Device and method suitable for controlling generation of medium-grade steam by power station fused salt heat storage system

Abstract

The invention discloses a device and method suitable for a power station fused salt heat storage system to control generation of medium-grade steam, and relates to the technical field of compressed air. The device comprises a control cabinet, a high-pressure steam conveying unit, a low-pressure steam conveying unit, a turbine transmission unit, a piston compression unit, a damping storage unit, a first medium-pressure steam conveying unit, a second medium-pressure steam conveying unit, a steam buffer mixing unit, a steam output unit and a molten salt tank, and the method comprises the steps S11, S12, S13, S14 and S15. The turbine transmission unit drives the piston compression unit to compress low-pressure steam for boosting, so that the treatment efficiency is improved; due to the fact that the pressure of the first medium-pressure steam and the pressure of the second medium-pressure steam which are mixed are close to each other, the two kinds of steam cannot collide intensely during mixing, energy loss of a traditional ejector device in the steam mixing process is avoided, and heat exchange efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of compressed air technology, and in particular to a device and method suitable for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station. Background Art

[0002] Currently, the ejector, a key power device based on the principles of fluid mechanics, consists of three core components: a Laval nozzle with a converging design, a Venturi mixing chamber with specific geometric parameters, and a gradually diverging pressure recovery section. High-pressure driven fluid creates a critical flow state at the nozzle throat, achieving a coordinated conversion of enthalpy and flow velocity, generating a low-pressure zone below ambient pressure, thereby enabling the ejection of the target fluid. Typical applications for the high-pressure driven fluid are superheated steam, and the target fluid is low-temperature regenerative steam. The two fluids undergo momentum exchange and energy recombination in the turbulent flow field of the mixing chamber. The kinetic energy is gradually converted into pressure energy through the diffuser flow channel, ultimately outputting a pressure-gained mixed fluid. This mixed fluid then generates low-pressure regenerative steam by driving the high-pressure steam. After mixing, it is pressurized and output through the diffuser. It is widely used in mixing, compression, vacuum transportation, and waste heat recovery.

[0003] The application, published as CN119713237A and titled "Thermoelectric Decoupling System with Molten Salt Energy Storage and Method for Improving Its Efficiency," extracts a portion of the main steam and reheat steam from the boiler under steady-state load conditions to store energy through heat-to-heat conversion. Due to the momentum and energy exchange between the two gases, the two steam streams, with their large pressure differential, collide violently and exchange energy, leading to irreversible losses. This reduces the efficiency of the jet pressure matcher and results in significant energy losses.

[0004] The application, published as CN119062416A, is titled "A Coal-fired Power Generation System with Steam-Heated Molten Salt Thermal Storage Coupled with a Steam Ejector and Its Operation Method." Due to the momentum and energy exchange between the two gases, the two steam streams with a large pressure difference collide violently and exchange energy, leading to irreversible losses. This reduces the efficiency of the jet-type pressure matcher and results in significant energy losses.

[0005] Traditional steam pressure matching devices generally use an ejector structure, which has significant drawbacks in the energy conversion process. The main steam (pressure P1, enthalpy H1) and the reheated steam (pressure P2, enthalpy H2) undergo non-isentropic mixing in the mixing chamber. This generates shock wave losses when ejected through the convergent-divergent nozzle. The shock wave number δ exceeds 0.3, and the Mach number in the diffuser exceeds the limit of Ma>0.6, leading to secondary vortex losses. CFD simulations have confirmed that traditional devices have an energy loss rate of 22-28%, and suffer from operating condition adaptability defects with a pressure fluctuation amplitude of ±8%.

[0006] Therefore, the large energy loss in the process of generating medium-grade steam has become a technical problem that needs to be solved urgently. Summary of the Invention

[0007] The present invention provides a device and method for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station, which solves the technical problem of large energy loss in the process of generating medium-grade steam.

[0008] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0009] In the first aspect, a device suitable for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station comprises a control cabinet, a high-pressure steam conveying unit, a low-pressure steam conveying unit, a turbine transmission unit, a piston compression unit, a damping storage unit, a first medium-pressure steam conveying unit, a second medium-pressure steam conveying unit, a steam buffer mixing unit, a steam output unit and a molten salt tank, wherein the high-pressure steam conveying unit, the turbine transmission unit and the first medium-pressure steam conveying unit are sequentially connected to the first input end of the steam buffer mixing unit, the low-pressure steam conveying unit, the piston compression unit, the damping storage unit and the second medium-pressure steam conveying unit are sequentially connected to the second input end of the steam buffer mixing unit, the output end of the steam buffer mixing unit is connected to the molten salt tank via the steam output unit, the turbine transmission unit is movably connected to the piston compression unit, and the control cabinet is electrically connected to the high-pressure steam conveying unit, the low-pressure steam conveying unit, the turbine transmission unit, the damping storage unit, the first medium-pressure steam conveying unit, the second medium-pressure steam conveying unit, the steam buffer mixing unit and the steam output unit respectively.

[0010] A further technical solution is that: the turbine transmission unit includes a steam turbine assembly, a motor and a speed sensor, the piston compression unit includes a crankshaft connecting rod mechanism and a piston compression mechanism, the damping storage unit includes a steam desuperheater, a continuous damping tank and a damping tank side pressure and temperature sensor, the high-pressure steam delivery unit is connected to the input end of the steam turbine assembly, the output end of the steam turbine assembly is connected to the input end of the first medium-pressure steam delivery unit, the rotating shaft of the motor is fixedly connected to the rotating shaft of the steam turbine assembly, the speed sensor is fixedly connected to the rotating shaft of the steam turbine assembly, and the rotating shaft of the steam turbine assembly It is rotatably connected to one end of the crankshaft connecting rod mechanism, and the other end of the crankshaft connecting rod mechanism is movably connected to the piston compression mechanism. The low-pressure steam delivery unit is connected and conducted with the input end of the piston compression mechanism, and the output end of the piston compression mechanism is connected and conducted with the input end of the continuous damping tank via the steam desuperheater. The output end of the continuous damping tank is communicated with the input end of the second medium-pressure steam delivery unit, and the damping tank side pressure and temperature sensor is fixedly connected to the continuous damping tank; the speed sensor and the damping tank side pressure and temperature sensor are respectively electrically connected to and communicate with the control cabinet, and the control cabinet is respectively electrically connected to the corresponding control ends of the motor and the steam desuperheater.

[0011] A further technical solution is that: the high-pressure steam delivery unit includes a high-pressure steam connecting pipe, a high-pressure steam side electric-controlled valve, a high-pressure steam side electro-hydraulic servo valve and a high-pressure steam side temperature regulating valve, the high-pressure steam connecting pipe is connected to the input end of the turbine transmission unit, the high-pressure steam side electric-controlled valve, the high-pressure steam side electro-hydraulic servo valve and the high-pressure steam side temperature regulating valve are all fixedly connected to the high-pressure steam connecting pipe, the high-pressure steam side electric-controlled valve, the high-pressure steam side electro-hydraulic servo valve and the high-pressure steam side temperature regulating valve are connected to the input end of the turbine transmission unit in sequence; the control cabinet is electrically connected to the corresponding control ends of the high-pressure steam side electric-controlled valve, the high-pressure steam side electro-hydraulic servo valve and the high-pressure steam side temperature regulating valve respectively.

[0012] A further technical solution is that: the low-pressure steam delivery unit includes a low-pressure steam connecting pipe, a low-pressure steam side electric-controlled valve, a low-pressure steam side electro-hydraulic servo valve, a low-pressure steam side temperature regulating valve, a low-pressure steam side check valve and an electric actuator, the low-pressure steam connecting pipe is connected to the input end of the piston compression unit, the electric actuator, the low-pressure steam side check valve, the low-pressure steam side temperature regulating valve, the low-pressure steam side electro-hydraulic servo valve and the low-pressure steam side electric-controlled valve are all fixedly connected to the low-pressure steam connecting pipe, the low-pressure steam side electric-controlled valve, the low-pressure steam side electro-hydraulic servo valve, the low-pressure steam side temperature regulating valve, the low-pressure steam side check valve and the electric actuator are connected to the input end of the piston compression unit in sequence; the control cabinet is electrically connected to the corresponding control ends of the electric actuator, the low-pressure steam side temperature regulating valve, the low-pressure steam side electro-hydraulic servo valve and the low-pressure steam side electric-controlled valve respectively.

[0013] A further technical solution is that: the first medium-pressure steam delivery unit includes a first medium-pressure steam connecting pipe, a first medium-pressure steam side pressure and temperature sensor, a first medium-pressure steam side electric control valve, a first medium-pressure steam side temperature regulating valve, a first medium-pressure steam side pressure regulating valve and a first medium-pressure steam side check valve, the output end of the turbine transmission unit is connected to the first input end of the steam buffer mixing unit through the first medium-pressure steam connecting pipe, the first medium-pressure steam side pressure and temperature sensor, the first medium-pressure steam side electric control valve, the first medium-pressure steam side temperature regulating valve, the first medium-pressure steam side pressure regulating valve and the first medium-pressure The steam side check valves are all fixedly connected to the first medium-pressure steam connecting pipe, and the first medium-pressure steam side pressure and temperature sensor, the first medium-pressure steam side electric-controlled valve, the first medium-pressure steam side temperature regulating valve, the first medium-pressure steam side pressure regulating valve and the first medium-pressure steam side check valve are sequentially connected to the first input end of the steam buffer mixing unit; the first medium-pressure steam side pressure and temperature sensor is electrically connected to and communicates with the control cabinet, and the control cabinet is respectively electrically connected to the corresponding control ends of the first medium-pressure steam side electric-controlled valve, the first medium-pressure steam side temperature regulating valve, the first medium-pressure steam side pressure regulating valve and the first medium-pressure steam side check valve;

[0014] The second medium-pressure steam delivery unit includes a second medium-pressure steam connecting pipe, a steam discharge valve, a second medium-pressure steam side electric-controlled valve, a second medium-pressure steam side temperature regulating valve, a second medium-pressure steam side pressure regulating valve and a second medium-pressure steam side check valve. The output end of the damping storage unit is connected to the second input end of the steam buffer mixing unit via the second medium-pressure steam connecting pipe. The steam discharge valve, the second medium-pressure steam side electric-controlled valve, the second medium-pressure steam side temperature regulating valve, the second medium-pressure steam side pressure regulating valve and the second medium-pressure steam side check valve are all fixedly connected to the second medium-pressure steam connecting pipe. The steam discharge valve, the second medium-pressure steam side electric-controlled valve, the second medium-pressure steam side temperature regulating valve, the second medium-pressure steam side pressure regulating valve and the second medium-pressure steam side check valve are connected to the second input end of the steam buffer mixing unit in sequence; the control cabinet is electrically connected to the corresponding control ends of the second medium-pressure steam side check valve, the second medium-pressure steam side pressure regulating valve, the second medium-pressure steam side temperature regulating valve, the second medium-pressure steam side electric-controlled valve and the steam discharge valve respectively.

[0015] A further technical solution is that: the steam buffer mixing unit includes a buffer mixer, a variable throat nozzle and a mixing side pressure and temperature sensor, the buffer mixer is equipped with a baffle, the variable throat nozzle is fixedly connected to the output end of the buffer mixer, the mixing side pressure and temperature sensor is fixedly connected to the buffer mixer, the variable throat nozzle is connected to the input end of the molten salt tank via the steam output unit; the mixing side pressure and temperature sensor is electrically connected to and communicates with the control cabinet;

[0016] The steam output unit includes an output steam connecting pipe, a pressure transmitter and a steam outlet valve. The output end of the steam buffer mixing unit is connected to the input end of the molten salt tank via the output steam connecting pipe. The pressure transmitter and the steam outlet valve are both fixedly connected to the output steam connecting pipe. The pressure transmitter and the steam outlet valve are connected to the input end of the molten salt tank in sequence; the pressure transmitter is electrically connected to and communicates with the control cabinet, and the control cabinet is electrically connected to the control end of the steam outlet valve.

[0017] In a second aspect, a further technical solution is that: it also includes a heater, the heater is fixedly connected to the first medium-pressure steam delivery unit, and the control cabinet is electrically connected to the heater.

[0018] In a third aspect, a method for controlling the generation of medium-grade steam in a molten salt heat storage system of a power plant is provided, based on the device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power plant described in the first aspect, comprising the following steps:

[0019] Step S11: The control cabinet controls the low-pressure steam delivery unit to operate and conduct, and the low-pressure steam P2 enters the piston compression unit and the damping storage unit through the low-pressure steam delivery unit;

[0020] Step S12: The control cabinet controls the operation of the motor of the turbine transmission unit and the damping storage unit. The motor of the turbine transmission unit drives the piston compression unit to compress the low-pressure steam P2 in the piston compression unit. The compressed steam is cooled and stored in the damping storage unit, causing the steam pressure in the damping storage unit to increase. The pressure and temperature sensor on the damping tank side of the damping storage unit monitors the pressure and temperature in the damping storage unit and informs the control cabinet.

[0021] Step S13: When the steam in the damping storage unit meets the discharge conditions, the control cabinet controls the high-pressure steam delivery unit to work and be turned on, the control cabinet controls the first medium-pressure steam delivery unit to work and be turned on, the control cabinet controls the motor of the turbine transmission unit to suspend work and keep it in a free rotation state, and the control cabinet controls the second medium-pressure steam delivery unit to work and be turned on; the high-pressure steam P1 enters the turbine transmission unit through the high-pressure steam delivery unit, and the turbine of the turbine transmission unit drives the piston compression unit to compress the low-pressure steam P2 in the piston compression unit, and the damping storage unit outputs the second medium-pressure steam P4, and the second medium-pressure steam P4 enters the steam buffer mixing unit through the second medium-pressure steam delivery unit; the high-pressure steam P1 outputs the first medium-pressure steam P3 through the turbine transmission unit, and the first medium-pressure steam P3 enters the steam buffer mixing unit through the first medium-pressure steam delivery unit; the first medium-pressure steam P3 and the second medium-pressure steam P4 are buffered and mixed in the steam buffer mixing unit, and the mixing side pressure and temperature sensors of the steam buffer mixing unit monitor the pressure and temperature in the steam buffer mixing unit and inform the control cabinet;

[0022] Step S14: When the steam in the steam buffer mixing unit meets the discharge conditions, the control cabinet controls the steam output unit to work and be turned on, and the steam P5 output by the steam buffer mixing unit enters the molten salt tank through the steam output unit;

[0023] Step S15: The high-pressure steam delivery unit obtains the pressure of the high-pressure steam P1 and informs the control cabinet, the turbine transmission unit obtains the speed of the turbine in the turbine transmission unit and informs the control cabinet, when the pressure of the high-pressure steam P1 is lower than the set pressure threshold and the speed of the turbine is lower than the set speed threshold, the control cabinet starts the motor of the turbine transmission unit, and the motor drives the turbine of the turbine transmission unit to rotate until the pressure of the high-pressure steam P1 exceeds the set pressure threshold, the speed of the turbine exceeds the set speed threshold and the time for maintaining this state exceeds the threshold time, and the control cabinet controls the motor to suspend work.

[0024] A further technical solution is: in step S13, the discharge condition of the steam in the damping storage unit is that the steam pressure is ≥8MPa and the temperature satisfies 500-530°C; in step S14, the discharge condition of the steam in the steam buffer mixing unit is that the steam pressure is ≥8MPa and the temperature satisfies 490-510°C; in step S15, the set pressure threshold is 15MPa.

[0025] In a fourth aspect, a method for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power plant is provided, based on the device for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power plant described in the second aspect, and includes the following steps:

[0026] Step S21: The control cabinet controls the low-pressure steam delivery unit to operate and conduct, and the low-pressure steam P2 enters the piston compression unit and the damping storage unit through the low-pressure steam delivery unit;

[0027] Step S22: the control cabinet controls the high-pressure steam delivery unit to operate and be turned on, controls the first medium-pressure steam delivery unit to operate and be turned on, controls the heater to operate, and controls the steam desuperheater of the damping storage unit to operate; the high-pressure steam P1 enters the turbine transmission unit through the high-pressure steam delivery unit, and the turbine of the turbine transmission unit drives the piston compression unit to compress the low-pressure steam P2 in the piston compression unit. The compressed steam is cooled by the steam desuperheater of the damping storage unit and then enters the damping storage unit, causing the steam pressure in the damping storage unit to rise. The pressure and temperature sensor on the damping tank side of the damping storage unit monitors the pressure and temperature in the damping storage unit and informs the control cabinet; the high-pressure steam P1 outputs the first medium-pressure steam P3 through the turbine transmission unit, and the first medium-pressure steam P3 enters the steam buffer mixing unit through the first medium-pressure steam delivery unit. The pressure and temperature sensor on the mixing side of the steam buffer mixing unit monitors the pressure and temperature in the steam buffer mixing unit and informs the control cabinet; when the steam in the damping storage unit meets the discharge condition, step S23 is executed synchronously; when the steam in the steam buffer mixing unit meets the discharge condition, step S24 is executed synchronously;

[0028] Step S23: The control cabinet controls the second intermediate-pressure steam delivery unit to operate and conduct; the damping storage unit outputs the second intermediate-pressure steam P4, and the second intermediate-pressure steam P4 enters the steam buffer mixing unit through the second intermediate-pressure steam delivery unit; the first intermediate-pressure steam P3 and the second intermediate-pressure steam P4 are buffered and mixed in the steam buffer mixing unit;

[0029] Step S24: The control cabinet controls the steam output unit to operate and be turned on, and the steam P5 output by the steam buffer mixing unit enters the molten salt tank through the steam output unit;

[0030] Step S25: The high-pressure steam delivery unit obtains the pressure of the high-pressure steam P1 and informs the control cabinet, the turbine transmission unit obtains the speed of the turbine in the turbine transmission unit and informs the control cabinet, when the pressure of the high-pressure steam P1 is lower than the set pressure threshold and the speed of the turbine is lower than the set speed threshold, the control cabinet starts the motor of the turbine transmission unit, and the motor drives the turbine of the turbine transmission unit to rotate until the pressure of the high-pressure steam P1 exceeds the set pressure threshold, the speed of the turbine exceeds the set speed threshold and the time maintained exceeds the threshold time, and the control cabinet controls the motor to suspend work.

[0031] The beneficial effects of adopting the above technical solution are:

[0032] In the first aspect, a device suitable for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station comprises a control cabinet, a high-pressure steam delivery unit, a low-pressure steam delivery unit, a turbine transmission unit, a piston compression unit, a damping storage unit, a first medium-pressure steam delivery unit, a second medium-pressure steam delivery unit, a steam buffer mixing unit, a steam output unit and a molten salt tank, wherein the high-pressure steam delivery unit, the turbine transmission unit and the first medium-pressure steam delivery unit are sequentially connected to the first input end of the steam buffer mixing unit, the low-pressure steam delivery unit, the piston compression unit, the damping storage unit and the second medium-pressure steam delivery unit are sequentially connected to the second input end of the steam buffer mixing unit, the output end of the steam buffer mixing unit is connected to the molten salt tank via the steam output unit, the turbine transmission unit is movably connected to the piston compression unit, and the control cabinet is electrically connected to the high-pressure steam delivery unit, the low-pressure steam delivery unit, the turbine transmission unit, the damping storage unit, the first medium-pressure steam delivery unit, the second medium-pressure steam delivery unit, the steam buffer mixing unit and the steam output unit respectively. Since the turbine transmission unit drives the piston compression unit to compress the low-pressure steam P2 and increase the pressure, the processing efficiency is improved. Since the pressures of the mixed first intermediate-pressure steam P3 and the second intermediate-pressure steam P4 are relatively close, there will be no violent collision between the two steam types during mixing, thus avoiding the energy loss of the traditional ejector device during the steam mixing process and improving the heat exchange efficiency.

[0033] When the pressure of the high-pressure steam P1 does not meet the pressure condition, the control cabinet controls the motor of the turbine transmission unit to assist in work. The motor assists in increasing the operating frequency of the piston compression unit, increasing the pressure of the low-pressure steam P2 entering the damping storage unit, and improving stability.

[0034] Secondly, the temperature of the first medium-pressure steam P3 flowing through the heater is increased by the heater, which shortens the steam temperature increase time in the steam buffer mixing unit and improves the processing efficiency.

[0035] In a third aspect, a method for controlling the generation of medium-grade steam in a molten salt heat storage system of a power plant is provided. The method is based on a device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power plant described in the first aspect, and includes steps S11, S12, S13, S14, and S15. Since the pressures of the mixed first intermediate-pressure steam P3 and the second intermediate-pressure steam P4 are relatively close, there will be no violent collision between the two steams during mixing, thereby avoiding the energy loss of the traditional ejector device during the steam mixing process and improving the heat exchange efficiency.

[0036] In the fourth aspect, a method for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station is provided, based on the device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station described in the second aspect, and includes steps S21, S22, S23, S24, and S25. In step S22, the temperature of the first medium-pressure steam P3 flowing through the heater is increased by a heater, which shortens the time for the steam to heat up in the steam buffer mixing unit and improves the processing efficiency. In step S22, if the steam in the damping storage unit does not meet the discharge conditions, but the steam in the steam buffer mixing unit meets the discharge conditions, the control cabinet controls the steam output unit to work and conduct, and outputs steam P5. Since the heated first medium-pressure steam P3 continuously enters the steam buffer mixing unit and fills the steam buffer mixing unit, the steam in the steam buffer mixing unit meets the technical conditions for discharge more quickly, which saves time and improves efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a structural diagram of embodiment 1 of the present invention;

[0038] Figure 2 This is a principle block diagram of embodiment 1 of the present invention;

[0039] Figure 3 This is a data relationship diagram of the working process of Example 1 of the present invention;

[0040] Figure 4 is a flow chart of Example 2 of the present invention;

[0041] Figure 5 is a structural diagram of embodiment 3 of the present invention;

[0042] Figure 6 This is a flowchart of Example 4 of the present invention.

[0043] Among them: 1 high-pressure steam side electric control valve, 2 high-pressure steam side electro-hydraulic servo valve, 3 high-pressure steam side temperature control valve, 4 high-pressure steam connecting pipe, 5 steam turbine assembly, 6 motor, 7 first medium-pressure steam side pressure and temperature sensor, 8 first medium-pressure steam side electric control valve, 9 first medium-pressure steam side temperature control valve, 10 first medium-pressure steam side pressure control valve, 11 first medium-pressure steam side check valve, 12 buffer mixer, 13 variable throat nozzle, 14 pressure transmitter, 15 steam outlet valve, 16 mixing side pressure and temperature sensor, 17 second medium-pressure steam side check valve Return valve, 18 second medium-pressure steam side pressure regulating valve, 19 second medium-pressure steam side temperature regulating valve, 20 second medium-pressure steam side electric control valve, 21 steam discharge valve, 22 damping tank side pressure and temperature sensor, 23 continuous damping tank, 24 steam desuperheater, 25 piston compression mechanism, 26 crankshaft connecting rod mechanism, 27 electric actuator, 28 low-pressure steam connecting pipe, 29 low-pressure steam side check valve, 30 low-pressure steam side temperature regulating valve, 31 low-pressure steam side electro-hydraulic servo valve, 32 low-pressure steam side electric control valve, 33 control cabinet, 34 molten salt tank, 35 heater. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its application or use. 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.

[0045] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0046] Example 1:

[0047] like Figure 1 and Figure 2As shown, the present invention discloses a device suitable for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station, comprising a control cabinet 33, a high-pressure steam delivery unit, a low-pressure steam delivery unit, a turbine transmission unit, a piston compression unit, a damping storage unit, a first medium-pressure steam delivery unit, a second medium-pressure steam delivery unit, a steam buffer mixing unit, a steam output unit and a molten salt tank 34. The high-pressure steam delivery unit comprises a high-pressure steam connecting pipe 4, a high-pressure steam side electric control valve 1, a high-pressure steam side electro-hydraulic servo valve 2 and a high-pressure steam side temperature regulating valve 3. The low-pressure steam delivery unit comprises a low-pressure steam connecting pipe 28, a low-pressure steam side electric control valve 32, a low-pressure steam side electro-hydraulic servo valve 31, a low-pressure steam side temperature regulating valve 30, a low-pressure steam side check valve 29 and an electric actuator 27. The turbine transmission unit comprises a steam turbine assembly 5, a motor 6 and a speed sensor. The piston compression unit comprises a crankshaft connecting rod mechanism 26 and an active The plug compression mechanism 25, the damping storage unit includes a steam desuperheater 24, a continuous damping tank 23 and a damping tank side pressure and temperature sensor 22, the first medium-pressure steam transmission unit includes a first medium-pressure steam connecting pipe, a first medium-pressure steam side pressure and temperature sensor 7, a first medium-pressure steam side electric-controlled valve 8, a first medium-pressure steam side temperature regulating valve 9, a first medium-pressure steam side pressure regulating valve 10 and a first medium-pressure steam side check valve 11, the second medium-pressure steam transmission unit includes a second medium-pressure steam connecting pipe, a steam discharge valve 21, a second medium-pressure steam side electric-controlled valve 20, a second medium-pressure steam side temperature regulating valve 19, a second medium-pressure steam side pressure regulating valve 18 and a second medium-pressure steam side check valve 17, the steam buffer mixing unit includes a buffer mixer 12, a variable throat nozzle 13 and a mixing side pressure and temperature sensor 16, and the steam output unit includes an output steam connecting pipe, a pressure transmitter 14 and a steam outlet valve 15.

[0048] like Figure 1 As shown, the high-pressure steam connecting pipe 4 is connected to the input end of the steam turbine assembly 5, the high-pressure steam side electric control valve 1, the high-pressure steam side electro-hydraulic servo valve 2 and the high-pressure steam side temperature regulating valve 3 are fixedly connected to the high-pressure steam connecting pipe 4, and the high-pressure steam side electric control valve 1, the high-pressure steam side electro-hydraulic servo valve 2, the high-pressure steam side temperature regulating valve 3 and the steam turbine assembly 5 are connected in sequence.

[0049] like Figure 1 As shown, the low-pressure steam connecting pipe 28 is connected to the input end of the piston compression mechanism 25, and the electric actuator 27, the low-pressure steam side check valve 29, the low-pressure steam side temperature regulating valve 30, the low-pressure steam side electro-hydraulic servo valve 31 and the low-pressure steam side electric control valve 32 are fixedly connected to the low-pressure steam connecting pipe 28, and the low-pressure steam side electric control valve 32, the low-pressure steam side electro-hydraulic servo valve 31, the low-pressure steam side temperature regulating valve 30, the low-pressure steam side check valve 29, the electric actuator 27 and the piston compression mechanism 25 are connected in sequence.

[0050] like Figure 1 As shown, the rotating shaft of the motor 6 is fixedly connected to the rotating shaft of the steam turbine assembly 5, the speed sensor is fixedly connected to the rotating shaft of the steam turbine assembly 5, the rotating shaft of the steam turbine assembly 5 is rotatably connected to one end of the crankshaft connecting rod mechanism 26, the other end of the crankshaft connecting rod mechanism 26 is movably connected to the piston compression mechanism 25, the output end of the piston compression mechanism 25 is connected to the input end of the continuous damping tank 23 through the steam desuperheater 24, and the damping tank side pressure and temperature sensor 22 is fixedly connected to the continuous damping tank 23.

[0051] like Figure 1 As shown, the output end of the steam turbine assembly 5 is connected to the first input end of the buffer mixer 12 via the first medium-pressure steam connecting pipe, the output end of the continuous damping tank 23 is connected to the second input end of the buffer mixer 12 via the second medium-pressure steam connecting pipe, the first medium-pressure steam side pressure and temperature sensor 7, the first medium-pressure steam side electric control valve 8, the first medium-pressure steam side temperature regulating valve 9, the first medium-pressure steam side pressure regulating valve 10 and the first medium-pressure steam side check valve 11 are fixedly connected to the first medium-pressure steam connecting pipe, the first medium-pressure steam side pressure and temperature sensor 7, the first medium-pressure steam side electric control valve 8, the first medium-pressure steam side The temperature regulating valve 9, the first medium-pressure steam side pressure regulating valve 10, the first medium-pressure steam side check valve 11 and the buffer mixer 12 are connected and conducted in sequence, the steam discharge valve 21, the second medium-pressure steam side electric control valve 20, the second medium-pressure steam side temperature regulating valve 19, the second medium-pressure steam side pressure regulating valve 18 and the second medium-pressure steam side check valve 17 are fixedly connected to the second medium-pressure steam connecting pipe, the steam discharge valve 21, the second medium-pressure steam side electric control valve 20, the second medium-pressure steam side temperature regulating valve 19, the second medium-pressure steam side pressure regulating valve 18, the second medium-pressure steam side check valve 17 and the buffer mixer 12 are connected and conducted in sequence.

[0052] like Figure 1 As shown, the buffer mixer 12 has a built-in baffle, the variable throat nozzle 13 is fixedly connected to the output end of the buffer mixer 12, and the mixing side pressure and temperature sensor 16 is fixedly connected to the buffer mixer 12. The variable throat nozzle 13 is connected to the input end of the molten salt tank 34 via the output steam connecting pipe, and the pressure transmitter 14 and the steam outlet valve 15 are fixedly connected to the output steam connecting pipe. The pressure transmitter 14, the steam outlet valve 15 and the molten salt tank 34 are connected in sequence.

[0053] like Figure 2As shown, the speed sensor, the first intermediate-pressure steam side pressure and temperature sensor 7, the pressure transmitter 14, the mixing side pressure and temperature sensor 16, and the damping tank side pressure and temperature sensor 22 are separately electrically connected to and communicate with the control cabinet 33. The control cabinet 33 is separately electrically connected to the corresponding control ends of the high-pressure steam side electric-controlled valve 1, the high-pressure steam side electro-hydraulic servo valve 2, the high-pressure steam side temperature regulating valve 3, the motor 6, the first intermediate-pressure steam side electric-controlled valve 8, the first intermediate-pressure steam side temperature regulating valve 9, the first intermediate-pressure steam side pressure regulating valve 10, the first intermediate-pressure steam side check valve 11, the steam outlet valve 15, the second intermediate-pressure steam side check valve 17, the second intermediate-pressure steam side pressure regulating valve 18, the second intermediate-pressure steam side temperature regulating valve 19, the second intermediate-pressure steam side electric-controlled valve 20, the steam discharge valve 21, the steam desuperheater 24, the electric actuator 27, the low-pressure steam side temperature regulating valve 30, the low-pressure steam side electro-hydraulic servo valve 31, and the low-pressure steam side electric-controlled valve 32.

[0054] The high-pressure steam delivery unit, the steam turbine assembly 5 and the motor 6 form a power unit, and the steam turbine assembly 5, the motor 6 and the crankshaft connecting rod mechanism 26 form a high-pressure steam driven turbine-crankshaft connecting rod power conversion unit.

[0055] The high-pressure steam side electro-hydraulic servo valve 2 and the low-pressure steam side electro-hydraulic servo valve 31 are both digital electro-hydraulic servo valves, which are high-precision, fast-response electro-hydraulic control elements that receive digital signals and convert them into accurate hydraulic flow or pressure output.

[0056] Steam turbine assembly 5: It adopts an axial turbine structure, the inlet flange is suitable for 17MPa high-pressure steam, the impeller is cast with nickel-based high-temperature alloy, and the blade surface is sprayed with ceramic wear-resistant coating.

[0057] Key parameter control: Turbine inlet steam enthalpy is calculated in real time using the IAPWS-IF97. Impeller speed is monitored using a magnetoelectric speed sensor with an accuracy of ±0.5%. A digital electro-hydraulic servo valve is used to dynamically adjust steam flow, with a response time of <50ms.

[0058] The piston compression unit is functionally a compression unit.

[0059] The piston compression mechanism 25 comprises a horizontal compressor body, a cast iron cylinder block and a forged steel piston assembly, and the piston ring is made of polytetrafluoroethylene composite material.

[0060] Crankshaft-connecting rod mechanism 26: Consists of a crank-slider assembly and coupling, featuring adjustable eccentricity and a maximum stroke of 150mm. The forged steel crankshaft is equipped with eight balance weights. The connecting rod is carburized 45# steel, and the piston pin bore is chrome-plated. The coupling comprises a universal joint and an elastic pin coupling, forming a reduction mechanism and expansion work transmission system. The universal joint has a torque capacity of ≥500N·m.

[0061] Continuous damping tank 23: includes a continuous damping tank interface, a DN200 quick-opening input hole, and a metal spiral wound gasket.

[0062] Damping tank side pressure and temperature sensor 22: This integrated pressure and temperature sensor utilizes distributed fiber optic sensing. For pressure monitoring, eight fiber Bragg grating sensors are arranged circumferentially around the continuous damping tank 23, with a range of 0 to 10 MPa. For temperature monitoring, S-shaped thermocouples are inserted to a depth ≥ 1 / 3 of the tank diameter.

[0063] Dynamic adjustment mechanism: The scavenging volume is adjusted by a variable frequency motor with a frequency range of 20 to 60 Hz.

[0064] Volumetric efficiency model: η v =1-C v *(P2 / P1) (1 / k) , C v =0.05, k=1.3.

[0065] Exhaust temperature control: water spray desuperheater, atomization particle size ≤ 50μm.

[0066] By dynamically adjusting the operating frequency of the piston compression mechanism 25, the turbine steam flow rate and the opening of the second intermediate-pressure steam side electric control valve 20, the pressure in the continuous damping tank 23 is stabilized within the range of 8.0±0.2 MPa.

[0067] The steam buffer mixing unit is a mixing unit in function and a graded pressure reducing mixing buffer mechanism in structure.

[0068] Buffer mixer 12: includes a multi-stage pressure reducing tower, a three-stage throttling orifice plate, with aperture decreasing from Φ5→Φ3→Φ2mm; a mixing chamber, a spiral guide vane, a lead of 150mm, and an inclination of 15°; a pressure balancing pipe, a DN50 two-way stop valve; and a built-in baffle.

[0069] Energy balance strategy:

[0070] Dynamic adjustment mechanism: Venturi tube flow measurement is adopted with a range ratio of 1:15; steam mixing enthalpy is monitored in real time through a thermal resistor network, with the measurement point spacing ≤ 200mm.

[0071] Pressure fluctuation suppression: Set a π-type damper, and the natural frequency is < 1 / 3 of the system's lowest frequency.

[0072] Control cabinet 33 is equipped with a Siemens S7-1500 PLC and WinCC monitoring interface. The sensor array includes 32 Pt100 RTDs and 8 K-type thermocouples. The main controller uses fuzzy-PID temperature-pressure decoupling control. The auxiliary controller provides steam superheat protection with a setpoint of ≥50°C. Fault diagnosis and vibration spectrum analysis are also available at a sampling rate of 10kHz.

[0073] The relationship between each device is explained in detail below.

[0074] 1. High-pressure steam P1 → turbine transmission unit.

[0075] Energy transfer: High-pressure steam P1 enters the turbine of the turbine transmission unit and expands to do work, converting heat energy and pressure energy into mechanical energy.

[0076] Mass flow: The steam pressure after expansion drops to about 8 MPa, which is the first intermediate pressure steam P3, and changes dynamically, and then enters the steam buffer mixing unit.

[0077] Control dependency: The control cabinet 33 adjusts the steam flow at the turbine inlet according to the pressure in the continuous damping tank 23 If the pressure in the continuous damping tank 23 is small, the opening of the electro-hydraulic servo valve 2 on the high-pressure steam side is increased, thereby increasing the flow of high-pressure steam P1 entering the turbine transmission unit, increasing the turbine speed, and then increasing the compression frequency of the piston compression unit, so as to increase the pressure in the continuous damping tank 23.

[0078] 2. Turbine transmission unit → steam buffer mixing unit.

[0079] Quality input: The first intermediate pressure steam P3 discharged from the turbine transmission unit enters the steam buffer mixing unit.

[0080] Energy correlation: The energy output by the turbine transmission unit covers the power consumption and energy loss of the piston compression unit, maintaining energy balance.

[0081] 3. Low-pressure steam P2 → piston compression unit.

[0082] Mass input: Low-pressure steam P2 enters the piston compression unit and is periodically compressed. After compression, it enters the damping storage unit, so that the pressure of the steam in the continuous damping tank 23 of the damping storage unit is increased to the target pressure of about 8 MPa.

[0083] Energy consumption: The power consumption of the piston compression unit is compensated by the output work of the turbine transmission unit.

[0084] 4. Piston compression unit → damping storage unit.

[0085] Mass input: The compressed steam is injected into the continuous damping tank 23 of the damping storage unit, directly increasing the pressure inside the tank.

[0086] Temperature influence: The compression process causes the steam temperature to rise, which is then cooled by the steam desuperheater 24 of the damping storage unit to maintain a stable temperature inside the tank, for example, 520°C.

[0087] 5.

[0088] Discharge condition: When the tank pressure Ptank ≥ 8.0 MPa, the control cabinet 33 controls the steam discharge valve 21 to open and discharge the second medium-pressure steam P4.

[0089] Flow regulation: The control cabinet 33 controls the opening of the second medium-pressure steam side electric control valve 20, and the discharge volume Dynamic adjustment ensures that the pressure remains stable within the target range.

[0090] Quality output: The discharged second intermediate pressure steam P4 flows into the steam buffer mixing unit.

[0091] 6. Control.

[0092] Signal input: The pressure and temperature sensor 22 on the damping tank side monitors the pressure Ptank and temperature Ttank in the continuous damping tank 23 in real time and informs the control cabinet 33.

[0093] Control output: The control cabinet 33 controls the opening of the electro-hydraulic servo valve 2 on the high-pressure steam side, regulating the steam flow entering the steam turbine assembly 5 of the turbine transmission unit The turbine speed of the steam turbine assembly 5 is controlled, the compression frequency of the piston compression mechanism 25 in the piston compression unit is controlled, and the pressure in the continuous damping tank 23 of the damping storage unit is controlled.

[0094] The working process of Example 1 is described as follows:

[0095] like Figure 1 and Figure 3 As shown, the pressure range of high-pressure steam P1 is 15MPa~17MPa, the temperature range of high-pressure steam P1 is 565~620℃, high-pressure steam is high-grade steam, and high-pressure steam P1 enters the high-pressure steam delivery unit through the high-pressure steam connecting pipe 4.

[0096] The pressure range of low-pressure steam P2 is 3MPa~5MPa, the temperature range of low-pressure steam P2 is 535~560℃, low-pressure steam is low-grade, and low-pressure steam P2 enters the low-pressure steam delivery unit through the low-pressure steam connecting pipe 28.

[0097] The control cabinet 33 controls the low-pressure steam side temperature regulating valve 30, the low-pressure steam side electro-hydraulic servo valve 31 and the low-pressure steam side electric control valve 32 to open and operate. The control cabinet 33 controls the electric actuator 27 to operate, and the low-pressure steam P2 enters the piston compression mechanism 25 and the continuous damping tank 23 through the low-pressure steam connecting pipe 28.

[0098] The control cabinet 33 controls the high-pressure steam side electric control valve 1, the high-pressure steam side electro-hydraulic servo valve 2 and the high-pressure steam side temperature regulating valve 3 to open and operate, and the control cabinet 33 controls the first medium-pressure steam side electric control valve 8, the first medium-pressure steam side temperature regulating valve 9, the first medium-pressure steam side pressure regulating valve 10 and the first medium-pressure steam side check valve 11 to open and operate, and the high-pressure steam P1 enters the steam turbine assembly 5 through the high-pressure steam connecting pipe 4.

[0099] The high-pressure steam P1 is depressurized by the steam turbine assembly 5 to output the first intermediate-pressure steam P3. The pressure range of the first intermediate-pressure steam P3 is about 8 MPa, and the temperature range of the first intermediate-pressure steam P3 is 380-420°C.

[0100] The low-pressure steam P2 is pressurized by the piston compression mechanism 25 and stabilized by the continuous damping tank 23. The low pressure limit of the continuous damping tank 23 is 6 MPa and the high pressure limit is 10 MPa.

[0101] The damping tank side pressure and temperature sensor 22 monitors the pressure and temperature in the continuous damping tank 23 and informs the control cabinet 33. When the pressure in the continuous damping tank 23 reaches the dischargeable pressure of 8MPa, the control cabinet 33 controls the second medium-pressure steam side check valve 17, the second medium-pressure steam side pressure regulating valve 18, the second medium-pressure steam side temperature regulating valve 19, the second medium-pressure steam side electric control valve 20 and the steam discharge valve 21 to open and work, and the continuous damping tank 23 outputs the second medium-pressure steam P4. The second medium-pressure steam P4 enters the buffer mixer 12 through the second medium-pressure steam connecting pipe. The pressure range of the second medium-pressure steam P4 is about 8MPa, and the temperature range of the second medium-pressure steam P4 is 500~530℃.

[0102] The first intermediate-pressure steam P3 and the second intermediate-pressure steam P4 enter the buffer mixer 12, where they are buffered and mixed. The mixing-side pressure and temperature sensor 16 monitors the pressure and temperature in the buffer mixer 12 and notifies the control cabinet 33. When the pressure in the buffer mixer 12 reaches the dischargeable pressure of 8 MPa, the control cabinet 33 controls the steam outlet valve 15 to open and operate. Steam P5 output from the variable throat nozzle 13 passes through the steam outlet valve 15 and enters the molten salt tank 34. The output steam P5 has a pressure range of approximately 8 MPa and a temperature range of 490-510°C.

[0103] The electro-hydraulic servo valve 2 on the high-pressure steam side collects the pressure of the high-pressure steam P1 in real time and informs the control cabinet 33. When the pressure of the high-pressure steam P1 does not meet the pressure condition of 15MPa, the control cabinet 33 starts the motor 6, and the motor 6 drives the turbine of the steam turbine assembly 5 to rotate. The motor 6 assists in doing work, reducing the sole dependence on the high-pressure steam P1 to do work. The motor 6 helps to increase the operating frequency of the piston compression mechanism 25, increases the pressure of the low-pressure steam P2 entering the continuous damping tank 23, and improves stability.

[0104] The technical effects of Example 1 are described as follows.

[0105] The use of a steam turbine to drive piston compression effectively solves the problem of significant energy loss and overcomes the low processing efficiency, small processing capacity, and inability to adapt to various operating conditions of existing ejectors. This application utilizes a turbine-driven piston compression to generate medium-grade steam, based on the varying steam pressure distribution within the power plant, to improve processing efficiency.

[0106] Adaptable to various working conditions, achieving accurate matching and efficient regulation of steam pressure. This application can work in different working conditions. The steam flow rate and flow rate can be adjusted by controlling the valve through the control cabinet 33. When the driving steam pressure is too low, the motor 6 is started through the control cabinet 33 to increase the speed of the steam turbine assembly 5, reducing steam loss and increasing the compression frequency of the piston compression mechanism 25, thereby increasing the pressure of the low-pressure steam.

[0107] The addition of a continuous damping tank in this application effectively resolves the instability issues associated with intermittent piston compression operation. By buffering pressure with the continuous damping tank, quasi-continuous operation is achieved. The steam buffer mixer incorporates built-in baffles to extend the steam mixing path and increase heat exchange efficiency. The buffering and storage provided by the continuous damping tank 23 ensures stable system operation.

[0108] The innovations are detailed below.

[0109] First, based on the combined structure of a turbine transmission unit, a piston compression unit, a damping storage unit, and a steam buffer mixing unit, turbine transmission and piston compression are combined. High-pressure steam P1 performs work on the turbine transmission unit, and the turbine transmission unit drives the piston compression unit to compress and increase the pressure of low-pressure steam P2 to second intermediate-pressure steam P4. After high-pressure steam P1 performs work on the turbine transmission unit, high-pressure steam P1 consumes heat energy, reduces its pressure to first intermediate-pressure steam P3, and is output from the turbine transmission unit. First intermediate-pressure steam P3 and second intermediate-pressure steam P4 are buffered and mixed in the steam buffer mixing unit before outputting steam P5. Because the turbine transmission unit drives the piston compression unit to compress and increase the pressure of low-pressure steam P2, processing efficiency is improved. Because the pressures of the mixed first intermediate-pressure steam P3 and second intermediate-pressure steam P4 are relatively close, there is no violent collision between the two steam types during mixing, avoiding the energy loss during the steam mixing process of traditional ejector devices and improving heat exchange efficiency.

[0110] Second, when the pressure of the high-pressure steam P1 does not meet the pressure condition of 15 MPa, the control cabinet 33 controls the motor 6 to assist in doing work. The motor 6 assists in increasing the operating frequency of the piston compression mechanism 25, increasing the pressure of the low-pressure steam P2 entering the continuous damping tank 23, and improving stability.

[0111] Example 2:

[0112] like Figure 4 As shown, the present invention discloses a method for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station, based on the device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station described in Example 1, comprising the following steps:

[0113] Step S11: The control cabinet 33 controls the low-pressure steam side temperature regulating valve 30, the low-pressure steam side electro-hydraulic servo valve 31 and the low-pressure steam side electric control valve 32 to open and operate. The control cabinet 33 controls the electric actuator 27 to operate, and the low-pressure steam P2 enters the piston compression mechanism 25 and the continuous damping tank 23 through the low-pressure steam connecting pipe 28.

[0114] Step S12: The control cabinet 33 controls the operation of the motor 6 and the steam desuperheater 24. The motor 6 drives the crankshaft connecting rod mechanism 26 to move and causes the piston compression mechanism 25 to compress the low-pressure steam P2 in the piston compression mechanism 25. The compressed steam is cooled by the steam desuperheater 24 and enters the continuous damping tank 23, causing the steam pressure in the continuous damping tank 23 to rise. The pressure and temperature sensor 22 on the damping tank side monitors the pressure and temperature in the continuous damping tank 23 and informs the control cabinet 33.

[0115] The specific details are described below.

[0116] The rotating shaft of the steam turbine assembly 5 drives the piston of the piston compression mechanism 25 to move and compress the low-pressure steam through the crankshaft connecting rod mechanism 26, and compresses the low-pressure steam into the continuous damping tank 23. The damping tank side pressure and temperature sensor 22 informs the control cabinet 33 of the pressure and temperature in the continuous damping tank 23.

[0117] Step S13: When the pressure of the steam in the continuous damping tank 23 is ≥8MPa and the temperature meets 500-530℃, the control cabinet 33 controls the high-pressure steam side electric control valve 1, the high-pressure steam side electro-hydraulic servo valve 2 and the high-pressure steam side temperature regulating valve 3 to open and work, the control cabinet 33 controls the first medium-pressure steam side electric control valve 8, the first medium-pressure steam side temperature regulating valve 9, the first medium-pressure steam side pressure regulating valve 10 and the first medium-pressure steam side check valve 11 to open and work, the control cabinet 33 controls the motor 6 to suspend work, the control cabinet 33 controls the second medium-pressure steam side check valve 17, the second medium-pressure steam side pressure regulating valve 18, the second medium-pressure steam side temperature regulating valve 19, the second medium-pressure steam side electric control valve 20 and the steam discharge valve 21 to open and work; the high-pressure steam Steam P1 enters the steam turbine assembly 5 through the high-pressure steam connecting pipe 4, the steam turbine assembly 5 drives the crankshaft connecting rod mechanism 26 to move and causes the piston compression mechanism 25 to compress the low-pressure steam P2 in the piston compression mechanism 25, the continuous damping tank 23 outputs the second medium-pressure steam P4, the second medium-pressure steam P4 enters the buffer mixer 12 through the second medium-pressure steam connecting pipe; the high-pressure steam P1 outputs the first medium-pressure steam P3 through the steam turbine assembly 5, the first medium-pressure steam P3 enters the buffer mixer 12 through the first medium-pressure steam connecting pipe; the first medium-pressure steam P3 and the second medium-pressure steam P4 are buffered and mixed in the steam buffer mixer 12, and the mixing side pressure and temperature sensor 16 monitors the pressure and temperature in the buffer mixer 12 and informs the control cabinet 33.

[0118] The specific details are described below.

[0119] High-pressure steam P1, transported through the molten salt pipeline, serves as driving steam. The high-pressure steam P1 drives the turbine of the steam turbine assembly 5 to produce work. Due to energy consumption, the steam pressure decreases. After being decompressed by the steam turbine assembly 5, the high-pressure steam P1 is output as first intermediate-pressure steam P3. The first intermediate-pressure steam P3 then slowly enters the buffer mixer 12 through the first intermediate-pressure steam connecting pipe.

[0120] When the pressure in the continuous damping tank 23 reaches the dischargeable pressure, the control cabinet 33 controls the second medium-pressure steam side check valve 17, the second medium-pressure steam side pressure regulating valve 18, the second medium-pressure steam side temperature regulating valve 19, the second medium-pressure steam side electric control valve 20 and the steam discharge valve 21 to operate, and the second medium-pressure steam P4 enters the buffer mixer 12.

[0121] Step S14: When the steam pressure in the buffer mixer 12 is ≥8 MPa and the temperature meets 490-510°C, the control cabinet 33 controls the steam outlet valve 15 to open and work, and the steam P5 output by the variable throat nozzle 13 enters the molten salt tank 34 through the steam outlet valve 15.

[0122] The specific details are described below.

[0123] The control cabinet 33 controls the opening and closing of each valve to achieve continuous mixing, and finally mixes the two types of steam to achieve dynamic balance of pressure and temperature.

[0124] Based on the detected pressure in the continuous damping tank 23, the control cabinet 33 controls the amount of steam entering the steam turbine assembly 5, thereby controlling the turbine speed and, in turn, the operating frequency of the piston compression mechanism 25. Specifically, the control cabinet 33 controls the openings of the high-pressure steam-side electro-hydraulic servo valve 2, the high-pressure steam-side temperature control valve 3, and the high-pressure steam-side electrically controlled valve 1 to adjust the steam flow rate entering the steam turbine assembly 5. By controlling the flow rate, the turbine speed of the steam turbine assembly 5 is controlled. A speed sensor detects the turbine speed and transmits it to the control cabinet 33. The rotating turbine drives the crankshaft connecting rod mechanism 26 to move left and right, which in turn drives the piston compression mechanism 25 to compress the low-pressure steam P2. The compressed steam then enters the continuous damping tank 23. The higher the turbine speed, the higher the operating frequency of the piston compression mechanism 25, which can be adjusted accordingly. The higher the operating frequency of the piston compression mechanism 25, the greater and more stable the output of the second intermediate-pressure steam P4.

[0125] The real-time pressure and temperature data collected by the damping tank-side pressure and temperature sensor 22 are transmitted to the control cabinet 33. This controls the steam discharge valve 21 to open, thereby controlling the opening of the second intermediate-pressure steam-side electrically controlled valve 20 to discharge the second intermediate-pressure steam P4 at the required pressure. The discharged second intermediate-pressure steam P4 passes through the second intermediate-pressure steam-side temperature regulating valve 19, the second intermediate-pressure steam-side pressure regulating valve 18, and the second intermediate-pressure steam-side check valve 17 and enters the buffer mixer 12 for further pressure matching and mixing.

[0126] Step S15: The electro-hydraulic servo valve 2 on the high-pressure steam side obtains the pressure of the high-pressure steam P1 and informs the control cabinet 33. The speed sensor obtains the speed of the turbine in the steam turbine assembly 5 and informs the control cabinet 33. When the pressure of the high-pressure steam P1 is lower than 15 MPa and the speed of the turbine is lower than the set speed threshold, the control cabinet 33 starts the motor 6, and the motor 6 drives the turbine of the steam turbine assembly 5 to rotate until the pressure of the high-pressure steam P1 exceeds 15 MPa, the speed of the turbine exceeds the set speed threshold and the time for maintaining this state exceeds the threshold time, the control cabinet 33 controls the motor 6 to suspend work.

[0127] The specific details are described below.

[0128] The motor 6 assists in doing work, reducing the sole reliance on the high-pressure steam P1 to do work. The motor 6 assists in increasing the operating frequency of the piston compression mechanism 25, increasing the pressure of the low-pressure steam P2 entering the continuous damping tank 23, and improving stability.

[0129] The technical effects of Example 2 are described in detail below.

[0130] The present application adopts a three-level energy transfer architecture of power-compression-energy storage, and realizes dynamic matching of steam parameters through a control cabinet 33. By collecting the real-time pressure and temperature in the continuous damping tank 23, the flow of the driving steam, the operating frequency of the piston compression mechanism 25 and the opening of the second medium-pressure steam side electric control valve 20 are controlled accordingly. The high-pressure steam P1 is used as the driving steam to drive the turbine to rotate, and the piston compression mechanism 25 is driven to move through the crankshaft connecting rod mechanism 26 to compress the low-pressure steam P2. The compressed steam is stored in the continuous damping tank 23. Through the buffering effect of the continuous damping tank 23, the steam discharged to the outside is in a balanced and stable state, thereby increasing the pressure of the low-pressure steam. The pressures of the two steams reach a balanced state to obtain medium-grade steam. The entire treatment process is quasi-continuous, which improves the steam treatment efficiency in the molten salt pipeline.

[0131] Technical advantages: improved energy efficiency, full system equivalence The efficiency reaches 76.5%, which is 19.2% higher than the traditional device.

[0132] Pressure matching accuracy: outlet steam pressure fluctuation standard deviation <0.3bar, traditional device >2.5bar.

[0133] Dynamic response characteristics: The time to recover to steady state when the load changes suddenly is less than 15s, and the conventional system is greater than 60s.

[0134] Example 3:

[0135] like Figure 5 As shown, the present invention discloses a device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power plant, comprising the device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power plant described in Example 1, and further comprising a heater 35, which is fixedly connected to the first intermediate-pressure steam connecting pipe, the first intermediate-pressure steam-side electrically controlled valve 8, the heater 35, and the first intermediate-pressure steam-side temperature regulating valve 9 being connected in sequence, and the control cabinet 33 being electrically connected to the heater 35. The similarities between Example 3 and Example 1 are not repeated here.

[0136] The working process of Example 3 is described as follows:

[0137] The first medium-pressure steam side pressure and temperature sensor 7 monitors the pressure and temperature of the first medium-pressure steam P3 and informs the control cabinet 33. Experiments show that the temperature range of the first medium-pressure steam P3 is 380~420℃, and the desired temperature range of the output steam P5 is 490~510℃. Since the temperature of the first medium-pressure steam P3 is relatively low, lower than the desired temperature range of the output steam P5, the control cabinet 33 controls the heater 35 to work, thereby increasing the temperature of the first medium-pressure steam P3 flowing through the heater 35. The heated first medium-pressure steam enters the buffer mixer 12. As long as the technical conditions for steam output are met, that is, the pressure of the steam in the buffer mixer 12 is ≥8MPa and the temperature meets 490~510℃, the control cabinet 33 controls the steam outlet valve 15 to open and work, thereby improving the processing efficiency.

[0138] The technical effects of Example 3 are described as follows.

[0139] The temperature of the first medium-pressure steam P3 flowing through the heater 35 is increased by the heater 35 , which shortens the time for the steam to be heated in the buffer mixer 12 and improves the processing efficiency.

[0140] Example 4:

[0141] like Figure 6 As shown, the present invention discloses a method for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station, based on the device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station described in Example 3, comprising the following steps:

[0142] Step S21: The control cabinet 33 controls the low-pressure steam side temperature regulating valve 30, the low-pressure steam side electro-hydraulic servo valve 31 and the low-pressure steam side electric control valve 32 to open and operate. The control cabinet 33 controls the electric actuator 27 to operate, and the low-pressure steam P2 enters the piston compression mechanism 25 and the continuous damping tank 23 through the low-pressure steam connecting pipe 28.

[0143] Step S22: The control cabinet 33 controls the high-pressure steam side electric control valve 1, the high-pressure steam side electro-hydraulic servo valve 2 and the high-pressure steam side temperature regulating valve 3 to open and work, the control cabinet 33 controls the first medium-pressure steam side electric control valve 8, the first medium-pressure steam side temperature regulating valve 9, the first medium-pressure steam side pressure regulating valve 10 and the first medium-pressure steam side check valve 11 to open and work, the control cabinet 33 controls the heater 35 to work, and the control cabinet 33 controls the steam desuperheater 24 to work; the high-pressure steam P1 enters the steam turbine assembly 5 through the high-pressure steam connecting pipe 4, the steam turbine assembly 5 drives the crankshaft connecting rod mechanism 26 to move and causes the piston compression mechanism 25 to compress the low-pressure steam P2 in the piston compression mechanism 25, and the compressed steam is cooled by the steam desuperheater 24 and enters the connecting pipe 4. The damping tank 23 is continued, so that the steam pressure in the continuous damping tank 23 rises, and the damping tank side pressure and temperature sensor 22 monitors the pressure and temperature in the continuous damping tank 23 and informs the control cabinet 33; the high-pressure steam P1 outputs the first medium-pressure steam P3 through the steam turbine assembly 5, and the first medium-pressure steam P3 enters the buffer mixer 12 through the first medium-pressure steam connecting pipe, and the mixing side pressure and temperature sensor 16 monitors the pressure and temperature in the buffer mixer 12 and informs the control cabinet 33; when the pressure of the steam in the continuous damping tank 23 is ≥8MPa and the temperature meets 500~530℃, step S23 is executed synchronously; when the pressure of the steam in the buffer mixer 12 is ≥8MPa and the temperature meets 490~510℃, step S24 is executed synchronously.

[0144] Step S23: The control cabinet 33 controls the second medium-pressure steam side check valve 17, the second medium-pressure steam side pressure regulating valve 18, the second medium-pressure steam side temperature regulating valve 19, the second medium-pressure steam side electric control valve 20 and the steam discharge valve 21 to open and work; the continuous damping tank 23 outputs the second medium-pressure steam P4, and the second medium-pressure steam P4 enters the buffer mixer 12 through the second medium-pressure steam connecting pipe; the first medium-pressure steam P3 and the second medium-pressure steam P4 are buffered and mixed in the steam buffer mixer 12.

[0145] Step S24 : the control cabinet 33 controls the steam outlet valve 15 to open and operate, and the steam P5 output by the variable throat nozzle 13 passes through the steam outlet valve 15 and enters the molten salt tank 34 .

[0146] Step S25: The electro-hydraulic servo valve 2 on the high-pressure steam side obtains the pressure of the high-pressure steam P1 and informs the control cabinet 33. The speed sensor obtains the speed of the turbine in the steam turbine assembly 5 and informs the control cabinet 33. When the pressure of the high-pressure steam P1 is lower than 15MPa and the speed of the turbine is lower than the set speed threshold, the control cabinet 33 starts the motor 6, and the motor 6 drives the turbine of the steam turbine assembly 5 to rotate until the pressure of the high-pressure steam P1 exceeds 15MPa, the speed of the turbine exceeds the set speed threshold and the time for maintaining this state exceeds the threshold time, the control cabinet 33 controls the motor 6 to suspend work.

[0147] The technical effects of Example 4 are described in detail below.

[0148] In step S22, the temperature of the first medium-pressure steam P3 flowing through the heater 35 is increased by the heater 35, thereby shortening the time for the steam to be heated in the buffer mixer 12 and improving the processing efficiency.

[0149] In step S22, if the steam in the continuous damping tank 23 does not meet the pressure ≥ 8 MPa and the temperature ≤ 500-530°C, but the steam in the buffer mixer 12 meets the pressure ≥ 8 MPa and the temperature ≥ 490-510°C, step S24 is executed. The control cabinet 33 controls the steam outlet valve 15 to open and operate, and the variable throat nozzle 13 outputs steam P5. Because the heated first intermediate-pressure steam P3 continuously enters the buffer mixer 12 and fills the buffer mixer 12, the steam in the buffer mixer 12 meets the discharge technical requirements more quickly, saving time and improving efficiency.

Claims

1. A device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station, characterized by: The invention comprises a control cabinet (33), a high-pressure steam delivery unit, a low-pressure steam delivery unit, a turbine transmission unit, a piston compression unit, a damping storage unit, a first medium-pressure steam delivery unit, a second medium-pressure steam delivery unit, a steam buffer mixing unit, a steam output unit and a molten salt tank (34), wherein the high-pressure steam delivery unit, the turbine transmission unit and the first medium-pressure steam delivery unit are sequentially connected to the first input end of the steam buffer mixing unit, the low-pressure steam delivery unit, the piston compression unit, the damping storage unit and the second medium-pressure steam delivery unit are sequentially connected to the second input end of the steam buffer mixing unit, the output end of the steam buffer mixing unit is connected to the molten salt tank (34) via the steam output unit, the turbine transmission unit is movably connected to the piston compression unit, and the control cabinet (33) is electrically connected to the high-pressure steam delivery unit, the low-pressure steam delivery unit, the turbine transmission unit, the damping storage unit, the first medium-pressure steam delivery unit, the second medium-pressure steam delivery unit, the steam buffer mixing unit and the steam output unit respectively.

2. The device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power plant according to claim 1, characterized in that: The turbine transmission unit comprises a steam turbine assembly (5), a motor (6) and a speed sensor; the piston compression unit comprises a crankshaft connecting rod mechanism (26) and a piston compression mechanism (25); the damping storage unit comprises a steam desuperheater (24), a continuous damping tank (23) and a damping tank side pressure and temperature sensor (22); the high-pressure steam delivery unit is connected to the input end of the steam turbine assembly (5); the output end of the steam turbine assembly (5) is communicated with the input end of the first medium-pressure steam delivery unit; the rotating shaft of the motor (6) is fixedly connected to the rotating shaft of the steam turbine assembly (5); the speed sensor is fixedly connected to the rotating shaft of the steam turbine assembly (5); the rotating shaft of the steam turbine assembly (5) is connected to one end of the crankshaft connecting rod mechanism (26); The second medium-pressure steam delivery unit is rotatably connected to the second medium-pressure steam delivery unit, the other end of the crankshaft connecting rod mechanism (26) is movably connected to the piston compression mechanism (25), the low-pressure steam delivery unit is connected and conducted with the input end of the piston compression mechanism (25), the output end of the piston compression mechanism (25) is connected and conducted with the input end of the continuous damping tank (23) via the steam desuperheater (24), the output end of the continuous damping tank (23) is communicated with the input end of the second medium-pressure steam delivery unit, the damping tank side pressure and temperature sensor (22) is fixedly connected to the continuous damping tank (23); the speed sensor and the damping tank side pressure and temperature sensor (22) are respectively electrically connected to and communicate with the control cabinet (33), and the control cabinet (33) is respectively electrically connected to the corresponding control ends of the motor (6) and the steam desuperheater (24).

3. The device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station according to claim 1, characterized in that: The high-pressure steam delivery unit comprises a high-pressure steam connecting pipe (4), a high-pressure steam side electric control valve (1), a high-pressure steam side electro-hydraulic servo valve (2) and a high-pressure steam side temperature regulating valve (3); the high-pressure steam connecting pipe (4) is connected to the input end of the turbine transmission unit; the high-pressure steam side electric control valve (1), the high-pressure steam side electro-hydraulic servo valve (2) and the high-pressure steam side temperature regulating valve (3) are all fixedly connected to the high-pressure steam connecting pipe (4); the high-pressure steam side electric control valve (1), the high-pressure steam side electro-hydraulic servo valve (2) and the high-pressure steam side temperature regulating valve (3) are sequentially connected to the input end of the turbine transmission unit; and the control cabinet (33) is electrically connected to the corresponding control ends of the high-pressure steam side electric control valve (1), the high-pressure steam side electro-hydraulic servo valve (2) and the high-pressure steam side temperature regulating valve (3).

4. The device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power plant according to claim 1, characterized in that: The low-pressure steam delivery unit comprises a low-pressure steam connecting pipe (28), a low-pressure steam side electric control valve (32), a low-pressure steam side electro-hydraulic servo valve (31), a low-pressure steam side temperature regulating valve (30), a low-pressure steam side check valve (29) and an electric actuator (27), wherein the low-pressure steam connecting pipe (28) is communicated with the input end of the piston compression unit, and the electric actuator (27), the low-pressure steam side check valve (29), the low-pressure steam side temperature regulating valve (30), the low-pressure steam side electro-hydraulic servo valve (31) and the low-pressure steam side electric control valve (32) are all fixedly connected to the low-pressure steam connecting pipe (28), and the low-pressure steam side electric control valve (32), the low-pressure steam side electro-hydraulic servo valve (31), the low-pressure steam side temperature regulating valve (30), the low-pressure steam side check valve (29) and the electric actuator (27) are sequentially connected to the input end of the piston compression unit; the control cabinet (33) is respectively electrically connected to the corresponding control ends of the electric actuator (27), the low-pressure steam side temperature regulating valve (30), the low-pressure steam side electro-hydraulic servo valve (31) and the low-pressure steam side electric control valve (32).

5. The device for controlling the generation of medium-grade steam in a molten salt heat storage system of a power station according to claim 1, characterized in that: The first medium-pressure steam delivery unit comprises a first medium-pressure steam connecting pipe, a first medium-pressure steam side pressure and temperature sensor (7), a first medium-pressure steam side electric control valve (8), a first medium-pressure steam side temperature regulating valve (9), a first medium-pressure steam side pressure regulating valve (10) and a first medium-pressure steam side check valve (11); the output end of the turbine transmission unit is connected to the first input end of the steam buffer mixing unit via the first medium-pressure steam connecting pipe; the first medium-pressure steam side pressure and temperature sensor (7), the first medium-pressure steam side electric control valve (8), the first medium-pressure steam side temperature regulating valve (9), the first medium-pressure steam side pressure regulating valve (10) and the first medium-pressure steam side check valve (11) are all fixedly connected. Connected to the first medium-pressure steam connecting pipe, the first medium-pressure steam side pressure and temperature sensor (7), the first medium-pressure steam side electric control valve (8), the first medium-pressure steam side temperature regulating valve (9), the first medium-pressure steam side pressure regulating valve (10) and the first medium-pressure steam side check valve (11) are sequentially connected to the first input end of the steam buffer mixing unit; the first medium-pressure steam side pressure and temperature sensor (7) is electrically connected to and communicates with the control cabinet (33), and the control cabinet (33) is electrically connected to the corresponding control ends of the first medium-pressure steam side electric control valve (8), the first medium-pressure steam side temperature regulating valve (9), the first medium-pressure steam side pressure regulating valve (10) and the first medium-pressure steam side check valve (11); The second medium-pressure steam delivery unit comprises a second medium-pressure steam connecting pipe, a steam discharge valve (21), a second medium-pressure steam side electric control valve (20), a second medium-pressure steam side temperature regulating valve (19), a second medium-pressure steam side pressure regulating valve (18) and a second medium-pressure steam side check valve (17); the output end of the damping storage unit is connected to the second input end of the steam buffer mixing unit via the second medium-pressure steam connecting pipe; the steam discharge valve (21), the second medium-pressure steam side electric control valve (20), the second medium-pressure steam side temperature regulating valve (19), the second medium-pressure steam side pressure regulating valve (18) and the second medium-pressure steam side check valve (17) are all fixedly connected to the second medium-pressure steam connecting pipe, and the steam discharge valve (21), the second medium-pressure steam side electric control valve (20), the second medium-pressure steam side temperature regulating valve (19), the second medium-pressure steam side pressure regulating valve (18) and the second medium-pressure steam side check valve (17) are sequentially connected to the second input end of the steam buffer mixing unit; the control cabinet (33) is respectively electrically connected to the corresponding control ends of the second medium-pressure steam side check valve (17), the second medium-pressure steam side pressure regulating valve (18), the second medium-pressure steam side temperature regulating valve (19), the second medium-pressure steam side electric control valve (20) and the steam discharge valve (21).

6. The device for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power station according to claim 1, characterized in that: The steam buffer mixing unit comprises a buffer mixer (12), a variable throat nozzle (13) and a mixing side pressure and temperature sensor (16); the buffer mixer (12) is equipped with a baffle; the variable throat nozzle (13) is fixedly connected to the output end of the buffer mixer (12); the mixing side pressure and temperature sensor (16) is fixedly connected to the buffer mixer (12); the variable throat nozzle (13) is connected to the input end of the molten salt tank (34) via the steam output unit; the mixing side pressure and temperature sensor (16) is electrically connected to and communicates with the control cabinet (33); The steam output unit comprises an output steam connecting pipe, a pressure transmitter (14) and a steam outlet valve (15); the output end of the steam buffer mixing unit is connected to the input end of the molten salt tank (34) via the output steam connecting pipe; the pressure transmitter (14) and the steam outlet valve (15) are both fixedly connected to the output steam connecting pipe; the pressure transmitter (14) and the steam outlet valve (15) are sequentially connected to the input end of the molten salt tank (34); the pressure transmitter (14) is electrically connected to and communicates with a control cabinet (33); and the control cabinet (33) is electrically connected to a control end of the steam outlet valve (15).

7. The device for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power station according to claim 1, characterized in that: It also includes a heater (35), which is fixedly connected to the first medium-pressure steam delivery unit, and the control cabinet (33) is electrically connected to the heater (35).

8. A method for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power plant, based on the device for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power plant according to any one of claims 1 to 6, characterized in that: The following steps are included: Step S11: the control cabinet (33) controls the low-pressure steam delivery unit to operate and conduct, and the low-pressure steam P2 enters the piston compression unit and the damping storage unit through the low-pressure steam delivery unit; Step S12: The control cabinet (33) controls the motor of the turbine transmission unit and the damping storage unit to operate. The motor of the turbine transmission unit drives the piston compression unit to compress the low-pressure steam P2 in the piston compression unit. The compressed steam is cooled and stored in the damping storage unit, so that the steam pressure in the damping storage unit increases. The pressure and temperature sensor on the damping tank side of the damping storage unit monitors the pressure and temperature in the damping storage unit and informs the control cabinet (33). Step S13: When the steam in the damping storage unit meets the discharge condition, the control cabinet (33) controls the high-pressure steam delivery unit to work and conduct, the control cabinet (33) controls the first medium-pressure steam delivery unit to work and conduct, the control cabinet (33) controls the motor of the turbine transmission unit to suspend work and maintain a free rotation state, and the control cabinet (33) controls the second medium-pressure steam delivery unit to work and conduct; the high-pressure steam P1 enters the turbine transmission unit through the high-pressure steam delivery unit, the turbine of the turbine transmission unit drives the piston compression unit to compress the low-pressure steam P2 in the piston compression unit, the damping storage unit outputs the second medium-pressure steam P4, the second medium-pressure steam P4 enters the steam buffer mixing unit through the second medium-pressure steam delivery unit; the high-pressure steam P1 outputs the first medium-pressure steam P3 through the turbine transmission unit, the first medium-pressure steam P3 enters the steam buffer mixing unit through the first medium-pressure steam delivery unit; the first medium-pressure steam P3 and the second medium-pressure steam P4 are buffered and mixed in the steam buffer mixing unit, and the mixing side pressure and temperature sensor of the steam buffer mixing unit monitors the pressure and temperature in the steam buffer mixing unit and informs the control cabinet (33); Step S14: When the steam in the steam buffer mixing unit meets the discharge condition, the control cabinet (33) controls the steam output unit to operate and conduct, and the steam P5 output by the steam buffer mixing unit enters the molten salt tank (34) through the steam output unit; Step S15: The high-pressure steam delivery unit obtains the pressure of the high-pressure steam P1 and informs the control cabinet (33), the turbine transmission unit obtains the rotational speed of the turbine in the turbine transmission unit and informs the control cabinet (33), when the pressure of the high-pressure steam P1 is lower than the set pressure threshold and the rotational speed of the turbine is lower than the set rotational speed threshold, the control cabinet (33) starts the motor of the turbine transmission unit, and the motor drives the turbine of the turbine transmission unit to rotate until the pressure of the high-pressure steam P1 exceeds the set pressure threshold, the rotational speed of the turbine exceeds the set rotational speed threshold and the time for maintaining this state exceeds the threshold time, the control cabinet (33) controls the motor to stop working.

9. The method for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power plant according to claim 8, characterized in that: In step S13, the discharge condition of the steam in the damping storage unit is that the steam pressure is ≥8 MPa and the temperature satisfies 500-530°C. In step S14, the discharge condition of the steam in the steam buffer mixing unit is that the steam pressure is ≥8 MPa and the temperature satisfies 490-510°C. In step S15, the set pressure threshold is 15 MPa.

10. A method for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power plant, based on the device for controlling the generation of medium-grade steam in a molten salt thermal storage system of a power plant according to claim 7, characterized in that: The following steps are included: Step S21: the control cabinet (33) controls the low-pressure steam delivery unit to operate and conduct, and the low-pressure steam P2 enters the piston compression unit and the damping storage unit through the low-pressure steam delivery unit; Step S22: the control cabinet (33) controls the high-pressure steam delivery unit to work and conduct, the control cabinet (33) controls the first medium-pressure steam delivery unit to work and conduct, the control cabinet (33) controls the heater (35) to work, and the control cabinet (33) controls the steam desuperheater of the damping storage unit to work; the high-pressure steam P1 enters the turbine transmission unit through the high-pressure steam delivery unit, the turbine of the turbine transmission unit drives the piston compression unit to compress the low-pressure steam P2 in the piston compression unit, and the compressed steam is cooled by the steam desuperheater of the damping storage unit and then enters the damping storage unit, so that the steam pressure in the damping storage unit rises, and the damping storage unit The damping tank side pressure and temperature sensor of the storage unit monitors the pressure and temperature in the damping storage unit and informs the control cabinet (33); the high-pressure steam P1 outputs the first medium-pressure steam P3 through the turbine transmission unit, and the first medium-pressure steam P3 enters the steam buffer mixing unit through the first medium-pressure steam delivery unit. The mixing side pressure and temperature sensor of the steam buffer mixing unit monitors the pressure and temperature in the steam buffer mixing unit and informs the control cabinet (33); when the steam in the damping storage unit meets the discharge condition, step S23 is synchronously executed; when the steam in the steam buffer mixing unit meets the discharge condition, step S24 is synchronously executed; Step S23: the control cabinet (33) controls the second medium-pressure steam delivery unit to operate and conduct; the damping storage unit outputs the second medium-pressure steam P4, and the second medium-pressure steam P4 enters the steam buffer mixing unit through the second medium-pressure steam delivery unit; the first medium-pressure steam P3 and the second medium-pressure steam P4 are buffered and mixed in the steam buffer mixing unit; Step S24: The control cabinet (33) controls the steam output unit to operate and conduct, and the steam P5 output by the steam buffer mixing unit enters the molten salt tank (34) through the steam output unit; Step S25: The high-pressure steam delivery unit obtains the pressure of the high-pressure steam P1 and informs the control cabinet (33), the turbine transmission unit obtains the rotational speed of the turbine in the turbine transmission unit and informs the control cabinet (33), when the pressure of the high-pressure steam P1 is lower than the set pressure threshold and the rotational speed of the turbine is lower than the set rotational speed threshold, the control cabinet (33) starts the motor of the turbine transmission unit, and the motor drives the turbine of the turbine transmission unit to rotate until the pressure of the high-pressure steam P1 exceeds the set pressure threshold and the rotational speed of the turbine exceeds the set rotational speed threshold and the time of maintaining exceeds the threshold time, the control cabinet (33) controls the motor to stop working.

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