Disclosure of Invention
Aiming at the problems, the invention is improved on the basis of the prior invention, and provides a novel heat collecting pipe with a heat pipe structure so as to realize the full utilization of solar energy.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a solar heat collector system comprises a heat collector and a radiator, wherein the heat collector is communicated with the radiator to form a circulation loop, the heat collector absorbs solar energy, and heated water enters the radiator through an outlet pipe and exchanges heat in the radiator;
the solar heat collection system is also provided with a bypass pipeline connected with the radiator pipeline in parallel, and the bypass pipeline is provided with a second valve and a second temperature sensor which are respectively used for controlling the flow of water on the bypass pipeline and detecting the temperature of the water; the radiator is arranged indoors, and a third temperature sensor is arranged indoors and used for detecting the indoor temperature; the first valve, the second valve, the first temperature sensor, the second temperature sensor and the third temperature sensor are in data connection with the central controller;
a temperature sensor is arranged in the heat collecting pipe and used for detecting the temperature of water in the heat collecting pipe, and the temperature sensor is in data connection with the central controller;
a third valve is arranged on an outlet pipe of the heat collector and is in data connection with the central controller;
the central controller automatically controls the opening and closing of the first valve, the second valve and the third valve according to the detected temperature of the radiator inlet pipe, the detected temperature of the collector pipe water and the detected temperature of the bypass pipeline.
Preferably, if the temperature of the radiator inlet pipe detected by the central controller is lower than the indoor temperature of the radiator, the central controller automatically closes the first valve and the third valve and opens the second valve; the water in the heat collecting pipe is continuously heated by solar energy, when the water temperature in the heat collecting pipe exceeds a certain indoor temperature value, the third valve is opened, the water flows through the bypass pipeline, if the water temperature detected by the bypass pipeline sensor exceeds a certain indoor temperature value, the second valve is closed, the first valve is opened, and therefore the water enters the radiator to be radiated.
Preferably, the bottom of the lower end of the heat pipe is the inner wall of the heat collecting pipe.
Preferably, a communication pipe is provided between at least two adjacent heat pipes.
Preferably, the center of the heat collecting tube is located at the focal position of the reflector.
Preferably, the bottom of the heat collecting pipe is provided with a header, and the lower part of the heat pipe is communicated with the header.
Preferably, the lower wall surface of the header is a surface of the bottom of the heat collecting pipe.
The external diameter of the heat pipe is d, the distance between the circle centers of the adjacent heat pipes in the same row is S, the circle center of each heat pipe and the circle centers of the adjacent two heat pipes in the adjacent row form an isosceles triangle, and the vertex angle of the isosceles triangle is A, so that the following requirements are met:
Sin(A)=a*(d/S)3-b*(d/S)2+ c (d/S) + e, where a, b, c, e are parameters, satisfying the following requirements:
8.20<a<8.22,6.19<b<6.21;0.062<c<0.063,0.83<e<0.84,0.12<d/S<0.55。
preferably, a is 8.21, b is 6.20, c is 0.0625, and d is 0.835;
preferably, the heat collecting pipes are multiple, and the multiple heat collecting pipes are in parallel connection.
Preferably, the heat collecting pipes are multiple, and the multiple heat collecting pipes are of a series-parallel mixed structure.
Compared with the prior art, the invention has the following advantages:
1) the invention provides an intelligent control solar heat collecting pipe, wherein a central controller automatically controls the opening and closing of a first valve, a second valve and a third valve of a valve according to the detected temperature of a radiator inlet pipe, the detected temperature of heat collector pipe water and the detected temperature of a bypass pipeline, so that the intelligent detection and control of a solar heat radiating system are realized.
2) The solar heat collecting tube is improved, and the heat tube is arranged at the bottom of the heat collecting tube, so that solar energy is quickly transmitted to the upper part of the heat collecting tube through the characteristic of high heat transmission speed of the heat tube, the heat transmission speed of the solar energy is improved, and the heat absorption capacity can be further met.
3) The communicating pipe is arranged between the adjacent heat pipes, so that uneven heating between the heat pipes can be avoided, pressure balance between the heat pipes is realized, and the defect caused by uneven heating between different heat pipes is avoided.
4) The invention can ensure that the pressure is balanced as soon as possible in the flowing process of the fluid through the distribution quantity of the communicating pipes and the change rule of the pipe diameters.
5) A large amount of numerical simulation and experimental research are carried out on the distribution rule of the heat pipes, and the optimal relational expression of the heat pipe distribution is summarized on the basis of the research.
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.
Fig. 1 discloses a solar energy system comprising a solar collector 5, which absorbs solar energy, heats a fluid flowing therethrough, and then the fluid enters a heat utilization device for utilization, and a heat utilization device 4.
As disclosed in fig. 2-5, the trough-type solar collector 5 using heat pipes, the collector 5 includes a reflector 1 and a heat collecting pipe 2, the heat collecting pipe 2 is located at a focal position of the reflector 1, the reflector 1 reflects solar energy to the heat collecting pipe 2 for heating water in the heat collecting pipe 2, the heat collecting pipe further includes a heat pipe 3 disposed in the heat collecting pipe 2, as shown in fig. 2, the heat pipe 3 is disposed inside the heat collecting pipe 2 and extends upward from the bottom of the heat collecting pipe 2, the heat pipes 3 are multiple, and the bottom of the lower end of the heat pipe is connected to the inner wall of the heat collecting pipe.
The traditional solar heat collecting pipe directly irradiates the heat collecting pipe through sunlight to generate steam, and the convection heat exchange inside the heat collecting pipe is utilized to carry out fluid convection heat exchange on the upper part and the lower part of the heat collecting pipe, but in the case, the lower part of hot fluid is required to naturally convect to the upper part, so that the heat exchange efficiency is low.
Preferably, the bottom of the lower end of the heat pipe 3 is the inner wall of the heat collecting pipe 2. Thus, the heat pipe and the heat collecting pipe can be taken as a whole, the inner wall of the heat collecting pipe is taken as the lower end wall surface of the heat pipe, the contact thermal resistance is reduced, the integral structure is compact,
Preferably, the heat collecting tube and the heat pipe are integrally manufactured.
Preferably, the communication pipe 6 is provided between at least two adjacent heat pipes 3. For example, as shown in fig. 3, a communication pipe 6 is provided between two heat pipes 3 adjacent to each other. Of course, FIG. 3 is merely a schematic illustration and, while only two heat pipes are shown, it is not intended to indicate only two heat pipes. By arranging the communicating pipe 6, uneven heating between the heat pipes 3 can be avoided, pressure balance between the heat pipes is realized, and the defect caused by uneven heating between different heat pipes is avoided.
Preferably, the distance between adjacent communication pipes 6 increases from the lower portion of heat pipe 3 to the upper portion of heat pipe 3. Because the heat pipe absorbs solar energy at the bottom and then releases heat in the heat collecting pipe. The fluid continuously releases heat along with the upward flow of the vertical part of the fluid of the heat pipe, and the pressure in different heat pipes is gradually reduced along with the continuous heat release of the fluid, so that the pressure balance can be ensured to be achieved as soon as possible in the flowing process of the fluid, the number of communicating pipes is saved, and materials are saved.
Preferably, the distance between adjacent communication pipes 6 increases from the lower portion of heat pipe 3 to the upper portion of heat pipe 3 to a larger extent. Experiments show that the arrangement can ensure that the pressure balance is achieved more optimally and more quickly in the fluid flowing process. This is also the best way of communicating by extensively studying the law of change of the pressure distribution.
Preferably, the diameter of communication pipe 6 is reduced from the lower portion of heat pipe 3 to the upper portion of heat pipe 3. The purpose is to ensure a larger communication area, because the fluid continuously releases heat along with the upward flow of the fluid, and the pressure in different heat pipes is smaller and smaller along with the continuous heat release of the fluid, so that the pressure balance can be ensured to be achieved as soon as possible in the flowing process of the fluid through the arrangement.
Preferably, the diameter of communication pipe 6 decreases from the lower portion of heat pipe 3 to the upper portion of heat pipe 3 to a larger extent. Experiments show that the arrangement can ensure that the pressure balance is achieved more optimally and more quickly in the fluid flowing process. This is also the best way of communicating by extensively studying the law of change of the pressure distribution.
Preferably, the center of the heat collecting tube is located at the focal position of the reflector. The center of the heat collecting tube is positioned at the focal position of the reflector, so that the heat collecting tube can be uniformly heated in all directions.
Preferably, the liquid medicine flows through the heat collecting pipe. The heat collecting pipe is a heat collecting pipe with a liquid medicine heating function.
Preferably, the heat collecting pipes 2 are multiple, and the multiple heat collecting pipes are in a series structure.
Preferably, as shown in fig. 5, the plurality of heat collecting pipes are in a series-parallel mixed structure.
The heat pipes are multiple, and the distribution density of the heat pipes is smaller and smaller along the central line of the bottom of the heat collecting pipe towards the two sides. In numerical simulation and experiments, the heat pipes are heated less and less along the radial direction from the center of the bottom of the heat collecting pipe to the outside, and the temperatures of the heat pipes at different positions are different, so that local heating is not uniform. Because the closer to the center, the more the focused solar energy is, the larger the heat receiving amount is, and the heat exchange capacity is also increased, therefore, the density of the heat pipes arranged at different positions of the bottom of the heat collecting pipe is different, so that the temperature of the whole heat pipe is kept basically the same, the whole heat exchange efficiency is improved, the material is saved, the local damage caused by uneven temperature is avoided, and the service life of the heat pipe is prolonged.
Preferably, the distribution density of the heat pipes is continuously increased in a smaller and smaller range along the radial direction from the center of the bottom of the heat collecting pipe to the outside. As the change of the distribution density of the heat pipe, the invention carries out a large number of numerical simulations and experiments, thereby obtaining the change rule of the distribution density of the heat pipe. Through the change rule, materials can be saved, and meanwhile, the heat exchange efficiency can be improved by about 9%.
Preferably, the diameter and length of each heat pipe 3 are the same.
Preferably, the heat pipes 3 are multiple, and the pipe diameters of the heat pipes are smaller and smaller along the central line of the bottom of the heat collecting pipe towards the two sides. The specific reason is the same as the reason of the distribution density of the heat pipes in the foregoing.
Preferably, the pipe diameter of the heat pipe is gradually increased in a smaller and smaller range along the central line of the bottom of the heat collecting pipe towards the two sides. The specific reason is the same as the reason of the distribution density of the heat pipes in the foregoing.
Preferably, the distribution density and the length of all the heat pipes 3 are the same.
The heat pipes 3 are multiple, and the distribution density of the heat pipes is increased along the flowing direction of fluid in the heat collecting pipes. In numerical simulation and experiments, the temperature of the fluid is higher and higher along the flowing direction of the fluid, so that the heat absorption capacity of the fluid is gradually reduced, the heat dissipation capacity of the heat pipe is gradually reduced, and the temperature of the heat pipe at different positions is different, thereby causing local uneven heating. The density of the heat pipes is different at different positions of the heat collecting pipe, so that the heat release capacity of the heat pipes is continuously reduced along the flowing direction of the fluid, and the heat is dispersed by distributing more heat pipes, so that the temperature of the whole heat pipes is kept basically the same, the whole heat exchange efficiency is improved, materials are saved, local damage caused by uneven temperature is avoided, and the service life of the heat pipes is prolonged.
Preferably, along the flowing direction of the fluid in the heat collecting pipe, the distribution density of the heat pipe is continuously increased with a larger and larger amplitude. As the change of the distribution density of the heat pipe, the invention carries out a large number of numerical simulations and experiments, thereby obtaining the change rule of the distribution density of the heat pipe. Through the change rule, materials can be saved, and meanwhile, the heat exchange efficiency can be improved by about 9%.
Preferably, the diameter and length of each heat pipe 3 are the same.
Preferably, the length of the heat collecting pipe is C, and the density of the heat pipe at the most front end along the flow direction of the heat collecting pipe fluid is MTailThen, the density M of the heat pipe at a distance of l from the foremost end of the heat pipe is as follows: m ═ b ═ MTail+c*MTail*(l/C)aWherein a, b and c are coefficients, and the following requirements are met:
1.075<a<1.119,0.94<b+c<0.99,0.465<b<0.548。
preferably, a gradually decreases as l/C increases.
Preferably, 1.09< a <1.11, b + c ═ 0.99, 0.503< b < 0.508;
the optimized formula is obtained through a large number of experiments and numerical simulation, the distribution density of the heat pipes can achieve optimized distribution, the heat distribution can be uniform on the whole, the heat exchange effect is good, and meanwhile materials can be saved.
Preferably, the number of the heat pipes is multiple, and the pipe diameter of each heat pipe is larger and larger along the flowing direction of the fluid in the heat collecting pipe.
Preferably, the pipe diameter of the heat pipe is continuously increased in a smaller and smaller range along the flowing direction of the fluid in the heat collecting pipe. See the heat pipe density variations for specific reasons.
Preferably, the distribution density and length of all heat pipes are the same.
Along the flowing direction of the flue gas, the length of the heat collecting pipe is C, and along the flowing direction of the flue gas, the pipe diameter of the heat pipe at the foremost end of the heat collecting pipe is DTailThen, the rule of the pipe diameter D of the heat pipe at the position l away from the tail of the heat pipe is as follows:
D2=b*(Dtail)2+c*(DTail)2*(l/C)aWherein a, b and c are coefficients, and the following requirements are met:
1.085<a<1.125,0.985<b+c<1.015,0.485<b<0.645。
preferably, a gradually decreases as l/C increases.
Preferably, 1.093< a <1.106, b + c ═ 1, 0.548< b < 0.573;
the optimized formula is obtained through a large number of experiments and numerical simulation, the distribution density of the heat pipes can achieve optimized distribution, the heat distribution can be uniform on the whole, the heat exchange effect is good, and meanwhile materials can be saved.
Preferably, the heat pipes 3 are multiple, and the distribution density of the communicating pipes is increased along the flowing direction of the fluid in the heat collecting pipe. In numerical simulation and experiments, the temperature of the fluid is higher and higher along the flowing direction of the fluid, so that the heat absorption capacity of the fluid is gradually reduced, the heat dissipation capacity of the heat pipe is gradually reduced, and the temperature of the heat pipe at different positions is different, thereby causing local uneven heating. The density of the communicating pipes is different at different positions of the heat collecting pipe, so that the heat release capacity of the heat pipe is continuously reduced along the fluid flowing direction, and the pressure is dispersed by distributing more communicating pipes, so that the temperature of the whole heat pipe is kept basically the same, the whole heat exchange efficiency is improved, materials are saved, local damage caused by uneven temperature is avoided, and the service life of the heat pipe is prolonged.
Preferably, along the flowing direction of the fluid in the heat collecting tube, the distribution density of the communicating tube is continuously increased in a larger and larger range. As the change of the distribution density of the communicating pipe, the invention carries out a large number of numerical simulations and experiments, thereby obtaining the change rule of the distribution density of the heat pipe. Through the change rule, materials can be saved, and meanwhile, the heat exchange efficiency can be improved by about 9%.
Preferably, the diameter and the length of each communication pipe are the same.
Preferably, the heat pipes 3 are multiple, and the diameter of the communicating pipe is larger and larger along the flowing direction of the fluid in the heat collecting pipe. In numerical simulation and experiments, the temperature of the fluid is higher and higher along the flowing direction of the fluid, so that the heat absorption capacity of the fluid is gradually reduced, the heat dissipation capacity of the heat pipe is gradually reduced, and the temperature of the heat pipe at different positions is different, thereby causing local uneven heating. The heat collecting pipe has the advantages that the diameters of the communicating pipes are different at different positions of the heat collecting pipe, so that the heat releasing capacity of the heat pipe is continuously reduced along the flowing direction of fluid, and the heat is dispersed by distributing more communicating pipes, so that the temperature of the whole heat pipe is kept basically the same, the whole heat exchange efficiency is improved, materials are saved, local damage caused by uneven temperature is avoided, and the service life of the heat pipe is prolonged.
Preferably, the diameter of the communicating pipe is increased along the flowing direction of the fluid in the heat collecting pipe. As the change of the diameter of the communicating pipe, the invention carries out a large number of numerical simulations and experiments, thereby obtaining the change rule of the distribution density of the heat pipe. Through the change rule, materials can be saved, and meanwhile, the heat exchange efficiency can be improved by about 9%.
Preferably, the distribution density of the communication pipes is the same as the length of each communication pipe.
Preferably, as shown in fig. 4, the heat pipes are arranged in a plurality of rows, viewed from the top downwards, or in horizontal projection, wherein two adjacent rows are arranged in a staggered manner; the circle centers of the heat pipes and the circle centers of the two adjacent heat pipes in the adjacent row form an isosceles triangle, and the circle centers of the heat pipes are located at the points of the vertex angles of the isosceles triangle.
Through numerical simulation and experiment, it is found that the distance between the heat pipes 3, including the distance between the same row and the distance between the adjacent rows can not be too small, the undersize can lead to the heat pipe to distribute too much, lead to the heat absorption capacity of every heat pipe not enough, too big can lead to the heat pipe to distribute too little, lead to the heat pipe overheated, consequently this application summarizes out the distribution of the optimization that the heat pipe 3 distributes through a large amount of numerical simulation and experiments for the heat pipe can neither the heat absorption capacity not enough, can not the heat absorption capacity too big again.
As shown in fig. 4, when the heat pipe is viewed from the top downwards, or in the horizontal plane projection, the outer diameter of the heat pipe is d, the distance between the centers of adjacent heat pipes in the same row is S, the vertex angle of the isosceles triangle formed by the center of the heat pipe and the centers of two adjacent heat pipes in the adjacent row is a, and the following requirements are met:
Sin(A)=a*(d/S)3-b*(d/S)2+ c (d/S) + e, where a, b, c, e are parameters, satisfying the following requirements:
8.20<a<8.22,6.19<b<6.21;0.062<c<0.063,0.83<e<0.84,0.12<d/S<0.55。
preferably, a is 8.21, b is 6.20, c is 0.0625, and d is 0.835;
preferably, as d/S is gradually decreased, a is larger, b is smaller, c is larger, and e is larger.
Preferably, 15 ° < a <80 °.
Further preferably, 20 ° < a <40 °.
Further preferably, 0.3< d/S < 0.5.
Preferably, along the flowing direction of the fluid in the heat collecting tube, a is larger, b is smaller, c is larger, and e is larger.
The above empirical formula is obtained through a large number of numerical simulations and experiments, and takes the form of a 3 rd order polynomial. The structure obtained by the relational expression can further realize the optimized heat pipe structure, and the error is basically within 2.5 percent through experimental verification, so that the error is further reduced.
Preferably, the tube diameter of the heat collecting tube is 400-600 mm, and more preferably 500 mm.
The outer diameter d of the heat pipe is 9 to 12 mm, and more preferably 11 mm.
Further preferably, as shown in fig. 6, the improved solar system includes a heat collector 5 and a heat utilization device 4, the heat collector includes a heat collection pipe 2, the heat collection pipe 2 is communicated with the heat utilization device 4 to form a circulation loop, the heat collection pipe 2 absorbs solar energy, heated water enters the heat utilization device 4 through an outlet pipe 8, and after heat exchange is performed in the heat utilization device 4, water flowing out of the heat utilization device 4 enters the heat collection pipe 2 through an inlet pipe 9 to be heated.
Preferably, the heat utilization device 4 is a heat sink 4.
Preferably, a valve 15 and a temperature sensor 16 are disposed on the radiator pipeline for controlling the flow rate of water entering the radiator 4 and detecting the temperature of water entering the radiator 4, and similarly, the solar heat radiation system further includes a bypass pipeline connected in parallel with the radiator pipeline, and a valve 13 and a temperature sensor 12 are disposed on the bypass pipeline for controlling the flow rate of water and detecting the temperature of water on the bypass pipeline. The radiator 4 is arranged indoors and used for indoor heating. Preferably, a temperature sensor is arranged in the room and used for detecting the temperature in the room. The valves 13, 15 and the temperature sensors 12, 16 as well as the indoor temperature sensor are in data connection with the central controller 7.
The outlet pipe 8 of the heat collector is provided with a temperature sensor 10 for detecting the water temperature on the outlet pipe 8 of the heat collector, the outlet pipe 8 of the heat collector is provided with an outlet pipe valve 11, and the temperature sensor of the outlet pipe of the heat collector, the outlet pipe valve 11 and the central controller 7 are in data connection.
A temperature sensor is arranged in the heat collecting pipe and used for detecting the water temperature in the heat collecting pipe. The temperature sensor is in data connection with a central controller 7.
The invention mainly aims to realize intelligent detection and control of a solar heat dissipation system, and the technical effects of the invention are realized through the following embodiments.
1. Example one
As a modification, the central controller 7 automatically controls the opening and closing of the valves 13, 15 based on the detected temperature in the room and the temperature of the water entering the radiator.
Preferably, during normal operation valve 15 is open and valve 13 is closed.
If the temperature in the room is higher than the temperature of the water entering the radiator, the central controller 7 automatically controls the valve 15 to close, while the valve 13 is open. It is ensured that water does not enter the radiator, because if water enters the radiator 4 at this time, not only the radiating effect is not achieved, but also the heat in the room is transferred to water, thereby reducing the radiating effect. Energy can thus be saved by this measure.
If the water temperature detected by the bypass pipeline temperature sensor 12 is higher than the indoor temperature, the central controller automatically controls the valve 15 to be opened and the valve 13 to be closed, so that the water can enter the radiator 4, and the radiating effect is achieved.
Preferably, a plurality of temperature sensors 16 are arranged on the radiator pipeline inlet pipe, and the temperature of the water on the radiator pipeline inlet pipe is measured through the plurality of temperature sensors 16.
Preferably, the central controller 7 controls the opening and closing of the valves 13 and 15 by an average value of the temperatures of the water measured by the plurality of temperature sensors 16.
Preferably, the central controller 7 controls the opening and closing of the valves 13 and 15 by the lowest value of the water temperature measured by the plurality of temperature sensors 16. By taking the lowest value, further accuracy of the data is enabled.
Preferably, said at least one temperature sensor is arranged in the radiator inlet pipe close to the radiator 4.
Preferably, the junction of the bypass line and the radiator line is located adjacent the radiator inlet. This avoids storing too much cold water on the radiator pipe that was stored when the valve 15 was last closed.
2. Example two
As a modification, the central controller 7 automatically controls the opening and closing of the valves 13 and 15 according to the detected temperature of the inlet pipe of the radiator 4, the temperature of the water at the outlet pipe of the heat collector and the temperature of the bypass pipeline.
If the central controller 7 detects that the radiator inlet pipe temperature is lower than the radiator chamber temperature, the central controller 7 automatically closes the valve 15 and opens the valve 13. Opening valve 13 ensures that water located between valves 11 and 15 can be recirculated through the bypass line to the collector for further heating, while water between valves 13, 15 which does not meet the temperature requirements is evacuated. Water in the heat collecting pipe 2 continues to be heated by solar energy, when the water temperature in the outlet pipe of the heat collector exceeds a certain value of indoor temperature, preferably more than 10 ℃, the valve 15 is opened, and the valve 13 is closed, so that water enters the radiator to dissipate heat.
Through the measures, the intelligent control of the heat dissipation of the radiator can be realized.
Preferably, the valve 11 is arranged on the collector outlet pipe close to the collector. This results in substantially no cold water being stored in the outlet line 17, ensuring a heat sink effect.
Preferably, a plurality of temperature sensors are arranged in the outlet position or the outlet header of the heat collector, and the temperature of the water is measured by the plurality of temperature sensors.
Preferably, a temperature sensor is arranged at the position of the outlet header of the heat collecting pipe 2, and the temperature of the water is measured by the temperature sensor.
Preferably, the central controller 7 controls the opening and closing of the valves 11, 13, 15 by an average value of the temperatures of the water measured by the plurality of temperature sensors.
Preferably, the central controller 7 controls the opening and closing of the valves 11, 13, 15 by the lowest value of the water temperature measured by the plurality of temperature sensors. By adopting the lowest value, the temperature of the water at all positions in the heat collecting pipe 2 can be ensured to reach the available temperature.
Preferably, the at least one temperature sensor is arranged in the heat collecting pipe 2 at a position close to the heat collector inlet pipe 9.
Preferably, the at least one temperature sensor is arranged in the heat collecting pipe 2 close to the outlet pipe 8 of the heat collector.
Preferably, the junction of the bypass line and the radiator line is located adjacent the radiator inlet. This avoids storing too much cold water on the radiator pipe that was stored when the valve 15 was last closed.
3. EXAMPLE III