A rapid chromatographic analysis system for ethylene cracking units

Abstract

The present application relates to the technical field of ethylene cracking detection, in particular to a rapid chromatographic analysis system for ethylene cracking device, which provides a rapid chromatographic analysis system using air as carrier gas, which can make the detection components operate normally only with air, so the detection components do not need additional carrier gas, greatly saving the cost of carrier gas, by setting the detection resistance as catalytic combustion resistance and coating catalyst on the surface, the carrier gas and ethylene cracking gas flameless combustion in the measurement channel, the combustion releases heat, the heat causes the resistance value of the measurement resistance to rise, breaking the balance of the electric bridge, and then generating a signal difference, which is used for detecting ethylene cracking gas, which no longer depends on H2 in principle, avoiding the risk of H2 leakage, using the multi-channel detection component composed of measurement components and reference components, a set of machine parts structure, which can realize the detection of two detection channels, saving the cost of machine parts and saving the column box space.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ethylene cracking detection, in particular to a rapid chromatographic analysis system for an ethylene cracking device. BACKGROUND

[0002] The core principle of chromatography for ethylene cracking gas is to use the separation technology of gas chromatography (GC) and the signal response of the detector to realize the qualitative and quantitative analysis of each component (such as ethylene, ethane, propylene, propane and other hydrocarbons and impurities) in the cracking gas.

[0003] Generally, TCD (thermal conductivity detector) or FID (hydrogen flame ionization detector) is used for detection, such as shown in Figure 1 and Figure 2 Taking TCD as an example, a detection unit is usually composed of a measurement flow path and a reference flow path. The gas introduced into the measurement flow path in this unit is carrier gas and ethylene cracking gas, and the reference flow path is introduced into the carrier gas. When only the carrier gas is passed, the circuit is in a balanced state, and a stable signal is output. Since the thermal conductivity of the gas produced by the ethylene cracking device is different from that of the carrier gas, the carrier gas in the measurement flow path and the reference flow path is continuously supplied, and the ethylene cracking gas is periodically introduced into the measurement flow path. When the ethylene cracking gas is introduced into the measurement flow path, the balance of the bridge is broken, and a signal difference is generated.

[0004] At the same time, H2 is usually used as the carrier gas for TCD detector, but the risk coefficient is high during the use of H2. Once H2 leaks, the consequences are unpredictable. Of course, TCD detector can also use He as the carrier gas, but He is expensive and has high investment cost. SUMMARY

[0005] The purpose of the present application is to provide a rapid chromatographic analysis system for an ethylene cracking device to solve the above problems.

[0006] The technical solution adopted by the present application is as follows: a rapid chromatographic analysis system for an ethylene cracking device, comprising a gas path box, a first column box, a second column box, a first electrical box and a second electrical box;

[0007] The gas path box is used to control and manage the flow of carrier gas.

[0008] The first column box and the second column box are arranged above and below, and are both arranged below the gas path box. The first column box and the second column box are used to provide a controllable temperature environment for the chromatographic column. The first column box is provided with an ethylene cracking device detection component suitable for air as carrier gas.

[0009] The first electrical box and the second electrical box are respectively arranged on one side of the first column box and the second column box. The first electrical box and the second electrical box are used for power supply, data acquisition, signal processing and communication.

[0010] Further, the detection component for ethylene cracking device using air as carrier gas comprises a shell, a measuring assembly and a reference assembly are arranged in the shell, wherein the measuring assembly is provided with two or more measuring components, the measuring component comprises a measuring resistor and a measuring channel, and the surface of each measuring resistor is coated with a catalyst, and the measuring resistor is located in the measuring channel;

[0011] The carrier gas and ethylene cracking gas are introduced into the measuring channel;

[0012] The catalyst can promote the flameless combustion of the carrier gas and the ethylene cracking gas in the measuring channel;

[0013] The reference assembly is provided with two or more reference components, and the number of reference components is equal to the number of measuring components, the reference component comprises a reference resistor and a reference channel, the reference resistor is located in the reference channel, the position of the reference resistor is matched with the position of the measuring resistor, and the reference resistor, the measuring resistor and an external resistor form a detection bridge;

[0014] The carrier gas is introduced into the reference channel;

[0015] The carrier gas is air.

[0016] Further, the measuring assembly comprises a first measuring component and a second measuring component, the first measuring component comprises a first measuring resistor R1 and a first measuring channel, and the second measuring component comprises a second measuring resistor R2 and a second measuring channel;

[0017] The reference assembly comprises a first reference component and a second reference component, the first reference component comprises a first reference resistor R1' and a first reference channel, and the second reference component comprises a second reference resistor R2' and a second reference channel.

[0018] Further, the first measuring channel, the second measuring channel, the first reference channel and the second reference channel all have an L-shaped structure, and the first measuring resistor R1, the second measuring resistor R2, the first reference resistor R1' and the second reference resistor R2' are arranged at the corner of the L-shaped structure.

[0019] At the same time, the measuring resistor R1 and the reference resistor R1' are arranged on the same side of the shell, and the measuring resistor R2 and the reference resistor R2' are arranged on the other side of the shell.

[0020] Further, the first measuring resistor R1, the first reference resistor R1', an external resistor Ra, an external resistor Rb and a power supply form a first detection unit channel one, the external resistor Ra and the external resistor Rb have the same resistance value and are arranged on an external circuit board, and the first measuring resistor R1 and the first reference resistor R1' have different resistance values.

[0021] Further, the first measuring resistor R1 and the first reference resistor R1' are connected in series to form a side bridge arm, and a common node is a detection bridge signal output end of channel one;

[0022] The external resistor Ra and the external resistor Rb are connected in series to form another side bridge arm, and a common node is another signal output end of the detection bridge of channel one;

[0023] The power supply is connected at the connection of the side bridge arm and the other side bridge arm.

[0024] Further, the second measuring resistor R2, the second reference resistor R2', the external resistor Rc, the external resistor Rd and the power supply form channel two of the first detection unit, the external resistor Rc and the external resistor Rd have the same resistance value and are arranged on an external circuit board, and the second measuring resistor R2 and the second reference resistor R2' have different resistance values.

[0025] Further, the second measuring resistor R2 and the second reference resistor R2' are connected in series to form a side bridge arm, and a common node is a detection bridge signal output end of channel two;

[0026] The external resistor Rc and the external resistor Rd are connected in series to form another side bridge arm, and a common node is another signal output end of the detection bridge of channel two;

[0027] The power supply is connected at the connection of the side bridge arm and the other side bridge arm.

[0028] Further, the rapid chromatographic analysis system for the ethylene cracking device further comprises a display panel, and the display panel is arranged outside the gas path box and is used for displaying working parameters of the gas path box, the first column box, the second column box, the first electrical box and the second electrical box.

[0029] The beneficial effects of the present application at least include one of the following;

[0030] 1. An air-based rapid chromatographic analysis system for an ethylene cracking device is provided, since air is used as the carrier gas, only air is needed to make the detection component normally operate, and a chemical plant is provided with an air compressor, and the air compressor can supply continuous air, so that the detection component does not need additional carrier gas, and the carrier gas cost is greatly saved.

[0031] 2. By setting the detection resistor as a catalytic combustion resistor, the surface is coated with a catalyst, so that the carrier gas and the ethylene cracking gas are flameless combustion in the measurement channel, the combustion releases heat, the heat causes the resistance value of the measuring resistor to rise, the balance of the bridge is broken, and then a signal difference is generated, which is used for detecting the ethylene cracking gas, and the principle no longer depends on H2, and the risk brought by H2 leakage is avoided.

[0032] 3. The multi-channel detection component is composed of a measuring component and a reference component, a set of machine parts structure, which can realize the detection of two detection channels, save the cost of machine parts, save the column box space, and make the column box more simple and beautiful. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a schematic diagram of an existing TCD structure;

[0034] Figure 2 is a circuit diagram of an existing TCD;

[0035] Figure 3 is a structure schematic diagram of an ethylene cracking detection component suitable for air as a carrier gas;

[0036] Figure 4 is a channel one circuit diagram of the first detection unit;

[0037] Figure 5 is a channel two circuit diagram of the first detection unit;

[0038] Figure 6 is a structure schematic diagram of a chromatographic analysis system;

[0039] Figure 7 is a concrete schematic diagram of the resistance in the channel one circuit diagram;

[0040] Figure 8 is a channel one column system diagram;

[0041] Figure 9 is a channel two column system diagram;

[0042] Figure 10 is a channel three column system diagram.

[0043] In the drawings:

[0044] 1 is a shell, 2 is a gas path box, 3 is a first column box, 4 is a second column box, 5 is a display panel, 6 is a first electrical box, 7 is a second electrical box, 8 is a platinum wire coil, 9 is a porous ceramic bead containing a catalyst, and 10 is a porous ceramic bead not containing a catalyst. DETAILED DESCRIPTION

[0045] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0046] The following detailed description of the embodiments of the application in the accompanying drawings is not intended to limit the scope of the application as claimed, but merely represents selected embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by those of ordinary skill in the art without creative effort fall within the scope of protection of the application.

[0047] It should be noted that the embodiments and features in the embodiments of the application can be combined with each other without conflict.

[0048] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0049] In the description of the application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second", etc. are only used for differentiation and cannot be understood as indicating or implying relative importance.

[0050] In the description of the application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0051] As shown in Figure 6 A chromatographic analysis system is provided, comprising a gas path box 2, a first column box 3, a second column box 4, a first electrical box 6 and a second electrical box 7;

[0052] The gas path box 2 is used to control and manage the flow of carrier gas;

[0053] The first column box 3 and the second column box 4 are arranged above and below, and are both arranged below the gas path box 2, and the first column box 3 and the second column box 4 are used to provide a controllable temperature environment for the chromatographic column, and the first column box 3 is provided with an ethylene cracking device detection part suitable for air as carrier gas;

[0054] The first electrical box 6 and the second electrical box 7 are respectively arranged at one side of the first column box 3 and the second column box 4, and are used for power supply, data acquisition, signal processing and communication.

[0055] The purpose of such design is to realize the detection of two detection channels by using a set of machine parts structure and multi-channel detection parts composed of measuring parts and reference parts, save the cost of machine parts, save the space of column box, and make the column box more simple and beautiful.

[0056] Meanwhile, the display panel 5 is arranged outside the gas path box 2 and is used for displaying the working parameters of the gas path box 2, the first column box 3, the second column box 4, the first electrical box 6 and the second electrical box 7.

[0057] As shown in the accompanying drawings, Figures 3 to 5 An ethylene cracking detection part suitable for air as carrier gas, comprising a shell 1, a measuring assembly and a reference assembly are arranged in the shell 1, wherein two or more measuring parts are arranged in the measuring assembly, the measuring part comprises a measuring resistor and a measuring channel, and each measuring resistor is coated with a catalyst on the surface, and the measuring resistor is located in the measuring channel;

[0058] The carrier gas and the ethylene cracking gas are introduced into the measuring channel;

[0059] The catalyst can promote the flameless combustion of the carrier gas and the ethylene cracking gas in the measuring channel;

[0060] Two or more reference parts are arranged in the reference assembly, and the number of reference parts is equal to the number of measuring parts, the reference part comprises a reference resistor and a reference channel, the reference resistor is located in the reference channel, the position of the reference resistor is matched with the position of the measuring resistor, and the reference resistor, the measuring resistor and an external resistor form a detection bridge;

[0061] The carrier gas is introduced into the reference channel;

[0062] The carrier gas is air.

[0063] The purpose of such design is to set the detection resistor as a catalytic combustion resistor, coat the surface with a catalyst, make the carrier gas and the ethylene cracking gas flameless in the measuring channel, release a large amount of heat during combustion, the heat causes the resistance value of the resistor to rise, breaks the balance of the Wheatstone bridge, and then generates a signal difference, which is used for detecting the ethylene cracking gas, and no longer depends on H2 in principle, avoids the risk of H2 leakage, solves the problem of high risk coefficient when using H2 as carrier gas in the existing TCD detector, and solves the problem of high investment cost when using He as carrier gas.

[0064] Meanwhile, it should be pointed out that the existing TCD cannot use air as carrier gas, the thermal conductivity of air is low, and the thermal conductivity of some gases is close to it. If the thermal conductivity of the measured gas is close to that of the carrier gas, the response on the detector is extremely low, or even no response. And the resistance of TCD will be oxidized by oxygen in the air, causing damage to the detector.

[0065] It should also be pointed out that the resistance increases with temperature, and the flameless combustion occurring in the measurement channel releases a large amount of heat, which causes the resistance to rise, thereby breaking the balance of the bridge and generating an electrical signal.

[0066] In addition, since air is used as the carrier gas, only air is needed to make the detection component work normally, and chemical plants are equipped with air compressors, which can supply a continuous supply of air. Therefore, the detection component does not require additional carrier gas, greatly saving the cost of carrier gas.

[0067] In this embodiment, two detection bridges are taken as an example, wherein the measurement assembly includes a first measurement component and a second measurement component, the first measurement component includes a first measurement resistance R1 and a first measurement channel, and the second measurement component includes a second measurement resistance R2 and a second measurement channel.

[0068] The reference assembly includes a first reference component and a second reference component, the first reference component includes a first reference resistance R1' and a first reference channel, and the second reference component includes a second reference resistance R2' and a second reference channel.

[0069] Meanwhile, the first measurement channel, the second measurement channel, the first reference channel and the second reference channel are all in L-shaped structure, and the first measurement resistance R1, the second measurement resistance R2, the first reference resistance R1' and the second reference resistance R2' are arranged at the corner of the L-shaped structure.

[0070] In addition, the first measurement resistance R1 and the first reference resistance R1' are arranged on the same side of the shell 1, and the second measurement resistance R2 and the second reference resistance R2' are arranged on the other side of the shell 1.

[0071] In actual use, the carrier gas and ethylene cracking gas flow into the measurement 1 inlet, and the flameless combustion occurs under the action of the first measurement resistance R1. The carrier gas carrying the gas generated by the combustion reaction flows out from the measurement 1 outlet. The opposite carrier gas flows into the reference 1 inlet from the reference 1 inlet, and the carrier gas flows out from the reference 1 outlet. The first reference resistance R1' does not participate in the reaction, and R2 and R2' are the same.

[0072] Meanwhile, the first measuring resistor R1, the first reference resistor R1', the external resistor Ra, the external resistor Rb and the power supply form a channel one of the first detection unit.

[0073] In addition, the first measuring resistor R1 and the first reference resistor R1' are connected in series to form a side bridge arm, and a common node is a detection bridge signal output end of the channel one.

[0074] The external resistor Ra and the external resistor Rb are connected in series to form another side bridge arm, and a common node is another signal output end of the detection bridge of the channel one.

[0075] The power supply is connected at the connection of the side bridge arm and the other side bridge arm.

[0076] The second measuring resistor R2, the second reference resistor R2', the external resistor Rc, the external resistor Rd and the power supply form a channel two of the first detection unit, the external resistor Rc and the external resistor Rd have the same resistance value, and are arranged on the external circuit board, the second measuring resistor R2 and the second reference resistor R2' have different resistance values.

[0077] The second measuring resistor R2 and the second reference resistor R2' are connected in series to form a side bridge arm, and a common node is a detection bridge signal output end of the channel two.

[0078] The external resistor Rc and the external resistor Rd are connected in series to form another side bridge arm, and a common node is another signal output end of the detection bridge of the channel two.

[0079] The power supply is connected at the connection of the side bridge arm and the other side bridge arm.

[0080] In actual use, R1 and R1' are a pair of resistors, different from each other, and R2 and R2' are also a pair of resistors, different from each other, and R1 and R2 are used for the measurement end, R1' and R2' are used for the reference end, and cannot be used interchangeably, R1 and R1' are located in the detector, and R2 and R2' are also located in the detector; Ra, Rb, Rc and Rd are the same resistors, Ra and Rb are located on the external circuit board, and Rc and Rd are located on another external circuit board.

[0081] Meanwhile, the existing TCD mostly uses rhenium tungsten wire as a resistor, and 4 rhenium tungsten wires are needed in a single detection unit, and in the technical scheme provided in the application, the selected catalytic combustion resistor needs 2 catalytic combustion resistors and 2 external supplementary resistors in a single detection unit, and the catalyst here can be platinum, and the specific process of the reaction is that the gas is adsorbed on the catalyst → the oxygen molecule is dissociated into active oxygen atoms → the C-H bond of the hydrocarbon molecule is broken → the surface oxidation reaction of the catalyst → the product falls off to generate carbon dioxide and water vapor.

[0082] like Figure 7 As shown, in the bridge structure of this embodiment, R1 is the first measuring resistor, which is usually made of platinum wire coil 8. Of course, in specific implementation, those skilled in the art can choose other precious metal coil materials. Its diameter is 25 μm. Platinum wire has a high temperature coefficient, and its resistance changes greatly when the temperature changes. The platinum wire coil 8 is provided with porous ceramic beads 9 containing catalyst. The inner layer of the porous ceramic beads 9 containing catalyst is ceramic matrix, and the outer layer is catalyst. The catalyst is a Pt-Pd / Al2O3 coating with a thickness of 50 μm. At 0°C, the resistance is about 10 Ω.

[0083] R1' is the first reference resistor. As a compensation element, its structure is the same as R1, except that the external part uses a porous ceramic bead 10 without a catalyst, that is, only ceramic matrix. R1 and R1' are located on two adjacent branches of the Wheatstone bridge circuit. The compensation element does not react and only compensates for changes in external temperature or humidity. At 0℃, the resistance is about 9Ω, which is lower than the measuring resistance.

[0084] Ra and Rb are low-temperature drift non-inductive resistors located on an external circuit board. Their resistance is not sensitive to temperature changes, and at 0°C, the resistance is approximately 10Ω.

[0085] It should also be noted that the flameless combustion temperature referred to in this embodiment is 300-450℃, which is lower than the auto-ignition point of combustible gases (such as methane, which has an auto-ignition point of 537℃) and lower than the open flame combustion temperature of combustible gases. In addition, the existing chromatographic analyzer uses an explosion-proof housing. Therefore, although flameless combustion is performed, this combustion is controllable and will not bring new risks. Furthermore, during the detection, the airtightness of the entire gas path is good, and combustible gases will not leak.

[0086] The rapid chromatographic analysis system used in ethylene cracking units consists of a chromatographic column, a ten-way valve, stainless steel tubing, and an ethylene cracking unit detection component suitable for using air as the carrier gas. The column system functions to perform separation and measurement, and the ethylene cracking unit detection component suitable for using air as the carrier gas is the part that performs the measurement within the column system.

[0087] In practical applications, the carrier gas periodically carries ethylene cracked gas into the rapid chromatographic analysis system. The sample gas is a mixture containing various components such as hydrogen, methane, ethylene, ethane, acetylene, propane, propylene, propadiene, and propyne.

[0088] If the mixed gas is not separated, only one total signal is obtained when the mixed gas reaches the detector. However, each component needs a corresponding response signal. Therefore, a column system is introduced to separate the mixed gas before detection. The ethylene cracking device detection unit in the column system using air as the carrier gas comprises two detection units. The first detection unit is divided into channel one and channel two, and the second detection unit is divided into channel three and an idle channel. That is, each detection unit has two channels. In the embodiment, only one channel, i.e., channel three, of the second detection unit is used, and the other channel is not used. The principle mode and circuit mode of channel three are the same as those of channel one and channel two, and will not be described here. The specific connection relationship is shown in Figs. Figure 8 , Figure 9 and Figure 10 .

[0089] Figures 8 to 10 In the above-mentioned column system, S1-S6 are all chromatographic columns, L1-L9 are all micro-regulating valves for adjusting the flow of gas, and V1-V3 are all ten-way valves, each of which has 10 interfaces, as shown by ①-⑩ in the figures.

[0090] In this way, the mixed gas of the carrier gas and the ethylene cracking gas is separated in the chromatographic columns. S1 and S2 of channel one are used to separate hydrogen, methane, ethylene, ethane and acetylene; S3 and S4 of channel two are used to separate propane, propylene and propadiene; and S5 and S6 of channel three are used to separate propyne.

[0091] The mixed gas of the carrier gas and the ethylene cracking gas is physically separated in the chromatographic columns. Specifically, the sample components are distributed between the mobile phase (carrier gas) and the stationary phase (filling in the chromatographic column). Because the interactions (such as adsorption, dissolution, distribution, etc.) between the components and the stationary phase are different, the migration speeds of the components in the column are different, and thus they are separated in time.

[0092] In this way, the analysis period is controlled within three minutes through the synchronous analysis of the three channels, which greatly shortens the analysis period. If only one channel is used to analyze all the components, the analysis period will be as long as ten minutes. If the analysis period is too long, the gas analysis in the ethylene cracking device process will lack timeliness, that is, the content of each component of the process gas may have changed, but the chromatographic system cannot obtain the changed process gas in time and analyze it.

[0093] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some of the technical features, as long as the modifications, equivalent replacements or improvements are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. shall be included in the protection scope of the present application.

Claims

1. A rapid chromatographic analysis system for an ethylene cracking unit, characterized in that, It includes a pneumatic box (2), a first column box (3), a second column box (4), a first electrical box (6), and a second electrical box (7); The gas box (2) is used to control and manage the flow of carrier gas; The first column box (3) and the second column box (4) are arranged one above the other and both are located below the gas path box (2). The first column box (3) and the second column box (4) are used to provide a controllable temperature environment for the chromatographic column. The first column box (3) is equipped with a detection component for an ethylene cracking device suitable for using air as the carrier gas. The first electrical box (6) and the second electrical box (7) are respectively located on one side of the first column box (3) and the second column box (4). The first electrical box (6) and the second electrical box (7) are used for power supply, data acquisition, signal processing and communication. The detection component of the ethylene cracking unit suitable for air as carrier gas includes a housing (1), and a measuring component and a reference component are provided inside the housing (1). The measuring component has two measuring components, each of which includes a measuring resistor and a measuring channel. Each measuring resistor is coated with a catalyst on its surface and is located inside the measuring channel. The measurement channel is filled with carrier gas and ethylene cracking gas. The catalyst promotes flameless combustion of the carrier gas and ethylene cracking gas in the measurement channel; The reference assembly contains two reference components, each including a reference resistor and a reference channel. The reference resistor is located within the reference channel, and its position is adapted to the position of the measuring resistor. Together with the measuring resistor and an external resistor, the reference resistor forms a detection bridge. Carrier gas is introduced into the reference channel; The measurement component includes a first measurement component and a second measurement component. The first measurement component includes a first measurement resistor R1 and a first measurement channel, and the second measurement component includes a second measurement resistor R2 and a second measurement channel. The reference component includes a first reference component and a second reference component. The first reference component includes a first reference resistor R1' and a first reference channel. The second reference component includes a second reference resistor R2' and a second reference channel. The first measurement channel, the second measurement channel, the first reference channel, and the second reference channel are all L-shaped structures, and the first measurement resistor R1, the second measurement resistor R2, the first reference resistor R1', and the second reference resistor R2' are located at the corners of the L-shaped structures; The first measuring resistor R1, the first reference resistor R1', the external resistor Ra, the external resistor Rb and the power supply constitute channel one of the first detection unit. The external resistor Ra and the external resistor Rb have the same resistance value and are both set on an external circuit board. The first measuring resistor R1 and the first reference resistor R1' have different resistance values. The second measuring resistor R2, the second reference resistor R2', the external resistor Rc, the external resistor Rd, and the power supply constitute channel two of the first detection unit. The external resistors Rc and Rd have the same resistance value and are both located on an external circuit board. The second measuring resistor R2 and the second reference resistor R2' have different resistance values.

2. The rapid chromatographic analysis system for an ethylene cracking unit according to claim 1, characterized in that, The first measuring resistor R1 and the first reference resistor R1' are located on the same side of the housing (1), and the second measuring resistor R2 and the second reference resistor R2' are located on the other side of the housing (1).

3. The rapid chromatographic analysis system for an ethylene cracking unit according to claim 1, characterized in that, The first measuring resistor R1 and the first reference resistor R1' are connected in series to form one side of the bridge arm, and the common node is the detection bridge signal output terminal of the channel one; The external resistors Ra and Rb are connected in series to form another bridge arm, and the common node is the other signal output terminal of the detection bridge of channel one. The power supply is connected at the junction of one bridge arm and the other bridge arm.

4. The rapid chromatographic analysis system for an ethylene cracking unit according to claim 1, characterized in that, The second measuring resistor R2 and the second reference resistor R2' are connected in series to form one side of the bridge arm, and the common node is the detection bridge signal output terminal of the second channel; The external resistors Rc and Rd are connected in series to form another bridge arm, and the common node is the other signal output terminal of the detection bridge of channel two. The power supply is connected at the junction of one bridge arm and the other bridge arm.

5. The rapid chromatographic analysis system for an ethylene cracking unit according to claim 1, characterized in that, It also includes a display panel (5), which is located outside the gas circuit box (2) and is used to display the working parameters of the gas circuit box (2), the first column box (3), the second column box (4), the first electrical box (6), and the second electrical box (7).

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