Tank-type fused salt steam generation system

Abstract

The utility model belongs to the technical field of fused salt heat storage application, and relates to a tank type fused salt steam generation system which comprises a fused salt tank, a pure water tank, a water supply valve, a cooling valve, a desuperheater and a main steam valve. A fused salt electric heating rod is inserted into the top of the cylinder body and is used for heating the heat storage phase change material; an input port and an output port of the S-shaped heat exchange pipe are respectively connected to a water supply valve and a desuperheater; the pure water tank provides pure water and feeds the pure water into the snake-shaped heat exchange pipe through the manual water supply valve to generate steam, and the output of the desuperheater is connected into the main steam valve and controls the flow speed of the steam. The cooling valve is connected between the desuperheater and the water supply valve; and after the water supply valve and the cooling valve are opened, water in the pure water tank is used for carrying out temperature reduction and temperature control on output steam. The system has the advantages of being compact in structure, convenient to machine, low in cost and high in heat transfer efficiency.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the molten salt heat storage application technical field relates to a tank type molten salt steam generation system. BACKGROUND

[0002] In a solar thermal power station, a molten salt steam generator system plays a key role in connecting a concentrating solar thermal system and a power generation system. The system uses liquid binary molten salt as a heat transfer and storage medium to convert solar radiation energy into high-temperature, high-pressure steam, which in turn drives a steam turbine to generate electricity.

[0003] The current molten salt steam generator system mainly includes a preheater, a steam generator, a steam drum, and a superheater. They complete the preheating, evaporation, and superheating processes of water through step-by-step heat exchange with high-temperature molten salt. The main heat exchangers are as follows: the preheater usually uses a horizontal tube-shell heat exchanger, the steam generator is a vertical tube-shell heat exchanger, and the superheater is a horizontal U-shaped tube-shell heat exchanger. The existing solar thermal power station molten salt steam generator system has the following problems: 1) The system structure is complex, composed of multiple heat exchange equipment such as preheaters, steam generators, superheaters, and various auxiliary equipment, resulting in large equipment volume, high material consumption, and increased equipment cost. 2) The heat exchange equipment uses a tube-shell heat exchanger with long heat exchange tubes, resulting in high flow resistance and increased operating costs. 3) The design and manufacturing difficulty is high, the tube plate and shell of the tube-shell heat exchanger are usually connected by welding, with numerous welds and prone to defects and residual stress. Under long-term experience of large temperature difference and frequent changes in working conditions, the vibration of the heat exchange tube bundle, structural thermal stress, and thermal fatigue problems are difficult to effectively solve, increasing the risk of heat exchanger leakage. With the global energy structure transformation and the promotion of clean energy, the molten salt steam generator has a more and more extensive prospect, and the above problems need to be solved. UTILITY MODEL CONTENTS

[0004] To solve the above technical problems in the prior art, the utility model provides a tank type molten salt steam generation system, which simplifies the composition of the existing molten salt steam generator complex system, reduces the volume and weight of the tube-shell heat exchanger, reduces the investment cost, reduces the design difficulty and welding manufacturing difficulty, improves the heat exchange efficiency of the main heat exchanger, and reduces the flow resistance. The specific technical scheme is as follows:

[0005] The application discloses a tank type molten salt steam generating system, which comprises a molten salt tank and a pure water tank, a water supply valve, a temperature reducing valve, a desuperheater and a main steam valve which are connected to the outside of the molten salt tank.

[0006] Further, the serpentine heat exchange pipes are distributed in a circle with the axis of the molten salt tank as the center.

[0007] Further, a plurality of temperature measuring points with different heights are arranged on the serpentine heat exchange pipes along the axis of the molten salt tank.

[0008] Further, the heat storage phase change material is a molten salt phase change material.

[0009] Further, a molten salt liquid level monitoring meter is arranged in the heat storage phase change material liquid.

[0010] Further, the molten salt electric heating rod heats the heat storage phase change material by discharging of a peak shaving power plant.

[0011] Further, the molten salt electric heating rod has six electric heating rods which are uniformly arranged on the top of the molten salt tank and located in the inner circle area of the serpentine heat exchange pipes.

[0012] The molten salt tank, the serpentine heat exchange pipes, the molten salt phase change material storage and heat release, the increased travel of cold and hot fluids in the heat storage device, the high heat conduction performance, the accelerated heat exchange speed of the fluids and the phase change material, the obviously shortened heat storage time of the phase change heat storage device, the improved heat storage performance of the phase change heat storage device, the in-out adjustment of the cold and hot fluids by the added valve, the high efficient heat exchange among the cold fluid, the hot fluid and the solid-liquid phase change material, the compact structure, the convenient processing, the low cost and the high heat transfer efficiency are realized. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 Fig. 1 is a structural schematic view of a tank type molten salt steam generating system according to the application;

[0014] Figure 2 Fig. 2 is a top view of a molten salt tank according to the application;

[0015] In the figure, 1-pure water tank; 2-feed water valve; 3-temperature reducing valve; 4-molten salt tank cylinder; 5-heat exchange pipe; 6-molten salt liquid level monitor; 7-molten salt electric heating rod; 8-temperature reducer; 9-main steam valve; 10-heat storage phase change material. DETAILED DESCRIPTION

[0016] The technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model.

[0017] As shown in Figure 1 and Figure 2 , the tank type molten salt steam generating system of the embodiment comprises a molten salt tank and a pure water tank 1, a feed water valve 2, a temperature reducing valve 3, a temperature reducer 8 and a main steam valve 9 arranged outside the molten salt tank.

[0018] The molten salt tank specifically comprises: a molten salt tank cylinder 4, the molten salt tank cylinder 4 is provided with a heat exchange pipe 5, the heat exchange pipe 5 is a pipe that meanders in a plane multiple times, the heat exchange pipe 5 is arranged in a circumferential array around an axis, due to the special curved surface structure, when the fluid flows through, centrifugal force is generated, due to the double-layer effect of the centrifugal force and the boundary layer at the elbow, secondary flow is generated, the secondary flow and the main fluid are superposed to form vortex flow, periodic radial flow velocity is generated, this flow can cause damage to the boundary layer, the near-wall zone turbulence is strengthened, heat transfer deterioration is inhibited, so that the effect of strengthening heat transfer is achieved, the pressure bearing capacity is strong, the wall thickness between the heat exchange channels can be greatly reduced, the heat exchange resistance is reduced, the volume and weight of the steam generator are reduced, and the structural reliability is high. The two ends of the heat exchange pipe 5 are fixedly connected with the feed water valve 2 and the temperature reducer 8 respectively; eight temperature measuring points of different heights are arranged on the heat exchange pipe 5 along the axial direction of the molten salt tank cylinder 4, so that temperature abnormalities caused by molten salt phase change during operation are prevented, the heat supply parameter fluctuation is effectively reduced, over-regulation or under-temperature and under-pressure conditions are avoided to a certain extent, and the safety of heat supply is improved. The space between the heat exchange pipe 5 and the molten salt tank cylinder 4 is filled with heat storage phase change material 10. The heat storage phase change material 10 is a molten salt phase change material. Two molten salt liquid level monitors 6 are arranged in the liquid of the heat storage phase change material 10 to monitor the liquid level of the molten salt phase change material, so as to ensure the safety of the operation of the molten salt steam generator.

[0019] The pure water tank 1 provides pure water and sends the pure water into the heat exchange pipe 5 in the molten salt tank cylinder 4 through the manual feed water valve 2. The temperature reducer 8 is also connected with the main steam valve 9 to control the flow rate of the steam. The temperature reducing valve 3 is connected between the temperature reducer 8 and the feed water valve 2, after the feed water valve 2 and the temperature reducing valve 3 are opened, the high-temperature steam generated by the molten salt tank can be temperature-reduced and controlled by using the water in the pure water tank 1.

[0020] The six evenly distributed molten salt electric heating rods 7 are inserted into the top of the molten salt tank cylinder 4, and the six molten salt electric heating rods 7 heat the molten salt in the molten salt tank by discharging of the peak shaving power plant.

[0021] When the temperature of the molten salt in the molten salt tank is high, the pure water from the pure water tank 1 is heated by the high-temperature molten salt, and under the action of the high-temperature molten salt, high-temperature steam enters the desuperheater 8, and the pure water in the pure water tank 1 is used to reduce the temperature of the high-temperature steam through the feed water valve 2 and the desuperheating valve 3 to meet the required steam conditions, and the steam meeting the working requirements is sent into the outlet through the main steam valve 9 to do work. When the molten salt in the molten salt tank is heated and the temperature is reduced, the six molten salt electric heating rods 7 inserted in the molten salt liquid heat the molten salt in the molten salt tank by discharging of the peak shaving power plant to heat the next round.

[0022] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture, and if the specific posture changes, the directionality indications will also change accordingly. In the present application, unless otherwise specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise specified. For ordinary skilled persons in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0023] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the implementation process of the present application has been described in detail in the foregoing, those skilled in the art can still modify the technical solutions recorded in the foregoing examples, or replace some of the technical features with equivalent ones. Any modification, equivalent replacement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A tank-type molten salt steam generation system comprising a molten salt tank and a pure water tank (1), a feed water valve (2), a desuperheating valve (3), a desuperheater (8), and a main steam valve (9) installed and connected outside thereof, characterized in that, The molten salt tank comprises a molten salt tank cylinder (4) with a serpentine heat exchange pipe (5) inside and filled with a heat storage phase change material (10) between the serpentine heat exchange pipe (5), and a molten salt electric heating rod (7) inserted into the top of the molten salt tank cylinder (4); the input and output of the serpentine heat exchange pipe (5) are connected to a water supply valve (2) and a desuperheater (8) respectively; the pure water tank (1) provides pure water and sends it into the serpentine heat exchange pipe (5) through the manual water supply valve (2) to generate steam, and the desuperheater (8) is connected to the main steam valve (9) and controls the steam flow rate; the cooling valve (3) is connected between the desuperheater (8) and the water supply valve (2), and the output steam is cooled by the water in the pure water tank (1) after the water supply valve (2) and the cooling valve (3) are opened.

2. The tanked molten salt steam generation system of claim 1, wherein, The serpentine heat exchange pipe (5) is distributed in a circle with the axis of the molten salt tank cylinder (4) as the center.

3. The tanked molten salt steam generation system of claim 1, wherein, There are several temperature measuring points of different heights along the axial direction of the serpentine heat exchange pipe (5) in the molten salt tank cylinder (4).

4. The tanked molten salt steam generation system of claim 1, wherein, The heat storage phase change material (10) is a molten salt phase change material.

5. The tanked molten salt steam generation system of claim 1, wherein, There is a molten salt liquid level monitoring meter (6) in the heat storage phase change material (10) liquid.

6. The tanked molten salt steam generation system of claim 1, wherein, The molten salt electric heating rod (7) uses the discharge of the peak shaving power plant to heat the heat storage phase change material (10).

7. The tanked molten salt steam generation system of claim 1, wherein, The molten salt electric heating rod (7) has 6, which are uniformly arranged in a ring at the top of the molten salt tank cylinder (4) and located in the inner circle area of the serpentine heat exchange pipe (5).

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