Passive cooling loop on-line resistance adjustment simulation system

Abstract

The invention belongs to the technical field of thermal hydraulic tests, and particularly relates to an online resistance adjustment simulation system for a passive cooling loop. The system comprises a cold source and a heat source which form a closed loop through an ascending pipeline and a descending pipeline, the descending pipeline is divided into an adjusting branch and an auxiliary branch, the adjusting branch is provided with a resistance adjusting device, the flow resistance is adjusted by increasing or decreasing the number of small balls in the device, the auxiliary branch is provided with an adjusting valve used for auxiliary adjustment of the flow resistance, double-path resistance adjustment is formed, and online adjustment of the flow resistance of the passive cooling loop is achieved. And the flow resistance adjusting efficiency and precision are improved.

Description

Technical Field

[0001] The present application belongs to the field of thermal hydraulic testing technology, and specifically relates to an online resistance adjustment simulation system for a passive cooling circuit. Background Art

[0002] During the simulation experiment of the natural circulation system, as the experimental research becomes more in-depth and detailed, it is necessary to adjust the flow resistance of the natural circulation to change the circulation characteristics or cooling capacity of the natural circulation.

[0003] When conducting natural circulation system experiments, the positions of the cold source and heat source and their connecting pipelines have been processed and installed. Usually, the method of adjusting the flow resistance is to set resistance parts on the connecting pipeline and change the flow resistance by replacing the resistance parts. However, this adjustment method cannot be adjusted online and the adjustment range is relatively limited. If the adjustment range of the flow resistance needs to be increased, it is often necessary to redesign, manufacture and install the cold and heat sources and connecting pipelines, which is costly and time-consuming. In addition, when the local resistance changes significantly, it may cause flow instability, which can easily lead to danger. Summary of the Invention

[0004] The purpose of this application is to provide a passive cooling circuit online resistance adjustment simulation system to solve the problem that resistance adjustment in simulation experiments is difficult and cannot be adjusted online.

[0005] Technical solution to achieve the purpose of this application:

[0006] The embodiment of the present application provides a passive cooling circuit online resistance adjustment simulation system, including a cold source and a heat source, wherein a downpipe is formed from the cold source outlet to the heat source inlet, and an uppipe is formed from the heat source outlet to the cold source inlet, and a natural circulation is established by the density difference between the cold source and the heat source;

[0007] The descending pipeline includes a resistance regulating device, in which small balls are installed. The flow resistance is adjusted by increasing or decreasing the number of small balls.

[0008] Optionally, the downpipe is divided into a regulating branch and an auxiliary branch;

[0009] The resistance adjustment device is arranged on the adjustment branch;

[0010] The auxiliary branch includes a regulating valve, which assists in regulating the flow resistance.

[0011] Optionally, the regulating device includes an inlet temporary storage chamber, a resistance regulating container, and an outlet temporary storage chamber;

[0012] The inlet temporary storage chamber is connected to the outside through the inlet valve, the inlet temporary storage chamber is connected to the resistance adjustment container through the inlet valve, the resistance adjustment container is connected to the outlet temporary storage chamber through the outlet valve, and the outlet temporary storage chamber is connected to the outside through the outlet valve;

[0013] The small spheres flow from the inlet temporary storage chamber to the outlet temporary storage chamber in the resistance regulating device.

[0014] Optionally, the auxiliary branch further includes a first stop valve and a second stop valve;

[0015] The first stop valve and the second stop valve are respectively located on both sides of the resistance regulating device to control the opening of the regulating branch.

[0016] Optionally, the regulating branch further includes a third stop valve and a fourth stop valve;

[0017] The third stop valve and the fourth stop valve are respectively located on both sides of the regulating valve to control the opening of the auxiliary branch.

[0018] Optionally, the resistance adjustment container is installed at an angle to provide a slope for the small sphere to fall.

[0019] Optionally, filters are respectively provided at the connection points between the two ends of the resistance adjustment container and the adjustment branch pipeline to prevent the small spheres from flowing out of the resistance adjustment container, and the filter holes are smaller than 30% of the diameter of the small spheres.

[0020] Optionally, the length of the resistance adjustment container is not less than dP / (600·u), where dP is the maximum resistance in the resistance adjustment container, and u is the flow rate of the medium in the descending pipeline.

[0021] Optionally, a first pressure measuring point and a first temperature measuring point are set at the upstream branch of the downcomer pipeline, and a second pressure measuring point and a second temperature measuring point are set at the downstream confluence of the regulating branch and the auxiliary branch;

[0022] Optionally, a pressure difference measuring point is set between the first pressure measuring point and the second pressure measuring point.

[0023] Optionally, the regulating branch and the auxiliary branch merge downstream of the downcomer and flow into the heat source through a flow meter;

[0024] Optionally, the volume of the inlet temporary storage chamber is 10% to 50% of the volume of the resistance adjustment container;

[0025] The volume of the outlet temporary storage chamber is equal to the volume of the inlet temporary storage chamber.

[0026] The beneficial technical effects of this application are:

[0027] An embodiment of the present application provides an online resistance adjustment simulation system for a passive cooling circuit, comprising a cold source and a heat source, a downpipe from the cold source outlet to the heat source inlet, and an uppipe from the heat source outlet to the cold source inlet, wherein a natural circulation is established by the density difference between the cold source and the heat source; the downpipe is divided into two branches, namely an adjustment branch and an auxiliary branch: small spheres are installed inside the resistance adjustment device of the adjustment branch, and the flow resistance is adjusted by increasing or decreasing the number of spheres, thereby realizing online adjustment of the flow resistance of the passive cooling circuit, avoiding frequent shutdowns caused by frequent adjustment of the circuit resistance, improving the flow resistance adjustment efficiency, and achieving high flow resistance matching accuracy, so that flow resistance sensitivity analysis can be carried out conveniently and at low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of an online resistance adjustment simulation system for a passive cooling circuit provided in an embodiment of the present application;

[0029] In the figure: 1-cold source; 2-heat source; 3-flow meter; 41-first stop valve; 42-second stop valve; 43-third stop valve; 44-fourth stop valve; 5-small sphere; 61-external inlet valve; 62-inner inlet valve; 63-inner outlet valve; 64-external outlet valve; 7-outlet temporary storage chamber; 8-resistance adjustment container; 9-inlet temporary storage chamber; 10-regulating valve; 11-downstream pipeline; 12-upstream pipeline; 13-first pressure measuring point; 14-first temperature measuring point; 15-second pressure measuring point; 16-second temperature measuring point; 17-differential pressure measuring point; 18-auxiliary branch; 19-regulating branch. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the embodiments described below are only part of the embodiments of the present application, not all of them. Based on the embodiments recorded in this application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0031] See also Figure 1 , this figure shows a passive cooling circuit online resistance adjustment simulation system provided in an embodiment of the present application.

[0032] The embodiment of the present application provides a passive cooling circuit online resistance adjustment simulation system, comprising a cold source 1 and a heat source 2. A downpipe 11 is provided from the outlet of the cold source 1 to the inlet of the heat source 2, and an uppipe 12 is provided from the outlet of the heat source 2 to the inlet of the cold source 1. Natural circulation is established by the density difference between the cold source 1 and the heat source 2.

[0033] The downpipe 11 is divided into two branches: a regulating branch 19 and an auxiliary branch 18. The two branches converge at the downstream of the downpipe 11 and flow into the heat source 2 through the flow meter 3. The flow meter is preferably an ultrasonic flow meter or other type of flow meter with low flow resistance to avoid affecting the flow process.

[0034] The regulating branch 19 includes a resistance regulating device, in which small balls 5 are installed. The flow resistance is adjusted by increasing or decreasing the number of the small balls 5.

[0035] The auxiliary branch 18 includes a regulating valve 10, which assists in adjusting the flow resistance;

[0036] It is understood that the resistance adjustment range of the regulating valve 10 should be able to cover the required resistance adjustment range and leave an appropriate margin;

[0037] Optionally, the regulating valve may also be a resistance member. When a resistance member is used, the resistance member structure should be designed and manufactured according to the required resistance and in accordance with the resistance manual.

[0038] It is understood that with the dual-path resistance adjustment mode, if the regulating branch 19 fails, the auxiliary branch 18 can be switched to perform resistance adjustment, allowing for maintenance and replacement of the faulty equipment without stopping the machine. The resistance adjustment device and regulating valve have a wide resistance adjustment range, enabling distributed resistance distribution when matching large resistances, thus avoiding flow oscillations caused by localized resistance concentration.

[0039] In some possible implementations of the embodiments of the present application, the resistance adjustment device includes an inlet temporary storage chamber 9, a resistance adjustment container 8, and an outlet temporary storage chamber 7;

[0040] The inlet temporary storage chamber 9 is connected to the outside through the inlet valve 61, the inlet temporary storage chamber 9 is connected to the resistance adjustment container 8 through the inlet valve 62, the resistance adjustment container 8 is connected to the outlet temporary storage chamber 7 through the outlet valve 63, and the outlet temporary storage chamber 7 is connected to the outside through the outlet valve 64;

[0041] The small spheres 5 flow from the inlet temporary storage chamber 9 to the outlet temporary storage chamber 7 in the resistance adjustment device.

[0042] In the first example, the resistance adjustment container 8 is installed tilted to provide a slope for the small ball 5 to fall;

[0043] Optionally, the tangent value of the inclination angle is 2 / 100 to 20 / 100, preferably 5 / 100;

[0044] Filters are respectively provided at the connection points between the two ends of the resistance adjustment container 8 and the adjustment branch 19 pipeline to prevent the small spheres 5 from flowing out of the resistance adjustment container 8. The filter holes are less than 30% of the diameter of the small spheres 5. Preferably, the filter holes should be as large as possible, as close to 30% of the diameter of the small spheres 5 as possible.

[0045] The length of the resistance regulating container 8 is not less than dP / (600·u), where dP is the maximum resistance in the resistance regulating container (8) and u is the flow rate of the medium in the descending pipe (11);

[0046] Optionally, the resistance adjustment container is a circular tube structure, and the diameter of the circular tube is generally 1 to 5 times, preferably 2 times, the diameter of the downpipe 11; the length of the resistance adjustment container 8 is generally 5 to 20 times the diameter of the circular tube.

[0047] In the second example, the volume of the inlet temporary storage chamber 9 is 10% to 50% of the volume of the resistance adjustment container 8 ; the volume of the outlet temporary storage chamber 7 is equal to the volume of the inlet temporary storage chamber 9 .

[0048] In the third example, the small sphere 5 is made of the same material as the downcomer 11 , and the diameter of the small sphere 5 is 1 / 60 to 1 / 10 of the diameter of the downcomer 11 .

[0049] In some possible implementations of the embodiment of the present application, the auxiliary branch 18 further includes a first stop valve 41 and a second stop valve 42;

[0050] The first stop valve 41 and the second stop valve 42 are respectively located on both sides of the regulating valve 10 to control the opening of the auxiliary branch 18 .

[0051] In some possible implementations of the embodiment of the present application, the regulating branch 19 further includes a third stop valve 43 and a fourth stop valve 44;

[0052] The third stop valve 43 and the fourth stop valve 44 are respectively located on both sides of the resistance adjustment device to control the opening of the adjustment branch 19.

[0053] In some possible implementations of the embodiments of the present application, a first pressure measuring point 13 and a first temperature measuring point 14 are provided at the upstream branch of the downcomer 11, and a second pressure measuring point 15 and a second temperature measuring point 16 are provided at the downstream confluence of the regulating branch 19 and the auxiliary branch 18;

[0054] A pressure difference measuring point 17 is provided between the first pressure measuring point 13 and the second pressure measuring point 15 .

[0055] It should be noted that the embodiment of the present application can achieve adaptive adjustment of online matching resistance by coupling the flow working fluid pressure difference measurement. At the same time, by observing the pressure difference, the switching speed of the regulating branch 19 and the auxiliary branch 18 can be adjusted to avoid large pressure fluctuations.

[0056] The specific operation method of the passive cooling circuit online resistance adjustment simulation system provided by the embodiment of the present application is described in detail below with reference to a specific example.

[0057] Step 1: Start the system to form a natural circulation flow between the cold source 1 and the heat source 2:

[0058] Close the first stop valve 41 and the second stop valve 42 of the auxiliary branch 18, and fully open the third stop valve 43 and the fourth stop valve 44 of the regulating branch 19;

[0059] Fill the fluid, and when the fluid begins to flow out, close the outgoing valve 64, the outgoing valve 63, and the incoming valve 62 in sequence;

[0060] Place the small balls 5 in the inlet temporary storage chamber 9 until it is filled as much as possible, and close the inlet valve 61;

[0061] Open the outlet valve 63 and the inlet valve 62 to increase the pressure as needed;

[0062] After the pressure stabilizes, close the outlet valve 63 and the inlet valve 62;

[0063] Start the heat source 2 and the cold source 1 to heat and cool the fluid medium respectively. Through the density difference between the two places, a passive natural circulation flow is formed from the heat source 2 through the rising pipe 12 to the cold source 1, and then back to the heat source 2 through the downpipe 11, thereby achieving a cooling effect on the heat source 2.

[0064] Step 2, opening the regulating branch 19, and adjusting the small spheres 5 in the resistance regulating container 8 by increasing or decreasing the resistance, so as to adaptively adjust the flow resistance;

[0065] Ways to increase flow resistance are:

[0066] Open the inlet valve 62 to allow the small balls 5 to continuously fall into the resistance adjustment container 8. As the number of small balls 5 increases, the resistance of the fluid medium flowing through the resistance adjustment container 8 gradually increases.

[0067] If the flow resistance does not reach the target value and all the small balls 5 in the inlet temporary storage chamber 9 have entered the resistance adjustment container 8, the inlet valve 62 is closed and the outer valve 61 is opened to add small balls 5 into the inlet temporary storage chamber 9. The outer valve 61 is then closed and the inner valve 62 is opened to continue increasing the flow resistance.

[0068] Until the flow resistance reaches the target value, the inlet valve 62 is closed;

[0069] Ways to reduce flow resistance are:

[0070] Open the inner valve 63, and the small balls 5 continuously flow out of the resistance adjustment container 8 and fall into the outlet temporary storage chamber 7. As the number of small balls 5 decreases, the resistance of the fluid medium flowing through the resistance adjustment container 8 gradually decreases;

[0071] If the flow resistance does not reach the target value, the outlet temporary storage chamber 7 is full, then the inner valve 63 is closed and the outer valve 64 is opened to take out the small ball 5, and then the outer valve 64 is closed again and the inner valve 63 is opened to further reduce the flow resistance;

[0072] When the flow resistance reaches the target value, the inner valve 63 is closed.

[0073] The specific operation method of dual-path switching in the dual-path resistance adjustment operation mode provided by the embodiment of the present application is described in detail below with reference to a specific example.

[0074] When the regulating branch 19 fails, the operation of the regulating branch 19 is switched to the auxiliary branch 18. The specific method is as follows:

[0075] Reduce the opening of the third stop valve 43 and the fourth stop valve 44 of the regulating branch 19, and at the same time increase the opening of the first stop valve 41 and the second stop valve 42 of the auxiliary branch 18, adjusting the opening by 1% to 3% each time;

[0076] Until the third stop valve 43 and the fourth stop valve 44 are completely closed, and the first stop valve 41 and the second stop valve 42 are completely opened;

[0077] During this process, monitor the differential pressure measurement point 17, indicating ΔP, to avoid large fluctuations;

[0078] As ΔP increases, the speed of opening the first stop valve 41 and the second stop valve 42 is accelerated, and the speed of closing the third stop valve 43 and the fourth stop valve 44 is reduced;

[0079] When ΔP decreases, the speed of opening the first stop valve 41 and the second stop valve 42 is reduced, and the speed of closing the third stop valve 43 and the fourth stop valve 44 is accelerated.

[0080] After the maintenance of regulating branch 19 is completed, it is necessary to switch from auxiliary branch 18 to regulating branch 19. The specific method is as follows:

[0081] According to the required flow resistance and previous operating experience, a portion of small spheres 5 are pre-installed;

[0082] By adjusting the opening by 1% to 3% each time, the opening of the first stop valve 41 and the second stop valve 42 of the auxiliary branch 18 is reduced, and at the same time, the opening of the third stop valve 43 and the fourth stop valve 44 of the regulating branch 19 is increased;

[0083] until the third stop valve 43 and the fourth stop valve 44 are fully opened, and the first stop valve 41 and the second stop valve 42 are fully closed;

[0084] Similarly, ΔP is monitored online during this process to avoid large fluctuations; the method for adjusting ΔP is the same as the principle of the above switching process.

[0085] The embodiments of the present application have the following beneficial effects:

[0086] (1) Realize online adjustment of the flow resistance of the passive cooling circuit, avoid frequent shutdowns caused by frequent adjustment of the circuit resistance, improve the efficiency of flow resistance adjustment, achieve high flow resistance matching accuracy, and conduct flow resistance sensitivity analysis conveniently and at low cost;

[0087] (2) A dual-branch resistance adjustment operation mode is adopted, which uses a regulating branch and an auxiliary branch. When a regulating branch fails, the auxiliary branch can be switched to perform resistance adjustment, and the faulty equipment can be repaired and replaced without stopping the machine.

[0088] (3) The resistance adjustment device and the regulating valve have a wide resistance adjustment range, which can achieve distributed resistance distribution when matching large resistance, avoiding flow oscillation caused by local resistance concentration;

[0089] (4) By coupling the flow working fluid pressure difference measurement, the adaptive adjustment of the online matching resistance can be achieved. By observing the pressure difference, the switching speed of the regulating branch and the auxiliary branch can be adjusted to avoid large pressure fluctuations;

[0090] (5) It can be transferred to actual natural circulation cooling system to achieve online adjustment of its flow resistance.

[0091] The present application has been described in detail above with reference to the accompanying drawings and embodiments. However, the present application is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by a person skilled in the art without departing from the purpose of the present application. Any content not described in detail in the present application may be based on existing technologies.

Claims

1. A passive cooling circuit online resistance adjustment simulation system, characterized in that: The invention comprises a cold source (1) and a heat source (2), wherein the outlet of the cold source (1) to the inlet of the heat source (2) is a descending pipe (11), and the outlet of the heat source (2) to the inlet of the cold source (1) is an ascending pipe (12), and a natural circulation is established through the density difference between the cold source (1) and the heat source (2); The descending pipeline (11) comprises a resistance regulating device, wherein small balls (5) are installed in the resistance regulating device, and the flow resistance is adjusted by increasing or decreasing the number of the small balls (5).

2. The passive cooling circuit online resistance adjustment simulation system according to claim 1, characterized in that: The downpipe (11) is divided into a regulating branch (19) and an auxiliary branch (18); The resistance adjustment device is arranged on the adjustment branch (19); The auxiliary branch (18) includes a regulating valve (10), and the regulating valve (10) assists in regulating the flow resistance.

3. The passive cooling circuit online resistance adjustment simulation system according to claim 1, characterized in that: The resistance adjustment device comprises an inlet temporary storage chamber (9), a resistance adjustment container (8), and an outlet temporary storage chamber (7); The inlet temporary storage chamber (9) is connected to the outside world through the inlet valve (61), the inlet temporary storage chamber (9) is connected to the resistance adjustment container (8) through the inlet valve (62), the resistance adjustment container (8) is connected to the outlet temporary storage chamber (7) through the outlet valve (63), and the outlet temporary storage chamber (7) is connected to the outside world through the outlet valve (64); The small sphere (5) flows from the inlet temporary storage chamber (9) to the outlet temporary storage chamber (7) in the resistance regulating device.

4. The passive cooling circuit online resistance adjustment simulation system according to claim 2, characterized in that: The auxiliary branch (18) further includes a first stop valve (41) and a second stop valve (42); The first stop valve (41) and the second stop valve (42) are respectively located on both sides of the regulating valve (10) to control the opening of the auxiliary branch (18).

5. The passive cooling circuit online resistance adjustment simulation system according to claim 2, characterized in that: The regulating branch (19) further includes a third stop valve (43) and a fourth stop valve (44); The third stop valve (43) and the fourth stop valve (44) are respectively located on both sides of the resistance regulating device to control the opening of the regulating branch (19).

6. The passive cooling circuit online resistance adjustment simulation system according to claim 3, characterized in that: The resistance adjustment container (8) is installed at an angle to provide a slope for the small sphere (5) to fall.

7. The passive cooling circuit online resistance adjustment simulation system according to claim 3, characterized in that: Filters are respectively provided at the connection points between the two ends of the resistance regulating container (8) and the regulating branch (19) pipeline to prevent the small spheres (5) from flowing out of the resistance regulating container (8).

8. The passive cooling circuit online resistance adjustment simulation system according to claim 3, characterized in that: The length of the resistance regulating container (8) is not less than dP / (600·u), dP is the maximum resistance in the resistance regulating container (8), and u is the flow rate of the medium in the descending pipeline (11).

9. The passive cooling circuit online resistance adjustment simulation system according to claim 2, characterized in that: A first pressure measuring point (13) and a first temperature measuring point (14) are provided at the upstream branch of the descending pipeline (11), and a second pressure measuring point (15) and a second temperature measuring point (16) are provided at the downstream confluence of the regulating branch (19) and the auxiliary branch (18); A pressure difference measuring point (17) is provided between the first pressure measuring point (13) and the second pressure measuring point (15).

10. The passive cooling circuit online resistance adjustment simulation system according to claim 2, characterized in that: The regulating branch (19) and the auxiliary branch (18) converge at the downstream of the descending pipe (11) and flow into the heat source (2) through the flow meter (3).

11. The passive cooling circuit online resistance adjustment simulation system according to claim 3, characterized in that: The volume of the inlet temporary storage chamber (9) is 10% to 50% of the volume of the resistance adjustment container (8); The volume of the outlet temporary storage chamber (7) is equal to the volume of the inlet temporary storage chamber (9).

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