A liquid injection control device for process gas chromatograph

Abstract

The present invention relates to the technical field of gas chromatography analysis, and in particular to a liquid injection control device for a process gas chromatograph, comprising a liquid-phase vaporization mechanism for vaporizing a liquid-phase sample and mixing it with a carrier gas, the device comprising a carrier gas regulating assembly, an atomizing assembly, and a vaporizing assembly connected end to end in sequence; a chromatographic column connector, which is arranged between the liquid-phase vaporization mechanism and the chromatographic column, and is used to transport the vaporized sample to the chromatographic column; and a vaporization monitoring unit, which comprises a vibration sensor arranged on the atomizing assembly and a second temperature sensor arranged on the chromatographic column connector, and is used to detect the vaporization process of the liquid-phase sample.

Description

Technical Field

[0001] The present invention relates to the technical field of gas chromatography analysis, in particular to a liquid injection control device for a process gas chromatograph. Background Art

[0002] In the field of gas chromatography technology, when injecting samples into traditional gas chromatographs, liquid samples need to be vaporized before entering the chromatographic column for separation. Traditional gas chromatograph injection devices mostly use manual or electric micro-injectors, which have the problem of uneven injection volume and the inability to ensure sample repeatability. At the same time, traditional gas chromatograph injection devices also mostly use independent external vaporization devices, which have no control over the vaporization process. Their vaporization efficiency is low and the vaporization is incomplete, which will cause serious tailing of the sample chromatographic peak and affect the chromatographic separation.

[0003] Chinese Patent Publication No. CN211122703U discloses a vaporization sampling device for online gas chromatography analysis of liquid samples, comprising: a four-way valve, a liquid sampling valve, and a vaporization device, wherein one end of the vaporization device is connected to the liquid sampling valve, and the other end of the vaporization device is connected to the four-way valve. The vaporization device is also connected to a chromatograph, and the liquid sampling valve is connected to the four-way valve. As can be seen, the vaporization sampling device for online gas chromatography analysis of liquid samples has the following problems: the liquid sample injection amount is controlled by a traditional liquid sampling valve, the injection amount is uneven, and the liquid pipeline is complicated; at the same time, the liquid sample is directly dripped into the heating chamber, easily adsorbed on the tube wall or the valve body, and the vaporization process of the liquid sample is not controlled, resulting in low vaporization efficiency and easy incomplete vaporization. Summary of the Invention

[0004] To this end, the present invention provides a liquid injection control device for a process gas chromatograph to overcome the problems in the prior art of uneven liquid sample injection volume, complex liquid pipelines prone to sample residue, low liquid sample vaporization efficiency, and incomplete vaporization.

[0005] To achieve the above-mentioned object, the present invention provides a liquid injection control device for a process gas chromatograph, comprising: a chromatographic column connector inside the process gas chromatograph, and further comprising:

[0006] The injection mechanism includes an injection needle, a telescopic probe assembly and a micro quantitative ring, wherein the telescopic probe assembly is used to drive the injection needle to input the liquid sample into the micro quantitative ring;

[0007] A liquid phase vaporization mechanism, connected to the sample injection mechanism, is used to convert the liquid phase sample and carrier gas into a carrier gas mixed gas phase sample after mixing, comprising a carrier gas regulating assembly, an atomizing assembly, and a vaporizing assembly connected end to end in sequence, wherein the carrier gas regulating assembly is used to adjust the pressure of the carrier gas to a target range so as to deliver the carrier gas to the atomizing assembly; the atomizing assembly is used to convert the liquid phase sample into a mist sample; the vaporizing assembly is used to vaporize the mist sample into a gas phase sample; the vaporizing assembly comprises a heating element, a glass vaporizing chamber, and an insulating wall;

[0008] a vaporization monitoring mechanism, which is connected to the sample injection mechanism and the liquid phase vaporization mechanism respectively, and is used to collect characteristic parameters of the sample injection, including the temperature of the gas in the vaporization component, the vibration amplitude of the atomization component, and the temperature of the chromatographic column connector;

[0009] A vaporization control mechanism is connected to the liquid-phase vaporization mechanism and the vaporization monitoring mechanism, respectively, and is used to adjust the carrier gas flow rate passing through the atomization assembly and the vaporization assembly according to the drop in the temperature of the chromatographic column connector, or to adjust the heating temperature of the vaporization assembly according to the vibration amplitude of the atomization assembly.

[0010] Furthermore, the telescopic probe rod assembly includes a cylinder, a piston arranged in the cylinder and connected to the injection needle, and a cylinder seal for preventing compressed air from leaking and external contaminants from entering the cylinder. A pair of air holes are provided on both sides of the piston on the cylinder to allow compressed air to enter and exit to drive the piston to move.

[0011] Furthermore, the vaporization monitoring mechanism includes:

[0012] a first temperature sensor connected to the injection needle and used to detect the temperature of the injection needle;

[0013] a second temperature sensor connected to the vaporization assembly and configured to detect the temperature of the mixed gas in the vaporization assembly;

[0014] a third temperature sensor, connected to the chromatographic column connector, for detecting the temperature of the chromatographic column connector;

[0015] A vibration sensor is connected to the atomizing assembly and is used to detect the vibration amplitude of the atomizing assembly.

[0016] Furthermore, the carrier gas regulating component includes:

[0017] A carrier gas pressure regulator is used to adjust the pressure of the carrier gas to the target pressure range and stabilize the pressure of the continuously input carrier gas;

[0018] an input carrier gas flow channel, which is arranged between the carrier gas storage device and the carrier gas pressure regulator and is used to input the carrier gas into the carrier gas pressure regulator;

[0019] The atomization carrier gas flow channel is arranged between the carrier gas pressure regulator and the atomization component, and is used to input the carrier gas that converts the liquid phase sample into the atomization sample into the atomization component.

[0020] Furthermore, the vaporization control mechanism is respectively used to communicate with the first temperature sensor and the second temperature sensor to obtain the temperature of the injection needle detected by the first temperature sensor and the temperature of the mixed gas in the vaporization component detected by the second temperature sensor, and under the condition that the temperature of the injection needle and the temperature of the mixed gas in the vaporization component are less than or equal to a preset temperature, it is determined that the heating temperature of the heating element in the vaporization component is insufficient, and its heating temperature is increased.

[0021] Furthermore, the vaporization control mechanism is connected to the first temperature sensor, the second temperature sensor and the vibration sensor respectively, so as to obtain the vibration amplitude of the atomization assembly when the temperature of the injection needle and the temperature of the mixed gas in the vaporization assembly are greater than the preset temperature, wherein,

[0022] If the vibration amplitude of the atomizing assembly is greater than a preset first vibration amplitude, the vaporization control mechanism determines that the vaporization state is unqualified;

[0023] If the vibration amplitude of the atomization assembly is less than or equal to the preset first vibration amplitude, the vaporization control mechanism determines that the vaporization state is qualified.

[0024] Furthermore, the vaporization control mechanism reduces the heating temperature of the vaporization component under the condition that the vibration amplitude of the atomization component is greater than or equal to a preset vibration amplitude.

[0025] Furthermore, the vaporization control mechanism is connected to the third temperature sensor to obtain the temperature of the chromatographic column connector.

[0026] If the temperature drop of the chromatographic column connector is greater than the preset drop, it is determined that the vaporization control mechanism is not sufficiently vaporized, and the flow rate of the carrier gas passing through the atomization component and the vaporization component is reduced.

[0027] Furthermore, the flow rate of the carrier gas passing through the atomization assembly and the vaporization assembly is negatively correlated with the drop amplitude of the chromatographic column connector.

[0028] Furthermore, the vaporization control mechanism also includes an air compressor for controlling the flow of compressed air into and out of the cylinder barrel, and a hydraulic power pump for driving the pressure regulation action of the carrier gas regulating assembly.

[0029] Compared with the prior art, the beneficial effect of the present invention lies in that, by setting a carrier gas adjustment component, an atomization component and a vaporization component, the injection control device of the present invention can determine, according to the temperature of the injection needle, whether the instability of the piston injection process is caused by the hot air flow of the heating element in the vaporization stage interfering with the temperature of the injection needle or by the vibration of the carrier gas and the injection structure due to the unsmooth vaporization process of the vaporization component, thereby reducing the influence of inaccurate identification of the cause of the instability of the injection needle on the accuracy of the injection control; by adjusting the heating temperature of the heating element close to the atomization component, adjusting the carrier gas flow rate and adjusting the overall heating temperature of the vaporization component, respectively overcome the problem of gas flow interfering with the injection process caused by the heat difference between the heating section and the air heat at the injection position, the problem of inaccurate subsequent detection caused by insufficient vaporization entering the chromatographic column connector and the boiling of the liquid sample at the inlet of the vaporization component, thereby achieving an overall improvement in the accuracy of liquid injection control.

[0030] Furthermore, the liquid-phase vaporization mechanism of the present invention stabilizes the pressure of the continuously input carrier gas and controls the input flow rate of the carrier gas in real time by providing a carrier gas regulating component, thereby controlling the vaporization process of the liquid-phase sample and improving the safety of the device.

[0031] Furthermore, the liquid-phase vaporization mechanism of the present invention improves the vaporization efficiency of the liquid-phase sample and reduces the possibility of insufficient vaporization of the liquid-phase sample by providing an atomization component.

[0032] Furthermore, the present invention sets a vibration sensor to detect the vibration amplitude of the atomization component. When the vibration amplitude exceeds the set threshold, the temperature of the electric heating wire is reduced to prevent the liquid sample from boiling at the inlet of the vaporization component, which causes the vaporization component inlet pipe to vibrate and the measurement value to fluctuate.

[0033] Furthermore, the present invention sets a third temperature sensor to detect the temperature change of the chromatographic column connector. When the temperature of the chromatographic column connector drops, the carrier gas flow rate is reduced to prevent part of the liquid sample from directly entering the chromatographic column due to insufficient vaporization and causing damage to the instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the structure of a liquid injection control device for a process gas chromatograph according to an embodiment of the present invention;

[0035] Figure 2 A schematic structural diagram of a carrier gas regulating assembly of a liquid injection control device for a process gas chromatograph according to an embodiment of the present invention;

[0036] In the figure: 121-cylinder; 122-first compressed air inlet; 123-second compressed air inlet; 13-micro quantitative loop; 23-third temperature sensor; 31-glass vaporization chamber; 32-insulation wall mounting flange; 33-insulation wall; 4101-upper shell; 4102-lower shell; 4103-valve port; 4104-connecting rod; 4105-sealing gasket; 4106-upper pressure-adjusting spring; 4107-lower pressure-adjusting spring; 4108-piston assembly; 4109-membrane assembly; 4110-sealing assembly; 4111-pressure flow channel; 42-input carrier gas flow channel; 43-atomization carrier gas flow channel; 5-chromatographic column connector; 61-sample inlet; 62-sample outlet; 7-diversion flow channel. DETAILED DESCRIPTION

[0037] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0038] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0039] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0040] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0041] See also Figure 1 As shown, an embodiment of the present invention provides a liquid injection control device for a process gas chromatograph, including a chromatographic column connector inside the process gas chromatograph, and further comprising:

[0042] The injection mechanism includes an injection needle, a telescopic probe assembly and a micro quantitative ring 13, wherein the telescopic probe assembly is used to drive the injection needle to input the liquid sample into the micro quantitative ring 13;

[0043] The liquid phase vaporization mechanism includes a carrier gas regulating assembly, an atomizing assembly, and a vaporizing assembly connected end to end in sequence; wherein the carrier gas input flow channel 42 connects the carrier gas pressure regulator and the carrier gas storage device to input the carrier gas to the carrier gas pressure regulator; the atomization carrier gas flow channel 43 connects the carrier gas pressure regulator and the atomizing assembly to allow the carrier gas to enter the atomizing assembly to atomize the liquid phase sample and enter the vaporizing assembly together with the liquid phase sample, and the vaporizing assembly is used to vaporize the atomized liquid phase sample;

[0044] The vaporization monitoring mechanism includes a first temperature sensor, which is connected to the injection needle to detect the temperature of the injection needle; a second temperature sensor, which is connected to the vaporization component to detect the temperature of the mixed gas in the vaporization component; a third temperature sensor 23, which is connected to the chromatographic column connector 5 to detect the temperature of the chromatographic column connector 5; and a vibration sensor, which is connected to the atomization component to detect the vibration amplitude of the atomization component.

[0045] The vaporization control mechanism is respectively used to obtain the temperature of the injection needle detected by the first temperature sensor and the temperature of the mixed gas in the vaporization component detected by the second temperature sensor, and under the condition that the temperature of the injection needle and the temperature of the mixed gas in the vaporization component are less than or equal to the preset temperature, it is determined that the heating temperature of the heating element in the vaporization component is insufficient, and its heating temperature is increased.

[0046] The vaporization control mechanism is connected to the first temperature sensor, the second temperature sensor and the vibration sensor respectively, and is used to obtain the vibration amplitude of the atomization component when the temperature of the injection needle and the temperature of the mixed gas in the vaporization component are greater than the preset temperature, wherein,

[0047] If the vibration amplitude of the atomizing assembly is greater than a preset first vibration amplitude, the vaporization control mechanism determines that the vaporization state is unqualified;

[0048] If the vibration amplitude of the atomization assembly is less than or equal to the preset first vibration amplitude, the vaporization control mechanism determines that the vaporization state is qualified.

[0049] The vaporization control mechanism reduces the heating temperature of the vaporization component under the condition that the vibration amplitude of the atomization component is greater than or equal to a preset vibration amplitude.

[0050] The vaporization control mechanism is connected to the third temperature sensor 23 to obtain the temperature of the chromatographic column connector 5.

[0051] If the temperature drop of the chromatographic column connector 5 is greater than the preset drop, it is determined that the vaporization control mechanism is not sufficiently vaporized, and the flow rate of the carrier gas passing through the atomization component and the vaporization component is reduced.

[0052] The flow rate of the carrier gas passing through the atomizing assembly and the vaporizing assembly is negatively correlated with the temperature drop of the chromatographic column connector 5 .

[0053] The chromatographic column connector 10 is disposed between the liquid-phase vaporization mechanism and the chromatographic column, and is used to transport the vaporized sample to the chromatographic column.

[0054] Specifically, see Figure 2 As shown, the carrier gas pressure regulating assembly includes:

[0055] The upper shell 4101 is sealed and connected with the diaphragm assembly 4109 and the lower shell 4102 in sequence. The upper end of the piston assembly 4108 is connected to the vaporization control mechanism, and the lower end is connected to the upper pressure-regulating spring 4106, and is arranged in the chamber formed by the diaphragm assembly 4109 and the upper shell 4101; the upper end of the lower shell 4102 and the diaphragm assembly 4109 form a pressure-regulating chamber, the inner side of the middle part is connected to the sealing assembly 4110 to form a connecting rod chamber, and the lower end is connected to the valve port 4103 to form a carrier gas chamber; the lower pressure-regulating spring 4107 is arranged in the pressure-regulating chamber, and the upper end is connected to the diaphragm assembly 4109 to form a connecting rod chamber. The membrane assembly 4109 is connected, the connecting rod 4104 passes through the connecting rod chamber and the lower pressure regulating spring 4107, the upper end is connected to the membrane assembly 4109, and the lower end is connected to the sealing gasket 4105. The sealing gasket 4105 and the valve port 4103 divide the pressure regulating chamber into an inlet chamber and an outlet chamber. The inlet chamber is connected to the input carrier gas flow channel 42, and the outlet chamber is connected to the atomizing carrier gas flow channel 43; the pressure taking flow channel 4111 connects the pressure regulating chamber and the atomizing carrier gas flow channel 43 to obtain the carrier gas pressure in the push atomizing carrier gas flow channel 43 and feed it back to the pressure regulating chamber;

[0056] It can be understood that the vaporization control mechanism controls the piston assembly 4108 to move up and down, adjusts the elastic force of the upper pressure regulating spring 4106 and the lower pressure regulating spring 4107 on the membrane assembly 4109; the carrier gas enters the inlet chamber through the input carrier gas flow channel 42, pushes the sealing gasket 4105 and the membrane assembly 4109 connected by the connecting rod 4104 to move downward, and a gap is generated between the sealing gasket 4105 and the valve port 4103, and the carrier gas flows into the outlet chamber and enters the atomizing carrier gas flow channel 43; at this time, the incoming carrier gas causes the atomizing carrier gas flow channel 4 3 rises and enters the pressure regulating chamber through the pressure taking flow channel 4111. The air pressure in the pressure regulating chamber also rises, pushing the membrane assembly 4109 and the sealing gasket 4105 connected by the connecting rod 4104 to move upward. The gap between the sealing gasket 4105 and the valve port 4103 decreases, and the flow rate of the carrier gas into the outlet chamber decreases. At this time, the air pressure in the atomized carrier gas flow channel 43 decreases, and the air pressure in the pressure regulating chamber also decreases. The above process is repeated until the flow rate of the carrier gas is stable, that is, the pressure of the carrier gas in the atomized carrier gas flow channel 43 is stable.

[0057] Specifically, the atomization assembly is disposed at the entrance of the glass vaporization chamber 31 and is connected to the atomization carrier flow channel 43 .

[0058] Specifically, the vaporization assembly 6 includes:

[0059] The glass vaporization chamber 31 is connected to the atomization assembly to vaporize the mist sample and fully mix it with the carrier gas; the insulation wall mounting flange 32 is provided at the end of the glass vaporization chamber 31 to mount the insulation wall.

[0060] Preferably, the glass vaporization chamber 31 is made of quartz glass, and the inner wall is coated with an inert silanized coating.

[0061] Preferably, the outlet temperature of the glass vaporization chamber 31 is set to be 20° higher than the inlet temperature.

[0062] Preferably, the heating element is an electric heating wire.

[0063] The working principle and workflow of the present invention are:

[0064] The electric heating wire is controlled to preheat the glass vaporization chamber 31 in sections, so that the temperature at the inlet end of the glass vaporization chamber 31 reaches the vaporization temperature required by the liquid sample, and the temperature at the outlet end is 20° higher than the temperature at the inlet end; compressed air enters the cylinder barrel 121 through the second compressed air inlet 123 to push the piston forward, and pushes the telescopic probe assembly to drive the injection needle to input the liquid sample into the micro-quantity loop 13;

[0065] The vaporization control mechanism controls the carrier gas to be pressure-regulated and stabilized by the pressure regulator, and then enters the atomization assembly through the atomization carrier flow channel 43 to atomize the liquid sample in the micro-quantitative ring 13, and sprays the liquid sample into the glass vaporization chamber 31; at this time, the liquid sample is vaporized in the glass vaporization chamber 31 and mixed with the carrier gas, and the subsequent continuously input carrier gas enters the diversion flow channel through the diversion part of the diversion valve, and is then transported to the process gas chromatograph through the chromatographic column connector 5 for analysis.

[0066] Specifically, the vaporization control mechanism is respectively used with the first temperature sensor and the second temperature sensor to obtain the temperature of the injection needle detected by the first temperature sensor and the temperature of the mixed gas in the vaporization component detected by the second temperature sensor, and under the condition that the temperature of the injection needle and the temperature of the mixed gas in the vaporization component are less than or equal to the preset temperature, it is determined that the heating temperature of the heating element in the vaporization component is insufficient, and its heating temperature is increased.

[0067] Optionally, the preset temperature of the injection needle has an optional range of [50, 80], in °C;

[0068] Preferably, the preset temperature of the injection needle is preferably 60°C;

[0069] In implementation, the heating temperature of the electric heating wire near the atomization assembly is negatively correlated with the swing amplitude of the injection needle. When the swing amplitude of the injection needle exceeds the preset swing amplitude, technical personnel in this field can set a gradient according to actual conditions to increase the heating temperature of the electric heating wire near the atomization assembly.

[0070] In practice, the injection control device of the present invention is provided with a carrier gas adjustment component, an atomization component and a vaporization component. When the stability of the piston injection process does not meet the requirements, it is determined according to the temperature of the injection needle whether the hot air flow of the heating element in the vaporization stage interferes with the temperature of the injection needle or the carrier gas and the injection structure vibrate due to the unsmooth vaporization process of the vaporization component, thereby reducing the influence of inaccurate identification of the cause of the instability of the injection needle on the accuracy of the injection control; by adjusting the heating temperature of the heating element close to the atomization component, adjusting the carrier gas flow rate and adjusting the overall heating temperature of the vaporization component, the problem of gas flow interfering with the injection process caused by the heat difference between the heating section and the air heat at the injection position, the problem of inaccurate subsequent detection caused by insufficient vaporization entering the chromatographic column connector and the boiling of the liquid sample at the inlet of the vaporization component causing the injection structure to be unstable is overcome respectively, thereby achieving an overall improvement in the accuracy of liquid injection control.

[0071] Specifically, the vaporization control mechanism is connected to the first temperature sensor and the vibration sensor respectively, and is used to obtain the vibration amplitude of the atomization assembly under the condition that the temperature of the injection needle is lower than the preset temperature and the swing amplitude of the injection needle is greater than or equal to the preset swing amplitude, wherein,

[0072] If the vibration amplitude of the atomizing assembly is greater than a preset first vibration amplitude, the vaporization control mechanism determines that the vaporization state is unqualified;

[0073] If the vibration amplitude of the atomization assembly is less than or equal to the preset first vibration amplitude, the vaporization control mechanism determines that the vaporization state is qualified.

[0074] Specifically, the vaporization control mechanism reduces the heating temperature of the vaporization component under the condition that the vibration amplitude of the atomization component is greater than or equal to a preset second vibration amplitude.

[0075] Optionally, the preset first vibration amplitude has an optional range of [0.5, 2], with the unit being mm.

[0076] Preferably, the preset first vibration amplitude is 1.5 mm.

[0077] Optionally, the optional range of the preset second vibration amplitude is [2.2, 3], and the unit is mm.

[0078] Preferably, the preset second vibration amplitude is 2.6 mm.

[0079] During implementation, the heating temperature of the vaporization component is reduced by 0.1°C every time the vibration amplitude of the atomization component exceeds the second vibration by 0.01mm. For example, when the vibration amplitude of the atomization component is 3.1mm, the current heating temperature of the vaporization component is 100°C, and the reduced heating temperature of the vaporization component is 100°C-(3.1mm-2.6mm) / 0.01×0.1°C=95°C.

[0080] During implementation, when it is identified based on the temperature of the injection needle that the vaporization process of the vaporization component is not smooth, resulting in vibration of the carrier gas and the injection structure, thereby causing instability in the piston injection process, and when the vibration amplitude of the atomization component exceeds the preset vibration amplitude, technical personnel in this field can control the cylinder drive mechanism to drive the carrier gas pressure regulator to reduce the carrier gas flow allowed to pass according to actual conditions.

[0081] In practice, when the vibration amplitude of the atomization component exceeds the preset second vibration amplitude, it indicates that the liquid sample boils at the inlet of the vaporization component, causing the injection structure to be unstable. Those skilled in the art can reduce the heating temperature of the electric heating wire according to actual conditions.

[0082] Specifically, if the vibration amplitude of the physical-chemical component is greater than the preset first vibration amplitude and less than the preset second vibration amplitude, the vaporization control mechanism preliminarily determines that the vaporization is insufficient and obtains the temperature drop of the chromatographic column connector.

[0083] If the temperature drop of the chromatographic column connector is greater than the preset drop, the vaporization control mechanism determines that the vaporization is insufficient for the second time and reduces the flow rate of the carrier gas passing through the atomization component and the vaporization component.

[0084] Optionally, the preset temperature drop range is in the range of [3, 5], with the unit being °C.

[0085] Preferably, the preset temperature drop is 3°C.

[0086] During implementation, for every 0.21°C drop in the column connector temperature beyond the preset drop, the carrier gas flow rate allowed to pass through will be reduced by 0.01 sccm (standard milliliters per minute). For example, when the vibration amplitude of the atomizer assembly is 2 mm, the current carrier gas flow rate is 15 sccm, and the reduced carrier gas flow rate is 15 sccm-(3.5°C-3°C) / 0.01×0.01 sccm=14.5 sccm.

[0087] During implementation, when the temperature drop of the chromatographic column connector exceeds a set threshold, it indicates that the liquid sample is not fully vaporized and enters the chromatographic column connector, and is retained in the chromatographic column connector as a liquid, and is then vaporized by the subsequent high-temperature carrier gas, causing the temperature of the chromatographic column connector to drop. Those skilled in the art can control the cylinder drive mechanism to drive the carrier gas pressure regulator to reduce the carrier gas flow allowed to pass through, thereby increasing the vaporization time of the liquid sample in the vaporization component according to actual conditions.

[0088] Specifically, the temperature drop of the chromatographic column connector is defined as: when the initial temperature of the chromatographic column connector minus the final temperature of the chromatographic column connector is positive within a unit time, the value is taken as the temperature drop of the chromatographic column connector.

[0089] Preferably, a possible embodiment of the unit time is 5s.

[0090] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A liquid injection control device for a process gas chromatograph, comprising a chromatographic column connector inside the process gas chromatograph, characterized in that: Also includes: The injection mechanism includes an injection needle, a telescopic probe assembly and a micro quantitative ring, wherein the telescopic probe assembly is used to drive the injection needle to input the liquid sample into the micro quantitative ring; a liquid-phase vaporization mechanism connected to the sample injection mechanism and configured to convert the liquid-phase sample into a carrier-gas-mixed gas-phase sample after mixing with a carrier gas, comprising a carrier gas regulating assembly, an atomizing assembly, and a vaporizing assembly connected end to end in sequence, wherein the carrier gas regulating assembly is configured to adjust the pressure of the carrier gas to a target range so as to deliver the carrier gas to the atomizing assembly; The atomization component is used to convert the liquid sample into a mist sample; the vaporization component is used to vaporize the mist sample into a gaseous sample; the vaporization component includes a heating element, a glass vaporization chamber and an insulation wall; a vaporization monitoring mechanism, which is connected to the sample injection mechanism and the liquid phase vaporization mechanism respectively, and is used to collect characteristic parameters of the sample injection, including the temperature of the gas in the vaporization component, the vibration amplitude of the atomization component, and the temperature of the chromatographic column connector; A vaporization control mechanism is connected to the liquid-phase vaporization mechanism and the vaporization monitoring mechanism, respectively, and is used to adjust the carrier gas flow rate passing through the atomization assembly and the vaporization assembly according to the drop in the temperature of the chromatographic column connector, or to adjust the heating temperature of the vaporization assembly according to the vibration amplitude of the atomization assembly.

2. The liquid injection control device for a process gas chromatograph according to claim 1, characterized in that: The telescopic probe assembly includes a cylinder, a piston arranged in the cylinder and connected to the injection needle, and a cylinder seal for preventing compressed air from leaking and external contaminants from entering the cylinder. A pair of air holes are provided on both sides of the piston on the cylinder to allow compressed air to enter and exit to drive the piston to move.

3. The liquid injection control device for a process gas chromatograph according to claim 2, characterized in that: The vaporization monitoring mechanism includes: a first temperature sensor connected to the injection needle and used to detect the temperature of the injection needle; a second temperature sensor connected to the vaporization assembly and configured to detect the temperature of the mixed gas in the vaporization assembly; a third temperature sensor, connected to the chromatographic column connector, for detecting the temperature of the chromatographic column connector; A vibration sensor is connected to the atomizing assembly and is used to detect the vibration amplitude of the atomizing assembly.

4. The liquid injection control device for a process gas chromatograph according to claim 3, characterized in that: The carrier gas regulating component comprises: A carrier gas pressure regulator is used to adjust the pressure of the carrier gas to the target pressure range and stabilize the pressure of the continuously input carrier gas; an input carrier gas flow channel, which is arranged between the carrier gas storage device and the carrier gas pressure regulator and is used to input the carrier gas into the carrier gas pressure regulator; The atomization carrier gas flow channel is arranged between the carrier gas pressure regulator and the atomization component, and is used for inputting the carrier gas that converts the liquid phase sample into the atomization sample into the atomization component.

5. The liquid injection control device for a process gas chromatograph according to claim 4, characterized in that: The vaporization control mechanism is respectively used to obtain the temperature of the injection needle detected by the first temperature sensor and the temperature of the mixed gas in the vaporization component detected by the second temperature sensor, and under the condition that the temperature of the injection needle and the temperature of the mixed gas in the vaporization component are less than or equal to the preset temperature, it is determined that the heating temperature of the heating element in the vaporization component is insufficient, and its heating temperature is increased.

6. The liquid injection control device for a process gas chromatograph according to claim 5, characterized in that: The vaporization control mechanism is connected to the first temperature sensor, the second temperature sensor and the vibration sensor respectively, and is used to obtain the vibration amplitude of the atomization component when the temperature of the injection needle and the temperature of the mixed gas in the vaporization component are greater than the preset temperature, wherein, If the vibration amplitude of the atomizing assembly is greater than a preset first vibration amplitude, the vaporization control mechanism determines that the vaporization state is unqualified; If the vibration amplitude of the atomization assembly is less than or equal to the preset first vibration amplitude, the vaporization control mechanism determines that the vaporization state is qualified.

7. The liquid injection control device for a process gas chromatograph according to claim 6, characterized in that: The vaporization control mechanism reduces the heating temperature of the vaporization component under the condition that the vibration amplitude of the atomization component is greater than or equal to a preset second vibration amplitude.

8. The liquid injection control device for a process gas chromatograph according to claim 7, characterized in that: The vaporization control mechanism is connected to the third temperature sensor to obtain the temperature of the chromatographic column connector. If the temperature drop of the chromatographic column connector is greater than the preset drop, it is determined that the vaporization control mechanism is not sufficiently vaporized, and the flow rate of the carrier gas passing through the atomization component and the vaporization component is reduced.

9. The liquid injection control device for a process gas chromatograph according to claim 8, characterized in that: The flow rate of the carrier gas passing through the atomizing assembly and the vaporizing assembly is negatively correlated with the temperature drop of the chromatographic column connector.

10. The liquid injection control device for a process gas chromatograph according to claim 9, characterized in that: The vaporization control mechanism also includes an air compressor for controlling the flow of compressed air into and out of the cylinder barrel and a hydraulic power pump for driving the pressure regulation action of the carrier gas regulating component.

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