A solar thermal collection system and operation method

Abstract

The present invention discloses a solar thermal collection system, including a solar thermal collection mirror field, a heat terminal and a storage and unloading medium tank. When the system is in operation, the working medium in the circulation loop expands due to heat, and the expanded working medium enters the storage and unloading medium tank for temporary storage to ensure the safe operation of the system; when the temperature or pressure of the working medium drops, the working medium flows back from the storage and unloading medium tank to the circulation loop. The storage and unloading medium tank is connected to an exhaust riser, and the exhaust end of the exhaust riser is higher than the highest point of the solar thermal collection mirror field. The exhaust end of the exhaust riser is the highest point of the entire system. There is no need to place the storage and unloading medium tank at a high position, and there is no need to install a constant pressure pump. The pipeline constant pressure and expansion problems of the solar thermal collection system can be solved, which simplifies the system structure, reduces costs, is simple to operate, and saves time and effort. The present invention also provides an operation method of the above-mentioned solar thermal collection system, which reduces the workload and difficulty of on-site construction and simplifies system control.

Description

Technical Field

[0001] The present invention relates to the field of solar energy engineering technology, and in particular to a solar energy heat collection system and an operation method thereof. Background Art

[0002] The traditional solar thermal collection system pipeline constant pressure adopts the high-position constant pressure method. The height of the solar collector is 10 meters. The storage and unloading medium tank must be placed at a height of more than 10 meters to achieve constant pressure. The construction is difficult and also wastes manpower and material resources. There is also a method that requires the installation of a constant pressure pump in front of the storage and unloading medium tank to achieve constant pressure, which increases construction costs, control costs, system operation risks and other costs. In the traditional solar thermal collection pipeline system, the pipeline is a circulating pipeline with long, complicated and complex pipeline lines. Especially when there are many solar collector groups, when the medium is first filled, because the pipeline is a circulating pipeline, the original gas in the pipeline can only be discharged through the vent valve installed on the pipeline, but the exhaust is very slow and not easy to exhaust, resulting in the presence of gas in the system for a long time, causing unstable system operation. Summary of the invention

[0003] The purpose of the present invention is to provide a solar thermal collection system and operation method to solve the problems existing in the above-mentioned prior art, simplify the system structure, solve the pressure and expansion problems of the solar thermal collection system pipeline, and reduce the system operation cost.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a solar thermal collection system, comprising:

[0006] A solar thermal collector field, which is used to collect solar radiation energy and convert it into thermal energy;

[0007] A heat-using terminal, which is connected to the solar thermal collector field and forms a circulation loop for the working medium to flow;

[0008] A storage and unloading medium tank, the storage and unloading medium tank is arranged between the solar thermal collector field and the heat user terminal, the storage and unloading medium tank can accommodate working medium; the storage and unloading medium tank is connected to a medium filling pipeline and an exhaust riser, the medium filling pipeline can be used to fill the storage and unloading medium tank with working medium, the storage and unloading medium tank can be connected to the circulation loop to realize the filling of working medium into the circulation loop, and the working medium can enter the storage and unloading medium tank when expanding, and can flow back from the storage and unloading medium tank to the circulation loop when contracting; one end of the exhaust riser is connected to the storage and unloading medium, the other end of the exhaust riser is an exhaust end and is connected to the external environment, and the exhaust end of the exhaust riser is higher than the highest point of the solar thermal collector field.

[0009] Preferably, the circulation loop is connected to the storage and unloading medium tank via a gas-liquid discharge pipeline.

[0010] Preferably, the gas-liquid discharge pipeline is connected to the upper part of the storage and unloading medium tank;

[0011] The gas-liquid discharge pipeline is provided with a gas-liquid discharge valve.

[0012] Preferably, the circulation loop is also connected to the storage and unloading medium tank via an expansion and fluid replenishment pipeline.

[0013] Preferably, the expansion and fluid replenishment pipeline is connected to the bottom of the storage and unloading medium tank;

[0014] The expansion and fluid replenishment pipeline is provided with an expansion and fluid replenishment valve.

[0015] Preferably, along the flow direction of the working medium flowing back from the heat-using terminal to the solar thermal collector field, the connection point between the gas-liquid discharge pipeline and the circulation loop is located upstream of the connection point between the expansion and fluid replenishment pipeline and the circulation loop, and a control valve is provided on the circulation loop, and the control valve is located between the connection point between the gas-liquid discharge pipeline and the circulation loop and the connection point between the expansion and fluid replenishment pipeline and the circulation loop.

[0016] Preferably, the medium filling pipeline and the exhaust riser are both connected to the top of the storage and unloading medium tank.

[0017] Preferably, the exhaust riser is arranged parallel to the vertical direction.

[0018] Preferably, a circulation pump is also provided on the circulation loop.

[0019] Furthermore, the present invention also provides an operation method of the above-mentioned solar thermal collection system:

[0020] When the system is running, the working medium in the circulation loop expands due to heat, and the expanded working medium enters the storage and unloading medium tank for temporary storage to ensure safe operation of the system; when the temperature or pressure of the working medium drops, the working medium flows back from the storage and unloading medium tank to the circulation loop;

[0021] When the system stops running, the pressure in the circulation loop is lower than the pressure in the storage and unloading medium tank, so as to prevent the working medium in the circulation loop from flowing into the storage and unloading medium tank;

[0022] When the system stops running and a leak occurs, the pressure at the leak and the pressure in the circulation loop are both lower than the pressure in the storage and unloading medium tank, thus preventing air from entering the system.

[0023] Compared with the prior art, the present invention has achieved the following technical effects: the solar thermal collection system of the present invention includes a solar thermal collection mirror field, a heat terminal and a storage and unloading medium tank, the solar thermal collection mirror field is used to collect solar radiation energy and convert it into thermal energy; the heat terminal is connected to the solar thermal collection mirror field and forms a circulation loop for the flow of working medium; the storage and unloading medium tank is arranged between the solar thermal collection mirror field and the heat terminal, and the storage and unloading medium tank can accommodate the working medium; the storage and unloading medium tank is connected to a medium filling pipeline and an exhaust riser, and the working medium can be filled into the storage and unloading medium tank by using the medium filling pipeline, the storage and unloading medium tank can be connected to the circulation loop to realize the filling of the working medium into the circulation loop, and the working medium can enter the storage and unloading medium tank when it expands, and can flow back from the storage and unloading medium tank to the circulation loop when it contracts; one end of the exhaust riser is connected to the storage and unloading medium, and the other end of the exhaust riser is an exhaust end and is connected to the external environment, and the exhaust end of the exhaust riser is higher than the highest point of the solar thermal collection mirror field.

[0024] In the solar thermal collection system of the present invention, when the system is in operation, the working medium in the circulation loop expands due to heat, and the expanded working medium enters the storage and unloading medium tank for temporary storage to ensure the safe operation of the system; when the temperature or pressure of the working medium drops, the working medium flows back from the storage and unloading medium tank to the circulation loop. The storage and unloading medium tank is connected to an exhaust riser, and the exhaust end of the exhaust riser is higher than the highest point of the solar thermal collection mirror field. The exhaust end of the exhaust riser is the highest point of the entire system. There is no need to place the storage and unloading medium tank at a high position, and there is no need to install a constant pressure pump. The pipeline constant pressure and expansion problems of the solar thermal collection system can be solved, which simplifies the system structure, reduces costs, is simple to operate, and saves time and effort. When the working medium is first filled, the end of the system is made an open system, and the gas in the system can enter the storage and unloading medium tank and be quickly discharged from the exhaust riser, which saves time and effort, and greatly reduces the workload of exhaust during the initial filling of the medium.

[0025] The present invention also provides an operation method of the above solar thermal collection system, which reduces the workload and difficulty of on-site construction, reduces engineering costs, simplifies system control, and improves system operation safety and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a schematic structural diagram of a solar thermal collection system disclosed in an embodiment of the present invention.

[0028] In the figure: 1. Solar collector field; 2. Exhaust riser; 3. Circulation pump; 4. Storage and unloading medium tank; 5. Expansion and liquid replenishment valve; 6. Control valve; 7. Gas-liquid discharge valve; 8. Heat terminal; 9. Medium filling pipeline; 10. Circulation loop; 11. Gas-liquid discharge pipeline; 12. Expansion and liquid replenishment pipeline. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The purpose of the present invention is to provide a solar thermal collection system and operation method to solve the problems existing in the above-mentioned prior art, simplify the system structure, solve the pressure and expansion problems of the solar thermal collection system pipeline, and reduce the system operation cost.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Embodiment 1

[0033] The present embodiment provides a solar thermal collection system, including a solar thermal collection mirror field 1, a heat terminal 8 and a storage and unloading medium tank 4. The solar thermal collection mirror field 1 is used to collect solar radiation energy and convert it into heat energy; the heat terminal 8 is connected to the solar thermal collection mirror field 1 and forms a circulation loop 10 for the flow of working medium; the storage and unloading medium tank 4 is arranged between the solar thermal collection mirror field 1 and the heat terminal 8, and the storage and unloading medium tank 4 can accommodate the working medium; the storage and unloading medium tank 4 is connected to a medium filling pipeline 9 and an exhaust riser 2, and the working medium can be filled into the storage and unloading medium tank 4 by using the medium filling pipeline 9, and the storage and unloading medium tank 4 can be connected to the circulation loop 10 to realize the filling of the working medium into the circulation loop 10, and the working medium can enter the storage and unloading medium tank 4 when expanding, and can flow back from the storage and unloading medium tank 4 to the circulation loop 10 when contracting; one end of the exhaust riser 2 is connected to the storage and unloading medium, and the other end of the exhaust riser 2 is an exhaust end and is connected to the external environment, and the exhaust end of the exhaust riser 2 is higher than the highest point of the solar thermal collection mirror field 1.

[0034] In the solar thermal collection system of the present invention, when the system is in operation, the working medium in the circulation loop 10 expands due to heat, and the expanded working medium enters the storage and unloading medium tank 4 for temporary storage to ensure the safe operation of the system; when the temperature or pressure of the working medium drops, the working medium flows back from the storage and unloading medium tank 4 to the circulation loop 10. The storage and unloading medium tank 4 is connected to the exhaust riser 2, and the exhaust end of the exhaust riser 2 is higher than the highest point of the solar thermal collection mirror field 1. The exhaust end of the exhaust riser 2 is the highest point of the entire system. There is no need to mount the storage and unloading medium tank 4 at a high position, and there is no need to install a constant pressure pump, so that the pipeline constant pressure and expansion problems of the solar thermal collection system can be achieved, which simplifies the system structure, reduces costs, is simple to operate, and saves time and effort. When the working medium is first filled, the end of the system is made an open system, and the gas in the system can enter the storage and unloading medium tank 4 and be quickly discharged from the exhaust riser 2, which saves time and effort, and greatly reduces the workload of exhaust during the initial filling of the medium.

[0035] The circulation loop 10 is connected to the storage medium tank 4 via the gas-liquid discharge pipe 11 . During the operation of the system, when the working medium temperature rises, the working medium expands and enters the storage medium tank 4 via the gas-liquid discharge pipe 11 .

[0036] It should also be noted that the working medium may evaporate and turn into gas when its temperature rises, and the gas-liquid discharge pipe 11 is connected to the upper part of the storage and unloading medium tank 4, so that the working medium after heating and expansion can smoothly enter the storage and unloading medium tank 4 through the gas-liquid discharge pipe 11, thereby realizing the smooth transportation of the working medium and improving the operating reliability of the system.

[0037] For the convenience of control, a gas-liquid discharge valve 7 is provided on the gas-liquid discharge pipeline 11 to facilitate control of the connection state between the gas-liquid discharge pipeline 11 and the circulation loop 10, thereby improving the convenience of system operation.

[0038] Correspondingly, the circulation loop 10 is also connected to the storage and unloading medium tank 4 via the expansion and replenishment pipe 12. During the operation of the system, when the working medium cools down and shrinks, the working medium in the storage and unloading medium tank 4 flows back to the circulation loop 10 via the expansion and replenishment pipe 12, thereby ensuring the stable operation of the solar thermal collection system.

[0039] In this specific embodiment, the expansion and fluid replenishment pipeline 12 is connected to the bottom of the storage and unloading medium tank 4 to ensure that the working medium in the storage and unloading medium tank 4 is smoothly output and enters the circulation loop 10.

[0040] Likewise, an expansion and fluid replenishment valve 5 is provided on the expansion and fluid replenishment pipeline 12, which is beneficial to improving the controllability of the system.

[0041] Specifically, along the flow direction of the working medium flowing back from the heat terminal 8 to the solar thermal collector field 1, the connection point between the gas-liquid discharge pipeline 11 and the circulation loop 10 is located upstream of the connection point between the expansion and fluid replenishment pipeline 12 and the circulation loop 10, so as to ensure the smooth circulation and transportation of the working medium, and a control valve 6 is provided on the circulation loop 10, and the control valve 6 is located between the connection point between the gas-liquid discharge pipeline 11 and the circulation loop 10 and the connection point between the expansion and fluid replenishment pipeline 12 and the circulation loop 10. The provision of the control valve 6 is conducive to improving the control convenience of the system.

[0042] It should also be noted that the medium filling pipeline 9 and the exhaust riser 2 are both connected to the top of the storage and unloading medium tank 4 to ensure the smooth addition of the working medium and the smooth discharge of excess gas.

[0043] In this specific embodiment, the exhaust riser 2 is arranged parallel to the vertical direction to ensure that the exhaust end of the exhaust riser 2 is the highest point of the system and the gas is discharged smoothly. In other specific embodiments of the present invention, the exhaust riser 2 can be set at a certain inclination angle to meet different construction requirements and improve the flexibility and adaptability of the system while ensuring the smooth discharge of gas and the position of the exhaust end.

[0044] In practical applications, a circulation pump 3 may be further provided on the circulation loop 10 to ensure smooth circulation of the working medium and improve the working reliability of the system.

[0045] The solar thermal collection system of this embodiment does not need to be mounted at a high position, nor does it need to be equipped with a constant pressure pump, and can achieve the constant pressure and expansion problem of the solar thermal collection system pipeline, simplifying the system, reducing costs, and being simple to operate, saving time and effort. When the medium is first filled, the end of the system is made an open system, and the gas in the system can enter the storage and unloading medium tank 4 through the gas-liquid discharge pipe, and the gas can be quickly discharged from the exhaust riser 2 on the storage and unloading medium tank 4, saving time and effort, and greatly reducing the workload of exhausting during the initial filling of the medium.

[0046] Embodiment 2

[0047] This embodiment provides an operation method of a solar thermal collection system, and utilizes the solar thermal collection system in the first embodiment.

[0048] When the system is running, the working medium in the circulation loop 10 expands due to heat, and the expanded working medium enters the storage and unloading medium tank 4 for temporary storage to ensure safe operation of the system; when the temperature or pressure of the working medium drops, the working medium flows back from the storage and unloading medium tank 4 to the circulation loop 10 to ensure that the working medium circulates in the system.

[0049] When the system stops running, the pressure in the circulation loop 10 is lower than the pressure in the storage and unloading medium tank 4, which prevents the working medium in the circulation loop 10 from flowing into the storage and unloading medium tank 4, thereby improving the operating stability of the system.

[0050] When the system stops running and a leak occurs, the pressure at the leak and the pressure in the circulation loop 10 are both lower than the pressure in the storage and unloading medium tank 4, thus preventing air from entering the system and improving the operating safety factor of the system.

[0051] Embodiment 3

[0052] In this embodiment, the highest point of the solar thermal mirror field 1 in the solar thermal collection system is about 10m high, and the exhaust end of the exhaust riser 2 connected to the storage and unloading medium tank 4 is about 12m high. The exhaust end of the exhaust riser 2 is the highest point of the system, and is at least 2m higher than the second highest point of the system (the highest point of the solar thermal mirror field 1). In order to reduce the construction difficulty as much as possible, this embodiment takes the exhaust end of the exhaust riser 2 as an example of being 2m higher than the highest point of the solar thermal mirror field 1.

[0053] The storage and unloading medium tank 4 will be designed with a volume according to the amount of working medium and the expansion amount of the working medium from the initial temperature to the operating temperature, and an exhaust riser 2 higher than the highest point of the solar energy pipeline system is connected above the storage and unloading medium tank 4. The storage and unloading medium tank 4 is connected to the circulation loop 10 through the expansion and liquid replenishment pipeline 12 where the expansion and liquid replenishment valve 5 is located. By installing a gas-liquid discharge valve 7 on the storage and unloading medium tank 4, the gas-liquid discharge pipeline 11 enters the storage and unloading medium tank 4 and the interface is located above the liquid level of the storage and unloading medium tank 4. When the working medium is first added to the system, the working medium is discharged through the gas-liquid discharge pipeline 11. The medium filling pipeline 9 is added to the storage and unloading medium tank 4, the expansion and liquid replenishing valve 5 and the circulation pump 3 are opened, the working medium is added to the circulation loop 10, the gas-liquid discharge valve 7 is opened, and the control valve 6 is closed, so that the end of the system is an open pipeline, and the working medium and gas in the system can quickly enter the storage and unloading medium tank 4 through the gas-liquid discharge pipeline 11, and the gas is discharged into the atmosphere through the exhaust riser 2 on the storage and unloading medium tank 4. Until the medium fills the circulation loop 10 and the gas in the circulation loop 10 is exhausted, the gas-liquid discharge valve 7 is closed, and the control valve 6 is opened, so that the system forms a circulation system and the system operates stably.

[0054] When the system is running, the working medium expands due to heat, and the expanded medium enters the storage and unloading medium tank 4 through the expansion and replenishment pipe 12 for temporary storage, ensuring the safe operation of the system without overpressure. When the temperature or pressure of the medium drops, the medium will return to the circulation loop 10 from the storage and unloading medium tank 4 through the expansion and replenishment pipe 12, ensuring the stable operation of the entire solar thermal collection system.

[0055] When the system stops operating, the pressure in the circulation loop 10 is the circulation static pressure (≤0.1MPa), and the pressure in the storage and unloading medium tank 4 is the atmospheric pressure + the storage and unloading medium tank static pressure (≥0.22MPa), and the medium in the system will not flow into the storage and unloading medium tank 4.

[0056] When the system stops running, a leak occurs, and its pressure is atmospheric pressure + static pressure at the leak (≤0.2MPa). The pressure inside the storage and unloading medium tank 4 is atmospheric pressure + static pressure of the storage and unloading medium tank (≥0.22MPa). The pressure inside the storage and unloading medium tank 4 is greater than the pressure inside the circulation loop 10, thereby ensuring that the system will not take in air.

[0057] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A solar thermal collection system, characterized in that: include: A solar thermal collector field, which is used to collect solar radiation energy and convert it into thermal energy; A heat-using terminal, which is connected to the solar thermal collector field and forms a circulation loop for the working medium to flow; A storage and unloading medium tank, the storage and unloading medium tank is arranged between the solar thermal collector field and the heat user terminal, the storage and unloading medium tank can accommodate working medium; the storage and unloading medium tank is connected with a medium filling pipeline and an exhaust riser, the medium filling pipeline can be used to fill the storage and unloading medium tank with working medium, the storage and unloading medium tank can be connected with the circulation loop to realize the filling of working medium into the circulation loop, and the working medium can enter the storage and unloading medium tank when expanding, and can flow back from the storage and unloading medium tank to the circulation loop when contracting; one end of the exhaust riser is connected with the storage and unloading medium tank, the other end of the exhaust riser is an exhaust end and is connected to the external environment, and the exhaust end of the exhaust riser is higher than the highest point of the solar thermal collector field; the medium filling pipeline and the exhaust riser are both connected with the top of the storage and unloading medium tank; the exhaust riser is arranged parallel to the vertical direction.

2. The solar thermal collection system according to claim 1, characterized in that: The circulation loop is connected to the storage and unloading medium tank by means of a gas-liquid discharge pipeline.

3. The solar thermal collection system according to claim 2, characterized in that: The gas-liquid discharge pipeline is connected to the upper part of the storage and unloading medium tank; The gas-liquid discharge pipeline is provided with a gas-liquid discharge valve.

4. The solar thermal collection system according to claim 3, characterized in that: The circulation loop is also connected to the storage and unloading medium tank by means of an expansion and fluid replenishment pipeline.

5. The solar thermal collection system according to claim 4, characterized in that: The expansion and fluid replenishment pipeline is connected to the bottom of the storage and unloading medium tank; The expansion and fluid replenishment pipeline is provided with an expansion and fluid replenishment valve.

6. The solar thermal collection system according to claim 4, characterized in that: Along the flow direction of the working medium flowing back from the heat-using terminal to the solar thermal collector field, the connection point between the gas-liquid discharge pipeline and the circulation loop is located upstream of the connection point between the expansion and fluid replenishment pipeline and the circulation loop, and a control valve is provided on the circulation loop, and the control valve is located between the connection point between the gas-liquid discharge pipeline and the circulation loop and the connection point between the expansion and fluid replenishment pipeline and the circulation loop.

7. The solar thermal collection system according to claim 1, characterized in that: The circulation loop is also provided with a circulation pump.

8. An operating method of a solar thermal collection system according to any one of claims 1 to 7, characterized in that: When the system is running, the working medium in the circulation loop expands due to heat, and the expanded working medium enters the storage and unloading medium tank for temporary storage to ensure safe operation of the system; when the temperature or pressure of the working medium drops, the working medium flows back from the storage and unloading medium tank to the circulation loop; When the system stops running, the pressure in the circulation loop is lower than the pressure in the storage and unloading medium tank, so as to prevent the working medium in the circulation loop from flowing into the storage and unloading medium tank; When the system stops running and a leak occurs, the pressure at the leak and the pressure in the circulation loop are both lower than the pressure in the storage and unloading medium tank, thus preventing air from entering the system.

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