A method and device for desalting blocked pipes of a molten salt heat absorber

Abstract

The present invention discloses a method and device for removing salt from blocked pipes in a molten salt heat absorber. The method involves identifying a blocked pipe area in the molten salt heat absorber and dividing it into several salt removal areas from bottom to top. Molten salt is then sequentially melted in each salt removal area from bottom to top by adjusting the energy output of the mirror field, thereby removing salt from the blocked pipes and clearing the blockage. Without adding equipment or disassembling the heat absorber, this method can reliably and effectively resolve heat absorber blockage incidents, reduce on-site power generation losses caused by accidental operating conditions, and improve the economic efficiency of the power station. This addresses the problem of existing solar thermal power stations being unable to remove salt from heat absorbers.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar thermal utilization, and in particular relates to a method and device for blocking and salting a molten salt heat absorber. Background Art

[0002] With the continuous depletion of fossil fuels and increasingly prominent environmental issues, available fossil energy resources are also decreasing, and society's demand for new energy is growing stronger. Solar energy, as a renewable energy source, is inexhaustible. Solar thermal power generation, as one of the main methods of utilizing solar energy, achieves high-efficiency photovoltaic conversion while storing solar energy as thermal energy in large-scale energy storage devices, maintaining stable power output when power is needed, such as at night.

[0003] Molten salts, with their high specific heat capacity and low vapor pressure, have been widely used in solar thermal power generation. Currently, the molten salts used in tower solar thermal power generation are primarily binary nitrates. Despite these advantages, molten salts also exhibit low-temperature solidification properties, solidifying at temperatures below approximately 230°C. Therefore, solar thermal power plants often utilize electric heating devices to heat pipes and other components. As a core component of tower solar thermal power plants, the molten salt receiver plays a crucial role in the stable and reliable operation of the power plant. During normal operation, molten salt flows within the receiver, absorbing the high-temperature energy generated by concentrated solar radiation and converting it into thermal energy. However, weather is extremely unpredictable. In extreme weather conditions, molten salt can solidify within the receiver tube panels, causing freezing and blockage of the receiver, leading to serious accidents such as receiver blockage.

[0004] Most of the existing solar thermal power plants are in the demonstration stage and do not have a reliable method to prevent absorber pipe blockage and salt formation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method and device for blocking the tubes of a molten salt heat absorber and salting it, so as to solve the problem that existing solar thermal power stations cannot achieve salting of the heat absorber.

[0006] In order to solve the above problems, the technical solution of the present invention is:

[0007] A method for blocking and salting a molten salt heat absorber according to the present invention comprises the following steps:

[0008] Step S1: Obtain the blocked pipe area and divide it into several salting areas from bottom to top;

[0009] Step S2: preparing the mirror field and delivering mirror field energy to the blocked pipe area for preheating;

[0010] Step S3: increasing the mirror field energy delivered to the lowermost salting area to perform salting operation on the lowermost salting area. After the salting is completed, step S4 is executed;

[0011] Step S4: increasing the mirror field energy delivered to the upper adjacent salting area, and performing the salting operation of the upper adjacent salting area until the salting is completed;

[0012] Step S5: Repeat step S4 until the salinization operation of the blocked pipe area is completed.

[0013] In the method for blocking and salting a molten salt heat absorber of the present invention, in step S3 and step S4, the high-temperature molten salt that has completed the salting operation is guided to be output to the upstream pipeline of the blocked pipe area.

[0014] In the molten salt heat absorber pipe plugging and salting method of the present invention, in step S2, step S3 and step S4, the spot shape and distribution of the pipe plugging area are obtained, and the mirror field arrangement is optimized according to the spot shape and distribution.

[0015] In the method for salting out a blocked pipe in a molten salt heat absorber of the present invention, in step S3, the temperature of the downstream pipe of the blocked pipe area is monitored, and whether salting out is completed is determined based on the temperature change.

[0016] In the method for blocking and salting a molten salt heat absorber of the present invention, in step S3 and step S4, the mirror field energy at the salting area after salting is completed remains unchanged.

[0017] A molten salt heat absorber pipe blocking and salting device of the present invention is applied to the above-mentioned molten salt heat absorber pipe blocking and salting method, comprising:

[0018] Heat absorber body;

[0019] A mirror field is provided on the peripheral side of the absorber body and is used to output mirror field energy to the absorber body;

[0020] A thermal sensing unit, used to sense temperature changes on the heat absorber body and obtain a pipe blockage area;

[0021] an exhaust pipe, the exhaust pipe being connected to the upstream of the heat absorber body;

[0022] A salt drainage pipeline is connected to the downstream of the heat absorber body and is used to output the melted molten salt to an external salt storage unit.

[0023] The molten salt heat absorber pipe blocking and salting device of the present invention also includes a circulation pipeline;

[0024] A booster pump is provided on the circulation pipeline; the input end of the circulation pipeline is connected to the salt-removing pipeline, and the output end of the circulation pipeline is connected to the exhaust pipeline or the upstream of the heat absorber body.

[0025] The molten salt heat absorber pipe blocking and salting device of the present invention is provided with an air pump and an air heater on the exhaust pipe.

[0026] The molten salt heat absorber pipe blocking and salting device of the present invention has a temperature measuring unit provided on the salt drainage pipeline.

[0027] The molten salt heat absorber pipe blocking and salting device of the present invention also includes a light spot sensing unit for detecting the shape and distribution of the light spot formed by the mirror field on the heat absorber body.

[0028] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0029] One embodiment of the present invention identifies the blocked area of a molten salt heat sink and divides it into several salt-dissolving zones from bottom to top. By adjusting the energy output of the mirror field, the molten salt is sequentially melted in each salt-dissolving zone from bottom to top, thereby dissolving and clearing the blocked tubes. Without adding equipment or disassembling the heat sink, this method reliably and effectively resolves heat sink blockages, reduces on-site power generation losses caused by accidents, and improves the economic efficiency of the power plant, resolving the problem of existing CSP plants being unable to dissolve the heat sinks. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the molten salt heat absorber pipe blocking and salting method of the present invention;

[0031] Figure 2 It is a schematic diagram of the molten salt heat absorber pipe blocking and salting device of the present invention.

[0032] Explanation of the reference numerals: 1: upper side of the absorber tube panel; 2: lower side of the absorber tube panel; 3: exhaust pipe; 4: desalting pipe; 5: circulation pipe; 6: booster pump; 7: exhaust valve; 8: air pump; 9: temperature measuring unit; 10: desalting valve; 11: mirror field; 12: thermal sensing unit. DETAILED DESCRIPTION

[0033] The following is a detailed description of a method and device for blocking and salting a molten salt heat absorber proposed by the present invention, with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0034] See Figure 1 and Figure 2 In one embodiment, a method for blocking and salting a molten salt heat absorber comprises the following steps:

[0035] Step S1: Obtain the blocked pipe area and divide it into several salting areas from bottom to top;

[0036] Step S2: The mirror field 11 is prepared and the mirror field energy is delivered to the blocked pipe area for preheating;

[0037] Step S3: increasing the mirror field energy delivered to the lowermost salting area to perform salting operation on the lowermost salting area. After the salting is completed, step S4 is executed;

[0038] Step S4: increasing the mirror field energy delivered to the upper adjacent salting area, and performing the salting operation of the upper adjacent salting area until the salting is completed;

[0039] Step S5: Repeat step S4 until the salinization operation of the blocked pipe area is completed.

[0040] This embodiment identifies the blocked area of a molten salt heat absorber and divides it into several salt-dissolving areas from bottom to top. By adjusting the energy output of the mirror field, the molten salt is sequentially melted in each salt-dissolving area from bottom to top, thereby dissolving and unblocking the blocked pipes in the molten salt heat absorber. Without adding equipment or disassembling the heat absorber, this method reliably and effectively resolves heat absorber blockages, reduces on-site power generation losses caused by accidents, improves the economic efficiency of the power plant, and addresses the problem of existing CSP plants being unable to dissolve the heat absorber salts.

[0041] The following is a further description of the steps of the molten salt heat absorber pipe blocking and salting method of this embodiment:

[0042] In this embodiment, the blocked pipe area can be obtained by a thermal sensing unit 12, such as an infrared camera, that is, by performing infrared sensing on the heat absorber body. When the temperature at a certain location is lower than a preset value, it is determined that the location is a blocked pipe area.

[0043] In step S3 and step S4 of this embodiment, the high-temperature molten salt that has completed the salting operation can be further guided to be output to the upstream pipeline of the blocked pipe area, and the liquid molten salt that has completed the salting operation can be used to infiltrate the solid molten salt in the blocked pipe area to assist the salting.

[0044] In steps S2, S3, and S4 of this embodiment, a light spot sensing unit (e.g., a light spot camera) may be further provided to obtain the light spot shape and distribution in the blocked pipe area, and the arrangement of the mirror field 11 may be optimized based on the light spot shape and distribution, so that the energy distribution of the mirror field is more reasonable, thereby achieving a better salt treatment effect.

[0045] In step S3 of this embodiment, the temperature of the pipeline downstream of the blocked area is monitored, and the completion of salting is determined based on the temperature change. To determine whether salting is complete, a temperature measuring unit 9 is installed in the pipeline downstream of the heat absorber body. When the molten salt melts within the heat absorber body, it flows to the downstream pipeline under the action of gravity. At this time, the temperature measuring unit 9 can detect the temperature change and thus determine whether salting is complete.

[0046] In steps S3 and S4 of this embodiment, the mirror field energy in the salt-forming area where salt-forming is completed remains unchanged. That is, although the salt-forming operation is completed at this area, the original mirror field energy must still be maintained to ensure that the molten salt in the upper salt-forming area does not re-solidify when flowing to the lower area.

[0047] The following uses the absorber body as an example to illustrate the molten salt absorber tube blocking and salt removal method of this embodiment through a specific example:

[0048] Step S11: preheating equipment and pipelines;

[0049] Step S21: preparing the mirror field 11;

[0050] Step S31: preheating the absorber tube panel;

[0051] Step S41: increasing the energy of the lower side 2 of the absorber tube panel to perform salt treatment on the lower side of the tube panel;

[0052] Step S51: increasing the energy of the upper side 1 of the absorber tube panel to perform salt treatment on the upper side of the tube panel (i.e., dividing the blocked tube area into two upper and lower salt treatment areas);

[0053] Step S61: complete salting.

[0054] If the salting of the lower side of the absorber tube panel 2 is not complete, the mirror field energy of the lower side of the absorber tube panel 2 will continue to be increased. If the salting of the lower side of the absorber tube panel 2 is complete, the energy of the upper side of the absorber tube panel 1 will be increased to carry out the salting of the upper side of the absorber tube panel 1. If the salting of the upper side of the absorber tube panel 1 is not complete, the mirror field energy of the upper side of the absorber tube panel 1 will continue to be increased to carry out the salting until the salting is complete. After the salting of the lower side is complete, the energy of the lower tube panel should still be maintained, while the energy of the upper tube panel should be increased to carry out the salting.

[0055] In other embodiments, step S42 can be performed between steps S41 and S51 to perform salt treatment in the middle of the tube panel. The energy of the tube panel is increased by first increasing the lower side of the tube panel, then the middle side, and then the upper side. (That is, the blocked tube panel area is divided into three salt treatment areas: upper, middle, and lower.)

[0056] Example 2

[0057] See Figure 2This embodiment provides a molten salt heat absorber pipe plugging and salt removal device, which is applied to the molten salt heat absorber pipe plugging and salt removal method described in the first embodiment. The specific structure may include a heat absorber body, a mirror field 11, a thermal sensing unit 12, an exhaust pipe 3, and a salt removal pipe 4.

[0058] A mirror field 11 is located around the heat absorber body and is used to output energy from the mirror field to the heat absorber body. A thermal sensing unit 12 is used to sense temperature changes on the heat absorber body and identify blocked pipe areas. An exhaust pipe 3 is connected upstream of the heat absorber body and is equipped with an exhaust valve 7. A salt drainage pipe 4 is connected downstream of the heat absorber body and is equipped with a salt drainage valve 10 to discharge the melted molten salt to an external salt storage unit.

[0059] By rationally adjusting the mirror field spot, the blocked tubes of the absorber body are gradually salted out from the bottom to the top. This can reliably and effectively solve the blockage accident of the absorber without adding equipment or disassembling the absorber, reduce the on-site power generation loss caused by the accident condition, and improve the economy of the power station.

[0060] The following takes the absorber body as an example of the absorber tube panel to further illustrate the specific structure of the molten salt absorber tube blocking and salting device of this embodiment:

[0061] In this embodiment, the molten salt heat absorber pipe plugging and salt removal device further includes a circulation pipeline 5. A booster pump 6 is provided on the circulation pipeline 5. The input end of the circulation pipeline 5 is connected to the salt removal pipeline 4, and the output end of the circulation pipeline 5 is connected to the exhaust pipeline 3 or upstream of the heat absorber tube panel. Its main function is to melt a portion of the frozen salt. The booster pump 6 can then pump molten salt into the exhaust pipeline or upstream of the heat absorber tube panel. The liquid molten salt penetrates the solid molten salt, assisting in salt removal.

[0062] In this embodiment, an air pump 8 and an air heater are provided on the exhaust pipe 3, and the heated high-pressure air is input into the absorber tube panel to assist in the deblocking of frozen salt in the absorber tube panel.

[0063] In this embodiment, a temperature measuring unit 9 is provided on the salt dilution pipeline 4. When the molten salt melts in the absorber tube panel, it will flow through the salt dilution pipeline under the action of gravity, so that the completion of the salt dilution can be determined based on the temperature change.

[0064] In this embodiment, the molten salt absorber pipe plugging and salt removal device also includes a spot sensing unit for detecting the shape and distribution of the spot formed by the mirror field 11 on the absorber body, thereby optimizing and adjusting the mirror field 11 based on the spot shape and distribution. Specifically, the thermal sensing unit 12 and the spot sensing unit can be an infrared camera and a spot camera, respectively, and their number can be arranged as needed.

[0065] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the scope of protection of the present invention.

Claims

1. A method for blocking and salting a molten salt heat absorber, characterized in that: Here are the steps: Step S1: Obtain the blocked pipe area and divide it into several salting areas from bottom to top; Step S2: preparing the mirror field and delivering mirror field energy to the blocked pipe area for preheating; Step S3: increasing the mirror field energy delivered to the lowermost salting area to perform salting operation on the lowermost salting area. After the salting is completed, step S4 is executed; Step S4: increasing the mirror field energy delivered to the upper adjacent salting area, and performing the salting operation of the upper adjacent salting area until the salting is completed; Step S5: Repeat step S4 until the salt treatment operation in the blocked pipe area is completed; In step S3 and step S4, the mirror field energy at the salt-treated area where salt treatment is completed remains unchanged.

2. The method for blocking and salting a molten salt heat absorber according to claim 1, wherein: In step S3 and step S4, the high-temperature molten salt that has completed the salting operation is guided to be output to the upstream pipeline of the pipe blocking area.

3. The method for blocking and salting a molten salt heat absorber according to claim 1, wherein: In the step S2, the step S3 and the step S4, the light spot shape and distribution of the pipe blocking area are obtained, and the mirror field arrangement is optimized according to the light spot shape and distribution.

4. The method for blocking and salting a molten salt heat absorber according to claim 1, wherein: In step S3, the temperature of the downstream pipeline of the blocked pipe area is monitored, and whether the salt treatment is completed is determined based on the temperature change.

5. A molten salt heat absorber pipe blocking and salting device, characterized in that: The method for blocking and salting a molten salt heat absorber according to claims 1 to 4 comprises: Heat absorber body; A mirror field is provided on the peripheral side of the absorber body and is used to output mirror field energy to the absorber body; A thermal sensing unit, used to sense temperature changes on the heat absorber body and obtain a pipe blockage area; an exhaust pipe, the exhaust pipe being connected to the upstream of the heat absorber body; A salt drainage pipeline is connected to the downstream of the heat absorber body and is used to output the melted molten salt to an external salt storage unit.

6. The molten salt heat absorber pipe blocking and salting device according to claim 5, characterized in that: Also includes circulation piping; A booster pump is provided on the circulation pipeline; the input end of the circulation pipeline is connected to the salt-removing pipeline, and the output end of the circulation pipeline is connected to the exhaust pipeline or the upstream of the heat absorber body.

7. The molten salt heat absorber pipe blocking and salting device according to claim 5, characterized in that: An air pump and an air heater are provided on the exhaust pipeline.

8. The molten salt heat absorber pipe blocking and salting device according to claim 5, characterized in that: A temperature measuring unit is provided on the salt diversion pipeline.

9. The molten salt heat absorber pipe blocking and salting device according to claim 5, characterized in that: It also includes a light spot sensing unit for detecting the shape and distribution of the light spot formed by the mirror field on the heat absorber body.

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