阅读说明：本技术 一种塔式太阳能电站的吸热和储热系统及方法 (Heat absorption and storage system and method for tower type solar power station ) 是由 余志勇 唐娟 陈明强 孙峰 周慧 王伟 于 2020-12-31 设计创作，主要内容包括：本发明涉及一种塔式太阳能电站的吸热和储热系统及方法,所述系统包括吸热系统和储热系统,吸热系统包括吸热介质供应回收罐和吸热介质循环回路,吸热介质循环回路包括上塔管道、吸热器、出口缓存罐、下塔管道和储热换热器,吸热器和出口缓存罐均设置在吸热塔的顶端；储热换热器包括吸热介质通道和储热介质通道,上塔管道、吸热器、出口缓存罐、下塔管道和吸热介质通道依次循环连通；吸热介质供应回收罐通过阀门与上塔管道相连；吸热介质供应回收罐设有泄压阀；吸热介质供应回收罐通过加压机构加压；储热系统包括设置在地面的低温储热罐和高温储热罐,低温储热罐通过储热泵与储热介质通道的入口连接,储热介质通道的出口与高温储热罐连接。(The invention relates to a heat absorption and storage system and a method of a tower-type solar power station, wherein the system comprises a heat absorption system and a storage system, the heat absorption system comprises a heat absorption medium supply and recovery tank and a heat absorption medium circulation loop, the heat absorption medium circulation loop comprises an upper tower pipeline, a heat absorber, an outlet cache tank, a lower tower pipeline and a heat storage heat exchanger, and the heat absorber and the outlet cache tank are both arranged at the top end of a heat absorption tower; the heat storage heat exchanger comprises a heat absorption medium channel and a heat storage medium channel, and the upper tower pipeline, the heat absorber, the outlet cache tank, the lower tower pipeline and the heat absorption medium channel are sequentially communicated in a circulating manner; the heat absorption medium supply and recovery tank is connected with the upper tower pipeline through a valve; the heat absorption medium supply and recovery tank is provided with a pressure release valve; the heat absorbing medium supply and recovery tank is pressurized by a pressurizing mechanism; the heat storage system comprises a low-temperature heat storage tank and a high-temperature heat storage tank which are arranged on the ground, the low-temperature heat storage tank is connected with an inlet of the heat storage medium channel through a heat storage pump, and an outlet of the heat storage medium channel is connected with the high-temperature heat storage tank.)

1. The heat absorption and storage system of the tower-type solar power station is characterized by comprising a heat absorption system and a heat storage system, wherein the heat absorption system comprises a heat absorption medium supply and recovery tank and a heat absorption medium circulation loop, the heat absorption medium circulation loop comprises an upper tower pipeline, a heat absorber, an outlet cache tank, a lower tower pipeline and a heat storage heat exchanger, and the heat absorber and the outlet cache tank are both arranged at the top end of a heat absorption tower; the heat storage heat exchanger comprises a heat absorption medium channel and a heat storage medium channel, the upper tower pipeline, the heat absorber, the outlet cache tank, the lower tower pipeline and the heat absorption medium channel are sequentially communicated in a circulating manner, and a heat absorption pump for providing power for the circulation of the heat absorption medium is arranged on the heat absorption medium circulating loop;

the heat-absorbing medium supply and recovery tank is a heat-absorbing medium storage container and is connected with the upper tower pipeline through a first pipeline, and a first valve is arranged on the first pipeline; the heat-absorbing medium supply and recovery tank is connected with the pressurizing mechanism through a second pipeline, and a second valve is arranged on the second pipeline; a pressure release valve is also arranged on the heat absorption medium supply and recovery tank;

the heat storage system comprises a low-temperature heat storage tank and a high-temperature heat storage tank which are arranged on the ground, the low-temperature heat storage tank and the high-temperature heat storage tank are respectively communicated with the inlet and the outlet of the heat storage medium channel, and when the heat storage system operates, the low-temperature heat storage tank conveys the low-temperature heat storage medium in the low-temperature heat storage tank to the heat storage medium channel through the heat storage pump.

2. The heat absorption and storage system of a tower solar power plant of claim 1 wherein said heat absorption pump is disposed on said outlet buffer tank for delivering heat absorption medium from said outlet buffer tank to said lower tower pipe.

3. The heat absorption and storage system of a tower solar power plant of claim 1 wherein the bottom of said outlet buffer tank is further vented with an outlet that communicates with said lower tower conduit via a third conduit, said third conduit being further provided with a third valve.

4. The heat absorption and storage system of a tower solar power plant of claim 1 wherein the outlet of said heat absorption medium channel is further provided with a heat absorption check valve.

5. The heat absorption and storage system of a tower solar power station of claim 1 wherein said pressurizing means is a gas pressurizing means.

6. The heat absorption and storage system of a tower solar power plant of claim 5 wherein said gas pressurization means comprises a gas compressor and a compressed gas storage tank, said gas compressor supplying gas to said heat absorption medium supply recovery tank through said compressed gas storage tank.

7. The heat absorption and storage system of a tower solar power plant of claim 1 wherein the storage volume of said heat absorption medium supply recovery tank is not less than the sum of the volume of the pipe connecting said heat absorption medium circulation circuit and said heat absorption medium circulation circuit;

in the case where the heat absorbing pump fails, the storage volume of the heat absorbing medium supply recovery tank is not less than the total amount of heat absorbing medium required for the heat absorber to operate normally for a preset time.

8. The heat absorption and storage system of a tower solar power plant of claim 7 wherein the storage volume of said heat absorption medium supply recovery tank is not less than the total amount of heat absorption medium for 1min of normal operation of said absorber in case of failure of said heat absorption pump.

9. The heat absorption and storage system of a tower solar power plant of claim 1 wherein said heat absorption medium supply recovery tank, outlet buffer tank, low temperature heat storage tank and high temperature heat storage tank are each fitted with at least one level gauge.

10. The heat absorption and storage system of a tower solar power plant according to claim 1, wherein all the equipment and piping in said system are equipped with condensation preventing heating means and temperature measuring means.

11. A method of absorbing and storing heat from a tower solar power plant, using the system of any one of claims 1 to 10, comprising:

s1: closing the pressure release valve, the second valve and the heat storage pump, opening the first valve, opening the heat absorption pump, and opening the second valve after the liquid level of the heat absorption medium supply recovery tank reaches a certain height;

s2: the pressure of the heat absorption medium supply and recovery tank is continuously increased, the liquid level is continuously reduced, and finally the heat absorption medium is maintained at a certain height and enters the heat absorber through the upper tower pipeline;

s3: after the heat absorption medium absorbs heat through the heat absorber, the high-temperature heat absorption medium sequentially enters an outlet cache tank, a lower tower pipeline and a heat absorption medium channel of the heat storage heat exchanger from an outlet pipeline of the heat absorber and sequentially circulates;

s4: when the temperature of the heat absorbing medium rises to a certain value, the heat storage pump is started, the low-temperature heat storage medium enters the heat storage medium channel of the heat storage heat exchanger from the low-temperature heat storage tank for heat exchange, the heat storage medium after heat exchange enters the high-temperature heat storage tank through the pipeline, and the heat storage medium flows in sequence.

Technical Field

The invention relates to the technical field of solar thermal power generation, in particular to a heat absorption and storage system and a heat absorption and storage method for a tower type solar power station.

Background

The solar thermal power generation technology uses solar energy to generate electric power, is an important direction for large-scale utilization of solar energy, has the most competitive advantage that the solar thermal power generation technology is easily combined with a heat storage system, and can get rid of the influence caused by unstable solar energy through the heat storage system. The molten salt has the characteristics of high use temperature, wide temperature range, good flow characteristic, large heat capacity and the like, can be used for large-scale heat storage of a solar thermal power station, and is a solar heat absorption and storage medium which is most widely applied at present.

The tower type photo-thermal power generation technology is one of the solar power generation technologies with the widest application prospect and has the characteristics of high heat collection multiple, high efficiency and the like. However, since the height of the heat absorption tower is high, a molten salt pump with high lift and high flow rate is required to convey molten salt to the heat absorber at the top of the tower. The vertical long-axis submerged molten salt pump installed on the top of a storage tank is adopted as a conveying pump at present, but the use limitation of the vertical long-axis submerged molten salt pump causes the following two problems: (1) the design and manufacturing difficulty of the vertical long-shaft submerged molten salt pump is high, particularly the design and manufacturing difficulty of the long-shaft molten salt pump with high lift and high flow rate, the number of manufacturers which can produce the long-shaft molten salt pump used for the tower-type solar power station in the world at present can be increased, the price is high, the supply period is long, and meanwhile, the reliability of equipment needs to be further verified due to the short application time of the pump engineering. (2) Because the height of the heat absorption tower is higher, the power of a molten salt pump for conveying molten salt to the heat absorber at the top of the tower is generally higher, so that the system consumes more station power in the operation process, and the economical efficiency of the power station operation is greatly influenced.

Therefore, how to solve the problems of cost increase, poor reliability and large service power consumption caused by the vertical long-shaft molten salt pump is one of the great problems urgently needed by the tower type photo-thermal power station at present.

Disclosure of Invention

In order to solve the above problems, the present invention provides a heat absorption and storage system of a tower-type solar power station, comprising a heat absorption system and a heat storage system, wherein the heat absorption system comprises a heat absorption medium supply and recovery tank and a heat absorption medium circulation loop, the heat absorption medium circulation loop comprises an upper tower pipeline, a heat absorber, an outlet buffer tank, a lower tower pipeline and a heat storage heat exchanger, and the heat absorber and the outlet buffer tank are both arranged at the top end of a heat absorption tower; the heat storage heat exchanger comprises a heat absorption medium channel and a heat storage medium channel, the upper tower pipeline, the heat absorber, the outlet cache tank, the lower tower pipeline and the heat absorption medium channel are sequentially and circularly connected, and a heat absorption pump for providing power for the circulation of the heat absorption medium is arranged on the heat absorption medium circulation loop;

the heat-absorbing medium supply and recovery tank is a heat-absorbing medium storage container and is connected with the upper tower pipeline through a first pipeline, and a first valve is arranged on the first pipeline; the heat-absorbing medium supply and recovery tank is connected with the pressurizing mechanism through a second pipeline, and a second valve is arranged on the second pipeline; a pressure release valve is also arranged on the heat absorption medium supply and recovery tank;

the heat storage system comprises a low-temperature heat storage tank and a high-temperature heat storage tank which are arranged on the ground, the low-temperature heat storage tank and the high-temperature heat storage tank are respectively communicated with the inlet and the outlet of the heat storage medium channel, and when the heat storage system operates, the low-temperature heat storage tank conveys the low-temperature heat storage medium in the low-temperature heat storage tank to the heat storage medium channel through the heat storage pump.

Preferably, the heat absorption pump is arranged on the outlet buffer tank and used for conveying the heat absorption medium in the outlet buffer tank to the lower tower pipeline.

Preferably, the bottom of the outlet buffer tank is further provided with an outlet, the outlet is communicated with the lower tower pipeline through a third pipeline, and the third pipeline is further provided with a third valve.

The structure of the valves is not particularly limited, and the valves are arranged on corresponding pipelines to adjust the on-off, the flow speed or the flow direction of the pipelines.

Preferably, the outlet of the heat absorbing medium channel is also provided with a heat absorbing check valve.

Preferably, the pressurizing mechanism is a gas pressurizing mechanism.

Preferably, the gas pressurizing mechanism includes a gas compressor and a compressed gas storage tank, and the gas compressor supplies gas to the heat absorbing medium supply and recovery tank through the compressed gas storage tank.

Preferably, the storage volume of the heat absorbing medium supply and recovery tank is not less than the sum of the volumes of the pipe connected with the heat absorbing medium circulation loop and the heat absorbing medium circulation loop;

in the case where the heat absorbing pump fails, the storage volume of the heat absorbing medium supply recovery tank is not less than the total amount of heat absorbing medium required for the heat absorber to operate normally for a preset time.

Preferably, in the case of a failure of the heat absorption pump, the storage volume of the heat absorption medium supply recovery tank is not less than the total amount of heat absorption medium for normal operation of the heat absorber for 1 min.

Preferably, the heat absorbing medium supply and recovery tank, the outlet buffer tank, the low-temperature heat storage tank and the high-temperature heat storage tank are all provided with at least one liquid level meter.

Preferably, all the devices and pipelines in the system are provided with the condensation-preventing heating device and the temperature measuring device.

The invention also provides a heat absorption and storage method of the tower type solar power station, and the system adopting the embodiment comprises the following steps:

s1: closing the pressure release valve, the second valve and the heat storage pump, opening the first valve, opening the heat absorption pump, and opening the second valve after the liquid level of the heat absorption medium supply recovery tank reaches a certain height;

s2: the pressure of the heat absorption medium supply and recovery tank is continuously increased, the liquid level is continuously reduced, and finally the heat absorption medium is maintained at a certain height and enters the heat absorber through the upper tower pipeline;

s3: after the heat absorption medium absorbs heat through the heat absorber, the high-temperature heat absorption medium sequentially enters an outlet cache tank, a lower tower pipeline and a heat absorption medium channel of the heat storage heat exchanger from an outlet pipeline of the heat absorber and sequentially circulates;

s4: when the temperature of the heat absorbing medium rises to a certain value, the heat storage pump is started, the low-temperature heat storage medium enters the heat storage medium channel of the heat storage heat exchanger from the low-temperature heat storage tank for heat exchange, the heat storage medium after heat exchange enters the high-temperature heat storage tank through the pipeline, and the heat storage medium flows in sequence.

Compared with the prior art, the invention has the following technical effects:

(1) the system adopts a heat exchange mode of the heat storage medium and the heat absorption medium to communicate the upper tower pipeline and the lower tower pipeline of the heat absorption system, the gravity of the heat storage medium in the lower tower pipeline is fully utilized, the lift of the heat storage pump is greatly reduced, the equipment reliability of the heat storage pump can be increased, the running power of the heat storage pump can be reduced, the service power consumption is reduced, and the economical efficiency of the system is provided;

(2) the system adopts a mode that the heat absorption medium is supplied to the recovery tank to store the heat absorption medium enough for the heat absorber to run for a reserved time (such as 1min), once the heat absorption pump fails, the heat absorption medium source (such as a compressed air source) can drive the heat absorption medium to continuously circulate in the heat absorption system, so that the heat absorber is prevented from being burnt, and the running safety of equipment is ensured;

(3) no matter in the heat absorption or non-heat absorption process of the system, the heat absorption medium is inside the heat absorption system, the process of charging and discharging the heat absorption medium does not exist in the upper tower pipeline and the lower tower pipeline, and compared with the traditional tower type photo-thermal power generation technology, the system has the characteristics of short starting time and short emptying time, and the economy of the whole system can be improved.

Of course, it is not necessary for any product in which the invention is practiced to achieve all of the above-described advantages at the same time.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts. In the drawings:

fig. 1 is a schematic structural diagram of a heat absorption and storage system of a tower-type solar power station according to a preferred embodiment of the present invention.

Detailed Description

The heat absorption and storage system of a tower-type solar power station provided by the present invention will be described in detail with reference to fig. 1, and the present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments, and those skilled in the art can modify and decorate the heat absorption and storage system without changing the spirit and content of the present invention.

Referring to fig. 1, a heat absorbing and storing system of a tower-type solar power station includes a heat absorbing system and a heat storing system, the heat absorbing system includes a heat absorbing medium supply and recovery tank 1 and a heat absorbing medium circulation loop:

the heat absorption medium circulation loop comprises an upper tower pipeline 12, a heat absorber 4, an outlet cache tank 5, a lower tower pipeline 11 and a heat storage heat exchanger 7, wherein the heat absorber 4 and the outlet cache tank 5 are both arranged at the top end of the heat absorption tower; the heat storage heat exchanger 7 comprises a heat absorption medium channel and a heat storage medium channel, the upper tower pipeline 12, the heat absorber 4, the outlet buffer tank 5, the lower tower pipeline 11 and the heat absorption medium channel are sequentially communicated in a circulating mode, and a heat absorption pump 6 for providing power for heat absorption circulation is arranged on the heat absorption medium circulating loop.

The invention does not specifically limit where the heat absorption pump 6 is arranged in the heat absorption medium circulation loop, and is preferably arranged on the outlet cache tank 5 or in the outlet cache tank 5, and specifically, the heat absorption pump 6 is arranged on the outlet cache tank 5 if the temperature of the heat absorption medium is higher according to the determination of the heat absorption medium, the inlet of the heat absorption pump extends into the outlet cache tank, and the outlet of the heat absorption pump is communicated with the lower tower pipeline.

In this embodiment, the inlet of the outlet buffer tank 5 is communicated with the outlet of the heat absorber 4 through a pipeline, and the inlet of the heat absorber 4 is connected with the upper end of the upper tower pipeline 12. The outlet of the outlet buffer tank 5 is arranged at the bottom of the outlet buffer tank 5, the outlet is communicated with the lower tower pipeline 11 through a third pipeline, and the third pipeline is further provided with a discharge valve 501.

The heat-absorbing medium supply and recovery tank 1 is arranged on the ground and is a storage container for heat-absorbing medium, and is communicated with the lower end of the upper tower pipeline 12 through a first pipeline, and a control valve 103 is arranged on the first pipeline; the heat-absorbing medium supply and recovery tank 1 is connected with a pressurizing mechanism through a second pipeline, and a stamping valve 101 is arranged on the second pipeline; the heat absorbing medium supply and recovery tank 1 is also provided with a pressure release valve 102, and when the heat absorbing medium needs to be recovered, the pressure release valve 102 is opened to reduce the pressure of the heat absorbing medium supply and recovery tank 1; with the control valve 103 open, the heat absorbing medium can be returned by gravity to the heat absorbing medium supply recovery tank 1.

The pressurizing mechanism is not particularly limited, for example, the heat-absorbing medium supply recovery tank 1 can be pressurized by gas, that is, the pressurizing mechanism is a gas pressurizing mechanism, the gas source can be air, but is not limited to air, and any gas which does not chemically react with the heat-absorbing medium can be used, such as nitrogen, argon, helium and the like. Specifically, the gas pressurizing mechanism comprises a gas compressor 3 and a compressed gas storage tank 2, and the gas compressor 3 supplies gas to the heat-absorbing medium supply and recovery tank 1 through the compressed gas storage tank 2.

And a heat absorption check valve 13 is further arranged at the outlet of the heat absorption medium channel, and specifically, the heat absorption check valve 13 is arranged on the upper tower pipeline 12 and is positioned between the control valve 103 and the outlet of the heat absorption medium channel.

In the present embodiment, when the heat-absorbing medium is required to be output to the outside from the heat-absorbing medium supply and recovery tank 1, the ram valve 101 is opened, the relief valve 102 is closed, the pressure of the heat-absorbing medium supply and recovery tank 1 is raised, and the heat-absorbing medium can be output to the outside with the control valve 103 opened.

The heat storage system comprises a low-temperature heat storage tank 8 and a high-temperature heat storage tank 10 which are arranged on the ground, the low-temperature heat storage tank 8 and the high-temperature heat storage tank 10 are respectively communicated with the inlet and the outlet of the heat storage medium channel, and when the heat storage system operates, the low-temperature heat storage tank 8 conveys the low-temperature heat storage medium in the heat storage medium channel to the heat storage medium channel through a heat storage pump 9. The heat storage pump 9 may be disposed in the low-temperature heat storage tank 8 or on the low-temperature heat storage tank 8, and specifically, when the heat storage medium is molten salt, the temperature of the molten salt is relatively high, so that the heat storage pump 9 is disposed on the low-temperature heat storage tank 8, an inlet of the heat storage pump extends into the low-temperature heat storage tank 8, and an outlet of the heat storage pump is communicated with an inlet of the heat storage medium channel.

In this embodiment, the heat storage pump 9 delivers the low-temperature heat storage medium in the low-temperature heat storage tank 8 to the heat storage medium channel of the heat storage heat exchanger 7, and exchanges heat with the heat absorbing medium in the heat absorbing medium channel to make the low-temperature heat storage medium become a high-temperature heat storage medium and return to the high-temperature heat storage tank 10, so as to realize heat storage. The invention does not specifically limit the type of the heat storage medium, such as molten metal, molten salt and the like, in the embodiment, the molten salt is taken as an example, the system adopts a heat exchange mode of the heat storage medium and the heat absorption medium to communicate the upper tower pipeline 12 and the lower tower pipeline 11 of the heat absorption system, the gravity of the molten salt in the lower tower pipeline 11 is fully utilized, the lift of the molten salt pump is greatly reduced, the equipment reliability of the molten salt pump can be increased, the running power of the molten salt pump can be reduced, the service power consumption is reduced, and the economical efficiency of the system is provided.

The heat absorbing medium supply and recovery tank 1 is a storage container for heat absorbing medium, and its storage volume needs to be simultaneously not less than (preferably greater than):

(1) the sum of the volume of a connecting pipeline between the heat absorbing medium supply and recovery tank 1 and the heat absorbing medium circulation loop and the volume of the whole heat absorbing medium circulation loop;

(2) and under the condition that the heat absorption pump 6 has a fault, ensuring the total amount of heat absorption medium of the heat absorber 4 which normally runs for 1 min.

In this embodiment, the heat-absorbing medium supply and recovery tank 1, the outlet buffer tank 5, the low-temperature heat storage tank 8 and the high-temperature heat storage tank 10 are all provided with at least one liquid level meter.

All equipment and pipelines in the system are provided with an anti-condensation heating device and a temperature measuring device.

The invention also provides a heat absorption and storage method of the tower type solar power station, and the system adopting the embodiment comprises the following steps:

s1: the pressure release valve 102, the stamping valve 101 and the heat storage pump 9 are closed, the control valve 103 is opened, the heat absorption pump 6 is opened, and the stamping valve 101 is opened after the liquid level of the heat absorption medium supply recovery tank 1 reaches a certain height;

s2: the pressure in the heat absorption medium supply and recovery tank 1 is continuously increased, the liquid level is continuously reduced, and finally the heat absorption medium is maintained at a certain height and enters the heat absorber 4 through the upper tower pipeline 12;

s3: after the heat absorption medium absorbs heat through the heat absorber 4, the high-temperature heat absorption medium sequentially enters the outlet cache tank 5, the lower tower pipeline 11 and the heat absorption medium channel of the heat storage heat exchanger 7 from the outlet pipeline of the heat absorber 4 and sequentially circulates;

s4: when the temperature of the heat absorbing medium rises to a certain value, the heat storage pump 9 is started, the low-temperature heat storage medium enters the heat storage medium channel of the heat storage heat exchanger 7 from the low-temperature heat storage tank 8 for heat exchange, the heat storage medium after heat exchange enters the high-temperature heat storage tank 10 through a pipeline, and the heat storage medium flows in sequence.