A passive flow control device

Abstract

The application discloses a kind of passive flow control equipment, including water inlet assembly, transition chamber and drain pipe, water inlet assembly is connected through the side wall of transition chamber, one end of horizontal conversion pipe is connected through the side wall of transition chamber, the other end of horizontal conversion pipe is communicated with the bottom end of vertical water inlet pipe, one end of horizontal water inlet pipe is connected through the side wall of transition chamber and the junction of one end of horizontal conversion pipe;Water from vertical water inlet pipe and water from horizontal water inlet pipe form a collision, the tangential component of total water flow momentum is cancelled out, and water flows vertically into the drain pipe;Realize large flow water inlet, and when water level drops, the internal installation of vertical water inlet pipe Ball will fall and cover the opening formed on ball seat, so that water flow can only flow from horizontal water inlet pipe, instantaneous cut-off of water flow in vertical water inlet pipe can realize high-low flow instantaneous switching, meet the requirement that safety injection tank is used for primary loop emergency coolant injection, the rated flow is large at the beginning of safety injection, the injection flow drops sharply after several tens of seconds, and is maintained at a lower level for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid resistance equipment, and in particular to a passive flow control device. Background Art

[0002] The nuclear power sector involves numerous flow regulation issues, particularly for safety-related systems such as injection, spray, and containment cooling systems. The reliability, timeliness, and accuracy of post-accident flow regulation are directly linked to nuclear power plant safety. The injection tank, a device used for emergency coolant injection in the primary circuit of a nuclear power plant in the event of a reactor accident, operates with a highly nonlinear flow rate. Initially, the rated flow rate is high, but after a few seconds, the flow rate is required to drop sharply and remain at a low level for an extended period. This presents significant challenges in designing the resistance of the injection tank. Summary of the Invention

[0003] In view of the defects existing in the prior art, the object of the present invention is to provide a passive flow control device that can achieve instantaneous switching between high and low flow rates.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A passive flow control device includes a water inlet assembly, a transition chamber and a drain pipe, wherein

[0006] The drainage pipe is connected to the bottom of the transition chamber;

[0007] The water inlet assembly is connected to the side wall of the transition chamber, and the water inlet assembly includes a vertical water inlet pipe, a horizontal conversion pipe and a horizontal water inlet pipe;

[0008] One end of the horizontal conversion pipe is connected to the side wall of the transition chamber, and the other end of the horizontal conversion pipe is connected to the bottom end of the vertical water inlet pipe;

[0009] One end of the horizontal water inlet pipe is connected to the side wall of the transition chamber and the connection of one end of the horizontal conversion pipe;

[0010] A water inlet is provided on the wall of the vertical water inlet pipe. A float and a ball seat are installed inside the vertical water inlet pipe. An opening is formed on the ball seat. The ball seat is fixed to the inner wall of the vertical water inlet pipe. The float is located above the ball seat and can operably cover the opening.

[0011] Furthermore, the transition chamber is cylindrical, the horizontal conversion tube is a straight tube, and the axis of the horizontal conversion tube is tangent to the side of the transition chamber.

[0012] Furthermore, the cross section of the horizontal water inlet pipe is wedge-shaped, and one wedge-shaped edge of the horizontal water inlet pipe is tangent to the side edge of the transition cavity.

[0013] Furthermore, the angle between the water flow direction of the horizontal water inlet pipe and the water flow direction of the horizontal conversion pipe is 5 to 10 degrees.

[0014] Furthermore, a vortex breaker is installed inside the vertical water inlet pipe and is located below the ball seat.

[0015] Furthermore, the float is a hollow ball, the hollow center of the float is located at the upper part of the float, and the hollow inside of the float is filled with nitrogen with a pressure between 1.5 MPa and 2 MPa.

[0016] Furthermore, the float is made of metal or plastic.

[0017] Furthermore, there are three groups of water inlet components, and the three groups of water inlet components are arranged at equal angles around the transition chamber.

[0018] Furthermore, the lengths of the vertical water inlet pipes in each group of water inlet components are different.

[0019] Furthermore, the bottom end of the vertical water inlet pipe is connected to the other end of the horizontal conversion pipe through a thread.

[0020] The beneficial effects of the present invention are as follows: the passive flow control device provided by the present invention is connected to the bottom of the transition chamber through a drain pipe, the water inlet assembly is connected to the side wall of the transition chamber, one end of the horizontal conversion pipe is connected to the side wall of the transition chamber, the other end of the horizontal conversion pipe is connected to the bottom end of the vertical water inlet pipe, and one end of the horizontal water inlet pipe is connected to the connection between the side wall of the transition chamber and one end of the horizontal conversion pipe. Therefore, water flowing from the vertical water inlet pipe changes direction after passing through the horizontal conversion pipe and will form an offset with the water flowing from the horizontal water inlet pipe. The tangential components of the total momentum of the two water flows are offset, and the water flows vertically into the drain pipe. Large flow rate water inflow is achieved. When the water level drops and the water pressure is insufficient to support the float, the float installed inside the vertical water inlet pipe will fall and cover the opening formed on the ball seat, so that water can only flow in from the horizontal water inlet pipe. Instantaneously cutting off the water flow in the vertical water inlet pipe can achieve instantaneous switching between high and low flow rates, meeting the requirements of the injection box for emergency coolant injection in a single circuit: the rated flow rate is large at the beginning of injection, the injection flow rate drops sharply after tens of seconds, and is maintained at a low level for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A three-dimensional diagram of a passive flow control device provided in an embodiment of the present invention;

[0022] Figure 2 A cross-sectional view of a passive flow control device provided in an embodiment of the present invention;

[0023] Figure 3 A partial cross-sectional view of a vertical water inlet pipe provided in an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the installation of a passive flow control device provided in an embodiment of the present invention;

[0025] Figure 5 A high-flow fluid velocity cloud diagram of a passive flow control device provided in an embodiment of the present invention;

[0026] Figure 6 This is a low-flow fluid velocity cloud diagram of the passive flow control device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementations.

[0028] Combine Figures 1 to 3 As shown, a passive flow control device of this embodiment includes a water inlet assembly 1, a transition chamber 2, and a drain pipe 3, wherein the drain pipe 3 is connected to the bottom of the transition chamber 2; the water inlet assembly 1 is connected to the side wall of the transition chamber 2, and the water inlet assembly 1 includes a vertical water inlet pipe 11, a horizontal conversion pipe 12, and a horizontal water inlet pipe 13. One end of the horizontal conversion pipe 12 is connected to the side wall of the transition chamber 2, and the other end is connected to the bottom end of the vertical water inlet pipe 11. In this embodiment, the bottom end of the vertical water inlet pipe 11 is connected to the other end of the horizontal conversion pipe 12 via a thread. One end of the horizontal water inlet pipe 13 is connected to the connection between the side wall of the transition chamber 2 and one end of the horizontal conversion pipe 12. A water inlet is formed in the wall of the vertical water inlet pipe 11. A float 14 and a ball seat 15 are installed inside the vertical water inlet pipe 11. The ball seat 15 has an opening formed therein and is fixed to the inner wall of the vertical water inlet pipe 11. The float 14 is located above the ball seat 15 and can be operated to cover the opening. It is worth noting that this embodiment comprises three groups of water inlet assemblies 1, which are arranged at equal angles around the transition chamber 2. Furthermore, the vertical water inlet pipes 11 in each group of water inlet assemblies 1 vary in length. The three types of vertical water inlet pipes 11 are evenly arranged counterclockwise around the circumference of the transition chamber 2, from highest to lowest. Of course, the number of water inlet assemblies 1 can be adjusted based on actual needs.

[0029] Furthermore, the transition chamber 2 of this embodiment is cylindrical, the horizontal conversion pipe 12 is a straight pipe, and the axis of the horizontal conversion pipe 12 is tangent to the side of the transition chamber 2. The cross-section of the horizontal water inlet pipe 13 is wedge-shaped, and one wedge-shaped edge of the horizontal water inlet pipe 13 is tangent to the side of the transition chamber 2. The angle between the water flow direction of the horizontal water inlet pipe 13 and the water flow direction of the horizontal conversion pipe 12 is 5 to 10 degrees, which can offset the tangential components of the total momentum of the two water flows, forming a counter-flow effect of the two incoming flows. It is easy to understand that the height and diameter of the vertical water inlet pipe 11 and the size of the horizontal water inlet pipe 13 can be adjusted according to application requirements, so as to achieve adjustment of different flow rates and corresponding injection times.

[0030] Furthermore, a vortex breaker 16 is installed inside the vertical water inlet pipe 11. The vortex breaker 16 is located below the ball seat 15. The vortex breaker 16 can prevent vortices from forming in the pipe and entraining gas into the transition chamber 2.

[0031] Furthermore, the float 14 is a hollow ball, with the hollow core located at the top of the float 14. The hollow core of the float 14 is filled with nitrogen at a pressure between 1.5 MPa and 2 MPa. It will be readily understood that the material of the float 14 can be selected based on actual needs. For example, the float 14 can be made of metal or plastic. In this embodiment, the plastic used is polyvinyl butyral. Of course, thermoplastics such as polycarbonate can also be used based on actual needs.

[0032] Combine Figures 4 and 5 As shown, the passive flow control device of this embodiment is connected to the bottom of the transition chamber 2 through the drain pipe 3, the water inlet assembly 1 is connected to the side wall of the transition chamber 2, one end of the horizontal conversion pipe 12 is connected to the side wall of the transition chamber 2, the other end of the horizontal conversion pipe 12 is connected to the bottom end of the vertical water inlet pipe 11, and one end of the horizontal water inlet pipe 13 is connected to the connection between the side wall of the transition chamber 2 and one end of the horizontal conversion pipe 12; then the water flowing in from the vertical water inlet pipe 11 will change direction after passing through the horizontal conversion pipe 12 and will form an offset with the water flowing in from the horizontal water inlet pipe 13, the tangential components of the total momentum of the two water flows will offset, and the water will flow vertically into the drain pipe 3; thereby achieving large-flow water inlet, and when the water level drops and the water pressure is insufficient to lift the float 14, the float 14 installed inside the vertical water inlet pipe 11 will fall and cover the opening formed on the ball seat 15, so that the water can only flow in from the horizontal water inlet pipe 13, at this time the fluid flows into the transition chamber 2 from the horizontal water inlet pipe 13, forming a vortex in the transition chamber 2. Instantaneously cutting off the water flow of the vertical water inlet pipe 11 can realize instantaneous switching between high and low flow rates, which meets the requirements that when the injection box is used for emergency coolant injection in a single circuit, the rated flow rate is large at the beginning of the injection, the injection flow rate drops sharply after tens of seconds, and is maintained at a low level for a long time, and has good practicality.

[0033] The device of the present invention is not limited to the embodiments in the specific implementation manner. As long as a person skilled in the art can derive other implementation manners based on the technical solution of the present invention, they also fall within the scope of technical innovation and protection of the present invention.

Claims

1. A passive flow control device, characterized in that: It includes water inlet assembly, transition chamber and drain pipe, The drainage pipe is connected to the bottom of the transition chamber; The water inlet assembly is connected to the side wall of the transition chamber, and the water inlet assembly includes a vertical water inlet pipe, a horizontal conversion pipe and a horizontal water inlet pipe; One end of the horizontal conversion pipe is connected to the side wall of the transition chamber, and the other end of the horizontal conversion pipe is connected to the bottom end of the vertical water inlet pipe; One end of the horizontal water inlet pipe is connected to the side wall of the transition chamber and the connection point of one end of the horizontal conversion pipe; A water inlet is formed on the wall of the vertical water inlet pipe, a float and a ball seat are installed inside the vertical water inlet pipe, an opening is formed on the ball seat, the ball seat is fixed to the inner wall of the vertical water inlet pipe, the float is located above the ball seat, and the float can operably cover the opening; The angle between the water flow direction of the horizontal water inlet pipe and the water flow direction of the horizontal conversion pipe is 5 to 10 degrees; The hollow of the float is located at the upper part of the float, and the hollow inside of the float is filled with nitrogen with a pressure between 1.5 MPa and 2 MPa.

2. The passive flow control device according to claim 1, characterized in that: The transition chamber is cylindrical, the horizontal conversion tube is a straight tube, and the axis of the horizontal conversion tube is tangent to the side of the transition chamber.

3. The passive flow control device according to claim 2, characterized in that: The cross section of the horizontal water inlet pipe is wedge-shaped, and a wedge-shaped edge of the horizontal water inlet pipe is tangent to the side edge of the transition cavity.

4. The passive flow control device according to claim 1, wherein: A vortex preventer is also installed inside the vertical water inlet pipe, and the vortex preventer is located below the ball seat.

5. The passive flow control device according to claim 1, wherein: The material of the float is metal or plastic.

6. The passive flow control device according to any one of claims 1 to 4, characterized in that: There are three groups of water inlet components, and the three groups of water inlet components are arranged at equal angles around the transition chamber.

7. The passive flow control device according to claim 6, characterized in that: The lengths of the vertical water inlet pipes in each group of the water inlet assemblies are different.

8. The passive flow control device according to any one of claims 1 to 4, characterized in that: The bottom end of the vertical water inlet pipe is connected to the other end of the horizontal conversion pipe through a thread.

Images