solar heat collector, the evaporation end is of a flat plate structure and comprises a heat collection area, the heat collection area comprises a transparent cover plate, a support plate, a capillary component, a first space and a second space, the transparent cover plate is arranged at the upper part, the second space is arranged at the upper part, the first space is arranged at the lower part, a separation component of the first space and the second space comprises a circular support plate, a through hole is formed in the support plate, the capillary component is arranged in the through hole, the through hole comprises a circle center through hole arranged at the circle center of the support plate and an annular through hole annularly arranged around the circle center, and therefore a central capillary component at the circle center and a peripheral capillary component arranged around the circle; each through hole is provided with a lens on the corresponding transparent cover plate correspondingly, and the through holes are positioned on the focus of the corresponding lenses.

2. A solar collector according to claim 1, wherein the capillary force of the central capillary element is greater than the capillary force of the surrounding capillary elements.

3. The solar collector of claim 1, wherein the peripheral capillary members are of a one-layer structure, the radius of the inner wall of the heat collecting region is K, the center of the central capillary member is arranged at the center of the heat collecting region, the distance between the center of the peripheral capillary member and the center of the heat collecting region is M, the centers of adjacent peripheral capillary members are respectively connected with the center of the heat collecting region, the included angle formed by the two connected lines is a, the capillary force of a single peripheral capillary member is F1, and the capillary force of a single central capillary member is F2, so that the following requirements are met:

F2/F1 ═ a-b ═ Ln (K/M); ln is a logarithmic function;

a, b are coefficients, wherein 1.5599< a <1.5605,0.4358< b < 0.4364;

1.23<K/M<2.05；

1.2<F2/F1<1.5；

wherein 40 ° < a <100 °.

4. A solar collector as claimed in claim 3, wherein the number of surrounding capillary elements is 4-8.

5. A solar collector as claimed in claim 3, wherein K is 1500-; m is 756 and 1260 mm.

6. A solar collector as claimed in claim 3, wherein a-1.5602 and b-0.4361.