Segmented heating high-voltage high-power fused salt electric heater

Abstract

The utility model discloses a segmented heating high-voltage high-power fused salt electric heater which comprises a cylinder body, the cylinder body comprises an upper cylinder body and a lower cylinder body, one end of the upper cylinder body is communicated with one end of the lower cylinder body through a connecting cylinder, the two ends of the upper cylinder body and the two ends of the lower cylinder body are respectively provided with a tube plate, and a fused salt outlet is formed in the end, opposite to the end connected with the connecting cylinder, of the upper cylinder body. A molten salt inlet is formed in the end, opposite to the end connected with the connecting cylinder, of the bottom of the lower cylinder, electric heating elements distributed in the axial direction are arranged in the upper cylinder and the lower cylinder respectively and connected with the tube plate, baffle plates distributed in a staggered mode are installed in the cylinders, molten salt flowing holes are formed in the baffle plates, and the electric heating elements are divided into multiple groups. According to the utility model, the multi-stage electric heating elements are arranged in the electric heater, so that the molten salt area is heated, and the phenomenon that the molten salt is heated and decomposed due to overtemperature of the molten salt can be obviously reduced on the premise of ensuring the flow of the molten salt, thereby improving the safety of a molten salt system.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of fused salt electric heater especially relates to a segmented heating high voltage high power fused salt electric heater. BACKGROUND

[0002] In recent years, with the continuous promotion of the "double carbon" goal, people have continuously increased the development of renewable energy such as wind power and solar power in order to achieve the purpose of reducing the use of fossil energy. However, renewable energy generally has the characteristics of intermittency and strong volatility, making its power output extremely unstable, which can seriously impact the safety of the power grid. In order to improve the stability of solar power generation and wind power generation and smooth power output, energy storage devices have begun to be widely used in renewable energy generation. Fused salt energy storage is to use the temperature difference of fused salt in the heat absorption and heat release process to realize heat storage, which has very small hysteresis and can quickly convert electrical energy into heat energy, especially suitable for large-scale wind power and solar power systems.

[0003] Fused salt electric heater is a device that converts electrical energy into heat energy. The common types include resistance type, electrode type and inductive type. Among them, the resistance type fused salt electric heater is widely used because of its simple structure, high reliability and high heating efficiency. With the increasing size of energy storage, the shortcomings of traditional low-voltage resistance type heaters, such as small heating power and high cost of power distribution equipment, become more and more obvious, and high-voltage heaters emerge as the times require. Compared with low-voltage electric heaters, high-voltage electric heaters can be directly connected to high-voltage power grids, eliminating the cost of power distribution equipment, while requiring lower cable diameters for the same power, greatly reducing manufacturing costs. However, high-voltage electric heaters have high heating power and high surface power of electric heating elements, which puts high requirements on the flow rate of fused salt. If the flow rate of fused salt is low, local overheating may occur inside the electric heater, causing the fused salt to overheat and decompose, seriously affecting the safety of the equipment. If the flow rate of fused salt is increased, the pressure drop of the equipment will increase sharply, and the flow distance of the fused salt will inevitably increase, resulting in a large size of the electric heater, which is not convenient for engineering application. Therefore, a segmented heating high-voltage high-power fused salt electric heater is needed to improve the above problems. SUMMARY

[0004] To solve the above technical problems, the utility model designs a segmented heating high-voltage high-power fused salt electric heater to solve the problem of local overheating of the prior art high-voltage resistance type heater.

[0005] The utility model adopts the following technical scheme:

[0006] The application discloses a segmented heating high-voltage high-power molten salt electric heater, which comprises a cylinder body, wherein the cylinder body comprises an upper cylinder body and a lower cylinder body, one end of the upper cylinder body and the lower cylinder body is communicated through a connecting cylinder, and the two ends of the upper cylinder body and the lower cylinder body are respectively provided with tube plates; a molten salt outlet is arranged on the upper cylinder body at the opposite end connected with the connecting cylinder; a molten salt inlet is arranged on the bottom of the lower cylinder body at the opposite end connected with the connecting cylinder; electric heating elements arranged in an axial direction are respectively arranged in the upper cylinder body and the lower cylinder body; the electric heating elements are connected with the tube plates; baffles arranged in a staggered mode are arranged in the cylinder body; the baffles are provided with molten salt flow holes; the electric heating elements are divided into groups and arranged in the upper cylinder body and the lower cylinder body; each group of electric heating elements is connected and controlled by an independent control box; and the heating power of electric heating elements in different groups gradually decreases along the molten salt flow direction.

[0007] Preferably, the cylinder body is composed of two cylinders with the same or different diameters, and the two cylinders are arranged in parallel.

[0008] Preferably, the two cylinders are arranged in a stacked mode.

[0009] Preferably, the cylinder body forms a certain angle with the horizontal direction, and a blowdown port is arranged at the bottom of the cylinder body, so that the internal molten salt can be quickly discharged under emergency working conditions.

[0010] Preferably, the angle between the cylinder body and the horizontal direction is 0.5-1°.

[0011] Preferably, a connecting plate is arranged between the upper cylinder body and the lower cylinder body.

[0012] Preferably, a base is arranged at the bottom of the cylinder body.

[0013] The application has the following beneficial effects: (1) the segmented multi-stage heating method is adopted, different heating powers are arranged in different heating sections, the molten salt heating efficiency is improved under the premise that the molten salt is not overheated, the size of the molten salt electric heating equipment is reduced, and the engineering site arrangement is more convenient; (2) the molten salt flow holes are arranged on the baffles, the flow dead zone caused by the baffles is weakened, and the temperature distribution of the electric heater is improved. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic diagram of the overall structure of the electric heater of the application;

[0015] Figure 2 is a schematic diagram of the internal structure of the electric heater of the application;

[0016] Figure 3 is the structure diagram of the baffle plate in the utility model;

[0017] In the figure: 1, cylinder, 11, upper cylinder, 12, lower cylinder, 13, connecting cylinder, 2, connecting plate, 3, base, 4, tube plate, 5, electric heating element, 51, first-stage electric heating element, 52, second-stage electric heating element, 53, third-stage electric heating element, 54, fourth-stage electric heating element, 6, baffle plate, 61, molten salt flow hole, 71, first control box, 72, second control box, 73, third control box, 74, fourth control box, 8, blowdown, 111, molten salt outlet, 121, molten salt inlet. DETAILED DESCRIPTION

[0018] The technical scheme of the utility model will be further described in detail below by means of specific embodiments and in combination with the drawings:

[0019] Embodiment: as shown in Figure 1 and Figure 2 A segmented heating high-voltage high-power molten salt electric heater, comprising: a cylinder 1, the cylinder comprising an upper cylinder 11 and a lower cylinder 12, the upper cylinder 11 and the lower cylinder 12 being communicated at one end through a connecting cylinder 13, and a connecting plate 2 being arranged between the two cylinders; a base 3 for supporting the electric heater is mounted at the bottom of the lower cylinder; a molten salt outlet 111 is arranged at the opposite end of the upper cylinder 11 connected with the connecting cylinder, and a molten salt inlet 121 is arranged at the opposite end of the lower cylinder 12 connected with the connecting cylinder; tube plates 4 are respectively mounted at the two ends of the upper cylinder 11 and the lower cylinder 12; electric heating elements 5 arranged along the axial direction of the cylinder are respectively mounted in the upper cylinder 11 and the lower cylinder 12, and the electric heating elements 5 are connected with the tube plates 4; baffle plates 6 arranged alternately are respectively mounted in the upper cylinder 11 and the lower cylinder 12, and the baffle plates 6 are provided with molten salt flow holes 61. The molten salt flow holes 61 can weaken the local flow dead zone of the baffle plate, avoiding the problem of excessively high temperature of the molten salt.

[0020] As shown in Figures 1 to 3 , a plurality of groups of electric heating elements are arranged in the cylinder along the molten salt flow direction in sequence, respectively comprising first-stage electric heating elements 51, second-stage electric heating elements 52, third-stage electric heating elements 53 and fourth-stage electric heating elements 54, each group of electric heating elements is connected with a respective control box, i.e. a first control box 71, a second control box 72, a third control box 73 and a fourth control box 74, and is independently controlled by the control box; the electric heating power gradually decreases from the first-stage electric heating elements 51 to the fourth-stage electric heating elements 54, and the principle is that the temperature of the molten salt is relatively low near the molten salt inlet 121, a larger electric heating power is arranged to rapidly increase the temperature of the molten salt, thereby increasing the total heating capacity of the equipment, the temperature of the molten salt is relatively high near the molten salt outlet 111, and the risk of overtemperature of the molten salt increases, so that a smaller electric heating power is adopted to reduce the possibility of overtemperature of the molten salt.

[0021] As shown in Figure 1 The barrel is provided with a blowdown opening 8 below, and the barrel is at a certain angle with the horizontal direction, preferably 0.5-1°, so as to quickly discharge the internal molten salt under emergency working conditions.

[0022] The above-described embodiment is only a preferred scheme of the present application, and does not limit the present application in any form, and other variants and modifications are possible without exceeding the technical scheme recorded in the claims.

Claims

1. A segmented heating high-voltage, high-power molten salt electric heater, characterized in that, It includes a cylinder, which consists of an upper cylinder and a lower cylinder. One end of the upper cylinder and the lower cylinder are connected by a connecting cylinder. Tube sheets are installed at both ends of the upper cylinder and the lower cylinder, respectively. A molten salt outlet is provided on the upper cylinder at the opposite end of the connection with the connecting cylinder, and a molten salt inlet is provided at the bottom of the lower cylinder at the opposite end of the connection with the connecting cylinder. Electric heating elements are arranged axially in the upper cylinder and the lower cylinder, and the electric heating elements are connected to the tube sheets. Baffles are installed inside the cylinder in a staggered manner, and molten salt flow holes are provided on the baffles. The electric heating elements are divided into multiple groups and placed in the upper cylinder and the lower cylinder. Each group of electric heating elements is connected to and controlled by an independent control box. The heating power of different groups of electric heating elements gradually decreases along the direction of molten salt flow.

2. The segmented heating high-voltage high-power molten salt electric heater according to claim 1, characterized in that, The cylinder is composed of two cylinders with the same or different diameters, which are arranged in parallel to each other.

3. A segmented heating high-voltage high-power molten salt electric heater according to claim 2, characterized in that, The two cylinders are arranged in a stacked manner, one above the other.

4. A segmented heating high-voltage high-power molten salt electric heater according to claim 2, characterized in that, The cylinder is at a certain angle to the horizontal direction, and a drain outlet is provided at the bottom of the cylinder.

5. A segmented heating high-voltage high-power molten salt electric heater according to claim 4, characterized in that, The angle between the cylinder and the horizontal direction is 0.5-1°.

6. A segmented heating high-voltage high-power molten salt electric heater according to claim 1, characterized in that, A connecting plate is provided between the upper cylinder and the lower cylinder.

7. A segmented heating high-voltage high-power molten salt electric heater according to claim 1, characterized in that, A base is provided at the bottom of the cylinder.

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