Molten salt pump inlet salt distribution device

Abstract

The utility model discloses a molten salt pump inlet salt distribution device which comprises a metal compensator, a molten salt collector ring, a plurality of distribution tee joints, an inlet metal filter screen and a collector ring support. The fused salt collector ring is erected on the tank bottom of the fused salt tank through the collector ring bracket; the metal compensator is used for connecting an outlet of the molten salt collector ring and an inlet of the molten salt pump; the plurality of distribution tee joints are arranged among the circumferential directions of the fused salt collector rings at intervals, main pipes of the adjacent distribution tee joints are communicated through the fused salt collector rings, and branch pipes of the distribution tee joints face downwards to the tank bottom; fused salt sequentially passes through the inlet metal filter screen, the distribution tee joint, the fused salt collector ring and the metal compensator from the periphery of the fused salt tank to enter the fused salt pump, and the inlet metal filter screen is used for filtering the fused salt entering the distribution tee joint. The technical problems that a molten salt pump is generally arranged on the edge of a molten salt tank, and non-flowing molten salt exists at the bottom of the molten salt tank are solved. The method has the advantage of reducing molten salt dead zones at the bottom of the molten salt tank, so that the bottom temperature field of the molten salt tank is stable.

Description

Technical Field

[0001] The utility model relates to the field of molten salt tank equipment, in particular to a molten salt pump inlet salt distribution device. Background Art

[0002] Molten salt energy storage technology is commonly used in solar thermal power generation, large-scale compressed air energy storage power plants, and thermal power plant flexibility improvements. The thermal storage system utilizes two hot and cold salt tanks for molten salt energy storage, a technology commonly used both domestically and internationally. The salt tanks are vertical, fixed, dome-shaped tanks to minimize energy loss due to the mixing of hot and cold molten salts.

[0003] Due to the high freezing point of molten salt, to prevent the molten salt from solidifying due to prolonged exposure to ambient heat, the molten salt pump must be a submersible pump mounted on the top of the tank and located in only one corner. Due to the high temperature, the pump's operation makes it difficult to uniformly distribute the molten salt throughout the tank, resulting in an unstable temperature field inside the tank and stress concentration points, which can easily cause leaks. Furthermore, the molten salt pump in molten salt thermal storage systems is typically a vertical suspended pump, located at the edge of the tank. The pump impeller is immersed in the tank bottom to pump the molten salt out. To ensure safe and stable operation, the pump's suction port is located at a certain height difference from the tank bottom, typically more than 1 meter. This creates a dead zone at the pump bottom, where the medium is largely stagnant, resulting in a large dead zone. For example, for a cold salt tank with a diameter of 30 meters and a height of 14.5 meters, and a hot salt tank with a diameter of 31.5 meters and a height of 14.5 meters, the dead zone holds approximately 2,700 tons of molten salt. Considering that the current price of molten salt is relatively expensive, reducing the dead volume can effectively reduce the initial investment.

[0004] Therefore, a molten salt pump inlet salt distribution device is needed to stir the bottom of the molten salt tank to reduce the waste caused by the dead zone volume of the molten salt at the bottom of the tank and the uneven temperature field at the bottom of the tank. Utility Model Content

[0005] The purpose of the utility model is to provide a molten salt pump inlet salt distribution device to stir the bottom of the molten salt tank, reduce the dead zone volume of the molten salt at the bottom of the tank, save costs, increase the uniformity of the temperature field at the bottom of the tank, and improve the safety of the molten salt tank.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] A molten salt pump inlet salt distribution device, comprising a metal compensator, a molten salt slip ring, a plurality of distribution tees, an inlet metal filter, and a slip ring bracket;

[0008] The slip ring bracket mounts the molten salt slip ring on the bottom of the molten salt tank;

[0009] The metal compensator is used to connect the outlet at the top of the molten salt slip ring and the inlet of the molten salt pump;

[0010] The plurality of distribution tees are spaced apart and arranged around the circumference of the molten salt convergence ring, the main pipes of adjacent distribution tees are connected by the molten salt convergence ring, and the branch pipes of the distribution tees are downwardly directed toward the bottom of the tank;

[0011] The molten salt enters the molten salt pump from the four sides of the molten salt tank through the inlet metal filter, the distribution tee, the molten salt collector ring, and the metal compensator in sequence. The inlet metal filter is used to filter the molten salt entering the distribution tee.

[0012] Furthermore, the inlet metal filter is cylindrical and arranged below the branch pipe of the distribution tee.

[0013] Furthermore, the pipe material of the molten salt slip ring is TP347H or Q345R.

[0014] Furthermore, the inner diameter of the pipe of the molten salt slip ring is consistent with the inlet specification of the molten salt pump.

[0015] Furthermore, a distribution tee is arranged every 45° on the circumference of the molten salt sink ring.

[0016] In the above technical solution, the utility model has the following beneficial effects:

[0017] When the molten salt pump is operating, a negative pressure zone forms at the pump inlet. Molten salt flows evenly from the perimeter of the storage tank through the inlet metal filter, distribution tee, molten salt collector ring, and metal compensator. This agitation of the molten salt beneath the pump increases the uniformity of the temperature field at the tank bottom, reduces stress concentration, and prevents leaks. This also reduces molten salt waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0019] Figure 1 This is a front view structural diagram of the molten salt pump inlet salt distribution device disclosed in the present utility model;

[0020] Figure 2 This is a schematic diagram of the top view of the salt distribution device at the inlet of the molten salt pump disclosed in the present utility model;

[0021] Figure 3 This is a structural diagram of the distribution tee disclosed in the utility model;

[0022] Figure 4 This is a schematic structural diagram of the molten salt sink ring disclosed in the present utility model;

[0023] Figure 5 This is a structural schematic diagram of the slip ring bracket disclosed in the present utility model.

[0024] Reference numerals:

[0025] Metal compensator 1, molten salt merge ring 2, distribution tee 3, inlet metal filter 4, merge ring bracket 5. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] It should be noted that the terms "above", "one end", "upper", etc. used in this article indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. Similar expressions are only for illustrative purposes, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; in addition, the terms "one part", "two parts", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] like Figure 1-3 The molten salt pump inlet salt distribution device shown is arranged inside the molten salt tank and includes a metal compensator 1, a molten salt slip ring 2, a plurality of distribution tees 3, an inlet metal filter 4, and a slip ring bracket 5.

[0029] The slip ring bracket 5 supports the molten salt slip ring 2 on the bottom of the molten salt tank. The slip ring bracket is preferably made of a support tube made of the same material as the molten salt slip ring. The upper portion of the support tube is welded to the molten salt slip ring, and the lower portion of the support tube is welded to the bottom of the molten salt tank to ensure that the molten salt slip ring is firmly supported on the bottom of the molten salt tank. The number and position of the slip ring brackets are generally determined based on stress calculations.

[0030] The metal compensator 1 connects the top outlet of the molten salt slip ring 2 to the inlet of the molten salt pump. The outlet can be located below the inlet of the molten salt pump. One end of the metal compensator is connected to the inlet of the molten salt pump, and the other end is connected to the molten salt slip ring. This flexible connection between the molten salt pump and the molten salt slip ring prevents vibration during operation of the molten salt pump from affecting the molten salt slip ring. It also absorbs thermal displacement caused by temperature differences between the molten salt pump and the molten salt slip ring, specifically the temperature changes between the tank when salt is stored and when it is empty.

[0031] When there are two molten salt pumps, the inlet of each molten salt pump is connected to the outlet at the top of a metal compensator 1 and a molten salt slip ring 2 respectively.

[0032] Multiple distribution tees 3 are spaced apart around the circumference of the molten salt merge ring 2. The horizontal main pipes of adjacent distribution tees 3 are connected by the molten salt merge ring 2. The branch pipes of the distribution tees 3 are arranged vertically and downward toward the bottom of the tank. The multiple segments of curved pipes in the molten salt merge ring 2 connect the horizontal main pipes of adjacent distribution tees 3.

[0033] Preferably, a distribution tee 3 is arranged every 45° around the circumference of the molten salt slip ring 2. A total of eight distribution tees are evenly spaced around the slip ring. The material used is the same as the slip ring, and forged tees are used to ensure strength. The suction port of the distribution tee, i.e., the end of the branch pipe, faces downward toward the bottom of the molten salt tank. This arrangement ensures that the suction port is as close to the bottom of the molten salt tank as possible, reducing dead space and conserving molten salt.

[0034] The molten salt collector ring is composed of multiple sections of circular pipes with circular cross-sections, and distribution tees 3 are connected between the ends of adjacent circular pipes. To ensure a reasonable flow rate of the medium in the molten salt collector ring, the inner diameter of the pipe of the molten salt collector ring 2 is preferably consistent with the inlet specifications of the molten salt pump. Preferably, the pipe material of the molten salt collector ring 2 is TP347H or Q345R. According to the operating temperature of the molten salt, the high-temperature molten salt tank is about 565°C, and the pipe material is TP347H; the low-temperature molten salt tank is about 290°C, and the pipe material is Q345R. The molten salt collector ring is set at the bottom of the molten salt tank, with the center approximately 500mm from the tank bottom. The center of the molten salt collector ring is approximately 1000mm from the molten salt tank wall, and a distribution pipe is set at an average of every 45° angle, which can evenly absorb the molten salt from all sides of the molten salt tank.

[0035] The molten salt enters the molten salt pump from the four sides of the molten salt tank through the inlet metal filter 4, the distribution tee 3, the outlet of the molten salt merge ring 2, and the metal compensator 1. The inlet metal filter 4 is used to filter the molten salt entering the distribution tee 3.

[0036] Preferably, the inlet metal filter 4 is cylindrical and is arranged below the branch pipe of the distribution tee 3.

[0037] The inlet metal screen 4, installed at the inlet of the distribution tee, is 100 mm from the bottom of the molten salt tank. It surrounds the bottom of the branch pipe of the distribution tee 3. The inlet screen is made of stainless steel and is the primary measure to prevent impurities in the molten salt tank from being drawn into the molten salt pump and causing damage.

[0038] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A molten salt pump inlet salt distribution device, characterized in that: It includes a metal compensator (1), a molten salt collector ring (2), a plurality of distribution tees (3), an inlet metal filter (4), and a collector ring bracket (5); The slip ring bracket (5) mounts the molten salt slip ring (2) on the bottom of the molten salt tank; The metal compensator (1) is used to connect the outlet at the top of the molten salt sink ring (2) and the inlet of the molten salt pump; A plurality of distribution tees (3) are arranged at intervals between the circumference of the molten salt confluence ring (2), the main pipes of adjacent distribution tees (3) are connected by the molten salt confluence ring (2), and the branch pipes of the distribution tees (3) are downwardly directed toward the bottom of the tank; The molten salt enters the molten salt pump from the four sides of the molten salt tank through the inlet metal filter (4), the distribution tee (3), the molten salt confluence ring (2), and the metal compensator (1). The inlet metal filter (4) is used to filter the molten salt entering the distribution tee (3).

2. A molten salt pump inlet salt distribution device according to claim 1, characterized in that: The inlet metal filter (4) is cylindrical and is arranged below the branch pipe of the distribution tee (3).

3. The molten salt pump inlet salt distribution device according to claim 1, characterized in that: The pipe material of the molten salt convergence ring (2) is TP347H or Q345R.

4. The molten salt pump inlet salt distribution device according to claim 1, characterized in that: The inner diameter of the pipe of the molten salt confluence ring (2) is consistent with the inlet specification of the molten salt pump.

5. The molten salt pump inlet salt distribution device according to claim 1, characterized in that: The distribution tee (3) is arranged every 45° in the circumferential direction of the molten salt confluence ring (2).

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