A solar thermal collection system

Abstract

The present invention provides a solar thermal collection system, which includes a main pipeline, and a first branch pipeline and a second branch pipeline arranged in parallel with the main pipeline, a plurality of heat accumulators arranged in parallel are arranged on the first branch pipeline, a heat accumulator valve is arranged on each heat accumulator inlet pipeline, a heat exchanger is arranged on the second branch pipeline, a heat exchanger valve is arranged on the second branch pipeline, a main valve is arranged on the main pipeline, a temperature sensor is arranged in the heat accumulator, which is used to detect the temperature of the heat storage material in the heat accumulator, and a controller controls the opening and closing of the corresponding heat accumulator valve according to the detected temperature of the heat storage material. The present invention opens or closes the heat accumulator valve in a targeted manner according to the temperature of the heat storage material, thereby storing heat in the heat accumulator in a targeted manner, so that the heat accumulator that has completed heat storage stops storing heat in time, and the heat is used for other heat storage, thereby avoiding heat waste.

Description

Technical Field

[0001] The invention relates to a solar energy system, in particular to a solar energy heat collection system. Background Art

[0002] With the rapid development of modern social economy, human beings have an increasing demand for energy. However, the reserves of traditional energy such as coal, oil, and natural gas are constantly decreasing and becoming increasingly scarce, causing prices to continue to rise. At the same time, the environmental pollution caused by conventional fossil fuels is becoming more and more serious, which greatly restricts the development of society and the improvement of human quality of life. The energy problem has become one of the most prominent problems in the contemporary world. Therefore, seeking new energy, especially pollution-free clean energy, has become a hot topic of research.

[0003] Solar energy is an inexhaustible clean energy source with huge resources. The total amount of solar radiation energy received by the earth’s surface each year is 1×10 18 kW·h, which is more than 10,000 times the world's total annual energy consumption. However, since the energy density of solar radiation reaching the earth is low (about 1 kilowatt per square meter) and it is discontinuous, it brings certain difficulties to large-scale development and utilization. Therefore, in order to widely use solar energy, not only technical problems must be solved, but also it must be able to compete with conventional energy in terms of economy.

[0004] In applications, it is found that continuous solar heat collection and heating or no heating at night will cause the internal fluid to become stable, that is, the fluid no longer flows or has very little fluidity, or the flow rate is stable, which greatly weakens the performance of the heat collection tube, thereby affecting the heating efficiency of the heat collection tube. Therefore, it is necessary to improve the above solar heat collection device.

[0005] For the excess solar energy, the heat can be stored by heat storage, but the utilization rate of solar energy heat storage is not high at present. To solve the above problems, the present invention provides a new intelligent controlled solar energy heat storage system, which performs heat storage operation according to different situations.

[0006] In response to the above-mentioned needs, the present invention has been improved to ensure that heat storage can be performed while meeting user needs, while also intelligently controlling the heat storage process in a targeted manner. Summary of the invention

[0007] In order to achieve the above object, the technical solution of the present invention is as follows:

[0008] A solar thermal collection system, the system comprising a main pipeline, and a first branch pipeline and a second branch pipeline arranged in parallel with the main pipeline, a plurality of heat accumulators arranged in parallel are arranged on the first branch pipeline, a heat accumulator valve is arranged on the inlet pipeline of each heat accumulator, a heat exchanger is arranged on the second branch pipeline, a heat exchanger valve is arranged on the second branch pipeline, a main valve is arranged on the main pipeline, a temperature sensor is arranged in the heat accumulator, and is used to detect the temperature of the heat storage material in the heat accumulator, and a controller controls the opening and closing of the corresponding heat accumulator valve according to the detected temperature of the heat storage material.

[0009] As an improvement, when the detected temperature of the heat storage material in the heat accumulator exceeds a predetermined value, the corresponding heat accumulator valve is closed; when the detected temperature of the heat storage material in the heat accumulator is lower than a predetermined value, the corresponding heat accumulator valve is opened.

[0010] As an improvement, the controller controls a part of the heat accumulator valves to open and another part of the heat accumulator valves to close, allowing the fluid to enter the heat accumulator for heat storage; when one of the heat accumulators completes heat storage, the corresponding heat accumulator valve is closed, and the controller opens one of the other part of the heat accumulator valves for heat storage.

[0011] As an improvement, the controller controls the heat exchanger valve to open, and at the same time adjusts a part of or all of the heat accumulator valves to close, so as to ensure the operation of the heat exchanger.

[0012] As an improvement, a valve is set at the collector outlet and a temperature sensor is set in the collector to detect the temperature of the fluid heated in the heater. When the detected fluid temperature in the collector is lower than a predetermined value, the controller controls the main line valve to open, the collector outlet valve to close, the heat exchanger valve to open, and at least a part of the heat accumulator valve to open, thereby forming a loop between the heat accumulator and the heat exchanger.

[0013] As an improvement, the controller controls some of the heat accumulator valves to open and other heat accumulator valves to close; when the temperature of the heat storage material in a certain heat accumulator is detected to be lower than the set value, the corresponding heat accumulator valve is closed and one of the other heat accumulator valves is opened to store heat.

[0014] As an improvement, the heat exchanger is a shell and tube heat exchanger.

[0015] As an improvement, a baffle is provided in the tube of the heat exchanger.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The present invention provides a plurality of heat accumulators, each of which is provided with a temperature sensor for detecting the temperature of the heat storage material, and then determines the heat storage condition of the heat accumulator according to the temperature condition of the heat storage material, and opens or closes the heat accumulator valve in a targeted manner, thereby storing heat in the heat accumulator in a targeted manner, so that the heat accumulator that has completed heat storage stops storing heat in time, and the heat is used for heat storage in other heat accumulators, thereby avoiding heat waste.

[0018] The present invention opens or closes one or more heat accumulators to perform heat storage operations according to the specific heat exchange conditions of the heat exchanger, and can store heat while meeting the heat exchange requirements of the heat exchanger, thereby achieving the dual requirements of heat storage and heat exchange.

[0019] The present invention can also intelligently realize the circulation of the heat accumulator and the heat exchanger pipeline according to the heat collection situation of the solar heat collector, thereby ensuring the normal operation of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the solar energy heat collection system of the present invention. DETAILED DESCRIPTION

[0021] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0022] In this article, unless otherwise specified, “ / ” represents division, and “×” and “*” represent multiplication.

[0023] Figure 1 A solar thermal collector system is disclosed. Figure 1 As shown, the solar main line 1, the first branch line 2 and the second branch line 3 are arranged in parallel with the main line. The hot fluid flowing in the solar main line 1 comes from the fluid heated in the solar collector. The preferred fluid is water.

[0024] like Figure 1 As shown, a plurality of heat accumulators 4 arranged in parallel are arranged on the first branch pipeline 2, a heat accumulator valve 5 is arranged on the inlet pipeline of each heat accumulator 4, a heat exchanger 6 is arranged on the second branch pipeline, a heat exchanger valve 7 is arranged on the second branch pipeline, an inlet valve 8 is arranged on the inlet pipe of the main pipeline 1, an outlet valve 9 is arranged on the outlet pipe, a main valve 10 is arranged on the pipeline in parallel with the main pipeline and the first branch pipeline, a temperature sensor is arranged in the heat accumulator 4 for detecting the temperature of the heat storage material in the heat accumulator, and the controller controls the opening and closing of the corresponding heat accumulator valve 5 according to the detected temperature of the heat storage material.

[0025] Preferably, the inlet valve 8 and the outlet valve 9 are opened, and the main pipe valve 10 is closed, and the fluid enters the heat accumulator and the heat exchanger 6 at this time.

[0026] Preferably, the inlet valve 8 and the outlet valve 9 are opened, the main valve 10 is closed, and at least a portion of the heat exchanger valve 7 and the heat accumulator valve are opened, so that the fluid can enter at least a portion of the heat accumulator and the heat exchanger for heat storage or heat exchange.

[0027] As an improvement, when the temperature of the heat storage material in the detected heat accumulator exceeds a predetermined value, it indicates that the heat accumulator has completed heat storage and cannot store heat again, and the corresponding heat accumulator valve 5 is closed; when the temperature of the heat storage material in the detected heat accumulator is lower than a predetermined value, it indicates that the heat accumulator can store heat, and the corresponding heat accumulator valve is opened.

[0028] The present invention provides a plurality of heat accumulators, each of which is provided with a temperature sensor for detecting the temperature of the heat storage material, and then determines the heat storage condition of the heat accumulator according to the temperature condition of the heat storage material, and opens or closes the heat accumulator valve in a targeted manner, thereby storing heat in the heat accumulator in a targeted manner, so that the heat accumulator that has completed heat storage stops storing heat in time, and the heat is used for heat storage in other heat accumulators, thereby avoiding heat waste.

[0029] As an improvement, the controller controls a part of the heat accumulator valves to open and another part of the heat accumulator valves to close, allowing the fluid to enter a part of the heat accumulator for heat storage; when the heat storage of one of the heat accumulators is completed, the corresponding heat accumulator valve is closed, and the controller opens one of the other part of the heat accumulator valves, allowing the hot fluid to enter a heat accumulator in another part for heat storage.

[0030] The above operation can ensure that a part of the heat storage is fully stored first, and then the next heat storage is continued to store heat, which can ensure that a part of the heat storage is first satisfied when the heat is not sufficient, avoid heat dispersion, and ensure that the stored heat can be fully exchanged.

[0031] As an improvement, the controller controls the heat exchanger valve to open, and at the same time adjusts a portion of the heat accumulator valve to close, to ensure the operation of the heat exchanger. Preferably, a temperature sensor is provided to detect the output temperature of the heat exchanger cold source, and a portion of the heat accumulator valve is controlled to open or close according to the output temperature.

[0032] Through the above control method, the present invention opens or closes one or more heat accumulators for heat storage operation according to the specific heat exchange conditions of the heat exchanger, and can store heat while meeting the heat exchange requirements of the heat exchanger, thereby achieving the dual requirements of heat storage and heat exchange.

[0033] As an improvement, when the detected output temperature of the heat exchanger cold source is lower than a predetermined value, all the heat accumulator valves are controlled to be closed to ensure that all the hot fluid enters the heat exchanger for heat exchange. When the detected output temperature of the heat exchanger cold source is higher than a predetermined value, at least one heat accumulator valve is controlled to be opened to perform heat storage operation. Preferably, the heat exchanger valve opening is controlled to be reduced at the same time. The number of heat accumulator valves opened is controlled according to the reduced opening. To ensure that the amount of fluid entering the heat accumulator corresponds to the reduced amount of fluid entering the heat exchanger.

[0034] As an improvement, a valve is provided at the outlet of the collector, and a temperature sensor is provided in the collector to detect the temperature of the fluid heated in the heater. When the detected temperature of the fluid in the collector is lower than a predetermined value, the controller controls the main line valve to open, the main line inlet valve 8 and outlet valve 9 to close, the heat exchanger valve to open, and at least a part of the heat accumulator valve to open, so that a loop is formed between the heat accumulator and the heat exchanger. The present invention can also intelligently realize the circulation of the heat accumulator and the heat exchanger pipeline according to the heat collection situation of the solar collector, thereby ensuring the normal operation of the heat exchanger.

[0035] As an improvement, the controller controls a part of the heat accumulator valves to open and another part of the heat accumulator valves to close; when the temperature of the heat storage material in a certain heat accumulator is detected to be lower than the set value, the corresponding heat accumulator valve is closed, and one of the other heat accumulator valves is opened to store heat. The above operation can ensure that the heat exchanger always maintains normal operation, avoiding the heat exchanger output temperature being too high when all the heat accumulators are opened at the beginning, thereby maintaining normal operation.

[0036] As an improvement, the heat exchanger is a shell and tube heat exchanger.

[0037] As an improvement, a baffle 11 is provided in the tube of the heat exchanger.

[0038] As an improvement, the shell and tube heat exchanger is a horizontal shell and tube heat exchanger.

[0039] As an improvement, the hot fluid flows through the tube side and the cold fluid flows through the shell side.

[0040] As an improvement, the shell side and the tube side are countercurrent flows. Along the flow direction of the fluid in the tube side, the spacing of the baffles increases continuously from the tube side inlet to the middle of the tube side. Then from the middle of the tube side to the tube side outlet, the spacing of the baffles decreases continuously. Because in the countercurrent process, the heat exchange of the shell side and the tube side per unit length along the flow process of the fluid is relatively uniform, so that the overall heat exchange effect is the best. However, it was found in experiments and simulations that the heat exchange in the middle is significantly greater than the heat exchange at the tube side inlet and outlet. Therefore, by changing the spacing between the baffles, the heat exchange area between the tube side fluid in the baffle and the shell side fluid source also changes. Therefore, the uneven heat exchange is compensated by the change in area, thereby further improving the heat exchange efficiency.

[0041] As an improvement, along the flow direction of the fluid in the tube, from the tube entrance to the middle of the tube, the distance between the baffles increases continuously. Then, from the middle of the tube to the tube exit, the distance between the baffles decreases continuously. The above changes in the range can make the heat exchange per unit length of the entire fluid movement more uniform, further improving the heat exchange efficiency.

[0042] The fluid in the shell side is gas. The baffles include multiple groups, each group of baffles includes a lower baffle located at the lower part of the tube shell and an upper baffle located at the upper part of the tube shell; along the flow direction of the gas in the shell side, the ratio of the area of ​​the lower baffle to the area of ​​the upper baffle in different groups of baffles is gradually reduced.

[0043] During the research process, it was found that the heat transfer of the baffles of the traditional heat exchanger is uneven in the cross section in the direction of gas flow. As the distance from the inlet increases, the heat transfer effect of the upper part of the shell becomes better and better, while the heat transfer effect of the lower part of the shell becomes worse and worse. The main reason is that as the gas continues to flow. Because the gas density is small, the gas flows upward, which significantly increases the heat exchange gas in the upper part, so it is necessary to design the heat exchange structure for improvement. In the present invention, along the flow direction of the gas, the area ratio of the area of ​​the lower baffle to the area of ​​the upper baffle in the baffle group changes. As the gas in the shell flows, it gradually moves closer to the center, so that the center of the fluid strengthens the heat exchange around the heat exchange tubes of the shell and tube, which changes the previous heat exchange method, enhances the heat exchange efficiency at different positions, makes the heat exchange uniform on the whole, and further achieves the purpose of enhanced heat transfer.

[0044] As an improvement, along the flow direction of the gas in the shell, the area ratio of the lower baffle to the upper baffle in the baffle group is gradually reduced. Through the above-mentioned change in amplitude, the overall heat exchange can be further uniform, further achieving the purpose of enhancing heat transfer.

[0045] Although the present invention has been disclosed as above with preferred embodiments, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A solar thermal collection system, the system comprising a main pipeline, and a first branch pipeline and a second branch pipeline arranged in parallel with the main pipeline, a plurality of heat accumulators arranged in parallel are arranged on the first branch pipeline, a heat accumulator valve is arranged on each heat accumulator inlet pipeline, a heat exchanger is arranged on the second branch pipeline, a heat exchanger valve is arranged on the second branch pipeline, a main valve is arranged on the main pipeline, a temperature sensor is arranged in the heat accumulator for detecting the temperature of the heat storage material in the heat accumulator, and a controller controls the opening and closing of the corresponding heat accumulator valve according to the detected temperature of the heat storage material; the heat exchanger is a horizontal shell and tube heat exchanger, a baffle is arranged in the tube side of the heat exchanger; the hot fluid flows through the tube side, the cold fluid flows through the shell side, and the shell side and the tube side are countercurrent Flow, along the flow direction of the fluid in the tube, from the tube entrance to the middle position of the tube, the spacing of the baffles increases continuously, and then from the middle position of the tube to the tube exit, the spacing of the baffles decreases continuously; along the flow direction of the fluid in the tube, from the tube entrance to the middle position of the tube, the spacing of the baffles increases continuously, and then from the middle position of the tube to the tube exit, the spacing of the baffles decreases continuously; the controller controls a part of the heat accumulator valves to open and another part of the heat accumulator valves to close, allowing the fluid to enter the heat accumulator for heat storage; when one of the heat accumulators completes heat storage, the corresponding heat accumulator valve is closed, and the controller opens one of the other part of the heat accumulator valves for heat storage.

2. The heat collection system according to claim 1, characterized in that: When the detected temperature of the heat storage material in the heat accumulator exceeds a predetermined value, the corresponding heat accumulator valve is closed; when the detected temperature of the heat storage material in the heat accumulator is lower than a predetermined value, the corresponding heat accumulator valve is opened.

3. The heat collection system according to claim 1, characterized in that: The controller controls the heat exchanger valve to open and adjusts part or all of the heat accumulator valves to close to ensure the operation of the heat exchanger.

4. The heat collection system according to claim 1, characterized in that: A valve is set at the collector outlet, and a temperature sensor is set in the collector to detect the temperature of the heated fluid in the collector. When the detected fluid temperature in the collector is lower than a preset value, the controller controls the main line valve to open, the collector outlet valve to close, the heat exchanger valve to open, and at least a part of the heat accumulator valve to open, thereby forming a loop between the heat accumulator and the heat exchanger.

5. The heat collection system according to claim 4, characterized in that: The controller controls a part of the heat accumulator valves to open and another part of the heat accumulator valves to close; when the temperature of the heat storage material in a certain heat accumulator detected is lower than the set value, the corresponding heat accumulator valve is closed, and at the same time, one of the other part of the heat accumulator valves is opened to store heat.

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