阅读说明：本技术 一种太阳能光热电站的熔融盐管路预热装置及预热方法 (Molten salt pipeline preheating device and method for solar photo-thermal power stations ) 是由 金建祥 徐能 宓霄凌 毕文剑 唐亚平 余志勇 陈明强 高越 戈晓闻 于 2019-10-21 设计创作，主要内容包括：本发明涉及一种太阳能光热电站的熔融盐管路预热装置及预热方法,其中,预热装置包括风机、空气预热器、冷盐罐空气预热系统和热盐罐空气预热系统,空气预热器依次与冷盐罐空气预热系统和热盐罐空气预热系统连接后,再分别与蒸汽发生系统和吸热系统连接后,最后再与空气预热器形成预热循环回路,流经熔融盐储热系统、蒸汽发生系统和吸热系统的空气经空气预热器对风机鼓出的常温空气预热后排入大气。本发明采用储罐内的热量直接对管道及设备进行预热,避免了现有采用电伴热预热的方式,减少了能源消耗,降低了吸热系统的启动成本,同时增加了系统的可靠性。(The invention relates to a molten salt pipeline preheating device and a preheating method of solar photo-thermal power stations, wherein the preheating device comprises a fan, an air preheater, a cold salt tank air preheating system and a hot salt tank air preheating system, the air preheater is sequentially connected with the cold salt tank air preheating system and the hot salt tank air preheating system, then respectively connected with a steam generation system and a heat absorption system, and finally forms a preheating circulation loop with the air preheater, and the air flowing through the molten salt heat storage system, the steam generation system and the heat absorption system preheats the normal temperature air blown out by the fan through the air preheater and then is discharged into the atmosphere.)

1, solar energy light and heat power station's fused salt pipeline preheating device, solar energy light and heat power station includes fused salt heat-retaining system, heat absorption system and steam generation system, fused salt heat-retaining system includes cold salt jar and hot salt jar, its characterized in that, preheating device includes fan, air heater, cold salt jar air preheating system and hot salt jar air preheating system:

the fan is sequentially connected with the cold salt tank air preheating system and the hot salt tank air preheating system through the air preheater through pipelines, the cold salt tank air preheating system comprises a cold salt tank air heat exchanger and a cold salt tank air heat exchanger bypass pipeline, the cold salt tank air heat exchanger is connected with the cold salt tank air heat exchanger bypass pipeline in parallel, the cold salt tank air heat exchanger is arranged in the cold salt tank, the cold salt tank air heat exchanger bypass pipeline is arranged outside the cold salt tank, and valves are arranged on the cold salt tank air heat exchanger bypass pipeline and the air inlet and outlet pipelines of the cold salt tank air heat exchanger;

the hot salt tank air preheating system comprises a hot salt tank air heat exchanger and a hot salt tank air heat exchanger bypass pipeline, the hot salt tank air heat exchanger is connected with the hot salt tank air heat exchanger bypass pipeline in parallel, the hot salt tank air heat exchanger is arranged in the hot salt tank, the hot salt tank air heat exchanger bypass pipeline is arranged outside the hot salt tank, and valves are arranged on the hot salt tank air heat exchanger bypass pipeline and the hot salt tank air heat exchanger air inlet and outlet pipelines;

the air preheater is sequentially connected with the cold salt tank air preheating system and the hot salt tank air preheating system, then respectively connected with the steam generation system and the heat absorption system, and finally forms a preheating circulation loop with the air preheater, and the air flowing through the molten salt heat storage system, the steam generation system and the heat absorption system is preheated by the air preheater and then discharged into the atmosphere after the normal temperature air blown out by the fan is preheated.

2. The molten salt pipeline preheating device for solar photo-thermal power stations, as claimed in claim 1, wherein the cold salt tank is connected to the heat absorption system through a molten salt ascending pipeline, a valve is provided on the molten salt ascending pipeline, this valve is located at the molten salt outlet end of the cold salt tank, the hot salt tank is connected to the heat absorption system through a molten salt descending pipeline, a valve is provided on the molten salt descending pipeline, this valve is located at the molten salt inlet end of the hot salt tank;

the air outlet of the hot salt tank air preheating system is connected with the molten salt descending pipeline through a preheating pipeline, the preheating pipeline is provided with a valve , the molten salt ascending pipeline is connected with the inlet of the air preheater through a pipeline, the pipeline is provided with a valve , or

The air outlet of the hot salt tank air preheating system is connected with the molten salt ascending pipeline through a pipeline, a valve is arranged on the pipeline, the molten salt descending pipeline is connected with the inlet of the air preheater through a pipeline, and a valve is arranged on the pipeline.

3. The molten salt pipeline preheating device for solar photothermal power stations according to claim 2, wherein a inlet buffer tank is further provided between the molten salt ascending pipeline and the heat absorption system, a outlet buffer tank is further provided between the molten salt descending pipeline and the heat absorption system, an inlet of the outlet buffer tank is connected to an outlet of the inlet buffer tank through a pipeline, an outlet of the outlet buffer tank is connected to an inlet of the inlet buffer tank through a pipeline, an upper header and a lower header of the heat absorption system are provided in parallel between the two pipelines, and an inlet end and an outlet end of each of the two pipelines are provided with a valve .

4. The molten salt pipeline preheating device for solar photo-thermal power stations according to claim 1, wherein an air outlet of the air preheating system of the hot salt tank is connected with an inlet of a molten salt pipeline of the steam generation system through a pipeline, and a valve is arranged on the pipeline;

and the outlet of the molten salt pipeline of the steam generation system is connected with the inlet of the air preheater through a pipeline, and a valve is arranged on the pipeline.

5. The preheating device for molten salt pipelines of solar photo-thermal power stations according to claim 1, wherein temperature sensors are disposed at the inlet and outlet of the air heat exchanger of the cold salt tank and the air heat exchanger of the hot salt tank.

6. The method for preheating the molten salt pipeline of solar photo-thermal power stations as claimed in any one of claims 1 to 5 and , wherein the method comprises the following steps:

s1, blowing air out of the fan, primarily heating the air by the air preheater, and then entering an air preheating system of the cold salt tank, wherein if the temperature of the air primarily heated by the air preheater is lower than the temperature of salt in the cold salt tank, the air enters an air heat exchanger of the cold salt tank to be continuously heated; if the temperature of the air primarily heated by the air preheater is higher than the temperature of salt in the cold salt tank, the air enters a bypass pipeline of an air heat exchanger of the cold salt tank;

s2, enabling air from the cold salt tank air preheating system to enter a hot salt tank air preheating system, and if the temperature of the air from the cold salt tank air preheating system meets the requirement, enabling the air to respectively enter pipelines of a steam generation system and a heat absorption system through a hot salt tank air heat exchanger bypass pipeline for preheating; if the temperature of the air from the cold salt tank air preheating system does not meet the requirement, the air firstly enters the hot salt tank air heat exchanger to be continuously heated and then respectively enters the steam generation system and the heat absorption system to be preheated;

and S3, preheating normal-temperature air blown out by the fan by the air preheater and then discharging the air flowing through the molten salt heat storage system, the steam generation system and the heat absorption system into the atmosphere.

Technical Field

The invention relates to the technical field of solar photo-thermal power stations, in particular to a molten salt pipeline preheating device and method for solar photo-thermal power stations.

Background

The solar thermal power generation technology uses solar energy to generate power, is important directions for large-scale solar energy utilization, has the most competitive advantage that the solar thermal power generation technology is easily combined with a heat storage system at , and can get rid of the influence caused by instability of solar energy through the heat storage system.

At present, a solar molten salt tower type power generation system comprises a heat collection system and a power generation system, wherein the heat collection system mainly conveys molten salt in a cold salt tank to a heat absorption system through a molten salt ascending pipeline, the cold molten salt obtains hot molten salt by absorbing heat energy converted from light energy in the heat absorption system, and the hot molten salt is conveyed to a hot salt tank through a molten salt descending pipeline to store heat; the power generation system mainly uses the heat in the hot salt tank to heat water to obtain hot steam to drive a generator to generate power, and finally the hot steam is output in the form of electric energy.

However, in the solar molten salt tower power generation system, molten salt with a high freezing point is used as a heat medium to transfer heat energy in the heat absorption tower, and when the operation of the heat collection system is stopped, the molten salt is solidified to block a pipeline. Therefore, the equipment and the pipelines in the system need to be preheated before the solar photo-thermal power station is started. The preheating mode mainly adopted at present is an electric tracing preheating mode, the defects that the electric tracing using amount is large, the electric tracing fault rate is high, the electric tracing fault rate is easy to damage and the like exist, meanwhile, the power consumption in the preheating process is large, the preheating time is long, and the condition that the station power consumption of a power station is high is caused.

Disclosure of Invention

In order to solve the above problems, the invention provides a molten salt pipeline preheating device of solar thermal power stations, wherein each solar thermal power station comprises a molten salt heat storage system, a heat absorption system and a steam generation system, the molten salt heat storage system comprises a cold salt tank and a hot salt tank, and the preheating device comprises a fan, an air preheater, a cold salt tank air preheating system and a hot salt tank air preheating system:

the fan is sequentially connected with the cold salt tank air preheating system and the hot salt tank air preheating system through the air preheater through pipelines, the cold salt tank air preheating system comprises a cold salt tank air heat exchanger and a cold salt tank air heat exchanger bypass pipeline, the cold salt tank air heat exchanger is connected with the cold salt tank air heat exchanger bypass pipeline in parallel, the cold salt tank air heat exchanger is arranged in the cold salt tank, the cold salt tank air heat exchanger bypass pipeline is arranged outside the cold salt tank, and valves are arranged on the cold salt tank air heat exchanger bypass pipeline and the air inlet and outlet pipelines of the cold salt tank air heat exchanger;

the hot salt tank air preheating system comprises a hot salt tank air heat exchanger and a hot salt tank air heat exchanger bypass pipeline, the hot salt tank air heat exchanger is connected with the hot salt tank air heat exchanger bypass pipeline in parallel, the hot salt tank air heat exchanger is arranged in the hot salt tank, the hot salt tank air heat exchanger bypass pipeline is arranged outside the hot salt tank, and valves are arranged on the hot salt tank air heat exchanger bypass pipeline and the hot salt tank air heat exchanger air inlet and outlet pipelines;

the air preheater is sequentially connected with the cold salt tank air preheating system and the hot salt tank air preheating system, then respectively connected with the steam generation system and the heat absorption system, and finally forms a preheating circulation loop with the air preheater, and the air flowing through the molten salt heat storage system, the steam generation system and the heat absorption system is preheated by the air preheater and then discharged into the atmosphere after the normal temperature air blown out by the fan is preheated.

Preferably, the cold salt tank is connected with the heat absorption system through a molten salt ascending pipeline, a valve is arranged on the molten salt ascending pipeline, the valve is positioned at the molten salt outlet end of the cold salt tank, the hot salt tank is connected with the heat absorption system through a molten salt descending pipeline, an valve is arranged on the molten salt descending pipeline, and the valve is positioned at the molten salt inlet end of the hot salt tank;

the air outlet of the hot salt tank air preheating system is connected with the molten salt descending pipeline through a preheating pipeline, the preheating pipeline is provided with a valve , the molten salt ascending pipeline is connected with the inlet of the air preheater through a pipeline, the pipeline is provided with a valve , or

The air outlet of the hot salt tank air preheating system is connected with the molten salt ascending pipeline through a pipeline, a valve is arranged on the pipeline, the molten salt descending pipeline is connected with the inlet of the air preheater through a pipeline, and a valve is arranged on the pipeline.

Preferably, an inlet buffer tank is further arranged between the molten salt ascending pipeline and the heat absorption system, a outlet buffer tank is further arranged between the molten salt descending pipeline and the heat absorption system, an inlet of the outlet buffer tank is connected with an outlet of the inlet buffer tank through a pipeline, an outlet of the outlet buffer tank is connected with an inlet of the inlet buffer tank through a pipeline, an upper header and a lower header of the heat absorption system are arranged between the two pipelines in parallel, and inlet ends and outlet ends of the two pipelines are provided with valves .

Preferably, an air outlet of the hot salt tank air preheating system is connected with a molten salt pipeline inlet of the steam generation system through a pipeline, and a valve is arranged on the pipeline;

and the outlet of the molten salt pipeline of the steam generation system is connected with the inlet of the air preheater through a pipeline, and a valve is arranged on the pipeline.

Preferably, temperature sensors are arranged on the inlet and the outlet of the air heat exchanger of the cold salt tank and the air heat exchanger of the hot salt tank.

The invention also provides a molten salt pipeline preheating method of solar photo-thermal power stations, which comprises the following steps:

s1, blowing air out of the fan, primarily heating the air by the air preheater, and then entering an air preheating system of the cold salt tank, wherein if the temperature of the air primarily heated by the air preheater is lower than the temperature of salt in the cold salt tank, the air enters an air heat exchanger of the cold salt tank to be continuously heated; if the temperature of the air primarily heated by the air preheater is higher than the temperature of salt in the cold salt tank, the air enters a bypass pipeline of an air heat exchanger of the cold salt tank;

s2, enabling air from the cold salt tank air preheating system to enter a hot salt tank air preheating system, and if the temperature of the air from the cold salt tank air preheating system meets the requirement, enabling the air to respectively enter pipelines of a steam generation system and a heat absorption system through a hot salt tank air heat exchanger bypass pipeline for preheating; if the temperature of the air from the cold salt tank air preheating system does not meet the requirement, the air firstly enters the hot salt tank air heat exchanger to be continuously heated and then respectively enters the steam generation system and the heat absorption system to be preheated;

and S3, preheating normal-temperature air blown out by the fan by the air preheater and then discharging the air flowing through the molten salt heat storage system, the steam generation system and the heat absorption system into the atmosphere.

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

according to the invention, the original preheating mode is replaced, the pipeline and the equipment are directly preheated by adopting the heat in the storage tank, the influence of overtemperature or damage of an electric tracing preheating mode on the system is avoided, the reliability of the system is increased, the energy consumption is reduced, the starting cost of the heat absorption system is reduced, and the efficiency and the economy of the system are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

FIG. 1 is a schematic structural diagram of a molten salt pipeline preheating device of a solar photothermal power station provided by embodiments of the invention;

fig. 2 is a schematic structural diagram of a molten salt pipeline preheating device of a solar photothermal power station according to another embodiments of the present invention.

Detailed Description

The molten salt pipeline preheating device for solar thermal power stations provided by the present invention will be described in detail with reference to fig. 1 to 2, and this 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 color the molten salt pipeline preheating device without changing the spirit and content of the present invention.