A high-pressure steam system based on molten salt energy storage

Abstract

The utility model discloses a kind of high-pressure steam systems based on molten salt energy storage, belong to molten salt energy storage steam supply technical field.The system includes sequentially interconnected desalted water tank, primary heater, deaerator, secondary heater, preheater, evaporator, steam drum and superheater, the desalted water tank and primary heater are communicated by desalted water pump, the deaerator and secondary heater are communicated by feed water pump;The preheater is heat exchanger, and cyclically communicated with hot molten salt tank and cold molten salt tank, the molten salt temperature in the hot molten salt tank is 550 DEG C;The exhaust port of the superheater is communicated steam supply pipeline, to output temperature not less than 320 DEG C, pressure not less than 6MPa high-pressure steam.The utility model aims at solving the problem that steam parameter is unstable when existing steam supply system utilizes molten salt energy storage, difficult to meet industrial high-pressure steam demand, directly provide high-pressure steam, reduce secondary pressurization or intermediate heat exchange link, system thermal efficiency is improved by 10%.

Description

Technical Field

[0001] This utility model belongs to the field of energy storage technology, specifically relating to a high-pressure steam system based on molten salt energy storage. Background Technology

[0002] Molten salt energy storage systems are widely used in the solar thermal field. They use heliostats and heat absorbers to heat molten salt and generate high-pressure steam to power turbine generator sets. Thermal power units are modified with electric heaters and molten salt systems to improve their flexibility, tapping into their peak-shaving capacity and supplying low-pressure steam or hot water. Electric heaters heat ternary molten salt and output low-pressure steam after heat exchange, which is used on a small scale in industrial parks.

[0003] Currently, direct steam supply systems using molten salt systems suffer from low steam flow, low temperature, and low pressure, as well as low conversion efficiency, failing to meet the demands of high-pressure, high-temperature industrial loads. Using thermal power units for heating involves energy efficiency losses due to recompression or pressurization and intermediate heat exchange, and also results in significant fluctuations in boiler output pressure. Utility Model Content

[0004] The purpose of this invention is to provide a high-pressure steam system for molten salt energy storage, thereby solving the aforementioned technical problems in the prior art.

[0005] Therefore, the technical solution provided by this utility model is as follows: A high-pressure steam system based on molten salt energy storage includes a demineralized water tank, a primary heater, a deaerator, a secondary heater, a preheater, an evaporator, a steam drum, and a superheater connected in sequence. The demineralized water tank and the primary heater are connected by a demineralized water pump, and the deaerator and the secondary heater are connected by a feed water pump. The preheater is a heat exchanger, and the preheater is circulated and connected to the hot molten salt tank and the cold molten salt tank. The temperature of the molten salt in the hot molten salt tank is 550°C. The exhaust port of the superheater is connected to the steam supply pipeline. The high-pressure steam temperature is not less than 320°C and the pressure is not less than 6MPa.

[0006] It also includes a water supply electric heater, a controller, and a temperature sensor. The water supply electric heater is located between the secondary heater and the preheater, and the temperature sensor is located at the inlet of the preheater. Both the water supply electric heater and the temperature sensor are electrically connected to the controller.

[0007] The superheater is connected to a steam bypass pipe, and an electric regulating valve is installed on the steam bypass pipe. The electric regulating valve is electrically connected to the controller.

[0008] The steam drum has a horizontal structure and is equipped with a secondary steam-water separator.

[0009] The evaporator is a U-shaped shell-and-tube heat exchanger.

[0010] The superheater is a horizontal hairpin heat exchanger, with the feed water flowing through the pipe side.

[0011] The beneficial effects of this utility model are as follows: This utility model provides a high-pressure steam system based on molten salt energy storage. Utilizing a binary molten salt energy storage system, it generates high-pressure superheated steam by exchanging energy between high-temperature molten salt and water vapor. This steam meets the process steam supply needs of industries such as chemical, power, and pharmaceutical, avoiding the energy efficiency losses of traditional electric boilers or steam recompression. It directly provides high-pressure steam, reducing secondary pressurization or intermediate heat exchange links, and improving system thermal efficiency by 10%. The output steam temperature and pressure are stable, ensuring the continuity of industrial processes. The steam supply load can be quickly switched within the range of 10%-100%, with a short response time.

[0012] This high-pressure steam system uses a temperature sensor installed at the preheater inlet to detect the feedwater temperature entering the preheater in real time and send the data to the controller. When the detected temperature is lower than the set value, the controller starts the feedwater electric heater to heat the water before it enters the preheater, ensuring that the feedwater temperature is higher than the molten salt anti-condensation temperature. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of one embodiment of the present invention.

[0014] Explanation of reference numerals in the attached diagram: 1. Demineralized water tank; 2. Demineralized water pump one; 3. Demineralized water pump two; 4. Primary heater; 5. Deaerator; 6. Electric feedwater pump one; 7. Electric feedwater pump two; 8. Electric feedwater pump three; 9. Secondary heater one; 10. Secondary heater two; 11. Feedwater electric heater; 12, 13. Preheater; 14. Evaporator one; 15. Evaporator two; 16. Steam drum one; 17. Steam drum two; 18. Superheater one; 19. Superheater two. Detailed Implementation

[0015] The following specific embodiments illustrate the implementation of the utility model. Those skilled in the art can easily understand other advantages and effects of the utility model from the content disclosed in this specification.

[0016] Exemplary embodiments of the utility model are now described with reference to the accompanying drawings. However, the utility model can be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the utility model and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments shown in the drawings is not intended to limit the utility model. In the drawings, the same units / elements are referred to by the same reference numerals.

[0017] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0018] Example 1 This utility model provides a high-pressure steam system based on molten salt energy storage, including a demineralized water tank 1, a primary heater 4, a deaerator 5, a secondary heater, a preheater, an evaporator, a steam drum, and a superheater connected in sequence. The demineralized water tank and the primary heater are connected by a demineralized water pump, and the deaerator and the secondary heater are connected by a feed water pump. The preheater is a heat exchanger, and the preheater is circulated and connected to the hot molten salt tank and the cold molten salt tank. The temperature of the molten salt in the hot molten salt tank is 550°C. The exhaust port of the superheater is connected to the steam supply pipeline. The high-pressure steam temperature is not less than 320°C and the pressure is not less than 6 MPa.

[0019] Working principle of this utility model: Chemically treated demineralized water is added to demineralized water tank 1. The demineralized water in tank 1, heated by a primary heater, is then pumped into the deaerator. The deaerated water is further heated in the deaerator and then pumped through a low-pressure feedwater pipeline into a secondary heater for further heating. It then sequentially enters the preheater, evaporator, steam drum, and superheater. The energy for heating and pressurizing the steam comes from the high-temperature molten salt system on the equipment shell side. Through staged heat exchange using hot molten salt, high-pressure superheated steam with a pressure of not less than 6 MPa and a temperature of not less than 320°C is generated, providing steam to industrial users.

[0020] Example 2 Based on Example 1, this example provides a high-pressure steam system based on molten salt energy storage, which also includes a feedwater electric heater 11, a controller, and a temperature sensor. The feedwater electric heater 11 is located between the secondary heater and the preheater, and the temperature sensor is located at the inlet of the preheater. Both the feedwater electric heater and the temperature sensor are electrically connected to the controller.

[0021] The high-pressure steam system uses a temperature sensor installed at the preheater inlet to detect the feedwater temperature entering the preheater in real time and send the data to the controller. When the detected temperature is lower than the set value, the controller starts the feedwater electric heater 11 to heat the water before it enters the preheater, ensuring that the feedwater temperature is higher than the molten salt anti-condensation temperature. When the detected feedwater temperature is higher than the set value, the controller sends a signal to shut down the feedwater electric heater 11.

[0022] Example 3 Based on Example 1, this example provides a high-pressure steam system based on molten salt energy storage. The superheater is connected to a steam bypass pipe, and the steam bypass pipe is equipped with an electric regulating valve. The electric regulating valve is electrically connected to the controller.

[0023] The opening of the electric regulating valve is adjusted by the controller, thereby adjusting and switching the steam supply load within a certain range. Commands can also be sent to the controller via a remote control unit (RTU), which, upon receiving the command, sends a signal to control the opening of the electric regulating valve.

[0024] Example 4 To provide a more detailed description of this utility model, this embodiment provides a high-pressure steam system based on molten salt energy storage, taking the generation of 8MPa / 350℃ superheated steam as an example.

[0025] like Figure 1 As shown, there is one demineralized water tank 1 with a volume of 150m³. 3 The auxiliary steam or demineralized water from the external system is heated to 80°C by the primary heater 4. The demineralized water is further heated to 160°C in the deaerator and then flows through the low-pressure feedwater pipeline to the secondary heater via the feedwater pump to heat the water temperature to 255°C. The heater is started to ensure that the feedwater temperature entering the preheater is higher than 255°C. The technical parameters for starting the feedwater heater are: initial temperature 160°C, target temperature 255°C, feedwater flow rate 55.5t / h, rated power 6600kW, and container material SA-240GR347H.

[0026] The demineralized water pump is used to provide demineralized water pressure to the deaerator. Two demineralized water pumps are configured (Demineralized Water Pump 1-2 and Demineralized Water Pump 2-3, one in operation and one on standby). The technical parameters are: design pressure 2.5MPa, design temperature 50℃, mass flow rate 330t / h, and head 112 meters.

[0027] The feedwater pump is used to supply water pressure to the steam generator. Three feedwater pumps are configured (electric feedwater pump 1-6, electric feedwater pump 2-7, and electric feedwater pump 3-8, one in operation and two on standby). The technical parameters are: design pressure 9.4MPa, design temperature 300℃, mass flow rate 528t / h, and head 975m.

[0028] Two preheaters (Preheater 1-12 and Preheater 2-13) are installed, with molten salt as the heat source. The preheaters are shell-and-tube heat exchangers, and the feedwater flows through the tube side. The tube-side technical parameters are: operating temperature (inlet / outlet) 250 / 296℃, design temperature (inlet / outlet) 325℃, operating pressure 8.8MPa, design pressure 9.7MPa, main material Q345R, and design dimension 8m. 1.3m 1.8m.

[0029] Two steam drums (Drum 1, unit 16; Drum 2, unit 17) are horizontal in structure and employ two-stage separation, achieving extremely high separation efficiency. The technical parameters of the steam drums are: design pressure 9.8 MPa, design temperature 325℃, working medium: water and steam, main material: 13MnNiMoR, and equipment volume: 30.4 m³. 3 The equipment weighs 102.4 tons and has a length of 17 meters. 2.1m 2.8m.

[0030] Two evaporators (Evaporator 14 and Evaporator 25) are the main heat exchange equipment in the steam-water evaporation system. They adopt U-tube shell-and-tube heat exchangers and consist of tube boxes, pipe systems, shells, and other components. Steam / water flows on the tube side. The technical parameters of the evaporators are as follows: equipment type BEU, working medium water and steam, working temperature (inlet / outlet) 299 / 300℃, design temperature (inlet / outlet) 325℃, working pressure 8.53MPa, design pressure 9.4MPa, net weight 36t, and main material 347H.

[0031] Two superheaters (superheater 18 and superheater 219) are used to improve the efficiency of the water vapor evaporation system by heating saturated steam to superheated steam.

[0032] In this embodiment, the superheater is a horizontal hairpin heat exchanger, with feedwater flowing through the tubes. The superheater's technical parameters are: equipment type BEU, working medium: steam, operating temperature (inlet / outlet): 299 / 355℃, design temperature (inlet / outlet): 370℃, operating pressure: 8.43MPa, design pressure: 9.3MPa, net weight: 4.75t, and dimensions: 4.45m. 0.8m 1.4m, main material 347H.

[0033] In summary, the high-pressure steam system based on molten salt energy storage provided by this utility model utilizes a binary molten salt energy storage system to generate high-pressure superheated steam through energy exchange between high-temperature molten salt and water vapor. This steam meets the process steam supply needs of industries such as chemical, power, and pharmaceutical, avoiding the energy efficiency losses of traditional electric boilers or steam recompression. It directly provides high-pressure steam, reducing secondary pressurization or intermediate heat exchange links, and improving the system thermal efficiency by 10%. The output steam temperature and pressure are stable, ensuring the continuity of industrial processes. The steam supply load can be quickly switched within the range of 10%-100%, with a short response time.

[0034] The examples above are merely illustrative of utility models and do not constitute a limitation on the scope of protection of utility models. All designs that are the same as or similar to utility models fall within the scope of protection of utility models.

Claims

1. A high-pressure steam system based on molten salt energy storage, characterized in that: It includes a demineralized water tank, a primary heater, a deaerator, a secondary heater, a preheater, an evaporator, a steam drum, and a superheater connected in sequence. The demineralized water tank and the primary heater are connected by a demineralized water pump, and the deaerator and the secondary heater are connected by a feed water pump. The preheater is a heat exchanger, and the preheater is circulated and connected to the hot molten salt tank and the cold molten salt tank. The temperature of the molten salt in the hot molten salt tank is 550°C. The exhaust port of the superheater is connected to the steam supply pipeline. The high-pressure steam temperature is not less than 320°C and the pressure is not less than 6MPa.

2. The high-pressure steam system based on molten salt energy storage according to claim 1, characterized in that: It also includes a water supply electric heater, a controller, and a temperature sensor. The water supply electric heater is located between the secondary heater and the preheater, and the temperature sensor is located at the inlet of the preheater. Both the water supply electric heater and the temperature sensor are electrically connected to the controller.

3. A high-pressure steam system based on molten salt energy storage according to claim 2, characterized in that: The superheater is connected to a steam bypass pipe, and an electric regulating valve is installed on the steam bypass pipe. The electric regulating valve is electrically connected to the controller.

4. A high-pressure steam system based on molten salt energy storage according to any one of claims 1-3, characterized in that: The steam drum has a horizontal structure and is equipped with a secondary steam-water separator.

5. A high-pressure steam system based on molten salt energy storage according to any one of claims 1-3, characterized in that: The evaporator is a U-shaped shell-and-tube heat exchanger.

6. A high-pressure steam system based on molten salt energy storage according to any one of claims 1-3, characterized in that: The superheater is a horizontal hairpin heat exchanger, with the feed water flowing through the pipe side.

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