CN202631013U - On-line coal gas flow monitoring system - Google Patents

Abstract

The utility model relates to an on-line monitoring system for gas flow. The system includes a PLC control system, an industrial computer, a flow sensor, a transmitter, and a photoelectric isolator. The PLC control system includes a CPU module and devices connected to the CPU module respectively. Power supply module, Ethernet communication module, analog input module, the flow sensor is installed in the gas pipe to be measured, the signal output end of the flow sensor is connected to the input end of the transmitter, the output end of the transmitter is connected to the photoelectric isolator The input terminal is connected, the output terminal of the photoelectric isolator is connected with the analog input module, and the industrial computer is connected with the Ethernet communication module. The system has the advantages of being able to measure and display the pressure value of the gas supply system in time, having strong working reliability and versatility, and strong expansion ability.

Description

Gas flow online monitoring system

technical field

The utility model relates to an on-line monitoring system, in particular to an on-line gas flow monitoring system.

Background technique

In the smelting industry, the clean gas obtained after blast furnace gas dry dedusting is exported to users. The amount of gas output is the primary factor affecting the economic interests of the enterprise and users. However, because the gas contains a certain amount of dust and water The accuracy of online actual measurement is a technical problem. When the gas supply system is unstable, if effective control measures cannot be taken in time, the follow-up furnace top gas differential pressure power generation TRT system or hot blast stove system will not be able to operate stably.

Utility model content

The purpose of the utility model is to provide an on-line gas flow monitoring system capable of timely measuring and displaying the pressure value of the gas supply system and having high working reliability.

The technical scheme adopted by the utility model for achieving the above purpose is: an on-line gas flow monitoring system, the system includes a PLC control system, an industrial computer, a flow sensor, a transmitter, a photoelectric isolator, and the PLC control system includes a CPU module and respectively The power module, Ethernet communication module, and analog input module connected to the CPU module, the flow sensor is installed in the gas pipe to be measured, the signal output end of the flow sensor is connected to the input end of the transmitter, and the output end of the transmitter It is connected with the input terminal of the photoelectric isolator, the output terminal of the photoelectric isolator is connected with the analog input module, and the industrial computer is connected with the Ethernet communication module.

Among them, the system is equipped with n flow sensors, n transmitters, and n photoelectric isolators, n is a natural number greater than 1, and n flow sensors are respectively installed in different positions in the same gas pipe or at different gas sources in the same delivery system. In the pipe, the signal output end of the flow sensor n is connected to the input end of the transmitter n, the output end of the transmitter n is connected to the input end of the photoelectric isolator n, and the output ends of the n photoelectric isolators are respectively connected to the analog input module connection.

Wherein the analog input module is an 8-way 12-bit 4-20mA 2-wire analog input module.

Wherein the power supply module is a DC24V direct current power supply module.

Due to the adoption of the above scheme, the utility model has the following beneficial effects compared with other existing similar technologies:

1. It can measure and display the pressure value of the gas supply system in time

The gas flow online monitoring system of the utility model has flow sensors installed in the gas pipes, and the flow sensors are respectively installed in different positions in the same gas pipe or in different gas pipes in the same delivery system, and the flow sensors can measure the differential pressure in the gas pipes signal, the transmitter converts the differential pressure signal into a current signal, and then transmits the current signal to the CPU module through the photoelectric isolator and the analog input module. After counting and analyzing the CPU module, the pressure value is displayed on the industrial computer monitor through the Ethernet communication module On the panel, set the normal pressure value in the system, as long as the detected pressure value exceeds the normal pressure value, the gas supply system can be controlled by the control system matched with the gas flow online monitoring system of the utility model.

2. Strong work reliability and versatility

The hardware part of the gas flow online monitoring system of the utility model is modularized. The transmitter converts the differential pressure signal into a current signal, and transmits it to the analog input module through a photoelectric isolator, so that the input and output are insulated and isolated, and the signal is transmitted in one direction without feedback. Impact, strong anti-interference, fast response, strong reliability and versatility in field work, friendly programming environment allows people to complete tedious task programming in the shortest time and can easily modify the program, especially easy to use .

3. Strong expansion ability

If you want to realize any other functions, you only need to add the input module and the configuration interface in the industrial computer, and add the program segment of the extended function on the basis of the original program.

The gas flow on-line monitoring system of the present utility model will be further described below in conjunction with the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is a structural block diagram of the utility model gas flow online monitoring system.

Detailed ways

As shown in Figure 1, the gas flow online monitoring system of the utility model includes a PLC control system, an industrial computer, a flow sensor, a transmitter, and a photoelectric isolator. The PLC control system 1 includes a CPU module, a power supply module connected to the CPU module, an Ethernet communication module, and an analog input module. The flow sensor and transmitter are installed in the gas pipe to be measured, the signal output of the flow sensor is connected to the input of the transmitter, the output of the transmitter is connected to the input of the photoelectric isolator, and the output of the photoelectric isolator The terminal is connected to the analog input module. The industrial computer is connected to the Ethernet communication module through the Ethernet network cable.

There are n flow sensors, n transmitters and n photoelectric isolators in this system (only 3 groups 1, 2 and n are shown in the figure), and n is a natural number greater than 1 (n is the number of monitoring points) , n flow sensors are respectively installed in different positions in the same gas pipe or in different gas pipes in the same delivery system. As shown in the figure, the signal output terminal of the flow sensor 1 is connected to the input terminal of the transmitter 1, the output terminal of the transmitter 1 is connected to the input terminal of the photoelectric isolator 1, and the signal output terminal of the flow sensor 2 is connected to the transmitter The input terminal of transmitter 2 is connected, the output terminal of transmitter 2 is connected with the input terminal of photoelectric isolator 2, the signal output terminal of flow sensor 3 is connected with the input terminal of transmitter 3, and the signal output terminal of flow sensor n is connected with the transformer The input terminal of transmitter n is connected, the output terminal of transmitter n is connected with the input terminal of photoelectric isolator n, and the output terminals of n photoelectric isolators are respectively connected with the analog input module. Of course, if the value of n is large and the interface of the analog input module is not enough, multiple analog input modules can be installed. At this time, multiple analog input modules are connected to the CPU module at the same time.

The analog input module is an 8-way 12-bit 4-20mA 2-wire analog input module, the transmitter is a 2-wire 4-20mA transmitter, and the transmitter is connected to 1 of the analog input module through a 2-core cable. Connect to an analog input channel terminal (not shown in the figure). The CPU module, power supply module, Ethernet communication module, and analog input module of the PLC control system 1 are respectively arranged on the PLC backplane, and the above-mentioned modules are directly connected through the PLC backplane. The power supply module is a DC24V direct current power supply module, and all modules inside the PLC control system 1 are powered by the DC24V direct current power supply module through the PLC backplane.

Measuring principle: The flowmeter is a plug-in flow measuring instrument. A flow sensor is inserted into the pipeline. When the fluid flows through the flow sensor, a high-pressure distribution area is generated in the upstream direction of the front of the flow sensor, and a high-pressure distribution area is generated in the rear of the flow sensor. Low pressure distribution area. The flow sensor has multiple pairs of pressure-taking holes (generally three pairs) arranged in certain rules in the high and low pressure areas, respectively measuring the total pressure of the fluid, including the average velocity pressure P1 and static pressure P2. Introduce P1 and P2 into the transmitter respectively, and measure the differential pressure △P=P1-P2, △P reflects the average velocity of the fluid, so the flow rate of the fluid can be calculated. The flow sensor inserted into the outlet pipe of the box body detects the differential pressure value in time and outputs it to the transmitter. If the differential pressure is outside the control range, there may be abnormal conditions such as excessive dust content.

When working, the flow sensor converts the on-site gas flow into a differential pressure signal, and the number of flow sensors, transmitters and photoelectric isolators can be increased according to the increase of on-site monitoring points; the transmitter converts the differential pressure signal detected by the flow sensor It is a standard 4-20mA current signal; the function of the photoelectric isolator is to transmit electrical signals, so that the input and output are isolated, the signal is transmitted in one direction, there is no feedback effect, the anti-interference is strong, and the response speed is fast; the PLC control system 1 is on-site The transmitted electrical signal is periodically calculated through the pre-written program, and the dust content value that the operator can directly see is obtained, and finally displayed in the format of numerical value or bar graph through the monitoring panel of the industrial computer, and set in the system Normal pressure value (can be set by software), as long as the detected pressure value exceeds the normal pressure value (abnormal situations such as excessive dust content may occur), the control system (control system) matched with the gas flow online monitoring system of the utility model can It is not the invention point of the present utility model, and will not be described in detail here) Take control measures for the gas supply system. Of course, we can also display the real-time curve of dust content on the display screen as needed, and can print reports and so on. When abnormal conditions such as dust content exceeding the standard appear at the monitoring point, the system also has an audible and visual alarm at this time, which is convenient for the operator to take necessary measures in time.

Claims (4)

1. A gas flow online monitoring system is characterized in that the system includes a PLC control system, an industrial computer, a flow sensor, a transmitter, a photoelectric isolator, and the PLC control system includes a CPU module and a power supply module connected to the CPU module respectively , Ethernet communication module, analog input module, the flow sensor is installed in the gas pipe to be measured, the signal output end of the flow sensor is connected to the input end of the transmitter, and the output end of the transmitter is connected to the input end of the photoelectric isolator Connection, the output terminal of the photoelectric isolator is connected with the analog input module, and the industrial computer is connected with the Ethernet communication module. 2. The gas flow online monitoring system as claimed in claim 1, wherein said system is provided with n flow sensors, n transmitters, n photoelectric isolators, n is a natural number greater than 1, n The flow sensors are respectively installed in different positions in the same gas pipe or in different gas pipes of the same delivery system. The signal output end of the flow sensor n is connected to the input end of the transmitter n, and the output end of the transmitter n is connected to the photoelectric isolator n The input terminals of n photoelectric isolators are respectively connected to the analog input modules. 3. The gas flow online monitoring system as claimed in claim 1, wherein said analog input module is an 8-way 12-bit 4-20mA 2-wire analog input module. 4. The gas flow online monitoring system according to claim 1, wherein the power supply module is a DC24V direct current power supply module.

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