System for detecting carbon dioxide in ship tail gas

Abstract

The utility model relates to the technical field of environment detection, and provides a system for detecting carbon dioxide in ship tail gas, which comprises a processor, an infrared transmitting module and an infrared receiving module, the infrared transmitting module is used for transmitting an infrared signal; the infrared receiving module is used for receiving an infrared reflection signal; the input end of the switching circuit is connected with the output end of the processor, the output end of the switching circuit is connected with the input end of the comparison circuit, and the output end of the comparison circuit is connected with the input end of the infrared emission circuit; the constant current circuit is used for providing constant current for the infrared emission circuit; the protection circuit is used for detecting the current of the constant current circuit and controls the switching circuit according to the size of the constant current circuit. The problem that a carbon dioxide detection system in the prior art is complex in circuit structure and prone to being affected by the environment is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental detection, and in particular to a carbon dioxide detection system in ship exhaust. Background Art

[0002] Ships are one of the main means of world trade transportation. However, the contribution of ship transportation to global climate change cannot be ignored. Ship exhaust mainly comes from the combustion process of ship engines, which contains many harmful substances. These substances will have a serious impact on the environment and human health. With the increasing number of transport ships, the pollution and harm caused by pollutants emitted by ships to the atmosphere and water bodies are becoming more and more serious. The pollutants emitted by ship diesel engines are mainly carbon dioxide CO2 and sulfur dioxide SO2. Carbon dioxide emitted by ships is one of the important components of global greenhouse gas emissions. According to statistics, global ship carbon dioxide emissions account for about 2.2% to 2.5% of total emissions. The growth rate of ship transportation is also much higher than other modes of transportation. Therefore, in order to strengthen the protection of the marine ecological environment, real-time monitoring of ship carbon dioxide emissions is very important, which can effectively assist maritime regulators in monitoring the exhaust emissions of ships in port areas. However, the circuit structure of the existing carbon dioxide detection system in ship exhaust is complex and easily affected by the environment, resulting in poor accuracy of the carbon dioxide detection system. Utility Model Content

[0003] The utility model provides a carbon dioxide detection system in ship exhaust gas, which solves the problem that the circuit structure of the carbon dioxide detection system in the related art is complex and easily affected by the environment.

[0004] The technical solution of the utility model is as follows:

[0005] The carbon dioxide detection system in ship exhaust gas includes a processor, an infrared transmitting module and an infrared receiving module;

[0006] The infrared transmitting module is used to transmit infrared signals;

[0007] The infrared receiving module is used to receive infrared reflection signals;

[0008] The input end of the switch circuit is connected to the output end of the processor, the output end of the switch circuit is connected to the input end of the comparison circuit, the output end of the comparison circuit is connected to the input end of the infrared emitting circuit, and the infrared emitting circuit;

[0009] The constant current circuit is used to provide a constant current for the infrared transmitting circuit;

[0010] The protection circuit is used to detect the current of the constant current circuit, and the protection circuit controls the switch circuit according to the size of the constant current circuit.

[0011] Furthermore, the switch circuit in the present invention includes a switch tube Q1 and a resistor R5;

[0012] The comparison circuit includes an operational amplifier U4;

[0013] The infrared transmitting circuit includes a switch tube Q5, an infrared transmitter LED1 and a resistor R8;

[0014] The control end of the switch tube Q1 is connected to the processor, the first end of the switch tube Q1 is connected to the 5V power supply through the resistor R5, the second end of the switch tube Q1 is grounded, the first end of the switch tube Q1 is connected to the inverting input end of the operational amplifier U4, the non-inverting input end of the operational amplifier U4 is connected to the first end of the resistor R8, the second end of the resistor R8 is grounded, the output end of the operational amplifier U4 is connected to the control end of the switch tube Q5, the first end of the switch tube Q5 is connected to the VCC power supply, the second end of the switch tube Q5 is connected to the first end of the infrared transmitter LED1, and the second end of the infrared transmitter LED1 is connected to the first end of the resistor R8.

[0015] Furthermore, the constant current circuit in the utility model includes a transistor Q2 and a resistor R9, the base of the transistor Q2 is connected to the first end of the resistor R8, the collector of the transistor Q2 is connected to the VCC power supply, the emitter of the transistor Q2 is connected to the first end of the resistor R9, and the second end of the resistor R9 is grounded.

[0016] Furthermore, the protection circuit in the utility model includes a resistor R10, a resistor R11 and a switch tube Q3, the first end of the resistor R10 is connected to the first end of the resistor R9, the second end of the resistor R10 is connected to the control end of the switch tube Q3, the second end of the resistor R10 is grounded through the resistor R11, the first end of the switch tube Q3 is connected to the control end of the switch tube Q1, and the second end of the switch tube Q3 is grounded.

[0017] Furthermore, the utility model also includes a driving circuit, which includes a NOT gate U5 and a switch tube Q4, the input end of the NOT gate U5 is connected to the processor, the output end of the NOT gate U5 is connected to the control end of the switch tube Q4, the first end of the switch tube Q4 is connected to a 5V power supply, and the second end of the switch tube Q4 is connected to the control end of the switch tube Q1.

[0018] Furthermore, in the present invention, the switch tube Q5 is replaced by the optocoupler U3;

[0019] The first input end of the optocoupler U3 is connected to a 5V power supply, the second input end of the optocoupler U3 is connected to the output end of the operational amplifier U4, the first output end of the optocoupler U3 is connected to a VCC power supply, and the second output end of the optocoupler U3 is connected to a first end of the infrared transmitter LED1.

[0020] Further, the infrared receiving module in the utility model includes an infrared receiver LED2, a resistor R2, a resistor R3 and a filter U1;

[0021] The first end of the infrared receiver LED2 is connected to the first input end of the filter U1, the second end of the infrared receiver LED2 is grounded, the first end of the resistor R2 is connected to a 5V power supply, the second end of the resistor R2 is grounded through the resistor R3, the second end of the resistor R2 is connected to the second input end of the filter U1, and the output end of the filter U1 is connected to the processor.

[0022] Furthermore, the infrared receiving module in the present utility model further includes an amplifier U2, a resistor R13, a resistor R15 and a resistor R14;

[0023] The first input end of the amplifier U2 is connected to the output end of the filter U1, the first output end of the amplifier U2 is connected to the second input end of the amplifier U2, the output end of the amplifier U2 is connected to the third input end of the amplifier U2, the fourth input end of the amplifier U2 is grounded through the resistor R14, the second output end of the amplifier U2 is connected to the fourth input end of the amplifier U2 through the resistor R15, and the second output end of the amplifier U2 is connected to the processor.

[0024] The working principle and beneficial effects of the utility model are:

[0025] In the utility model, the content of carbon dioxide in the exhaust gas of a ship is detected by the infrared gas detection principle. The infrared transmitting module is responsible for generating an infrared light signal in the gas chamber. The infrared receiving module is used to detect the remaining infrared light signal and convert the detected infrared light signal into a corresponding electrical signal and send it to the main processor. The processor determines the content of carbon dioxide in the exhaust gas of the ship according to the size of the received electrical signal.

[0026] The infrared transmitting module is composed of a switch circuit, a comparison circuit, an infrared transmitting circuit, a constant current circuit and a protection circuit. When working, the processor outputs a pulse control instruction, and the switch circuit realizes switch control according to the pulse control instruction output by the processor. The switch circuit is used to connect the control voltage. When the switch circuit is connected, the comparison circuit is used to compare the control voltage with the reference voltage, thereby controlling the infrared transmitting circuit to send an infrared light signal. The constant current circuit plays a role of shunting, and is used to provide a constant working current for the infrared transmitting circuit, ensuring that the intensity of the infrared light signal output by the infrared transmitting circuit is stable and unchanged, thereby improving the accuracy of the carbon dioxide content in the ship's exhaust gas. When the current flowing through the constant current circuit exceeds the set value, the protection circuit controls the switch circuit to disconnect, and the infrared transmitting circuit stops working, thereby protecting the infrared transmitting circuit. Therefore, the carbon dioxide detection system in the utility model is composed of two modules, the infrared transmitting module and the infrared receiving module, and the circuit structure is simple. When working, it can ensure that the intensity of the output infrared light signal is stable and unchanged. Under the action of the constant current circuit, it is ensured that the intensity of the infrared light signal is not affected by the environment, thereby improving the accuracy of detecting the carbon dioxide content in the ship's exhaust gas, and providing reliable and effective detection data for maritime regulators. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0028] Figure 1 A structural block diagram of a carbon dioxide detection system provided in an embodiment of the present utility model;

[0029] Figure 2 A circuit diagram of an infrared transmitting module provided in an embodiment of the present utility model;

[0030] Figure 3 A circuit diagram of an infrared transmitting module provided in another embodiment of the utility model;

[0031] Figure 4 This is a circuit diagram of the infrared receiving module of the utility model. DETAILED DESCRIPTION

[0032] In order to make the technical personnel in the technical field better understand the present solution, the technical solution in the present solution embodiment will be clearly described below in combination with the drawings in the present solution embodiment. Obviously, the described embodiment is a part of the present solution embodiment, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0033] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0034] like Figure 1 As shown, this embodiment proposes a carbon dioxide detection system in ship exhaust gas, including a processor, an infrared transmitting module and an infrared receiving module; the infrared transmitting module is used to transmit infrared signals; the infrared receiving module is used to receive infrared reflection signals; the input end of the switch circuit is connected to the output end of the processor, the output end of the switch circuit is connected to the input end of the comparison circuit, the output end of the comparison circuit is connected to the input end of the infrared transmitting circuit, and the infrared transmitting circuit; the constant current circuit is used to provide a constant current for the infrared transmitting circuit; the protection circuit is used to detect the current of the constant current circuit, and the protection circuit controls the switch circuit according to the size of the constant current circuit.

[0035] In this embodiment, the content of carbon dioxide in the ship exhaust is detected by the infrared gas detection principle, wherein the infrared transmitting module is responsible for generating an infrared light signal in the air chamber, and the air chamber is the transmission channel of the ship exhaust to be tested. The infrared light signal will selectively transmit infrared radiation of a specific wavelength through a filter to reduce interference. After the infrared light signal contacts the ship exhaust to be tested, the carbon dioxide in the ship exhaust will absorb the infrared light signal, and then the intensity of the infrared light signal in the air chamber will weaken. The infrared receiving module is used to detect the remaining infrared light signal, and convert the detected infrared light signal into a corresponding electrical signal and send it to the main processor. The processor determines the content of carbon dioxide in the ship exhaust according to the size of the received electrical signal.

[0036] The infrared transmitting module is composed of a switching circuit, a comparison circuit, an infrared transmitting circuit, a constant current circuit and a protection circuit. When working, the processor outputs a pulse control instruction, and the switching circuit realizes switch control according to the pulse control instruction output by the processor. The switching circuit is used to connect the control voltage. When the switching circuit is connected, the comparison circuit is used to compare the control voltage with the reference voltage, thereby controlling the infrared transmitting circuit to emit an infrared light signal. The constant current circuit plays a shunt role and is used to provide a constant working current for the infrared transmitting circuit to ensure that the intensity of the infrared light signal output by the infrared transmitting circuit is stable and unchanged, thereby improving the accuracy of the carbon dioxide content in the ship's exhaust gas. The current flowing through the constant current circuit is proportional to the current flowing through the infrared transmitting circuit. When the current flowing through the constant current circuit exceeds the set value, the working current of the infrared transmitting circuit will exceed the set maximum allowable value. At this time, if the infrared transmitting circuit continues to work, it may heat up seriously due to excessive current, thereby affecting the normal operation or damage of the infrared transmitting circuit. The protection circuit is used to detect the current flowing through the constant current circuit. When the current flowing through the constant current circuit exceeds the set value, the protection circuit controls the switch circuit to disconnect, and the infrared transmitting circuit stops working, thereby protecting the infrared transmitting circuit.

[0037] Therefore, the carbon dioxide detection system in this embodiment is composed of two modules, an infrared transmitting module and an infrared receiving module. The circuit structure is simple. When working, it can ensure that the intensity of the output infrared light signal is stable and unchanged. Under the action of the constant current circuit, the intensity of the infrared light signal is not affected by the environment, thereby improving the accuracy of detecting the carbon dioxide content in the ship's exhaust gas and providing maritime regulators with reliable and effective detection data.

[0038] like Figure 2 As shown, in this embodiment, the switch circuit includes a switch tube Q1 and a resistor R5; the comparison circuit includes an operational amplifier U4; the infrared transmitting circuit includes a switch tube Q5, an infrared transmitter LED1 and a resistor R8; the control end of the switch tube Q1 is connected to the processor, the first end of the switch tube Q1 is connected to the 5V power supply through the resistor R5, the second end of the switch tube Q1 is grounded, the first end of the switch tube Q1 is connected to the inverting input end of the operational amplifier U4, the non-inverting input end of the operational amplifier U4 is connected to the first end of the resistor R8, the second end of the resistor R8 is grounded, the output end of the operational amplifier U4 is connected to the control end of the switch tube Q5, the first end of the switch tube Q5 is connected to the VCC power supply, the second end of the switch tube Q5 is connected to the first end of the infrared transmitter LED1, and the second end of the infrared transmitter LED1 is connected to the first end of the resistor R8.

[0039] In this embodiment, an STM32 single-chip microcomputer is used as a processor. When detecting the carbon dioxide content in the exhaust gas of a ship, the processor outputs a PWM signal, and the switch tube Q1 and the resistor R5 constitute a switching circuit. When the PWM signal is at a low level, the switch tube Q1 is cut off, and the first end of the switch tube Q1 is at a high level of 5V. The high level is added to the inverting input terminal of the operational amplifier U4. The operational amplifier U4 constitutes a comparison circuit. At this time, the inverting input terminal of the operational amplifier U4 is 5V, which is greater than the voltage at the inverting input terminal of the operational amplifier U4, and the operational amplifier U4 outputs a low level. The switch tube Q5, infrared transmitter LED1 and resistor R8 constitute an infrared transmitting circuit, wherein a P-channel enhanced field effect transistor is used as the switch tube Q5. When the operational amplifier U4 outputs a low level, the switch tube Q5 is turned on, and the VCC power supply is supplied to the infrared transmitter LED1 after passing through the switch tube Q5. The infrared transmitter LED1 emits an infrared light signal, and a voltage signal is generated on the resistor R8, and the capacitor C6 is charged at the same time. When the infrared transmitter LED1 is working, the voltage on the capacitor C6 is lower than the voltage at the inverting input terminal of the operational amplifier U4, so the operational amplifier U4 will continue to output a low level. When the PWM signal becomes a high level, the switch tube Q1 is turned on, and the inverting input terminal of the operational amplifier U4 becomes a low level, which is lower than the voltage on the capacitor C6. During the period when the PWM signal is a high level, the capacitor C6 is discharged, the operational amplifier U4 outputs a high level, the switch tube Q5 is turned off, and the infrared transmitter LED1 stops working until the PWM signal turns to a low level again, and the infrared transmitter LED1 emits an infrared light signal again, thus forming a cycle. Therefore, the infrared transmitter LED1 generates a pulse infrared light signal under the action of the PWM signal.

[0040] like Figure 2 As shown, in this embodiment, the constant current circuit includes a transistor Q2 and a resistor R9, the base of the transistor Q2 is connected to the first end of the resistor R8, the collector of the transistor Q2 is connected to the VCC power supply, the emitter of the transistor Q2 is connected to the first end of the resistor R9, and the second end of the resistor R9 is grounded.

[0041] In this embodiment, the transistor Q2 and the resistor R9 form a constant current circuit. When the infrared transmitter LED1 is working, a voltage is generated on the resistor R8, which provides a base current for the base of the transistor Q2. When the current flowing through the infrared transmitter LED1 increases, the voltage on the resistor R8 increases, so the base current of the transistor Q2 also increases, and the transistor Q2 works in an anti-amplification state. When the base current of the transistor Q2 increases, the collector of the transistor Q2 can divide a larger current, and the transistor Q2 can play a shunt role. The larger the current flowing through the infrared transmitter LED1, the larger the shunt of the transistor Q2, and the smaller the current flowing through the infrared transmitter LED1, the smaller the shunt of the transistor Q2, thereby ensuring that the infrared transmitter LED1 works in a constant current state and keeping the intensity of the infrared light signal stable.

[0042] like Figure 2 As shown, in this embodiment, the protection circuit includes a resistor R10, a resistor R11 and a switch tube Q3, a first end of the resistor R10 is connected to a first end of the resistor R9, a second end of the resistor R10 is connected to a control end of the switch tube Q3, a second end of the resistor R10 is grounded through the resistor R11, a first end of the switch tube Q3 is connected to the control end of the switch tube Q1, and a second end of the switch tube Q3 is grounded.

[0043] Resistors R10, R11 and switch tube Q3 form a protection circuit. When the infrared transmitter LED1 is in working state, transistor Q2 can shunt the infrared transmitter LED1, so a voltage will be generated on resistor R9. Resistors R10 and R11 form a voltage divider circuit. When the current flowing through the infrared transmitter LED1 is normal, the voltage on resistor R11 is lower than the turn-on voltage of switch tube Q3, and switch tube Q3 is cut off. When the current flowing through the infrared transmitter LED1 exceeds the set value, the voltage on resistor R9 increases, and the voltage on resistor R11 will exceed the turn-on voltage of switch tube Q3. At this time, switch tube Q3 is turned on, and the first end of switch tube Q1 is pulled down, thereby stopping the infrared transmitter LED1 from working.

[0044] like Figure 2 As shown, this embodiment also includes a driving circuit, which includes a NOT gate U5 and a switch tube Q4. The input end of the NOT gate U5 is connected to the processor, the output end of the NOT gate U5 is connected to the control end of the switch tube Q4, the first end of the switch tube Q4 is connected to a 5V power supply, and the second end of the switch tube Q4 is connected to the control end of the switch tube Q1.

[0045] In this embodiment, the driving ability of the PWM signal output by the processor is weak and easily interfered. For this reason, a driving circuit is added between the processor and the switch circuit in this embodiment to improve the driving ability of the PWM signal. When the PWM signal output by the processor is at a high level, it is converted to a low level through the NOT gate U5. The NOT gate can play a shaping role, and then the control end of the switch tube Q4 is at a low level, the switch tube Q4 is turned on, and the 5V power supply is added to the control end of the switch tube Q1 after the switch tube Q4; when the PWM signal is at a low level, it is converted to a high-low level after the NOT gate U5, the switch tube Q4 is turned off, and the control end of the switch tube Q1 becomes a low level. The switch tube Q4 is used to improve the driving ability of the PWM signal.

[0046] like Figure 3 As shown, in this embodiment, the switch tube Q5 is replaced by an optocoupler U3; the first input end of the optocoupler U3 is connected to a 5V power supply, the second input end of the optocoupler U3 is connected to the output end of the operational amplifier U4, the first output end of the optocoupler U3 is connected to the VCC power supply, and the second output end of the optocoupler U3 is connected to the first end of the infrared transmitter LED1.

[0047] The detection environment of ship exhaust is relatively complex. The circuit signal in the infrared transmitting module may be interfered during transmission, thereby affecting the switching state of the switch tube Q5. In order to improve the stability of the circuit, in this embodiment, the optocoupler U3 is used to replace the switch tube Q5. The optocoupler U3 plays a role in signal isolation. When the operational amplifier U4 outputs a low level, the optocoupler U3 is turned on, and the infrared transmitter LED1 starts working. When the operational amplifier U4 outputs a high level, the optocoupler U3 is cut off, and the infrared transmitter LED1 stops working.

[0048] like Figure 4 As shown, the infrared receiving module in this embodiment includes an infrared receiver LED2, a resistor R2, a resistor R3 and a filter U1; the first end of the infrared receiver LED2 is connected to the first input end of the filter U1, the second end of the infrared receiver LED2 is grounded, the first end of the resistor R2 is connected to a 5V power supply, the second end of the resistor R2 is grounded through the resistor R3, the second end of the resistor R2 is connected to the second input end of the filter U1, and the output end of the filter U1 is connected to the processor.

[0049] In the infrared receiving module, the infrared receiver LED2 is used to detect the remaining infrared light signals, and convert the detected infrared light signals into corresponding electrical signals and send them to the main processor. However, the electrical signals output by the infrared receiver LED2 are relatively weak and easily affected by environmental noise. In order to improve the detection accuracy of the carbon dioxide content, this embodiment performs filtering processing on the electrical signals output by the infrared receiver LED2, wherein the filter U1 is used to filter out the noise and other interference signals in the electrical signals output by the infrared receiver LED2, and then send the filtered signals to the processor for processing.

[0050] like Figure 4 As shown, the infrared receiving module in this embodiment also includes an amplifier U2, a resistor R13, a resistor R15 and a resistor R14; the first input end of the amplifier U2 is connected to the output end of the filter U1, the first output end of the amplifier U2 is connected to the second input end of the amplifier U2, the output end of the amplifier U2 is connected to the third input end of the amplifier U2, the fourth input end of the amplifier U2 is grounded through the resistor R14, the second output end of the amplifier U2 is connected to the fourth input end of the amplifier U2 through the resistor R15, and the second output end of the amplifier U2 is connected to the processor.

[0051] In this embodiment, the signal output by the infrared receiver LED2 is relatively weak, and there will be a certain loss in the electric signal after filtering, which makes the useful electric signal even weaker, resulting in the processor being unable to effectively identify the electric signal. Therefore, an amplifier U2 is added between the output end of the filter U1 and the processor. Four operational amplifiers are integrated inside the amplifier U2. The first input end of the amplifier U2, the second input end of the amplifier U2 and the first output end of the amplifier U2 form an independent operational amplifier, which constitutes a follower circuit to reduce the loss of the signal on the line. The third input end of the amplifier U2, the fourth input end of the amplifier U2 and the second output end of the amplifier U2 constitute an amplifier circuit for amplifying the electric signal output by the filter, and finally sending the filtered electric signal to the processor.

[0052] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. The carbon dioxide detection system in ship exhaust gas is characterized by: It includes a processor, an infrared transmitting module and an infrared receiving module; The infrared transmitting module includes: a switching circuit, a protection circuit, a constant current circuit, a comparison circuit and an infrared transmitting circuit; The infrared transmitting module is used to transmit infrared signals; The infrared receiving module is used to receive infrared reflection signals; The input end of the switch circuit is connected to the output end of the processor, the output end of the switch circuit is connected to the input end of the comparison circuit, the output end of the comparison circuit is connected to the input end of the infrared emitting circuit, and the infrared emitting circuit; The constant current circuit is used to provide a constant current for the infrared transmitting circuit; The protection circuit is used to detect the current of the constant current circuit, and the protection circuit controls the switch circuit according to the size of the constant current circuit; The switch circuit includes a switch tube Q1 and a resistor R5; The comparison circuit includes an operational amplifier U4; The infrared transmitting circuit includes a switch tube Q5, an infrared transmitter LED1 and a resistor R8; The control end of the switch tube Q1 is connected to the processor, the first end of the switch tube Q1 is connected to the 5V power supply through the resistor R5, the second end of the switch tube Q1 is grounded, the first end of the switch tube Q1 is connected to the inverting input end of the operational amplifier U4, the non-inverting input end of the operational amplifier U4 is connected to the first end of the resistor R8, the second end of the resistor R8 is grounded, the output end of the operational amplifier U4 is connected to the control end of the switch tube Q5, the first end of the switch tube Q5 is connected to the VCC power supply, the second end of the switch tube Q5 is connected to the first end of the infrared transmitter LED1, and the second end of the infrared transmitter LED1 is connected to the first end of the resistor R8; The constant current circuit comprises a transistor Q2 and a resistor R9, the base of the transistor Q2 is connected to the first end of the resistor R8, the collector of the transistor Q2 is connected to the VCC power supply, the emitter of the transistor Q2 is connected to the first end of the resistor R9, and the second end of the resistor R9 is grounded; The protection circuit includes a resistor R10, a resistor R11 and a switch tube Q3, wherein a first end of the resistor R10 is connected to a first end of the resistor R9, a second end of the resistor R10 is connected to a control end of the switch tube Q3, a second end of the resistor R10 is grounded through the resistor R11, a first end of the switch tube Q3 is connected to the control end of the switch tube Q1, and a second end of the switch tube Q3 is grounded.

2. The carbon dioxide detection system in ship exhaust gas according to claim 1 is characterized in that: It also includes a driving circuit, which includes a NOT gate U5 and a switch tube Q4. The input end of the NOT gate U5 is connected to the processor, the output end of the NOT gate U5 is connected to the control end of the switch tube Q4, the first end of the switch tube Q4 is connected to a 5V power supply, and the second end of the switch tube Q4 is connected to the control end of the switch tube Q1.

3. The carbon dioxide detection system in ship exhaust gas according to claim 1, characterized in that: Replace the switch tube Q5 with the optocoupler U3; The first input end of the optocoupler U3 is connected to a 5V power supply, the second input end of the optocoupler U3 is connected to the output end of the operational amplifier U4, the first output end of the optocoupler U3 is connected to a VCC power supply, and the second output end of the optocoupler U3 is connected to a first end of the infrared transmitter LED1.

4. The carbon dioxide detection system in ship exhaust gas according to claim 1, characterized in that: The infrared receiving module includes an infrared receiver LED2, a resistor R2, a resistor R3 and a filter U1; The first end of the infrared receiver LED2 is connected to the first input end of the filter U1, the second end of the infrared receiver LED2 is grounded, the first end of the resistor R2 is connected to a 5V power supply, the second end of the resistor R2 is grounded through the resistor R3, the second end of the resistor R2 is connected to the second input end of the filter U1, and the output end of the filter U1 is connected to the processor.

5. The carbon dioxide detection system in ship exhaust gas according to claim 4, characterized in that: The infrared receiving module also includes an amplifier U2, a resistor R13, a resistor R15 and a resistor R14; The first input end of the amplifier U2 is connected to the output end of the filter U1, the first output end of the amplifier U2 is connected to the second input end of the amplifier U2, the output end of the amplifier U2 is connected to the third input end of the amplifier U2, the fourth input end of the amplifier U2 is grounded through the resistor R14, the second output end of the amplifier U2 is connected to the fourth input end of the amplifier U2 through the resistor R15, and the second output end of the amplifier U2 is connected to the processor.

Images