一.Smart Environmental Protection Background

• Government Level

           On March 11, 2018, the 13th National People's Congress passed the "Amendment to the Constitution of the People's Republic of China", which pointed out: to promote the coordinated development of material civilization, political civilization, spiritual civilization, social civilization, and ecological civilization.

 

         The "Decision of the Central Committee of the Communist Party of China on Several Major Issues Concerning Comprehensively Deepening the Reform" adopted by the Third Plenary Session of the 18th Central Committee elevated the construction of an ecological civilization and a beautiful China into a national strategy. Marked by the "Overall Plan for the Reform of Ecological Civilization System", the reform of the basic system of environmental governance has been deepened and reformed rapidly. "A series of reform actions such as vertical management have brought great challenges to environmental protection work.

 

• Economic Level

          After entering the new normal, the downward pressure on my country's economy has increased significantly. However, due to the long-term and extensive economic development model, my country's ecological environment resources have been greatly damaged. The current environmental conditions are getting worse, the environmental carrying capacity may have reached the limit, the environmental quality is poor, the pollutant discharge is large, and the ecological damage is serious. become a bottleneck restricting the sustainable development of the economy. China is facing the dual risks of ecological collapse and economic collapse.

 

二. On-line Monitoring Of Air Quality (tvocs) Requirements

• TVOCS 

     Total Volatile Organic Compounds (TVOCs, Total Volatile Organic Compounds), also known as volatile organic compounds (VOCs). Based on different fields of use, there are different definitions:

     My country (GB/T18883-2002) and "Technical Specifications for Indoor Ambient Air Quality Monitoring" (HJ/T167-2004) define it as: sampling with Tenax GC or Tenax TA, non-polar chromatographic column (polarity index less than 10) For analysis, volatile organic compounds with retention times between and n-hexadecane. The definition in my country's "Limits of Hazardous Substances in Interior Wall Coatings for Interior Decoration Materials" is: the total volatile content in the coating minus the moisture content, that is, the content of volatile organic compounds in the coating. "R Refining and Petrochemical Industry Air Pollutant Emission Standard" (DB11/447-2007) is defined as: the vapor pressure at 20 ℃ is greater than or equal to 0.01kPa, or all organic compounds with corresponding volatility under specific applicable conditions collectively. The American ASTM D 3960-98 standard defines it as: any organic compound that can participate in atmospheric photochemical reactions. The United States Environmental Protection Agency (EPA) defines it as: volatile organic compounds are any carbon compounds that participate in atmospheric photochemical reactions except CO, CO2, H2CO3, metal carbides, metal carbonates and ammonium carbonate. (WHO, 1989) defines total volatile organic compounds as the general term for volatile organic compounds whose melting point is lower than room temperature and whose boiling point is between 50 and 260 °C.

 

• Sources OF Tvocs Pollution

     Its emission sources are also very complex and can be divided into categories, mainly including natural sources and anthropogenic sources. Natural sources are mainly vegetation emissions, forest fires, wildlife emissions and wetland anaerobic process emissions, which are currently uncontrollable. Man-made sources include mobile sources such as automobiles, ships, and airplanes, as well as industrial sources and living sources; living sources include architectural decoration, oil fume emission, garbage incineration, straw incineration, clothing dry cleaning, and so on. Among them, the largest emissions are from industrial sources. According to the anthropogenic source emissions estimated by the Ministry of Environmental Protection, industrial source emissions, including solvent use, account for up to 55.5% of the total anthropogenic source emissions.

 

• The Harm OF Tvocs To Human Body

      There are many types of VOCs, which not only have potential impact on the atmospheric environment, but also have a serious impact on indoor air quality and human health. These pollutants can also affect the growth of crops and even lead to the death of crops. In terms of environmental impact, VOCs will react under the action of light and heat to form ozone, resulting in poor air quality; VOCs themselves are an important component of atmospheric PM2.5, and some PM2.5 is converted from VOCs; most VOCs are Greenhouse gases cause global warming.

      As for the harm to human health, VOCs have different toxicity and irritation. When the concentration exceeds a certain level, it will irritate people's eyes and respiratory tract, causing skin allergies, sore throat and fatigue. Nervous system function, damage to digestive system, liver function and hematopoietic system, etc. Some VOCs have been classified as carcinogens, such as vinyl chloride, benzene, polycyclic aromatic hydrocarbons, etc. Among them, benzene and formaldehyde can cause cancer (leukemia); nitriles can cause breathing difficulties, severe suffocation, loss of consciousness and even death; anilines can cause hypoxia when entering the human body; organophosphorus compounds can reduce blood cholinesterase activity, causing dysfunction of the nervous system, etc. In addition, a large part of VOCs have obvious odor, which will seriously affect people's quality of life and cause regional conflicts and complaints.

 

• The need for TVOCS online monitoring

     The harm of TVOCS to people and the environment is so great. In order to protect the environment and reduce the emission of industrial TVOCS, there is an urgent need for accurate online monitoring of TVOCS.

 

三.TVOCS Online Monitoring Solution

      Hengyi Technology has developed a TVOCS online monitoring solution, which includes a monitoring platform, wireless transmission, and front-end TVOCS sensors. Its block diagram is as follows:

 

       

 

四．TVOCS Online Monitoring System Product Parameter Description

     4.1 TVOCS Sensor Parameter Description

  

 

 

 

    

Name	Parameter
Detect gas	TVOC
Detection principle	PID Principle
Detection method	Fixed Online Long-term Continuous Detection, Pumping Detection Method
Measuring range	0-1ppm,20ppm、50ppm、200ppm、2000ppm、6000ppm、10000ppm、0-5mg/m3、0-20 mg/m3、0-100 mg/m3、0-500 mg/m3、0-1000 mg/m3、0-5000 mg/m3、0-10000 mg/m3 (Optional, The Range Not Listed Can Be Customized)
Resolution	0.001ppm ,0.01ppm，0.1ppm，1ppm、0.01 mg/m3、0.1 mg/m3、1 mg/m3
Precision	≤±2%(Actual concentration, higher accuracy requirements are determined according to sensor performance)
Zero drift	≤±1%（F.S/year）
Response time	≤15 second
Recovery Time	≤20 second
Protection class	IP65
Installation method	vertical cabinet
Size	550mm*550mm*800mm
Operating Temperature	-20℃～+60℃（Special requirements need to be customized）
Working humidity	≤95%rh, No Condensation (humidity>90%rh, Filter Can Be Equipped For Condensation)
Work Pressure	≤200Kpa
Executive Standard	GB15322.1-2003，GB3836.1-2010，GB3836.2-2010，GB3836.4-2010

 

 

 

        4.2 Environmental Monitoring Dtu Parameter Description

   

 

  

Parameter		Describe
Master	Master	Industrial Grade Cpu, Main Frequency 540mhz
	DDR	64m Byte, The Highest Frequency Supports Up To 360mhz
	FLASH	32M Byte
Wireless	LORA	430~434mhz, Others Can Be Customized 913~918mhz
	WIFI	2.4ghz, Support Ieee802.11b/g/n
	2G/3G/4G	FDD-LTE/TDD-LTE/DC-HSPA+/HSPA+/HSPA/WCDMA/TD-SCDMA/GSM/GPRS/EDGE
	SUB 1G（custom made）	430~434MHZ, others can be customized 866~918MHz
Hardware Parameters	Data Interface	1 Ethernet interface, 1 WIFI, 1 2/3/4G, 1 RS485
	Supply Voltage	DC 6V~14V input; can be customized DC6-36V
	Working Environment	Working temperature -10℃~75℃, humidity 0%~90%RH
	Current Consumption	Working current: <200mA/12V, maximum current 500mA/12V
Software Agreement	Operating System	LINUX 3.4
	Network Protocol	IP,TCP,UDP,HTTP,HTTPS
	Wireless Protocol	LORA, WIFI protocol, ad-hoc network LORA protocol
	RS485	MOBUS, custom 485 communication protocol

 

 

     4.3 Monitoring Platform Function Description