TVOC online analyzer

1. System Introduction

This technical document is applicable to the TVOC online continuous monitoring system, which is a high-quality product that complies with current Chinese or international general standards, and meets relevant metrological regulations, environmental protection regulations and standards, as well as the technical requirements proposed by the industry regarding the system's functional design, structure, performance, installation, and testing.

2. The function of the system

At present, it is mainly used for continuous monitoring of various industrial waste gas treatment sources, including thermal power plants, waste incineration power plants, chemical plants, paper mills and other industries. It has strong applicability and can measure TVOC online; VOCS； Multiple gas parameters such as SO2 concentration, CO concentration, particulate matter concentration, oxygen content, temperature and humidity, pressure, and flow rate.

At the same time, it can be used as teaching equipment in school laboratories. Corresponding adjustments can be made to the online monitoring system for this condition, simplifying the configuration for use in complex working conditions and conditions on industrial sites. This can effectively improve system performance and enhance cost-effectiveness.

2、 System Design

1. System composition

The gas monitoring subsystem (TVOC) consists of sampling probes, heat tracing pipelines, filtration systems, and control systems. The gaseous monitoring subsystem is mainly used to monitor the concentration of gaseous TVOC gas; Sampling probes are used for collecting on-site gases and primary filtration; The heat tracing pipeline is used to heat the gas and; The control system is used for the entire control process.

This technical method is based on heat tracing extraction measurement. The system analysis instrument adopts PID gas analyzer, and the preprocessing part is integrated domestically. This system can output all monitoring signals as isolated 4-20mADC signals or digital signals, which can be customized according to requirements.

For the above-mentioned TVOC monitoring system, our company can provide a data acquisition subsystem (DAS) to measure real-time data of the monitoring items in the gas through DAS, and can centrally realize data acquisition, processing, storage, and output. Fixed source gas monitoring needs to be installed in an air-conditioned instrument room, which is within the scope of the demand party.

The system adopts modular integrated design according to the above monitoring items (including control and data acquisition system).

The analytical instruments in the system should have self diagnostic functions, and the system should also have main component fault alarm functions, including failure of measuring elements/detection probes, out of range situations, and situations where there is insufficient sampling flow capacity. Analytical instruments have functions such as data storage and report generation, alarm recording, etc.

2. TVOC6000 gas monitoring

2.1 Applicable norms and standards

The equipment provided by the supplier meets but is not limited to the following standards. The standards mentioned in this bidding document are valid in all versions listed at the time of publication of this specification.

Atmospheric Emission Standards (GB 13223)

GB/T16157 Determination of particulate matter and sampling methods for gaseous matter in fixed source exhaust

HJ/T57 Determination of Sulfur Dioxide in Fixed Source Exhaust Gas

Technical Specification for Continuous Monitoring of TVOC Emissions (HJ/T75-2007)

HJ/T76-2007 Technical Requirements and Testing Methods for Continuous Monitoring System of Fixed Source Emission Smoke

2.3 Working principle and characteristics of the system

After years of experience, the gas analysis system has been optimized and configured reasonably.

Designed a primary filtration system and equipped it with a heated back blowing filtration probe to ensure stable operation and accurate measurement of the gas analyzer;

For gas humidity, a high-temperature drying and filtering probe is used to ensure high-precision filtering performance of the probe. At the same time, high-temperature drying method and pulse type vibration blowback technology are utilized to automatically clean impurities on the probe filter element; The unique quick disassembly design makes maintenance convenient and requires minimal maintenance work. At the same time, high-temperature ultrasonic probes can be optionally selected to effectively prevent blockages.

The entire dry process of the system uses 316L anti-corrosion stainless steel, polytetrafluoroethylene material or special anti-corrosion treatment for the sampler, sampling tube, suction pump, and various pipe joints, which improves the system's anti-corrosion performance and ensures its service life.

The data acquisition system is highly integrated into the cabinet, with a more reasonable and user-friendly interface. It also includes periodic adjustments such as sampling and blowback.

The WBXY-TVOC5000 analyzer has high accuracy and good stability.

It has functions such as data comparison, processing, automatic calibration, range setting, and over limit alarm interlocking.

The system adopts PLC control and intelligent analytical instruments, with high degree of automation, low maintenance workload, and fast and convenient data processing

The sampling probe adopts the internationally advanced internal and external pulse vibration blowback technology, and its unique fast disassembly design makes maintenance convenient and requires minimal maintenance work.

2.4 Control Unit

Using PLC as the control center, complete the automatic blowing of the system sampling pipeline and sampling probe filter, complete the automatic calibration and calibration of the system, as well as various internal alarms and interlocks such as low flow rate, analysis value exceeding limit, and faults, and connect with DAS station.

Its main functions include:

Automatically control gas extraction and provide analytical sample gas for the analyzer;

Perform zero and full-scale calibration of the analyzer;

Automatic blowback;

Display TVOC monitoring

Alarm, calculation, definition, and expansion;

Communicate with DAS system;

When measuring at multiple points, control the gas path switching, sampling sorting, and sampling period.

PLC provides a 24-hour recording interface system that can transmit processed data to DAS, and its control instructions are in system status (sampling/zero calibration/cross calibration/blowback).

Technical parameters

1. Product selection:

Product Name

TVOC online analyzer

gas detection

Volatile Organic Compounds (TVOC) (optional: temperature, pressure, humidity, flow rate, flow direction, etc.)

Detection Principle

PID optical principle, thermal conductivity principle, infrared principle, optional

Measurement range 0-2 ppm、0～10ppm、0～50ppm、0～100ppm、0～500ppm、0～1000ppm、0～2000ppm、0～10000ppm optional

Resolution of 0.01ppm (0-100pm); 0.1ppm（0～1000ppm）； 1ppm (1000ppm and above)

Sampling method: pump suction

Installation method: Wall mounted

Indication error ≤ ± 3% FS (higher accuracy required based on sensor performance)

Repeatability ≤± 3%

Zero drift ≤± 3% (FS/year)

Response time ≤ 60 seconds (higher requirement based on sensor performance)

Recovery time ≤ 30 seconds (higher requirement based on sensor performance)

Power supply 220VAC

Power ≤ 4.5 W (DC24V) with longer sampling cable length

Environmental pressure ranging from 86kPa to 106kPa

Environmental temperature -20 ℃~+55 ℃ (typical value) -40 ℃~+70 ℃ (limit value)

(For higher temperature and humidity detection environments, you can choose our pre treated gas monitoring system.)

Environmental humidity 10% to 95% RH (no condensation)

Main material carbon steel spray coating

Output signals 232, 485, 4-20mA, switch quantity (optional)

Alarm method: sound and light alarm, optional sound and light alarm, alarm sound:<90 decibels

Alarm point setting A1 alarm value and A2 alarm value;

Display screen 7-inch touch screen

Direct reading of measurement values, automatic storage of historical records, reports, and alarm records, with optional storage intervals, continuously storing 300000 sets of date and time data

Calibrate 2 or more points

Dimensions: 700mm in height, 500mm in width, and 250mm in thickness

Weight less than 30KG