Cryogenic distillation column with improved automatic exhaust and detection of impurities and control method thereof

Abstract

The present invention relates to a cryogenic distillation column with improved automatic exhaust and detection of impurities and a control method thereof, the cryogenic distillation column comprising: an inlet thermometer (T1) capable of measuring the inlet temperature of a cooling source of a cryogenic distillation tower; an outlet thermometer (T2) capable of measuring the outlet temperature of the cooling source of the cryogenic distillation tower; an expansion turbine output detection unit for detecting the output (RPM) of an expansion turbine; and a controller 1 for setting an exhaust mode and controlling a flow rate by using a temperature difference between the inlet thermometer (T1) and the outlet thermometer (T2) and the output (RPM) of the expansion turbine. According to the present embodiment, it is possible to constantly maintain the internal pressure of the cryogenic distillation tower by measuring the temperature of the cooling source of the cryogenic distillation tower, setting the exhaust mode and controlling the flow rate by using the temperature difference and the output (RPM) of the expansion turbine, monitoring the upper pressure of the cryogenic distillation tower, and controlling a deuterium supply flow rate using the upper pressure.

Description

Ultra-low temperature distiller with improved automatic impurity exhaust and detection and its control method

[0001] The present invention relates to an ultra-low temperature distillation apparatus with improved automatic impurity exhaust and detection and a control method thereof, and more particularly, to an ultra-low temperature distillation apparatus with improved automatic impurity exhaust and detection and a control method thereof, which measures the temperature of a cooling source of an ultra-low temperature distillation column, sets an exhaust mode and controls a flow rate using a temperature difference and an expansion turbine output (RPM), monitors an upper pressure of an ultra-low temperature distillation column, and controls a deuterium supply flow rate using this pressure to maintain a constant pressure inside the ultra-low temperature distillation column.

[0002] In general, in the rapidly changing international energy environment, such as resource depletion, the enforcement of the Kyoto Protocol, and the surge in oil prices, the relative economic feasibility of new and renewable energy is becoming more advantageous, and the energy market based on new energy technologies such as hydrogen, fuel cells, and solar cells is expected to rapidly emerge as a huge industry that surpasses IT and BT. Accordingly, we have entered a global development competition system for the future new energy industry, and we need to prepare nationally to take the lead in the global market.

[0003] Nuclear power plants have been established as an important means of power generation, demonstrating superior operating performance compared to hydroelectric or thermal power plants in terms of economic feasibility, safety, and environmental conservation.

[0004] Nuclear power generation uses the energy generated during the nuclear fission process of fissile material to produce electricity. However, if an accident occurs in which radioactive materials generated during this process leak abnormally, there is a risk that it could develop into a large-scale disaster. Therefore, the safety of nuclear power plants has always been treated as a top priority.

[0005] Accordingly, although existing nuclear power plants are evaluated as having reasonable safety, the development of next-generation reactors with dramatically improved safety is actively underway worldwide.

[0006] Meanwhile, the Wolseong TRF (Tritium Removal Facility) is being operated to remove tritium in the heavy water reactor system of the nuclear power plant, and an ultra-low temperature still is being used in the tritium enrichment stage.

[0007] At the top of this ultra-low temperature still, the difference in condensation points between tritium and deuterium causes tritium to condense and deuterium to remain in a gaseous state.

[0008] In the past, tritium existing in the cooling water or system water of a heavy water reactor may decay to produce helium, or helium gas may remain in the system after being used for cleaning, and for other reasons, gaseous impurities (such as nitrogen) may exist in the ultra-low temperature distillation tower, hindering heat exchange.

[0009] In addition, helium has a lower liquefaction point than hydrogen, so it exists in a gaseous state in the ultra-low temperature distillation unit and collects at the top of the ultra-low temperature distillation tower. If it accumulates beyond a certain amount, tritium enrichment becomes impossible and operation must be stopped.

[0010] In addition, other impurity gases solidify inside the distiller, hindering heat exchange, and when they accumulate to a certain amount, they reduce the performance of the reheater and require operation to be stopped.

[0011] Additionally, although there is conventional exhaust equipment to remove helium gas, it is difficult to respond to sudden changes because the capacity is small and the user must set it.

[0012] In addition, the internal pressure of a conventional ultra-low temperature distillation column determines the condensation point of tritium and the boiling point of deuterium, but there is no means to independently control it, which can cause transient phenomena.

[0013] The technical problem to be achieved by the present invention is to improve the conventional problems, and to provide an ultra-low temperature distillation machine with improved automatic impurity exhaust and detection, and a control method thereof, which measures the cooling source temperature of an ultra-low temperature distillation column, sets the exhaust mode and controls the flow rate using the temperature difference and the expansion turbine output (RPM), monitors the upper pressure of the ultra-low temperature distillation column, and controls the flow rate of deuterium supply using this pressure to keep the internal pressure of the ultra-low temperature distillation column constant.

[0014] In addition, the technical task to be achieved by the present invention is to improve the conventional problems, and to provide an ultra-low temperature distillation machine with improved automatic impurity exhaust and detection, which can respond to sudden changes and independently control the condensation point of tritium and the boiling point of deuterium by the internal pressure of the ultra-low temperature distillation column, and a control method thereof.

[0015] The ultra-low temperature distiller with improved automatic impurity exhaust and detection according to the features of the present invention to solve these problems is:

[0016] An inlet thermometer (T1) capable of measuring the inlet temperature of the cooling source of the ultra-low temperature distillation column;

[0017] An outlet thermometer (T2) capable of measuring the outlet temperature of the cooling source of the ultra-low temperature distillation column;

[0018] An expansion turbine output detection unit that detects the output (RPM) of the expansion turbine;

[0019] It includes a controller 1 that sets the exhaust mode and controls the flow rate by using the temperature difference between the inlet thermometer (T1) and the outlet thermometer (T2) and the output (RPM) of the expansion turbine.

[0020] A pressure monitoring unit (P1) that monitors the upper pressure of the ultra-low temperature distillation column;

[0021] It further includes a controller 2 that controls the flow rate of deuterium supply using the upper pressure of the ultra-low temperature distillation column to maintain the internal pressure of the ultra-low temperature distillation column constant.

[0022] The above controller 2 has a bumpless function to ensure stable control even when the control mode changes.

[0023] Controller 3 that maintains the set temperature by adjusting the expansion turbine output (RPM) according to the temperature of the cooling source from the ultra-low temperature refrigerator;

[0024] It further includes a controller 4 that operates a reboiler according to the water level of the ultra-low temperature distillation tower to control a constant water level.

[0025] When ΔT and expansion turbine RPM decrease below the set value, a signal is output from the controller 1 to change the controller 2 to pressure control mode,

[0026] The above controller 2 controls the deuterium supply flow rate by using flow rate control during normal operation, and when it receives a pressure control mode signal from the controller 1, it controls the upper pressure (P1) of the ultra-low temperature distillation tower.

[0027] When helium gas is exhausted from the top of the ultra-low temperature distillation column, heat exchange occurs normally and the amount of condensation increases rapidly, so the amount of condensation is controlled by setting the expansion turbine set temperature to a value higher than the operating temperature.

[0028] When the exhaust flow rate increases by the above controller 1, helium gas is exhausted and ΔT increases, and when the above ΔT exceeds the set value, the exhaust flow rate of the above controller 1 is normalized and the above controller 2 is changed to the flow rate control mode to prepare for normal operation.

[0029] The present invention provides a method for controlling an ultra-low temperature distiller with improved automatic impurity exhaust and detection to solve these problems.

[0030] Step (S201) where controller 1 determines whether the pressure change (ΔP) is within the normal range;

[0031] If the pressure change (ΔP) is within the normal range, the controller 1 determines whether the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K (S203);

[0032] If the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K, the controller 1 determines whether the turbine output value decreases (S204);

[0033] When the turbine output value decreases, the controller 2 changes to the deuterium supply flow rate (V2) control mode (S205);

[0034] Step 2 of the above controller increasing the turbine setpoint by 0.1K;

[0035] Step (S207) in which the above controller 2 determines whether the pressure change (ΔP) is maintained;

[0036] When the pressure change (ΔP) is maintained, the controller 2 opens the non-condensable gas (V1) exhaust to increase the exhaust amount (S208);

[0037] Step (S209) in which the above controller 2 determines whether the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K;

[0038] If the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K, controller 2 performs a step (S210) of normalizing the exhaust flow rate of non-condensable gas (V1);

[0039] Step (S211) in which the above controller 2 normalizes the control mode of the deuterium supply flow rate (V2);

[0040] Step (S212) in which the above controller 2 reduces the turbine setting value by 0.1K;

[0041] Step (S213) in which the above controller 2 determines whether the pressure change (ΔP) increases;

[0042] When the pressure change (ΔP) increases, the controller 2 includes a step (S214) in which normal operation is performed.

[0043] According to one embodiment, a cryogenic distillation unit with improved automatic exhaust and detection of impurities and a control method thereof can be provided, which measures the temperature of a cooling source of a cryogenic distillation unit, sets an exhaust mode and controls a flow rate using a temperature difference and an expansion turbine output (RPM), monitors the upper pressure of the cryogenic distillation unit, and controls the flow rate of deuterium supplied using this pressure to maintain a constant pressure inside the cryogenic distillation unit.

[0044] In addition, according to one embodiment, an ultra-low temperature distillation unit with improved automatic impurity exhaust and detection, capable of responding to sudden changes and independently controlling the condensation point of tritium and the boiling point of deuterium by the internal pressure of the ultra-low temperature distillation column, and a control method thereof can be provided.

[0045] Figure 1 is a block diagram of an ultra-low temperature distiller with improved automatic impurity exhaust and detection according to an embodiment of the present invention.

[0046] FIG. 2 is a drawing showing a control method of an ultra-low temperature distiller with improved automatic impurity exhaust and detection according to an embodiment of the present invention.

[0047] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0048] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0049] Figure 1 is a schematic diagram of an ultra-low temperature distiller with improved automatic impurity exhaust and detection according to an embodiment of the present invention.

[0050] Referring to FIG. 1, an ultra-low temperature distiller with improved automatic impurity exhaust and detection according to an embodiment of the present invention is

[0051] An inlet thermometer (T1) capable of measuring the temperature of the cooling source inlet of the ultra-low temperature distillation column (160);

[0052] An outlet thermometer (T2) capable of measuring the outlet temperature of the cooling source of the ultra-low temperature distillation column (160);

[0053] An expansion turbine output detection unit that detects the output (RPM) of the expansion turbine;

[0054] It includes a controller 1 (110) that sets the exhaust mode and controls the flow rate using the temperature difference between the inlet thermometer (T1) and the outlet thermometer (T2) and the output (RPM) of the expansion turbine.

[0055] A pressure monitoring unit (P1) that monitors the upper pressure of the ultra-low temperature distillation column (160);

[0056] It further includes a controller 2 (120) that controls the flow rate of deuterium supply using the upper pressure of the ultra-low temperature distillation tower (160) to maintain the internal pressure of the ultra-low temperature distillation tower (160) constant.

[0057] The above controller 2 (120) has a bumpless function to ensure stable control even when the control mode changes.

[0058] Controller 3 (130) that maintains the set temperature by controlling the expansion turbine output (RPM) according to the temperature of the cooling source from the ultra-low temperature refrigerator;

[0059] It further includes a controller 4 (140) that operates the reboiler according to the water level of the ultra-low temperature distillation tower (160) to control the water level to a certain level.

[0060] The operation of the ultra-low temperature distiller with improved automatic impurity exhaust and detection according to the features of the present invention having such a configuration is described as follows.

[0061] First, the ultra-low temperature distillation tower (160) receives deuterium and outputs purified gas and purified liquid. At this time, the ultra-low temperature refrigerator and heat exchanger perform a cooling function by exchanging heat with the ultra-low temperature distillation tower (160).

[0062] And controller 4 (140) operates the reboiler according to the water level of the ultra-low temperature distillation tower (160) to control the water level so that a constant water level is maintained.

[0063] Additionally, controller 3 (130) controls the expansion turbine output (RPM) according to the temperature of the cooling source from the ultra-low temperature refrigerator to maintain the set temperature at a predetermined temperature.

[0064]

[0065] Meanwhile, controller 1 monitors ΔT of the inlet thermometer (T1) and the outlet thermometer (T2) when the differential pressure (DP) of the ultra-low temperature distillation column (160) condenser is formed.

[0066] When helium gas accumulates at the top of the distillation tower (160), it interferes with the heat exchange of the condenser, lowering the temperature of the outlet thermometer (T2), reducing ΔT and reducing the output (RPM) of the expansion turbine by the amount of the lowered inlet temperature.

[0067] Then, when ΔT and expansion turbine RPM decrease below the set value, a signal is output from controller 1 (110) to change controller 2 (120) to pressure control mode.

[0068] Then, controller 2 (120) controls the deuterium supply flow rate (V2) using flow rate control during normal operation, and when it receives a pressure control mode signal from controller 1 (110), it controls the upper pressure (P1) of the ultra-low temperature distillation tower (160).

[0069] At this time, the pressure (P1) setting is preset by the user. The pressure is maintained constant, so that the phase change temperature in the condenser and heater remains constant.

[0070] Since normal heat exchange can occur when helium gas is exhausted from the top, leading to a rapid increase in condensation volume, the expansion turbine setpoint temperature can be set slightly higher than the operating temperature to pre-regulate the condensation volume. For example, it can be set 2 to 5 degrees higher.

[0071] When the exhaust flow rate increases by controller 1 (110), helium gas is exhausted and ΔT increases. Then, when the ΔT setting value is exceeded, the exhaust flow rate of controller 1 (110) is normalized and controller 2 (120) is changed to flow control mode to prepare for normal operation.

[0072] Afterwards, the exhaust operation is completed by normalizing the expansion turbine set temperature while monitoring the differential pressure (DP).

[0073] FIG. 2 is a drawing showing a control method of an ultra-low temperature distiller with improved automatic impurity exhaust and detection according to an embodiment of the present invention.

[0074] Referring to Figure 2, controller 1 determines whether the pressure change (ΔP) is within the normal range (S201). Here, since monitoring is performed during normal operation, the differential pressure (water level) is within the normal range.

[0075] If the pressure change (ΔP) is within the normal range, controller 1 determines whether the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0 K (S203).

[0076] If the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0 K, controller 1 determines whether the turbine output value decreases (S204).

[0077] When the turbine output value decreases, controller 2 changes to the deuterium supply flow rate (V2) control mode (S205). Here, when ΔT and the expansion turbine RPM decrease below the set value, a signal is output from controller 1 (110) to change controller 2 (120) to the pressure control mode, and then controller 2 (120) controls the deuterium supply flow rate (V2) using flow rate control during normal operation, and when it receives a pressure control mode signal from controller 1 (110), it controls the upper pressure (P1) of the ultra-low temperature distillation column (160).

[0078] Accordingly, the pressure at the top of the distillation tower (160) is maintained constant to prevent changes in the phase change temperature. The flow rate is changed from the set value to the design pressure. The reboiler flow rate is controlled by the water level.

[0079] Meanwhile, in the above step, if the pressure change (ΔP) is not within the normal range, the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is not 6.0 K, or the turbine output value does not decrease, normal operation is performed (S202).

[0080]

[0081] Next, controller 2 increases the turbine setpoint by 0.1K (S206).

[0082] Here, the T1 temperature before removing the non-condensable gas is increased (set slightly lower than the tritium condensation temperature). This prevents rapid condensation when heat exchange returns to normal. The increased upper pressure ensures smooth exhaust.

[0083] Next, controller 2 (120) determines whether the pressure change (ΔP) is maintained (S207).

[0084] This is to create sufficient pressure within the distillation tower (160) and prevent pressure changes before increasing the exhaust volume.

[0085] If the pressure change (ΔP) is maintained, controller 2 opens the non-condensable gas (V1) exhaust to increase the exhaust volume (S208).

[0086] Next, controller 2 determines whether the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K (S209).

[0087] If the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0 K, controller 2 normalizes the exhaust flow rate of non-condensable gas (V1) (S210).

[0088] Next, controller 2 (120) normalizes the control mode of the deuterium supply flow rate (V2) (S211). At this time, the standard is changed from pressure standard to flow rate standard.

[0089] Next, controller 2 decreases the turbine setpoint by 0.1K (S212).

[0090] Next, controller 2 (120) determines whether the pressure change (ΔP) increases (S213).

[0091] When the pressure change (ΔP) increases, controller 2 (120) operates normally (S214).

[0092] In the above process, if helium gas is exhausted from the top, heat exchange may occur normally and the condensation amount may increase rapidly. Therefore, the expansion turbine set temperature may be adjusted slightly higher than the operating temperature (set value) to control the condensation amount in advance.

[0093] Specifically, the heat exchange with non-condensable gas is reduced, so the temperature of the refrigerant at the rear of the distillation chamber decreases (CD inlet 18K, CD outlet 24.1K → 22K).

[0094] And, as the turbine inlet temperature decreases, controller 1 lowers the expansion turbine operating RPM (expansion turbine inlet 24.1K → 22K, expansion turbine outlet 18K).

[0095] Additionally, TBN RPM setting can be changed by controller 1 (110) intervention.

[0096] Controller 1 (110) can gradually increase the turbine set temperature by 0.1K up to -0.4K of the target condensation temperature, thereby reducing the turbine output RPM.

[0097] And V1 non-condensable gas exhaust control and V2 pressure control suppress CD pressure increase.

[0098] And, as the amount of condensation increases after helium removal, the vacuum pressure of the condenser increases and the CD pressure decreases.

[0099] Meanwhile, as the CD outlet temperature increases, the turbine inlet temperature increases, and accordingly, the expansion turbine RPM increases, but the turbine trip is prevented at the preset turbine set temperature, a rapid drop in the CD inlet temperature is suppressed, and excessive condensation of the condensed gas is prevented.

[0100] And in the present invention, it is possible to check whether the temperature difference between the refrigerant inlet and outlet is within a normal range.

[0101] Once the above transient condition is overcome, the helium refrigerant inlet / outlet temperature difference increases normally. When the refrigerant outlet temperature rises sufficiently, control intervention is discontinued.

[0102] According to one embodiment, the temperature of the cooling source of the ultra-low temperature distillation column is measured, the exhaust mode is set and the flow rate is controlled using the temperature difference and the expansion turbine output (RPM), the upper pressure of the ultra-low temperature distillation column is monitored, and the deuterium supply flow rate is controlled using this pressure to maintain the internal pressure of the ultra-low temperature distillation column constant.

[0103] In addition, according to one embodiment, it is possible to respond to sudden changes and independently control the condensation point of tritium and the boiling point of deuterium by the internal pressure of the ultra-low temperature distillation column.

[0104] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

Claims

1. An inlet thermometer (T1) capable of measuring the inlet temperature of the cooling source of the ultra-low temperature distillation column; An outlet thermometer (T2) capable of measuring the outlet temperature of the cooling source of the ultra-low temperature distillation column; An expansion turbine output detection unit that detects the output (RPM) of the expansion turbine; An ultra-low temperature distiller with improved automatic impurity exhaust and detection, including a controller 1 that sets an exhaust mode and controls the flow rate using the temperature difference between the inlet thermometer (T1) and the outlet thermometer (T2) and the output (RPM) of the expansion turbine.

2. In paragraph 1, A pressure monitoring unit (P1) that monitors the upper pressure of the ultra-low temperature distillation column; An ultra-low temperature distillation unit with improved automatic impurity exhaust and detection, further comprising a controller 2 that controls the flow rate of deuterium supply using the upper pressure of the ultra-low temperature distillation unit to maintain the internal pressure of the ultra-low temperature distillation unit constant.

3. In paragraph 2, The above controller 2 is an ultra-low temperature distiller with improved automatic impurity exhaust and detection, equipped with a bumpless function to ensure stable control even when the control mode changes.

4. In paragraph 3, Controller 3 that maintains the set temperature by adjusting the expansion turbine output (RPM) according to the temperature of the cooling source from the ultra-low temperature refrigerator; An ultra-low temperature distillation column with improved automatic impurity exhaust and detection, further comprising a controller 4 that operates a reboiler according to the water level of the ultra-low temperature distillation column to control a constant water level.

5. In paragraph 4, When ΔT and expansion turbine RPM decrease below the set value, a signal is output from the controller 1 to change the controller 2 to pressure control mode, The above controller 2 is an ultra-low temperature distillation device with improved automatic impurity exhaust and detection that controls the supply flow rate of deuterium using flow rate control during normal operation and controls the upper pressure (P1) of the ultra-low temperature distillation column when receiving a pressure control mode signal from the above controller 1.

6. In paragraph 5, When helium gas is exhausted from the top of the ultra-low temperature distillation column, heat exchange occurs normally, causing a rapid increase in the RPM and condensate of the expansion turbine. Therefore, the expansion turbine set temperature is set to a value higher than the operating temperature to prevent expansion turbine tripping and control the condensate amount. An ultra-low temperature distillation column with improved automatic impurity exhaust and detection.

7. In paragraph 6, An ultra-low temperature distillation device with improved automatic impurity exhaust and detection, in which when the exhaust flow rate increases by the above controller 1, helium gas is exhausted and ΔT increases, and when the above ΔT exceeds a set value, the exhaust flow rate of the above controller 1 is normalized and the above controller 2 is changed to a flow rate control mode to prepare for normal operation.

8. Step (S201) where controller 1 determines whether the pressure change (ΔP) is within the normal range; If the pressure change (ΔP) is within the normal range, the controller 1 determines whether the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K (S203); If the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K, the controller 1 determines whether the turbine output value decreases (S204); When the turbine output value decreases, the controller 2 changes to the deuterium supply flow rate (V2) control mode (S205); Step 2 of the above controller increasing the turbine setpoint by 0.1K; Step (S207) in which the above controller 2 determines whether the pressure change (ΔP) is maintained; When the pressure change (ΔP) is maintained, the controller 2 opens the non-condensable gas (V1) exhaust to increase the exhaust amount (S208); Step (S209) in which the above controller 2 determines whether the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K; If the temperature difference (ΔT) between the inlet thermometer (T1) and the outlet thermometer (T2) is 6.0K, controller 2 performs a step (S210) of normalizing the exhaust flow rate of non-condensable gas (V1); Step (S211) in which the above controller 2 normalizes the control mode of the deuterium supply flow rate (V2); Step (S212) in which the above controller 2 reduces the turbine setting value by 0.1K; Step (S213) in which the above controller 2 determines whether the pressure change (ΔP) increases; A control method for an ultra-low temperature distiller with improved automatic impurity exhaust and detection, including a step (S214) in which controller 2 performs normal operation when the pressure change (ΔP) increases.

Images