Steam supply equipment and system for coal power unit

Abstract

The utility model relates to the technical field of power generation, and discloses a steam supply device and system for a coal power unit, in the steam supply device for the coal power unit, a pipeline for introducing main steam is communicated with a steam inlet of a main steam heat exchange device, and an outlet of a first fused salt tank is communicated with a fused salt inlet of the main steam heat exchange device; a fused salt outlet of the main steam heat exchange device is communicated with an inlet of the second fused salt tank; an outlet of the second fused salt tank is communicated with a fused salt inlet of the fused salt heat exchange device, a fused salt outlet of the fused salt heat exchange device is communicated with an inlet of the first fused salt tank, an outlet of the water feeding pump is communicated with a water feeding inlet of the fused salt heat exchange device, and a steam outlet of the fused salt heat exchange device is communicated with an inlet of the medium-pressure heat supply header. Therefore, when the coal power unit is in the deep peak regulation stage, heat in the high-temperature fused salt can be released to generate steam for steam supply, and therefore the coal power unit can meet the heat supply requirements of heat consumers in the deep peak regulation stage.

Description

Technical Field

[0001] The present application relates to the technical field of power generation, and in particular to a steam supply device for a coal-fired power unit and a steam supply system for a coal-fired power unit. Background Art

[0002] Under the trend of global low-carbon economy and energy revolution, new energy power generation such as photovoltaic and wind power has ushered in rapid development, and will eventually gradually replace thermal power generation from auxiliary energy to become the main energy source.

[0003] As the proportion of new energy generation such as photovoltaic and wind power increases, thermal power units will become the main force of peak load regulation, and the duration of peak and valley of power grid will gradually increase. In actual applications, the parameters of industrial heating are generally high, for example, the steam pressure is generally 1MPa~4MPa, and the steam temperature is generally 300℃~400℃, which makes it difficult for thermal power units to provide heat during deep peak load regulation.

[0004] Therefore, there is an urgent need for new heating methods to meet the heating needs of heat users. Utility Model Content

[0005] The purpose of this application is to overcome the problem of difficulty in heating thermal power units during deep peak regulation in the prior art, and to provide a steam supply device and system for coal-fired power units.

[0006] In a first aspect, the present application provides a coal-fired power unit steam supply device, the coal-fired power unit steam supply device comprising a steam heat storage unit, a molten salt energy storage unit and a steam generation unit;

[0007] The steam heat storage unit includes a pipeline for introducing main steam and a main steam heat exchange device; the molten salt energy storage unit includes a first molten salt tank, a second molten salt tank and a first transmission pipeline; the steam generation unit includes a feed water pump, a molten salt heat exchange device and a medium-pressure heating manifold;

[0008] The pipeline for introducing main steam is connected to the steam inlet of the main steam heat exchange device, the outlet of the first molten salt tank is connected to the molten salt inlet of the main steam heat exchange device through the first delivery pipeline, and the molten salt outlet of the main steam heat exchange device is connected to the inlet of the second molten salt tank;

[0009] The outlet of the second molten salt tank is connected to the molten salt inlet of the molten salt heat exchanger, the molten salt outlet of the molten salt heat exchanger is connected to the inlet of the first molten salt tank, the outlet of the water feed pump is connected to the water feed inlet of the molten salt heat exchanger, and the steam outlet of the molten salt heat exchanger is connected to the inlet of the medium-pressure heating manifold.

[0010] In an embodiment of the present application, the steam thermal storage unit further includes a pipeline for introducing reheated steam and a reheated steam heat exchange device, and the molten salt energy storage unit further includes a second transport pipeline;

[0011] The pipeline for introducing reheated steam is connected to the steam inlet of the reheated steam heat exchanger, the steam outlet of the reheated steam heat exchanger is connected to the inlet of the medium-pressure heating manifold, the outlet of the first molten salt tank is connected to the molten salt inlet of the reheated steam heat exchanger through the second conveying pipeline, and the molten salt outlet of the reheated steam heat exchanger is connected to the inlet of the second molten salt tank.

[0012] In the embodiment of the present application, the steam heat storage unit further includes a pipeline for introducing four-extraction steam, a four-extraction steam heat exchange device and a low-pressure heating manifold, and the molten salt energy storage unit further includes a third transmission pipeline;

[0013] The pipeline for introducing four-extraction steam is connected to the steam inlet of the four-extraction steam heat exchange device, the steam outlet of the four-extraction steam heat exchange device is connected to the inlet of the low-pressure heating manifold, the outlet of the first molten salt tank is connected to the molten salt inlet of the four-extraction steam heat exchange device through the third conveying pipeline, and the molten salt outlet of the four-extraction steam heat exchange device is connected to the inlet of the second molten salt tank.

[0014] In the embodiment of the present application, the main steam heat exchange device includes a main steam superheater, a main steam condenser and a condensed water subcooler connected in sequence;

[0015] The main steam introduced into the main steam heat exchange device flows through the main steam superheater, the main steam condenser and the condensate subcooler in sequence;

[0016] The molten salt transported by the first transport pipeline flows through the condensate subcooler, the main steam condenser and the main steam superheater in sequence.

[0017] In an embodiment of the present application, the molten salt heat exchange device comprises a molten salt superheater, a molten salt evaporator and a molten salt preheater connected in sequence;

[0018] The molten salt outputted from the second molten salt tank flows through the molten salt superheater, the molten salt evaporator and the molten salt preheater in sequence;

[0019] The water output by the water feed pump flows through the molten salt preheater, the molten salt evaporator and the molten salt superheater in sequence.

[0020] In an embodiment of the present application, the coal-fired power unit steam supply equipment further includes a main steam temperature reduction and pressure reduction valve, and the main steam temperature reduction and pressure reduction valve is arranged on the pipeline for introducing main steam.

[0021] In an embodiment of the present application, the coal-fired power unit steam supply equipment further includes a reheated steam temperature reduction and pressure reduction valve, and the reheated steam temperature reduction and pressure reduction valve is arranged on the pipeline for introducing reheated steam.

[0022] In an embodiment of the present application, the coal-fired power unit steam supply equipment further includes a four-extraction steam temperature and pressure reduction valve, and the four-extraction steam temperature and pressure reduction valve is arranged on the pipeline for introducing four-extraction steam.

[0023] In the embodiment of the present application, the first molten salt tank and the second molten salt tank are both provided with a molten salt distribution ring pipe, a liquid level sensor, a temperature sensor, a pressure sensor and a breathing valve.

[0024] A second aspect of the present application provides a steam supply system for a coal-fired power plant, wherein the steam supply system comprises a controller and the steam supply equipment for the coal-fired power plant described in the first aspect, and the controller is connected to the steam supply equipment for the coal-fired power plant.

[0025] By adopting the above scheme, the steam supply equipment of the coal-fired power unit includes a steam heat storage unit, a molten salt energy storage unit and a steam generating unit; the steam heat storage unit includes a pipeline for introducing main steam and a main steam heat exchange device; the molten salt energy storage unit includes a first molten salt tank, a second molten salt tank and a first transmission pipeline; the steam generating unit includes a feed water pump, a molten salt heat exchange device and a medium-pressure heating manifold; wherein, the pipeline for introducing main steam is connected to the steam inlet of the main steam heat exchange device, the outlet of the first molten salt tank is connected to the molten salt inlet of the main steam heat exchange device through the first transmission pipeline, and the molten salt outlet of the main steam heat exchange device is connected to the inlet of the second molten salt tank; the outlet of the second molten salt tank is connected to the molten salt inlet of the molten salt heat exchange device, the molten salt outlet of the molten salt heat exchange device is connected to the inlet of the first molten salt tank, the outlet of the feed water pump is connected to the feed water inlet of the molten salt heat exchange device, and the steam outlet of the molten salt heat exchange device is connected to the inlet of the medium-pressure heating manifold. Based on the solution provided in the embodiment of the present application, when the coal-fired power generation unit is not in short supply and has the ability to supply steam to the outside, the heat of the main steam can be used to heat the low-temperature molten salt to obtain the high-temperature molten salt to store the heat; when the coal-fired power unit is in the deep peak-shaving stage, the heat in the high-temperature molten salt can be released to generate steam for steam supply. In this way, the coal-fired power unit can also meet the heating needs of heat users in the deep peak-shaving stage.

[0026] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0028] Figure 1 The structural diagram of a steam supply device for a coal-fired power unit according to an embodiment of the present application is schematically shown.

[0029] Description of Reference Numerals

[0030] 100—steam supply equipment for coal-fired power units; 1011—main steam superheater; 1012—main steam condenser; 1013—condensate subcooler; 102—first molten salt tank; 103—second molten salt tank; 104—feedwater pump; 1051—molten salt superheater; 1052—molten salt evaporator; 1053—molten salt preheater; 106—medium-pressure heating manifold; 107—high-pressure cylinder; 108—main steam desuperheating and pressure reducing valve; 109—main steam flow regulating valve; 110—main steam desuperheating water flow regulating valve ; 111—main steam stop valve; 112—reheat steam heat exchange device; 113—intermediate pressure cylinder; 114—reheat steam temperature reduction and pressure reducing valve; 115—reheat steam flow regulating valve; 116—reheat steam temperature reduction water flow regulating valve; 117—reheat steam stop valve; 118—four-extraction steam heat exchange device; 119—low-pressure heating manifold; 120—four-extraction steam temperature reduction and pressure reducing valve; 121—four-extraction steam flow regulating valve; 122—four-extraction steam temperature reduction water flow regulating valve; 123—four-extraction steam stop valve. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0032] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), such directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0033] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0034] As described in the background technology, as the proportion of new energy power generation such as photovoltaic and wind power increases, thermal power units will become the main force of peak regulation, and the duration of peak and valley of the power grid will gradually increase. In actual applications, the parameters of industrial heating are generally high (for example, the steam pressure is generally 1MPa~4MPa, and the steam temperature is generally 300℃~400℃), and there are many heat users with different heating parameter requirements. This makes it difficult for thermal power units to take into account the needs of high-parameter industrial heat users during deep peak regulation, and the heating capacity is also insufficient, making heating difficult.

[0035] In view of this, in one embodiment of the present application, a coal-fired power unit steam supply device 100 is provided, such as Figure 1 As shown, the coal-fired power unit steam supply equipment 100 may include a steam heat storage unit, a molten salt energy storage unit and a steam generating unit; the steam heat storage unit includes a pipeline A for introducing main steam and a main steam heat exchange device; the molten salt energy storage unit includes a first molten salt tank 102, a second molten salt tank 103 and a first transmission pipeline B; the steam generating unit includes a feed water pump 104, a molten salt heat exchange device and a medium-pressure heating manifold 106; the pipeline A for introducing main steam is connected to the steam inlet of the main steam heat exchange device, and the first molten salt tank 10 The outlet of 2 is connected with the molten salt inlet of the main steam heat exchanger through the first conveying pipeline B, and the molten salt outlet of the main steam heat exchanger is connected with the inlet of the second molten salt tank 103; the outlet of the second molten salt tank 103 is connected with the molten salt inlet of the molten salt heat exchanger, the molten salt outlet of the molten salt heat exchanger is connected with the inlet of the first molten salt tank 102, the outlet of the feed water pump 104 is connected with the feed water inlet of the molten salt heat exchanger, and the steam outlet of the molten salt heat exchanger is connected with the inlet of the medium-pressure heating manifold 106.

[0036] Among them, the coal-fired power unit steam supply equipment 100 provided in the embodiment of the present application may also include a high-pressure cylinder 107. The pipeline A for introducing main steam can draw out the main steam from the pipeline that transports the main steam to the high-pressure cylinder 107, and introduce the main steam into the main steam heat exchange device.

[0037] The main steam heat exchange device can be used to exchange heat between the main steam and the molten salt with a lower temperature output by the first molten salt tank 102. In order to realize the step-by-step utilization of energy, so that the energy is fully utilized, in the embodiment of the present application, the main steam heat exchange device may include a main steam superheater 1011, a main steam condenser 1012 and a condensate supercooler 1013 connected in sequence, the main steam introduced into the main steam heat exchange device flows through the main steam superheater 1011, the main steam condenser 1012 and the condensate supercooler 1013 in sequence, and the molten salt transported by the first delivery pipeline B flows through the condensate supercooler 1013, the main steam condenser 1012 and the main steam superheater 1011 in sequence. After the main steam is finally heat exchanged in the condensate supercooler 1013, it can be transported to the deaerator, and the molten salt transported by the first delivery pipeline B can be transported to the second molten salt tank 103 after finally heat exchanged in the main steam superheater 1011.

[0038] In practical applications, in order to avoid thermal shock, the coal-fired power unit steam supply equipment 100 may also include a main steam temperature reduction and pressure relief valve 108; the main steam temperature reduction and pressure relief valve 108 is arranged on the pipe A for introducing the main steam. The main steam temperature reduction and pressure relief valve 108 can be used to reduce the pressure of the main steam, and can introduce cooling water to cool the main steam. In this way, the equipment can be prevented from being damaged due to excessive pressure or temperature, thereby improving the safety and stability of the equipment. In specific operations, the main steam temperature reduction and pressure relief valve 108 can be adjusted to slowly heat up the equipment.

[0039] Furthermore, the coal-fired power unit steam supply equipment 100 may also include a main steam flow regulating valve 109, a main steam desuperheating water flow regulating valve 110, and a main steam stop valve 111. The main steam flow regulating valve 109 and the main steam stop valve 111 may be sequentially arranged on the pipeline A for introducing the main steam along the main steam flow direction, and the main steam desuperheating water flow regulating valve 110 may be arranged on the desuperheating water input pipeline. Specifically, the main steam flow regulating valve 109 may be arranged upstream of the main steam desuperheating and pressure reducing valve 108, and the main steam stop valve 111 may be arranged downstream of the main steam desuperheating and pressure reducing valve 108.

[0040] In the embodiment of the present application, the temperature of the molten salt stored in the first molten salt tank 102 is lower than the temperature of the molten salt stored in the second molten salt tank 103. Therefore, the first molten salt tank 102 may also be called a low-temperature molten salt tank, and the second molten salt tank 103 may also be called a high-temperature molten salt tank.

[0041] In practical applications, the molten salt energy storage unit may also include a cold salt pump and a hot salt pump. The cold salt pump is used for the first molten salt tank 102 to output molten salt, and the hot salt pump is used for the second molten salt tank 103 to output molten salt. The first molten salt tank 102 may be provided with a molten salt distribution loop, a liquid level sensor, a temperature sensor, a pressure sensor, a basic cooling pipe, and a breathing valve, etc. The first molten salt tank 102 may specifically be a carbon steel tank (SA516Gr70). Similarly, the second molten salt tank 103 may be provided with a molten salt distribution loop, a liquid level sensor, a temperature sensor, a pressure sensor, a basic cooling pipe, and a breathing valve, etc. The second molten salt tank 103 may specifically be a carbon steel tank (SA516Gr70). In specific implementation, two cold salt pumps and two hot salt pumps may be provided, one for use and one for backup.

[0042] The molten salt heat exchange device can be used to exchange heat between the feed water with a lower temperature output by the feed water pump and the molten salt with a higher temperature output by the second molten salt tank 103. In order to realize the step-by-step utilization of energy, so that the energy is fully utilized, in the embodiment of the present application, the molten salt heat exchange device may include a molten salt superheater 1051, a molten salt evaporator 1052 and a molten salt preheater 1053 connected in sequence; the molten salt output by the second molten salt tank 103 flows through the molten salt superheater 1051, the molten salt evaporator 1052 and the molten salt preheater 1053 in sequence; the water output by the feed water pump 104 flows through the molten salt preheater 1053, the molten salt evaporator 1052 and the molten salt superheater 1051 in sequence. The molten salt output from the second molten salt tank 103 is finally heat exchanged in the molten salt preheater 1053 to become low-temperature molten salt, and can be transported back to the first molten salt tank 102. The water output from the water pump 104 is finally heat exchanged in the molten salt superheater 1051 and can be transported to the medium-pressure heating manifold 106.

[0043] In the above embodiment, the molten salt preheater 1053 can use the heat of the molten salt to preliminarily preheat the water output by the feed water pump 104; after the water output by the feed water pump 104 is preheated, it further enters the molten salt evaporator 1052 to exchange heat with the molten salt and evaporate into steam; the steam then enters the molten salt superheater 1051 to exchange heat with the molten salt to obtain steam with a higher temperature, which is then output to the medium-pressure heating manifold 106 to provide steam to the outside. In a specific implementation, the steam provided to the outside can be returned to the steam turbine to generate power or to provide heat to the outside. In a specific implementation, the water output by the feed water pump 104 can be condensed water from a low-pressure heater. In addition, two feed water pumps can be set up, one for use and one for backup.

[0044] It can be understood that the steam supply equipment 100 of the coal-fired power unit provided in the embodiment of the present application includes a steam heat storage unit, a molten salt energy storage unit and a steam generating unit; the steam heat storage unit includes a pipeline A for introducing main steam and a main steam heat exchange device; the molten salt energy storage unit includes a first molten salt tank 102, a second molten salt tank 103 and a first transmission pipeline B; the steam generating unit includes a feed water pump 104, a molten salt heat exchange device and a medium-pressure heating manifold 106; the pipeline A for introducing main steam is connected to the steam inlet of the main steam heat exchange device, The outlet of the first molten salt tank 102 is connected to the molten salt inlet of the main steam heat exchanger through the first delivery pipeline B, and the molten salt outlet of the main steam heat exchanger is connected to the inlet of the second molten salt tank 103; the outlet of the second molten salt tank 103 is connected to the molten salt inlet of the molten salt heat exchanger, the molten salt outlet of the molten salt heat exchanger is connected to the inlet of the first molten salt tank 102, the outlet of the water supply pump 104 is connected to the water supply inlet of the molten salt heat exchanger, and the steam outlet of the molten salt heat exchanger is connected to the inlet of the medium-pressure heating manifold 106. Based on the scheme provided in the embodiment of the present application, when the coal-fired power generation unit is not tight and has the ability to supply steam to the outside, the heat of the main steam can be used to heat the low-temperature molten salt to obtain high-temperature molten salt to store heat; when the coal-fired power unit is in the deep peak-shaving stage, the heat in the high-temperature molten salt can be released to generate steam for steam supply. As a result, the coal-fired power unit can also meet the heating needs of heat users in the deep peak-shaving stage.

[0045] In order to further improve the energy storage of molten salt to ensure that the heating needs of heat users are met, and to further improve the flexibility of energy storage and heating, in one embodiment, the steam heat storage unit also includes a pipeline C for introducing reheated steam and a reheated steam heat exchanger 112, and the molten salt energy storage unit also includes a second transmission pipeline D; the pipeline C for introducing reheated steam is connected to the steam inlet of the reheated steam heat exchanger 112, and the steam outlet of the reheated steam heat exchanger 112 is connected to the inlet of the medium-pressure heating manifold 106, and the outlet of the first molten salt tank 102 is connected to the molten salt inlet of the reheated steam heat exchanger 112 through the second transmission pipeline D, and the molten salt outlet of the reheated steam heat exchanger 112 is connected to the inlet of the second molten salt tank 103.

[0046] Among them, the coal-fired power unit steam supply equipment 100 provided in the embodiment of the present application may also include an intermediate pressure cylinder 113, and the pipeline C for introducing reheated steam can draw out reheated steam from the pipeline that transports reheated steam to the intermediate pressure cylinder 113, and introduce the reheated steam into the reheated steam heat exchange device 112.

[0047] The reheat steam heat exchange device 112 can be used to exchange heat between the reheat steam and the molten salt with a lower temperature output from the first molten salt tank 102. After the reheat steam is heat exchanged by the reheat steam heat exchange device 112, it can be transported to the medium-pressure heating manifold 106. After the molten salt transported by the second transport pipeline D is heat exchanged by the reheat steam heat exchange device 112, it can be transported to the second molten salt tank 103. The reheat steam heat exchange device 112 can specifically be a reheat steam superheater.

[0048] In order to avoid thermal shock, the coal-fired power unit steam supply equipment 100 may also include a reheated steam temperature reduction and pressure relief valve 114; the reheated steam temperature reduction and pressure relief valve 114 is arranged on the pipe C for introducing reheated steam. The reheated steam temperature reduction and pressure relief valve 114 can be used to reduce the pressure of the reheated steam, and can introduce cooling water to cool the reheated steam. In this way, the equipment can be prevented from being damaged due to excessive pressure or temperature, thereby improving the safety and stability of the equipment. In specific operation, the reheated steam temperature reduction and pressure relief valve 114 can be adjusted to slowly heat up the equipment.

[0049] Furthermore, the coal-fired power unit steam supply equipment 100 may also include a reheated steam flow regulating valve 115, a reheated steam desuperheating water flow regulating valve 116, and a reheated steam stop valve 117. The reheated steam flow regulating valve 115 and the reheated steam stop valve 117 may be sequentially arranged on the pipeline C for introducing the reheated steam along the reheated steam flow direction, and the reheated steam desuperheating water flow regulating valve 116 may be arranged on the desuperheating water input pipeline. Specifically, the reheated steam flow regulating valve 115 may be arranged upstream of the reheated steam desuperheating and pressure reducing valve 114, and the reheated steam stop valve 117 may be arranged downstream of the reheated steam desuperheating and pressure reducing valve 114.

[0050] In order to further improve the energy storage of molten salt and further improve the flexibility of energy storage and heating, the steam heat storage unit may also include a pipeline E for introducing four-extraction steam, a four-extraction steam heat exchange device 118 and a low-pressure heating manifold 119, and the molten salt energy storage unit also includes a third transmission pipeline F; the pipeline E for introducing four-extraction steam is connected to the steam inlet of the four-extraction steam heat exchange device 118, and the steam outlet of the four-extraction steam heat exchange device 118 is connected to the inlet of the low-pressure heating manifold 119, the outlet of the first molten salt tank 102 is connected to the molten salt inlet of the four-extraction steam heat exchange device 118 through the third transmission pipeline F, and the molten salt outlet of the four-extraction steam heat exchange device 118 is connected to the inlet of the second molten salt tank 103.

[0051] Among them, the pipeline E for introducing four-extraction steam can introduce four-extraction steam from the medium-pressure cylinder 113 to the four-extraction steam heat exchange device 118.

[0052] The four-extraction steam heat exchange device 118 can be used to exchange heat between the four-extraction steam and the molten salt with a lower temperature output from the first molten salt tank 102. After the four-extraction steam is heat exchanged by the four-extraction steam heat exchange device 118, it can be transported to the low-pressure heating manifold 119, and the molten salt transported by the third transport pipeline F can be transported to the second molten salt tank 103 after heat exchange by the four-extraction steam heat exchange device 118. The four-extraction steam heat exchange device 118 can specifically be a four-extraction steam superheater.

[0053] In order to avoid thermal shock, the coal-fired power unit steam supply equipment 100 may also include a four-extraction steam temperature reduction and pressure relief valve 120; the four-extraction steam temperature reduction and pressure relief valve 120 is arranged on the pipeline E for introducing the four-extraction steam. The four-extraction steam temperature reduction and pressure relief valve 120 can be used to reduce the pressure of the four-extraction steam, and can introduce cooling water to cool the four-extraction steam using the cooling water. In this way, the equipment can be prevented from being damaged due to excessive pressure or temperature, thereby ensuring the safety and stability of the equipment system. In specific operations, the four-extraction steam temperature reduction and pressure relief valve 120 can be adjusted to slowly heat up the equipment.

[0054] Furthermore, the coal-fired power unit steam supply equipment 100 may also include a four-extraction steam flow regulating valve 121, a four-extraction steam cooling water flow regulating valve 122, and a four-extraction steam stop valve 123. Among them, the four-extraction steam flow regulating valve 121 and the four-extraction steam stop valve 123 can be sequentially arranged on the pipeline E for introducing the four-extraction steam along the flow direction of the four-extraction steam, and the four-extraction steam cooling water flow regulating valve 122 can be arranged on the cooling water input pipeline. Specifically, the four-extraction steam flow regulating valve 121 can be arranged upstream of the four-extraction steam cooling and pressure reducing valve 120, and the four-extraction steam stop valve 123 can be arranged downstream of the four-extraction steam cooling and pressure reducing valve 120.

[0055] It can be understood that the embodiment of the present application increases the external steam supply capacity of the unit by constructing a coal-fired power unit steam supply equipment 100. Under deep peak regulation and top peak conditions, molten salt heat release can be used to generate steam for external steam supply, thereby solving the problem of industrial heating difficulties under deep peak regulation of coal-fired units.

[0056] On the other hand, through the above-mentioned coal-fired power unit steam supply equipment 100, thermal and electrical decoupling can be achieved, that is, the boiler and the steam turbine generator set can be decoupled, thereby improving the flexibility of heating supply.

[0057] In addition, the randomness, volatility and anti-peak characteristics of current renewable energy sources have brought tremendous pressure to the power balance of the power system, becoming the main obstacle to the consumption of renewable energy. Based on the above-mentioned coal-fired power unit steam supply equipment 100, the molten salt energy storage unit therein can be used to consume renewable energy, thereby providing favorable conditions for the connection of renewable energy to the grid.

[0058] In addition, compared with other energy storage technologies, molten salt energy storage has the advantages of better safety, no geographical restrictions, wide range of energy storage capacity, relatively low cost, fast response speed, high power and energy density, etc. The coal-fired power unit steam supply equipment 100 provided in the above embodiment of the present application, by constructing a molten salt energy storage unit, can achieve time shifting of energy and rapid and accurate regulation of active power through optimized configuration and coordinated control of the three sides of the source, grid and load, play a role in system peak shaving and valley filling, peak supply guarantee, safety and stability, frequency and voltage regulation, etc., and form regulation capabilities with flexible regulation resources on the source and load sides, support the stability and efficiency of the new power system, and help achieve source-load decoupling and production-consumption asynchrony.

[0059] Based on the coal-fired power unit steam supply equipment provided in the above embodiments of the present application, the embodiments of the present application also provide a coal-fired power unit steam supply system, which may include a controller and the coal-fired power unit steam supply equipment provided in any of the above embodiments, wherein the controller is connected to the coal-fired power unit steam supply equipment.

[0060] The controller is connected to the steam supply equipment of the coal-fired power unit, and specifically can be connected to various valves, various pumping devices, and various sensors in the steam supply equipment of the coal-fired power unit. For example, the controller can be connected to the main steam supply flow regulating valve 109, the main steam supply desuperheating water flow regulating valve 110, the main steam supply stop valve 111, the reheat steam supply flow regulating valve 115, the reheat steam supply desuperheating water flow regulating valve 116, the reheat steam supply stop valve 117, the four-extraction steam flow regulating valve 121, the four-extraction steam desuperheating water flow regulating valve 122, the four-extraction steam stop valve 123, the cold salt pump, the hot salt pump, and the feed water pump 104.

[0061] As a result, the controller can select different steam supply methods according to the changes in the unit's electrical load and thermal load, with the goal of maximizing energy conversion efficiency, and can choose when to perform molten salt energy storage and heat release.

[0062] For example, the steam supply methods may include at least the following three:

[0063] Method 1: When the unit is operating in normal heating conditions, that is, when the unit is not in a tight power generation situation and has the ability to supply steam to the outside, the unit can supply steam to the outside, and steam can be extracted from the unit to use molten salt for heat storage. Specifically, the main steam can be introduced into the main steam superheater, the main steam condenser and the condensate subcooler, so that the main steam can exchange heat with the low-temperature molten salt transported from the first transmission pipeline; after the main steam heat exchange is completed, it can be transported to the deaerator, and the low-temperature molten salt is heated and transported to the second molten salt tank for storage. At the same time, the four-extraction steam can be introduced into the four-extraction steam heat exchange device, so that the four-extraction steam can exchange heat with the low-temperature molten salt transported from the third transmission pipeline; after the four-extraction steam heat exchange is completed, it can be transported to the low-pressure heating manifold to supply steam to the outside, and the low-temperature molten salt is heated and transported to the second molten salt tank for storage.

[0064] Method 2: When the unit is operating in the peak power generation heating condition, the unit cannot extract steam in order to ensure high-load power generation. At this time, the molten salt can be used to release heat for steam supply. Specifically, the high-temperature molten salt can be introduced into the molten salt superheater, the molten salt evaporator and the molten salt preheater. At the same time, the feed water pump inputs water into the molten salt preheater, the molten salt evaporator and the molten salt superheater, so that the high-temperature molten salt and the water can exchange heat. After the heat exchange, the temperature of the high-temperature molten salt is reduced to become low-temperature molten salt and return to the first molten salt tank. After the heat exchange, the water is heated to superheated steam and enters the medium-pressure heating manifold to supply steam to the outside.

[0065] Method three, when the unit is operating in the low power generation valley condition, the four-extraction steam pressure can no longer meet the heating parameter requirements of the heat user, and a composite steam supply method can be used at this time. That is, the unit itself supplies steam and the molten salt releases heat to supply steam. Specifically, the main steam can be introduced into the main steam superheater, the main steam condenser and the condensate subcooler, and the reheated steam can be introduced into the reheated steam heat exchange device, so that the main steam is heat exchanged with the low-temperature molten salt transported from the first transmission pipeline, and the reheated steam is heat exchanged with the low-temperature molten salt transported from the second transmission pipeline. After the main steam heat exchange is completed, it is transported to the deaerator, and after the reheated steam heat exchange is completed, it is transported to the medium-pressure heating manifold for external steam supply. After the low-temperature molten salt is heated, it is transported to the second molten salt tank for storage. At the same time, the high-temperature molten salt can be introduced into the molten salt superheater, the molten salt evaporator and the molten salt preheater, and the water feed pump inputs water into the molten salt preheater, the molten salt evaporator and the molten salt superheater, so that the high-temperature molten salt and water are heat exchanged. After heat exchange, the high-temperature molten salt is cooled to low-temperature molten salt and returns to the first molten salt tank. After heat exchange with water, it is heated to superheated steam and enters the medium-pressure heating manifold to supply steam to the outside.

[0066] It can be understood that the steam supply system for coal-fired power units provided in the above embodiments of the present application can be used so that when the coal-fired power unit is not in short supply and has the ability to supply steam to the outside, the heat of the steam can be used to heat the low-temperature molten salt to obtain the high-temperature molten salt to store the heat; when the coal-fired power unit is in the deep peak-shaving stage, the heat in the high-temperature molten salt can be released to generate steam for steam supply, so that the coal-fired power unit can also meet the heating needs of heat users in the deep peak-shaving stage. At the same time, based on the steam supply system for coal-fired power units provided in the embodiments of the present application, it is also possible to select an appropriate steam supply method according to the changes in the electrical load and thermal load of the unit to improve the economic efficiency of heating and realize intelligent steam supply.

[0067] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0068] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A steam supply device for a coal-fired power unit, characterized in that: The steam supply equipment of the coal-fired power unit includes a steam heat storage unit, a molten salt energy storage unit and a steam generation unit; The steam heat storage unit includes a pipeline for introducing main steam and a main steam heat exchange device; the molten salt energy storage unit includes a first molten salt tank, a second molten salt tank and a first transmission pipeline; the steam generation unit includes a feed water pump, a molten salt heat exchange device and a medium-pressure heating manifold; The pipeline for introducing main steam is connected to the steam inlet of the main steam heat exchange device, the outlet of the first molten salt tank is connected to the molten salt inlet of the main steam heat exchange device through the first delivery pipeline, and the molten salt outlet of the main steam heat exchange device is connected to the inlet of the second molten salt tank; The outlet of the second molten salt tank is connected to the molten salt inlet of the molten salt heat exchanger, the molten salt outlet of the molten salt heat exchanger is connected to the inlet of the first molten salt tank, the outlet of the water feed pump is connected to the water feed inlet of the molten salt heat exchanger, and the steam outlet of the molten salt heat exchanger is connected to the inlet of the medium-pressure heating manifold.

2. The steam supply equipment for coal-fired power generation unit according to claim 1, characterized in that: The steam heat storage unit further includes a pipeline for introducing reheated steam and a reheated steam heat exchange device, and the molten salt energy storage unit further includes a second transport pipeline; The pipeline for introducing reheated steam is connected to the steam inlet of the reheated steam heat exchanger, the steam outlet of the reheated steam heat exchanger is connected to the inlet of the medium-pressure heating manifold, the outlet of the first molten salt tank is connected to the molten salt inlet of the reheated steam heat exchanger through the second conveying pipeline, and the molten salt outlet of the reheated steam heat exchanger is connected to the inlet of the second molten salt tank.

3. The steam supply equipment for coal-fired power generation unit according to claim 2, characterized in that: The steam heat storage unit also includes a pipeline for introducing four-extraction steam, a four-extraction steam heat exchange device and a low-pressure heating manifold, and the molten salt energy storage unit also includes a third transmission pipeline; The pipeline for introducing four-extraction steam is connected to the steam inlet of the four-extraction steam heat exchange device, the steam outlet of the four-extraction steam heat exchange device is connected to the inlet of the low-pressure heating manifold, the outlet of the first molten salt tank is connected to the molten salt inlet of the four-extraction steam heat exchange device through the third conveying pipeline, and the molten salt outlet of the four-extraction steam heat exchange device is connected to the inlet of the second molten salt tank.

4. The steam supply equipment for coal-fired power generation unit according to claim 1, characterized in that: The main steam heat exchange device comprises a main steam superheater, a main steam condenser and a condensed water subcooler which are connected in sequence; The main steam introduced into the main steam heat exchange device flows through the main steam superheater, the main steam condenser and the condensate subcooler in sequence; The molten salt transported by the first transport pipeline flows through the condensate subcooler, the main steam condenser and the main steam superheater in sequence.

5. The steam supply equipment for coal-fired power generation unit according to claim 1, characterized in that: The molten salt heat exchange device comprises a molten salt superheater, a molten salt evaporator and a molten salt preheater which are connected in sequence; The molten salt outputted from the second molten salt tank flows through the molten salt superheater, the molten salt evaporator and the molten salt preheater in sequence; The water output by the water feed pump flows through the molten salt preheater, the molten salt evaporator and the molten salt superheater in sequence.

6. The steam supply equipment for coal-fired power generation unit according to claim 1, characterized in that: The coal-fired power unit steam supply equipment also includes a main steam temperature reduction and pressure reduction valve, and the main steam temperature reduction and pressure reduction valve is arranged on the pipeline for introducing main steam.

7. The steam supply equipment for coal-fired power generation unit according to claim 2, characterized in that: The coal-fired power unit steam supply equipment also includes a reheated steam temperature reduction and pressure reduction valve, and the reheated steam temperature reduction and pressure reduction valve is arranged on the pipeline for introducing reheated steam.

8. The steam supply equipment for coal-fired power generation unit according to claim 3, characterized in that: The coal-fired power unit steam supply equipment also includes a four-extraction steam temperature and pressure reduction valve, and the four-extraction steam temperature and pressure reduction valve is arranged on the pipeline for introducing the four-extraction steam.

9. The steam supply equipment for coal-fired power generation unit according to claim 1, characterized in that: The first molten salt tank and the second molten salt tank are both provided with a molten salt distribution ring pipe, a liquid level sensor, a temperature sensor, a pressure sensor and a breathing valve.

10. A steam supply system for a coal-fired power unit, characterized in that: The steam supply system comprises a controller and the steam supply equipment for the coal-fired power generation unit according to any one of claims 1 to 9, and the controller is connected to the steam supply equipment for the coal-fired power generation unit.

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