Cooling capacity recovery device of liquid argon conveying pipeline, control method and argon supply system

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a cooling capacity recovery device of a liquid argon conveying pipeline, a control method and an argon supply system. The liquid argon conveying pipeline is arranged in a channel of the sleeve type heat exchange assembly in a penetrating mode, and an annular gap formed between the outer wall of the pipeline and the inner wall of the channel serves as an air heat transfer medium, so that the cooling capacity of liquid argon is transmitted into box body cooling water immersing the outer wall of a sleeve through annular gap air, the inner wall of the sleeve type heat exchange assembly and the pipe wall in sequence. The low-temperature cooling capacity dissipated by the liquid argon conveying pipeline is efficiently recycled and directionally transferred to process circulating cooling water, so that the problems that the refrigerating load of a circulating water system is sharply increased due to sudden rise of the environment temperature, the electric energy consumption of refrigerating equipment is greatly increased, and the operation cost of a factory is increased are solved; and the operation stability and reliability of the whole cooling system are improved, the product yield of monocrystalline silicon is ensured, and the service life of key equipment is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, and particularly relates to a cold energy recovery device of a liquid argon conveying pipeline, a control method and an argon gas supply system. TECHNICAL BACKGROUND

[0002] In the process of growing a silicon single crystal rod, argon (boiling point -185.9℃) as a key protective gas and carrier gas is usually stored in a storage tank in a low-temperature liquid state (<-196℃), conveyed to a gasifier through a pipeline, and converted into a gaseous state for use in a crystal pulling furnace and other equipment.

[0003] During the conveying of liquid argon, ice layers with considerable thickness can condense on the outer wall of the pipeline due to the low-temperature environment, and the surface temperature can reach -30℃ to -50℃. These ice layers continuously release a large amount of low-temperature cold energy to the ambient air, resulting in significant energy waste. Especially in the context of large-scale and continuous production of crystal rods, this part of energy loss is huge.

[0004] At the same time, in the process of growing a single crystal silicon, the stability of the process cooling water temperature is extremely high. However, in summer or high-temperature areas, the sudden rise in ambient temperature leads to a sharp increase in the refrigeration load of the circulating water system. The chiller unit often needs to run at high load for a long time or additional standby units are activated to maintain the required water temperature, which not only leads to a substantial increase in the power consumption of the equipment, increasing the operating cost of the factory, but also reduces the stability and reliability of the entire cooling system, posing a potential threat to the product yield of single crystal silicon and the service life of key equipment. SUMMARY

[0005] Therefore, it is necessary to provide a cold energy recovery device of a liquid argon conveying pipeline to recover the cold energy lost by the liquid argon conveying pipeline and apply it to the circulating water cooling system of a single crystal silicon growth process, so as to reduce the refrigeration energy consumption of the circulating water system and improve the energy utilization efficiency and system stability.

[0006] In a first aspect, the present application provides a cold energy recovery device of a liquid argon conveying pipeline, comprising a box body containing cooling water, a double-pipe heat exchange assembly, and a cooling water circulation assembly.

[0007] The jacketed heat exchange assembly is fixedly arranged in the box, and a channel is formed in the jacketed heat exchange assembly for the liquid argon conveying pipeline to pass through. The liquid argon conveying pipeline is arranged in the channel of the jacketed heat exchange assembly, and an annular gap is formed between the outer wall of the liquid argon conveying pipeline and the inner wall of the channel of the jacketed heat exchange assembly. The outer surface of the jacketed heat exchange assembly is immersed in the cooling water in the box. The cold energy of the liquid argon in the liquid argon conveying pipeline is transmitted to the inner wall of the jacketed heat exchange assembly through the air in the annular gap, and then the cold energy is transmitted to the cooling water in the box through the wall of the jacketed heat exchange assembly, so as to reduce the temperature of the cooling water. The cooling water circulating assembly is used to input the warmed cooling water into the box and output the cooled cooling water in the box.

[0008] Preferably, the cooling water circulating assembly comprises a variable frequency water pump, a solenoid valve, a temperature monitoring assembly and a controller. The temperature monitoring assembly comprises a first temperature sensor and a second temperature sensor. The first temperature sensor is arranged on the pipe section before the liquid argon conveying pipeline enters the jacketed heat exchange assembly, so as to monitor the input temperature T in of the liquid argon. The second temperature sensor is arranged on the pipe section after the liquid argon conveying pipeline extends out of the jacketed heat exchange assembly, so as to monitor the output temperature T out of the liquid argon. The controller is electrically connected with the first temperature sensor, the second temperature sensor, the variable frequency water pump and the solenoid valve. The controller is pre-set with a safety threshold ΔT max . The controller receives the liquid argon input temperature T in signal from the first temperature sensor and the liquid argon output temperature T out signal from the second temperature sensor, and calculates the temperature difference ΔT between the liquid argon output temperature T out signal and the liquid argon input temperature signal T in . The controller is used to adjust the operating frequency of the variable frequency water pump and the opening degree of the solenoid valve according to the temperature difference ΔT, so as to control the size of the cooling water circulating flow. The controller is also used to compare the temperature difference ΔT with the safety threshold ΔT max , and when ΔT ≥ ΔT max , the solenoid valve and the variable frequency water pump are turned off.

[0009] Preferably, the cooling water circulation assembly further includes an inlet pipe and an outlet pipe; the bottom of the housing is provided with an inlet and an outlet, one end of the outlet pipe is connected to the outlet of the housing, and the other end of the outlet pipe is connected to the inlet of the monocrystalline silicon circulating water system, one end of the inlet pipe is connected to the outlet of the monocrystalline silicon circulating water system, and the other end of the inlet pipe is connected to the inlet of the housing, so as to form a cooling water circulation circuit, the variable frequency water pump and the solenoid valve are sequentially arranged on the outlet pipe, and the controller is fixedly installed on the variable frequency water pump.

[0010] Preferably, the outer wall of the shell-and-tube heat exchange assembly is provided with axially extending heat-conducting fins, which are evenly distributed around the axis of the shell-and-tube heat exchange assembly. The shell-and-tube heat exchange assembly is provided with a channel through which a liquid argon delivery pipeline passes, the diameter of which is not less than twice the diameter of the liquid argon delivery pipeline. An insulation layer is provided on the outer wall of the box, and a drain pipe is provided at the bottom of the box, with a ball valve installed on the drain pipe.

[0011] Preferably, the temperature monitoring component further includes a third temperature sensor; the third temperature sensor is disposed on the housing and near the bottom of the housing, and is electrically connected to the controller to monitor the temperature T of the cooling water inside the housing. W and the temperature T of the cooling water W The signal is transmitted to the controller; the controller is used to control the temperature T. W and the preset cooling water safety temperature T S Compare and at the temperature T of the cooling water W ≤ Cooling water safety temperature T S When this occurs, the solenoid valve is closed and the variable frequency water pump is stopped.

[0012] Preferably, the controller is preset with a desired cooling water temperature T; the controller is used to ensure that ΔT < ΔT max And T W >T S At the same time, increase the operating frequency of the variable frequency water pump and / or increase the opening degree of the solenoid valve to make T W Approaching T, and with ΔT ≥ 0.9ΔT max Stop increasing the operating frequency of the variable frequency water pump and the opening degree of the solenoid valve.

[0013] Secondly, the present invention provides an argon gas supply system with a cold energy recovery function, including an argon gas supply component and a cold energy recovery device for the liquid argon transport pipeline mentioned above.

[0014] The argon gas supply assembly comprises a low-temperature liquid argon storage tank, a liquid argon conveying pipeline, a gasifier and an argon gas conveying pipeline, the low-temperature liquid argon storage tank is used to store low-temperature liquid argon, the outlet of the low-temperature liquid argon storage tank is connected to one end of the liquid argon conveying pipeline, the other end of the liquid argon conveying pipeline is connected to the gasifier, so as to convey the low-temperature liquid argon to the gasifier for gasification, the outlet of the gasifier is connected to the argon gas conveying pipeline, so as to convey the normal-temperature gaseous argon to a use end, and the cold energy recovery device of the liquid argon conveying pipeline is arranged on the liquid argon conveying pipeline.

[0015] In a third aspect, the present application provides a control method of the cold energy recovery device of the liquid argon conveying pipeline, which is applied to the cold energy recovery device of the liquid argon conveying pipeline in the first aspect and the second aspect, and the control method comprises the following steps:

[0016] S1: acquiring a liquid argon input temperature value T in collected by a first temperature sensor on the cold energy recovery device of the liquid argon conveying pipeline in real time out ;

[0017] S2: calculating a difference value between the liquid argon output temperature value T out and the liquid argon input temperature value T in , to obtain a temperature difference value ΔT;

[0018] S3: dynamically adjusting according to the temperature change value ΔT to generate a control instruction, the control instruction is used to adjust the operating frequency of the variable-frequency water pump and the opening degree of the electromagnetic valve, so as to dynamically match the current recoverable cold energy level with the flow of the cooling water, and maintain the expected liquid argon temperature to avoid the gasification of the liquid argon.

[0019] Preferably, the S3 comprises:

[0020] when ΔT shows an increasing trend, according to the increasing amplitude of ΔT, the operating frequency of the variable-frequency water pump is reduced and / or the opening degree of the electromagnetic valve is reduced;

[0021] when ΔT shows a decreasing trend, according to the decreasing amplitude of ΔT, the operating frequency of the variable-frequency water pump is increased and / or the opening degree of the electromagnetic valve is increased;

[0022] when the trend of ΔT is stable, the current operating parameters are maintained.

[0023] Preferably, the control method of the cold energy recovery device of the liquid argon conveying pipeline further comprises S4:

[0024] (1) acquiring a cooling water temperature value T W collected by the third temperature sensor in the tank in real time;

[0025] (2) The controller pre-stores or receives a user-set cooling water desired temperature T;

[0026] (3) The cooling water temperature value T W is compared with a pre-set cooling water safety temperature T S , and when the cooling water temperature T W ≤ cooling water safety temperature T S , the solenoid valve is closed and the variable frequency water pump stops running; and when the cooling water temperature T W > cooling water safety temperature T S , the cooling water temperature deviation δT = T W - T is calculated;

[0027] (4) A temperature adjustment instruction is generated according to the size of δT, and the variable frequency water pump running frequency and the solenoid valve opening degree are adjusted so that the cooling water temperature T W tends to the cooling water desired temperature T;

[0028] (5) It is judged whether ΔT ≥ 0.9ΔT max ; and when ΔT ≥ 0.9ΔT max , the adjustment of the variable frequency water pump running frequency and the solenoid valve opening degree is stopped.

[0029] In the above-mentioned liquid argon conveying pipeline cold energy recovery device, control method and argon gas supply system, the liquid argon conveying pipeline is arranged in the passage of the jacketed heat exchange assembly, and the annular gap formed between the outer wall of the pipeline and the inner wall of the passage is used as an air heat transfer medium, so that the low-temperature cold energy lost by the liquid argon conveying pipeline is efficiently recovered and directly transmitted to the process circulating cooling water through the air in the annular gap, the inner wall and the wall of the jacketed heat exchange assembly and the cooling water in the tank immersed in the jacketed heat exchange assembly. At the same time, the control method relies on multi-stage temperature monitoring (T in , T out , T W ) and pre-set threshold values (ΔT max , T S , T) to build a closed-loop feedback mechanism, the controller dynamically analyzes the liquid argon temperature change value ΔT and its trend, the real-time cooling water temperature T W and the deviation δT from the target value, and precisely controls the cooling water circulating flow by cooperatively adjusting the frequency of the variable frequency water pump and the opening degree of the solenoid valve, so as to ensure that the liquid argon temperature rise ΔT is strictly lower than the safety threshold value ΔT max (ΔT < ΔT max ) to avoid the risk of phase change of the liquid argon in the pipeline, and also maintain the cooling water temperature T W higher than the anti-freezing safety temperature T S (T W > T S ), and finally, under the satisfaction of the above-mentioned constraint conditions, T WThe expected temperature T set by the user is approached to maximize the cold recovery benefit, and when ΔT approaches the threshold (≥0.9ΔTmax), the temperature regulation is actively stopped to reserve a safety margin; in this way, not only does it solve the problem of the sharp increase in the refrigeration load of the circulating water system due to the sudden rise in ambient temperature, the large increase in power consumption of the refrigeration equipment, and the increase in the operating cost of the factory, but it also improves the operation stability and reliability of the entire cooling system, ensures the product yield of monocrystalline silicon, and prolongs the service life of the key equipment. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Structure diagram of an argon gas supply system with cold recovery function.

[0031] Figure 2 Structure diagram of a cold recovery device for a liquid argon delivery pipeline.

[0032] Figure 3 Structure diagram of a cold recovery device for a liquid argon delivery pipeline from another perspective.

[0033] Figure 4 Sectional view diagram of a cold recovery device for a liquid argon delivery pipeline.

[0034] Figure 5 Dynamic adjustment flowchart of a control method for a cold recovery device for a liquid argon delivery pipeline.

[0035] Figure 6 Cooling water temperature adjustment flowchart of a control method for a cold recovery device for a liquid argon delivery pipeline.

[0036] Figure 7 Protection judgment and execution flowchart of a control method for a cold recovery device for a liquid argon delivery pipeline.

[0037] In the figure: argon gas supply system 10, argon gas supply assembly 11, low-temperature liquid argon storage tank 111, liquid argon delivery pipeline 112, gasifier 113, cold recovery device for liquid argon delivery pipeline 12, box 121, drain pipe 1211, ball valve 1212, support foot 1213, sleeve heat exchange assembly 122, heat-conducting fin 1221, stainless steel pipe 1222, cooling water circulation assembly 123, frequency conversion water pump 1231, electromagnetic valve 1232, temperature monitoring assembly 1233, first temperature sensor 12331, second temperature sensor 13332, third temperature sensor 12333, water inlet pipe 1234, water outlet pipe 1235. DETAILED DESCRIPTION

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0039] Please refer to Figures 1 to 7 The present application provides a cold energy recovery device 12 of a liquid argon delivery pipeline, which comprises a box 121 containing cooling water, a double-pipe heat exchange assembly 122, and a cooling water circulation assembly 123.

[0040] The double-pipe heat exchange assembly 122 is fixedly arranged inside the box 121, and a passage is formed inside the double-pipe heat exchange assembly 122 for the liquid argon delivery pipeline 112 to pass through. The liquid argon delivery pipeline 112 is arranged in the passage of the double-pipe heat exchange assembly 122, and there is an annular gap between the outer wall of the liquid argon delivery pipeline 112 and the inner wall of the passage of the double-pipe heat exchange assembly 122. The outer surface of the double-pipe heat exchange assembly 122 is immersed in the cooling water in the box 121. The cold energy of the liquid argon in the liquid argon delivery pipeline 112 is transmitted to the inner wall of the double-pipe heat exchange assembly 122 through the air in the annular gap, and then transmitted to the cooling water in the box 121 through the pipe wall of the double-pipe heat exchange assembly 122, so as to reduce the temperature of the cooling water. The cooling water circulation assembly 123 is used to input the heated cooling water into the box 121 and output the cooling water after heat exchange and temperature reduction in the box 121.

[0041] In the present embodiment, the cold energy of the liquid argon in the liquid argon delivery pipeline 112 is transmitted to the inner wall of the double-pipe heat exchange assembly 122 through the air in the annular gap, and then transmitted to the cooling water in the box 121 through the pipe wall of the double-pipe heat exchange assembly 122, so as to reduce the temperature of the cooling water. In another embodiment, the annular gap can be closed and filled with a heat-conducting medium with better performance than air, such as heat-conducting oil, so as to improve the heat exchange efficiency and avoid the waste of cold energy caused by the direct contact of the liquid argon delivery pipeline 112 with the air in the external environment.

[0042] Further, the cooling water circulation assembly 123 comprises a variable frequency water pump 1231, an electromagnetic valve 1232, a temperature monitoring assembly 1233, and a controller. The temperature monitoring assembly 1233 comprises a first temperature sensor 12331 and a second temperature sensor 13332. The first temperature sensor 12331 is arranged on the pipe section before the liquid argon delivery pipeline 112 enters the double-pipe heat exchange assembly 122, so as to monitor the input temperature T in of the liquid argon. The second temperature sensor 13332 is arranged on the pipe section after the liquid argon delivery pipeline 112 extends out of the double-pipe heat exchange assembly 122, so as to monitor the output temperature T outThe controller is electrically connected with the first temperature sensor 12331, the second temperature sensor 13332, the variable frequency water pump 1231 and the electromagnetic valve 1232, and the controller is preset with a safety threshold AT max The controller receives the liquid argon input temperature T in signal from the first temperature sensor 12331 and the liquid argon output temperature T out signal from the second temperature sensor 13332, and calculates the temperature difference AT between the liquid argon output temperature T out signal and the liquid argon input temperature signal T in ; and the controller is used to adjust the operating frequency of the variable frequency water pump 1231 and the opening degree of the electromagnetic valve 1232 according to the temperature difference AT, so as to control the size of the cooling water circulation flow; the controller is also used to compare the temperature difference AT with the safety threshold AT max , and when AT≥AT max , the electromagnetic valve 1232 and the variable frequency water pump 1231 are turned off.

[0043] In this embodiment, the box body 121 is a rectangular box body 121 made of 304 stainless steel, and is provided with an openable box cover at the top for easy maintenance, and is provided with a supporting foot 1213 at the bottom, and the height of the foot can be adjusted to adapt to different installation environments. The cooling water inlet is arranged at the bottom of one side of the box body 121, and the specification is DN50 flange interface; the cooling water outlet is arranged at the position close to the top of the other side, and the specification is also DN50. The cooling water outlet is connected to the inlet of the variable frequency water pump 1231 through a pipeline, and the specific model of the variable frequency water pump 1231 is GRANDUO CRN15 series variable frequency pump (rated flow 10-50 m 3 / h, head 20-60 meters), and the outlet thereof is connected to the water supply pipeline of the user cooling point through a pipeline. The return water pipeline of the user cooling point is connected to the cooling water inlet. The specific model of the electromagnetic valve 1232 is ASCO 8220G series (passage diameter DN40, pressure grade PN16), which is installed on the outlet of the variable frequency water pump 1231 or the user water supply pipeline, and is used for quickly cutting off the cooling water flow.

[0044] The double-pipe heat exchange assembly 122 adopts a single-layer pipe structure and is fixedly arranged inside the box 121 and is composed of at least one 316L stainless steel pipe 1222. The inner diameter of the pipe is greater than the outer diameter of the liquid argon conveying pipeline 112, and the two are coaxially assembled to form an annular gap. The gap width is optimized to 50-100 mm to strengthen the natural air convection heat exchange efficiency and control the heat resistance increment. The stainless steel pipe 1222 is fixed on the two end plates of the box 121 through flanges or welding sealing to ensure the airtightness of the inside of the box 121. The liquid argon conveying pipeline 112 penetrates the center of the outer pipe and extends out of the box 121 at both ends to connect the upstream liquid argon source and the downstream user end respectively. The stainless steel pipe 1222 is completely immersed in the cooling water in the box 121, and the liquid argon cooling capacity is transmitted to the cooling water medium through the air in the annular gap.

[0045] The first temperature sensor 12331 is a Pt100 resistance temperature sensor (precision ±0.1°C, protection level IP68) installed close to the outer wall of the liquid argon conveying pipeline 112 and located on the pipe section before entering the box 121 and the inlet of the double-pipe heat exchange assembly 122 to accurately capture the liquid argon input temperature T in . The second temperature sensor 13332 also adopts a Pt100 resistance temperature sensor and is installed on the pipe section after extending out of the outlet of the double-pipe heat exchange assembly 122 and away from the box 121 to monitor the liquid argon output temperature T out .

[0046] The control logic of the controller is realized based on a Siemens S7-1500 PLC, which is equipped with a human-machine interface (such as a Siemens KTP700 touch screen) for parameter setting. The controller calculates ΔT=T out- T in in real time. When it is monitored that ΔT approaches the preset ΔT max (e.g. reaches 80% of ΔT max ) or detects that ΔT presents a stable upward trend, it indicates that the heat exchange strength in the double-pipe heat exchange assembly 122 may be too large, and there is a risk of liquid argon temperature being too high near the outlet section (T out monitoring point) close to gasification. To avoid the case of ΔT≥ΔT max , the controller will actively reduce the operating frequency of the variable frequency water pump 1231 (e.g. from 70% rated frequency to 50%) and reduce the opening of the electromagnetic valve 1232 (if not in full closed state), thereby reducing the cooling water circulation flow and the convective heat transfer coefficient of the outer pipe surface to weaken the cooling capacity transmission strength and slow down the liquid argon temperature drop speed, ensuring that ΔT is stable within a safe range. If the controller determines that ΔT≥the preset ΔT maxIf ΔT > ΔTsafe, then immediately close the electromagnetic valve 1232 and stop the variable frequency water pump 1231 from running, terminate the cooling capacity recovery process by forcibly stopping the cooling water circulation to gradually reduce the temperature of the liquid argon, avoid excessive recovery of cooling capacity to cause the liquid argon in the liquid argon delivery pipeline 112 to gasify, causing two-phase flow; wherein the safety threshold ΔTsafe max The initial value is set to 5-20℃ (dynamically adjusted according to the saturation temperature of liquid argon, pipeline insulation performance and process requirements), and can be corrected in real time through the PLC man-machine interface to adapt to different working conditions and equipment state changes.

[0047] Further, the cooling water circulation assembly 123 further comprises an inlet pipe 1234 and an outlet pipe 1235; the bottom of the box body 121 is provided with an inlet and an outlet, one end of the outlet pipe 1235 is connected to the outlet of the box body 121, the other end of the outlet pipe 1235 is connected to the inlet of the circulating water system for single crystal silicon, one end of the inlet pipe 1234 is connected to the outlet of the circulating water system for single crystal silicon, and the other end of the inlet pipe 1234 is connected to the inlet of the box body 121, to form a cooling water circulation waterway, the variable frequency water pump 1231 and the electromagnetic valve 1232 are sequentially arranged on the outlet pipe 1235, and the controller is fixedly installed on the variable frequency water pump 1231.

[0048] In the embodiment, the bottom of the box body 121 is provided with a cooling water inlet and a cooling water outlet, the axes of the two are parallel and the center distance is not less than 300mm, to avoid water flow short circuit. The inlet pipe 1234 is a DN50 stainless steel bellows, one end of which is connected to the cooling water inlet of the box body 121 through a flange, and the other end extends to the cooling water outlet of the external water equipment; the outlet pipe 1235 is a pipe of the same specification, one end of which is connected to the cooling water outlet of the box body 121 through a flange, and the other end is connected to the cooling water inlet of the external water equipment, thereby forming a closed cooling water circulation waterway.

[0049] The variable frequency water pump 1231 and the electromagnetic valve 1232 are installed in series along the axis of the outlet pipe 1235, the base of the variable frequency water pump 1231 is rigidly fixed to the ground through bolts, the inlet thereof is butt-jointed to the first pipe section of the outlet pipe 1235, the outlet thereof extends horizontally to connect the second pipe section, the electromagnetic valve 1232 is installed in the middle of the second pipe section, the axis of the valve body coincides with the center line of the pipe, and ≥5 times the pipe diameter of straight pipe sections are reserved on both sides of the valve body to ensure stable flow state, and the controller is embeddedly installed in the protection box on the top of the shell of the variable frequency water pump 1231, the box body is provided with a heat dissipation grid, and the signal lines of the controller are connected to the water pump power terminal, the coil of the electromagnetic valve 1232 and the temperature sensor cable through waterproof connectors.

[0050] The cooling water from the tank 121 cooling water outlet enters the frequency conversion water pump 1231 through the first pipe section of the outlet pipe 1235, is pressurized, flows through the electromagnetic valve 1232 to adjust the flow, and is finally delivered to the external water cooling cavity of the water equipment; the temperature-increasing cooling water after heat exchange returns to the tank 121 cooling water inlet through the inlet pipe 1234, to form a closed loop system for continuous cold energy transfer.

[0051] Further, the outer wall of the double-pipe heat exchange assembly 122 is provided with axially extending heat-conducting fins 1221, which are distributed at equal intervals around the axis of the double-pipe heat exchange assembly 122. The double-pipe heat exchange assembly 122 is provided with a passage through which the liquid argon delivery pipeline 112 passes, and the diameter of the passage is not less than twice the diameter of the liquid argon delivery pipeline 112. The outer wall of the tank 121 is provided with a thermal insulation layer, and the bottom of the tank 121 is further provided with a drain pipe 1211, which is provided with a ball valve 1212.

[0052] In this embodiment, the outer wall of the double-pipe heat exchange assembly 122 is provided with axially extending heat-conducting fins 1221, which are integrally extruded from high-thermal-conductivity aluminum-magnesium alloy (λ≥160 W / m·K) and distributed at equal intervals along the axis of the heat exchange assembly. The number of fins is 24-36 per circumference, the height of a single fin is 15±0.5 mm, and the thickness is 2±0.1 mm. This structure design significantly enhances the conduction efficiency of cold energy to cooling water by increasing the heat exchange surface area (3.8 times the effective heat exchange area of a smooth pipe), and at the same time, the gap between the fins (6±0.2 mm) forms a turbulent flow channel to destroy the thermal boundary layer, so that the convective heat transfer coefficient of the cooling water in the tank 121 is increased to the order of 1200-1800 W / (m 2 ·K).

[0053] The passage through which the double-pipe heat exchange assembly 122 is provided with the liquid argon delivery pipeline 112 is designed to have a diameter of 2.2 times the nominal diameter of the liquid argon delivery pipeline 112 (for example, DN50 liquid argon pipe corresponds to DN110 passage), and this size redundancy not only provides sufficient air space for the annular gap (50-100 mm) to ensure that the liquid argon cold energy is efficiently transferred to the pipe wall through natural convection, but also reserves the heat shrinkage allowance of the pipeline (steel pipe shrinkage rate is about 0.12% under liquid argon working condition), to avoid the thermal expansion and contraction caused by sudden temperature change.

[0054] The outer wall of the tank 121 is coated with a 80 mm thick polyurethane rigid foam thermal insulation layer (thermal conductivity ≤0.022 W / m·K) to maintain the temperature of the cooling water. The bottom of the tank 121 is provided with a DN40 drain pipe 1211, and the end of the drain pipe 1211 is installed with a 304 stainless steel ball valve 1212 (such as the FV540 series of the United States Tyco), which can withstand a low temperature environment of -196℃. The valve stem sealing structure can be used to quickly drain the cooling water in the tank 121 during device maintenance.

[0055] Furthermore, the temperature monitoring component 1233 also includes a third temperature sensor 12333; the third temperature sensor 12333 is disposed on the housing 121 and near the bottom of the housing 121, and is electrically connected to the controller to monitor the temperature T of the cooling water inside the housing 121. W and set the temperature T of the cooling water W The signal is transmitted to the controller; the controller is used to control the temperature T. W and the preset cooling water safety temperature T S Compare and at the temperature T of the cooling water W ≤ Cooling water safety temperature T S When this occurs, close solenoid valve 1232 and stop the operation of variable frequency water pump 1231.

[0056] In this embodiment, the temperature monitoring component 1233 is equipped with a third temperature sensor 12333. This sensor is a Pt100 platinum resistance thermometer (accuracy ±0.15℃, protection rating IP68). Its probe is inserted into the M20 threaded interface reserved at the bottom of the housing 121, ensuring that the temperature sensing part is submerged ≥100mm below the cooling water surface, for real-time monitoring of the cooling water temperature T inside the housing 121. W The third temperature sensor, 12333, is electrically connected to the controller (Siemens S7-1500 PLC) via a shielded cable, transmitting the temperature signal to the controller in real time. The controller has a pre-stored safe cooling water temperature T. S (T S =Current water freezing point temperature + 5℃), when T W ≤T S At that time, regardless of ΔT(T) out- T in If the limit is exceeded, the controller will immediately execute the highest priority protection action, simultaneously closing the solenoid valve 1232 and stopping the operation of the variable frequency water pump 1231. This protection mechanism is independent of the original ΔT over-limit protection and is specifically designed to prevent the risk of cooling water freezing due to excessive recovery of cold energy.

[0057] Furthermore, the controller is preset with a desired cooling water temperature T; the controller is used to ensure that ΔT < ΔT max And T W >T S At the same time, increase the operating frequency of the variable frequency water pump and / or increase the opening degree of the solenoid valve to make T W Approaching T, and with ΔT ≥ 0.9ΔT max Stop increasing the operating frequency of the variable frequency water pump and the opening degree of the solenoid valve.

[0058] In this embodiment, the controller (Siemens S7-1500 PLC) pre-stores the user-settable cooling water desired temperature T, which is input through the KTP700 touch screen and stored in the controller. When the double safety condition (ΔT < ΔT max and T W > T S ) is met, the controller dynamically calculates the control amount by the PID algorithm, preferentially increases the operating frequency of the variable frequency water pump 1231 (step size ≤ 5% rated frequency / sec), and if the single water pump frequency adjustment cannot make T W tend to T, then the opening of the electromagnetic valve 1232 is simultaneously increased (opening increment ≤ 10% / sec), until the cooling water temperature T W enters the target interval of T±0.5℃. This process maximizes the cooling efficiency by strengthening the cooling water circulation flow (maximum increase of 150% of the rated value), accelerating the heat exchange between the outer wall heat conduction fins 1221 of the jacketed heat exchange assembly 122 and the cooling water, and achieving maximum cooling efficiency. When ΔT ≥ 0.9ΔT max (i.e. 90% of the emergency threshold is reached), regardless of whether T W reaches T, the controller immediately terminates the temperature regulation action and freezes the current water pump frequency and valve opening. This design prevents excessive pursuit of cooling water temperature reduction from causing liquid argon gasification, and maintains the safety margin ΔT ≥ 10%.

[0059] The application provides an argon gas supply system 10, which comprises an argon gas supply assembly 11 and a cooling recovery device 12 of a liquid argon delivery pipeline as described above.

[0060] The argon gas supply assembly 11 comprises a low-temperature liquid argon storage tank 111, a liquid argon delivery pipeline 112, a gasifier 113 and an argon gas delivery pipeline. The low-temperature liquid argon storage tank 111 is used to store low-temperature liquid argon. The outlet of the low-temperature liquid argon storage tank 111 is connected to one end of the liquid argon delivery pipeline 112. The other end of the liquid argon delivery pipeline 112 is connected to the gasifier 113, so as to deliver the low-temperature liquid argon to the gasifier 113 for gasification. The outlet of the gasifier 113 is connected to the argon gas delivery pipeline, so as to deliver the normal-temperature gaseous argon to a use end. The cooling recovery device 12 of the liquid argon delivery pipeline is arranged on the liquid argon delivery pipeline 112.

[0061] The application further provides a control method of the cooling recovery device 12 of the liquid argon delivery pipeline. The method is realized based on the controller of the cooling recovery device 12 of the liquid argon delivery pipeline and comprises the following steps.

[0062] S1: Real-time acquisition of a liquid argon input temperature value T in collected by a first temperature sensor 12331 on the cooling recovery device 12 of the liquid argon delivery pipeline and a liquid argon output temperature value T out collected by a second temperature sensor 12332.

[0063] S2: Calculate the liquid argon output temperature value T out from the difference between the liquid argon input temperature value T in , to obtain the temperature difference value ΔT (ΔT = T out- T in ) ;

[0064] S3: Generate a control instruction according to the temperature change value ΔT; the control instruction is used to adjust the operating frequency of the variable frequency water pump 1231 and the opening of the electromagnetic valve 1232, so that the flow of cooling water dynamically matches the current recoverable cold level, and the desired liquid argon temperature is maintained to avoid liquid argon gasification.

[0065] Further, S3 includes:

[0066] When ΔT shows an increasing trend, according to the ΔT increasing amplitude, the operating frequency of the variable frequency water pump 1231 is reduced and / or the opening of the electromagnetic valve 1232 is reduced;

[0067] When ΔT shows a decreasing trend, according to the ΔT decreasing amplitude, the operating frequency of the variable frequency water pump 1231 is increased and / or the opening of the electromagnetic valve 1232 is increased;

[0068] When the trend of ΔT is stable, the current operating parameters are maintained.

[0069] In this embodiment, the control method is implemented on a Siemens S7-1500 PLC controller, and the specific implementation process is as follows:

[0070] S1: Real-time acquisition of liquid argon input temperature T in and output temperature T out by Pt100 resistance temperature sensor with 100ms sampling period; the sensor signal is transmitted to the PLC analog input module through a 4-20mA transmitter, and a median value filtering algorithm is used to eliminate transient disturbance error.

[0071] S2: Perform real-time operation of ΔT = T out- T in (every 200ms refresh).

[0072] S3: If ΔT < 0.7ΔT max , linearly increase the frequency of the variable frequency water pump 1231 (upper limit 85%) and the opening of the electromagnetic valve 1232 (upper limit 90%); if 0.7ΔT max ≤ ΔT < 0.9ΔT max , maintain the current device state; if ΔT ≥ 0.9ΔT max , trigger the frequency / opening synchronous attenuation mode (decrease by 3% per second).

[0073] Further, the control method of the cold energy recovery device 12 of the liquid argon conveying pipeline further includes S4:

[0074] (1) Real-time acquisition of the cooling water temperature value T in the tank 121 collected by the third temperature sensor 12333 W ;

[0075] (2) The controller pre-stores or receives the user-set cooling water desired temperature T;

[0076] (3) Comparing the cooling water temperature value T W with the pre-set cooling water safety temperature T S , and when the temperature T W of the cooling water ≤ the cooling water safety temperature T S , the solenoid valve 1231 is closed and the variable frequency water pump 1232 is stopped; and when the temperature T W of the cooling water > the cooling water safety temperature T S , the cooling water temperature deviation δT = T W -T is calculated;

[0077] (4) According to the size of δT, the temperature adjustment instruction is generated, and the variable frequency water pump 1231 running frequency and the solenoid valve 1232 opening degree are adjusted, so that the cooling water temperature T W tends to the cooling water desired temperature T;

[0078] (5) Determine whether ΔT ≥ 0.9ΔT max ; and when ΔT ≥ 0.9ΔT max , stop adjusting the variable frequency water pump 1231 running frequency and the solenoid valve 1232 opening degree.

[0079] In this embodiment, (1) the Pt100 third temperature sensor 12333 (precision ±0.15℃) immersed in the tank 121 bottom liquid surface ≥100mm place, with 2Hz sampling frequency real-time acquisition of the cooling water temperature value T W , the signal is input to the analog input module of Siemens S7-1500 PLC after EMC filtering processing;

[0080] (2) The controller pre-stores the default cooling water desired temperature T = 10℃ (adjustable range 5-15℃), and at the same time receives the user-set value through the KTP700 touch screen and stores it;

[0081] (3) The built-in floating-point calculator calculates the temperature deviation δT = T W -T every 200ms, and the calculation result precision reaches ±0.05℃;

[0082] (4) Based on the absolute value and sign of delta T, a three-stage regulation strategy is executed: when |delta T|>2℃, the frequency of the variable frequency water pump 1231 and the opening of the electromagnetic valve 1232 are simultaneously increased (the increase amplitude is less than or equal to 8% of the rated value per second and 12% per second, respectively), so that the cooling water flow is increased to 180% of the rated value within 15 seconds; when 0.5℃<|delta T|<=2℃, the water pump frequency is preferentially regulated (the step is plus or minus 3 Hz), and the temperature of the water pump motor is monitored; when |delta T|<=0.5℃, the water pump frequency is preferentially regulated (the step is plus or minus 3 Hz), and the temperature of the water pump motor is monitored. W The approach rate is controlled at 0.2℃ / s; when |delta T|<=0.5℃, the sleep mode is entered, and the current parameters are maintained;

[0083] (5) Before each regulation action, the high-speed comparator judges whether delta T is greater than or equal to 0.9*delta Tmax in real time; if delta T is greater than or equal to 0.9*delta Tmax (i.e., 90% of the safety threshold is reached), all regulation instructions are immediately frozen, and the priority interrupt program is triggered to lock the water pump frequency and the valve opening in the current state. The judgment step is executed by the Siemens S7-1500 PLC (500) at a high-speed sampling period of 10 ms, and is detected in real time by the built-in high-speed comparator.

[0084] The modules or units in the device of the embodiments of the present application can be combined, divided, and deleted according to actual needs. The above disclosed is only the preferred embodiments of the present application, and of course cannot limit the scope of the rights of the present application, and those skilled in the art can understand that all or part of the processes of the above embodiments are implemented, and equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A cold energy recovery device for a liquid argon transport pipeline, characterized in that: Includes a tank for holding cooling water, a shell-and-tube heat exchange assembly, and a cooling water circulation assembly; The shell-and-tube heat exchange assembly is fixedly installed inside the housing. A channel for a liquid argon delivery pipe is formed inside the shell-and-tube heat exchange assembly. The liquid argon delivery pipe passes through the channel of the shell-and-tube heat exchange assembly, and an annular gap exists between the outer wall of the liquid argon delivery pipe and the inner wall of the channel of the shell-and-tube heat exchange assembly. The outer surface of the shell-and-tube heat exchange assembly is immersed in the cooling water inside the housing. The cooling capacity of the liquid argon in the liquid argon delivery pipe is transferred to the inner wall of the shell-and-tube heat exchange assembly through the air in the annular gap, and then transferred to the cooling water inside the housing through the pipe wall of the shell-and-tube heat exchange assembly to lower the temperature of the cooling water. The cooling water circulation assembly is used to introduce the heated cooling water into the housing and to output the cooled cooling water after heat exchange and cooling within the housing.

2. The cold energy recovery device for the liquid argon transport pipeline according to claim 1, characterized in that: The cooling water circulation assembly includes a variable frequency water pump, a solenoid valve, a temperature monitoring assembly, and a controller; the temperature monitoring assembly includes a first temperature sensor and a second temperature sensor, the first temperature sensor being installed on the pipe section before the liquid argon delivery pipeline enters the shell-and-tube heat exchange assembly to monitor the input temperature T of the liquid argon. in The second temperature sensor is installed on the section of the liquid argon delivery pipeline after it extends out of the sleeve-type heat exchange assembly to monitor the output temperature T of the liquid argon. out The controller is electrically connected to the first temperature sensor, the second temperature sensor, the variable frequency water pump, and the solenoid valve. The controller has a preset safety threshold ΔT. max The controller receives the liquid argon input temperature T from the first temperature sensor. in The signal and the liquid argon output temperature T from the second temperature sensor out The signal is used to calculate the liquid argon output temperature T. out Signal and liquid argon input temperature signal T in The controller is configured to adjust the operating frequency of the variable frequency water pump and the opening degree of the solenoid valve according to the temperature difference ΔT, so as to control the cooling water circulation flow rate; the controller is also configured to set the temperature difference ΔT and the safety threshold ΔT. max Compare, and when ΔT ≥ ΔT max When necessary, shut off the solenoid valve and the variable frequency water pump.

3. The cold energy recovery device for the liquid argon transport pipeline according to claim 2, characterized in that: The cooling water circulation assembly also includes an inlet pipe and an outlet pipe; the bottom of the housing is provided with an inlet and an outlet, one end of the outlet pipe is connected to the outlet of the housing, and the other end of the outlet pipe is connected to the inlet of the monocrystalline silicon circulating water system, one end of the inlet pipe is connected to the outlet of the monocrystalline silicon circulating water system, and the other end of the inlet pipe is connected to the inlet of the housing, so as to form a cooling water circulation circuit, the variable frequency water pump and the solenoid valve are sequentially arranged on the outlet pipe, and the controller is fixedly installed on the variable frequency water pump.

4. The cold energy recovery device for the liquid argon transport pipeline according to claim 1, characterized in that: The outer wall of the shell-and-tube heat exchange assembly is provided with axially extending heat-conducting fins, which are evenly distributed around the axis of the shell-and-tube heat exchange assembly. The shell-and-tube heat exchange assembly is provided with a channel through which a liquid argon delivery pipeline passes, and its diameter is not less than twice the diameter of the liquid argon delivery pipeline. The outer wall of the box is provided with a heat insulation layer, and a drain pipe is provided at the bottom of the box, with a ball valve installed on the drain pipe.

5. The cold energy recovery device for the liquid argon transport pipeline according to claim 2, characterized in that: The temperature monitoring component further includes a third temperature sensor; the third temperature sensor is disposed on the housing and near the bottom of the housing, and is electrically connected to the controller to monitor the temperature T of the cooling water inside the housing. W and the temperature T of the cooling water W The signal is transmitted to the controller; the controller is used to control the temperature T. W and the preset cooling water safety temperature T S Compare and at the temperature T of the cooling water W ≤ Cooling water safety temperature T S When this occurs, the solenoid valve is closed and the variable frequency water pump is stopped.

6. The cold energy recovery device for the liquid argon transport pipeline according to claim 2, characterized in that: The controller is preset with a desired cooling water temperature T; the controller is used to operate when ΔT < ΔT max And T W >T S At the same time, increase the operating frequency of the variable frequency water pump and / or increase the opening degree of the solenoid valve to make T W Approaching T, and with ΔT ≥ 0.9ΔT max Stop increasing the operating frequency of the variable frequency water pump and the opening degree of the solenoid valve.

7. An argon gas supply system, characterized in that it includes an argon gas supply component and a cold energy recovery device for a liquid argon transport pipeline as described in any one of claims 1-6; The argon supply assembly includes a cryogenic liquid argon storage tank, a liquid argon delivery pipeline, a vaporizer, and an argon delivery pipeline. The cryogenic liquid argon storage tank is used to store cryogenic liquid argon. The outlet of the cryogenic liquid argon storage tank is connected to one end of the liquid argon delivery pipeline, and the other end of the liquid argon delivery pipeline is connected to the vaporizer to deliver the cryogenic liquid argon to the vaporizer for vaporization. The outlet of the vaporizer is connected to the argon delivery pipeline to deliver room temperature gaseous argon to the user end. A cold energy recovery device is installed on the liquid argon delivery pipeline.

8. A control method for a cold energy recovery device of a liquid argon transport pipeline, the method being applied to the cold energy recovery device of the liquid argon transport pipeline according to any one of claims 1-6 and the argon supply system according to claim 7, the control method comprising the following steps: S1: Real-time acquisition of the liquid argon input temperature T collected by the first temperature sensor on the cold energy recovery device of the liquid argon delivery pipeline. in and the liquid argon output temperature value T collected by the second temperature sensor. out ; S2: Calculate the liquid argon output temperature value T out With liquid argon input temperature value T in The difference is used to obtain the temperature difference ΔT; S3: Generate a control command based on the temperature change value ΔT; the control command is used to adjust the operating frequency of the variable frequency water pump and the opening degree of the solenoid valve so that the flow rate of the cooling water dynamically matches the current recoverable cold energy level and maintains the desired liquid argon temperature to prevent liquid argon from vaporizing.

9. The control method for the cold energy recovery device of the liquid argon conveying pipeline according to claim 8, characterized in that: S3 includes: When ΔT shows an increasing trend, the operating frequency of the variable frequency water pump and / or the opening degree of the solenoid valve are reduced according to the increase of ΔT. When ΔT shows a decreasing trend, the operating frequency of the variable frequency water pump and / or the opening degree of the solenoid valve are increased according to the magnitude of the decrease in ΔT. When the ΔT trend is stable, maintain the current operating parameters.

10. The control method for the cold energy recovery device of the liquid argon conveying pipeline according to claim 8, characterized in that: The control method for the cold energy recovery device of the liquid argon transport pipeline further includes S4: (1) Real-time acquisition of the cooling water temperature T inside the box collected by the third temperature sensor. W ; (2) The controller pre-stores or receives the user-set desired cooling water temperature T; (3) Regarding the cooling water temperature value T W With the preset cooling water safety temperature T S Compare and in the temperature T of the cooling water W ≤ Cooling water safety temperature T S When the temperature T of the cooling water is reached, the solenoid valve is closed and the variable frequency water pump is stopped; and when the temperature T of the cooling water is reached... W Cooling water safety temperature T S When calculating the cooling water temperature deviation δT = T W -T; (4) Generate a temperature regulation command based on the magnitude of δT, and adjust the operating frequency of the variable frequency water pump and the opening degree of the solenoid valve to adjust the cooling water temperature T. W Approaching the desired cooling water temperature T; (5) Determine whether ΔT ≥ 0.9ΔT max ; and in ΔT≥0.9ΔT max When this happens, stop adjusting the operating frequency of the variable frequency water pump and the opening degree of the solenoid valve.

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