Gas Monitoring System

1. Gas Monitoring System Project Introduction

Gas Monitoring System is used to monitor the concentration and emission rate of particulate matter and gaseous pollutants in the flue gas emitted by fixed pollution sources.According to your measurement requirements, the Gas Monitoring System launched by Fengtu Technology can continuously monitor SO2, NOX, 02 (standard, wet basis, dry basis and conversion), particulate matter concentration, flue gas temperature, pressure, flow rate and other related parameters, and calculate emission rate, total emission, etc., so as to effectively manage the measured data.

The Gas Monitoring System consists of four mandatory subsystems: gaseous pollutant (SO2, NOX, O2, etc.) monitoring, particulate matter monitoring, flue gas parameter (temperature, pressure, flow rate, etc.) monitoring, and data acquisition and processing.

The monitoring of gaseous pollutants adopts the extractive condensation method, the principle of which is to use the ultraviolet differential method to measure the SO2 and NOX content in the flue gas, measure the wet oxygen content by the electrochemical method, and then calculate the dry flue gas concentration of SO2, NOX, and 02 by dry-wet conversion.

The particle monitoring adopts the laser backscattering method, the flue gas temperature is measured by a temperature sensor, the flue gas pressure is measured by a pressure sensor, and the flue gas flow rate is measured by a Pitot tube; all measurement signals are sent to the data acquisition and processing system.

The output processing system has the functions of real-time transmission of field data, remote fault diagnosis, report statistics and graphic data analysis, realizing unattended work on site. The whole system has a simple structure, wide dynamic range, strong real-time performance, flexible networking and low operating cost. At the same time, the system adopts a modular structure, which is easy to combine and can fully meet the requirements of communication with the DCS system within the enterprise and the data system of the environmental protection department.

000011 Project Implementation Standards

The design, manufacture and acceptance of this system are mainly carried out in accordance with the following standards and technical specifications:

u GB3095-1996 "Air Environment Quality Standard"

u GB13223-2003 "Emission Standards of Air Pollutants from Thermal Power Plants"

u GB18485-2007 "Standards for Control of Pollutants from Incineration of Domestic Waste"

u HJ/T75-2007 Technical Specifications for Continuous Monitoring of Flue Gas Emissions in Thermal Power Plants

u CJJ90—2002 Technical Specifications for Urban Domestic Waste Incineration Engineering

u CJ/T118—2002 Technical Specifications for Municipal Solid Waste Incinerators

u HJ/T76-2007 Technical Requirements and Detection Methods for Continuous Monitoring System of Flue Gas Emissions from Stationary Pollution Sources

u GB16297-1996 Comprehensive Emission Standards for Air Pollutants

GB/T16157-1996 "Determination of particulate matter in exhaust gas from solid pollution sources and sampling methods for gaseous pollutants"

u GB9078-1996 Comprehensive Emission Standards of Air Pollutants from Industrial Furnaces

u GB 3095-1996 "Ambient Air Quality Standard"

u GB12519-1990 "General Technical Requirements for Analytical Instruments"

000012 Project Plan

000012.1 Measurement items

ØSO2, NOX, O2, smoke, temperature, pressure, flow rate

000012.2 Measurement method

ØFlue gas sampling method: Extractive condensation method

ØSO2, NOX monitoring method: Differential optical absorption spectroscopy

ØO2 monitoring method: electrochemical method

ØSmoke measurement method: laser backscattering method

ØTemperature measurement method: temperature sensor

ØHumidity measurement method: humidity sensor

ØPressure measurement method: pressure sensor

ØFlow rate measurement method: differential pressure method (Pitot tube)

2. Gas Monitoring System General Principles

The technical requirements of the functional design, structure, performance, installation and testing of the system equipment are in line with the relevant national environmental protection standards and meet the standards of the environmental protection industry of the People's Republic of China (HJ/T75-2007, HJ/T76-2007).

Our company's CEMS system consists of a gaseous pollutant monitoring subsystem, a particulate matter monitoring subsystem, a flue gas parameter monitoring subsystem, and a data acquisition and processing subsystem. The gaseous pollutant monitoring subsystem and the data acquisition and processing subsystem are installed in a standard 19-inch cabinet. The system composition is shown in the following figure:

Figure 1. CEMS system composition diagram

ØGaseous pollutant monitoring subsystem: consists of sampling unit, pretreatment unit and analysis unit.

ØParticle monitoring subsystem: uses laser backscattering method smoke monitor.

ØSmoke parameter monitoring subsystem: Pitot tube is used to measure flow rate, pressure sensor is used to measure pressure, temperature sensor is used to measure temperature, and high temperature capacitance humidity sensor is used to measure smoke humidity.

ØData acquisition and processing subsystem: consists of data collector, industrial computer, display and system software.

The above subsystems can be tailored according to different customer needs.

Figure 2. CEMS system installation diagram

3. Gas Monitoring System Composition

3.1 Monitoring of gaseous pollutants

3.1.1 Sampling and pretreatment unit

The sample gas is taken out by the sampling probe under the suction force of the sampling pump. Most of the particles in the sample gas are filtered out by the filter in the sampling probe, and then transported to the refrigeration system by the heating pipeline for condensation and dehydration, and then sent to the analysis unit for analysis. The condensed water is discharged through the drainage system. The control unit realizes functions such as backflush, calibration, refrigeration temperature alarm prompt, and displays various working states of the system.

The pretreatment system uses a first-stage rapid condensation to remove water to ensure that the gas composition remains unchanged. A second-stage fine filtration is used to ensure that the gas measurement chamber is not contaminated, thereby increasing the service life of the analyzer. The figure below is a flow chart of the gaseous pollutant monitoring system.

3.1.2 Gas analyzer

Instrument: UV spectrometer gas analyzer

Model: FT-UVA-100

Measurement principle: Differential Optical Absorption Spectroscopy (DOAS)

Measuring principle

The UV spectrometer gas analyzer is a gas analysis instrument based on multi-channel spectral analysis technology (OMA) and differential optical absorption spectroscopy technology (DOAS). The light beam emitted by the light source converges into the optical fiber, and is transmitted to the gas chamber through the optical fiber. After passing through the gas chamber, it is absorbed by the gas to be measured, and then transmitted to the spectrometer by the optical fiber. After grating spectroscopy inside the spectrometer, the array sensor converts the split light signal into an electrical signal to obtain the continuous absorption spectrum information of the gas. Based on this spectral information, the instrument uses the differential absorption spectroscopy algorithm (DOAS) and the partial least squares algorithm (PLS) to process and obtain the concentration of the measured gas.

ØMulti-band spectral analysis technology (OMA)

Since various gas molecules have different absorption of light waves in different bands, the simultaneous measurement of multiple gases can be achieved by analyzing the continuous spectrum after gas absorption.

The ultraviolet spectroscopic gas analyzer uses ultraviolet light sources and sensors to measure the concentration of gases that absorb light waves in the ultraviolet band, such as SO2, NO, NO2 and other gases.

ØDifferential Optical Absorption Spectroscopy (DOAS)

The core idea of DOAS is to decompose the absorption spectrum of gas into two parts: fast-changing and slow-changing. The fast-changing part is related to the structure of gas molecules and the elements they are composed of, and is the characteristic part of the absorption spectrum of gas molecules; the slow-changing part is related to the interference of smoke, water vapor, background gas, and changes in the measurement system, and is the interference part. DOAS uses the fast-changing part to calculate the concentration of the measured gas, and the measurement results are not interfered with and have high accuracy.

The UV spectrum gas analyzer adopts a unique processing method that combines the DOAS algorithm and the PLS algorithm to eliminate the interference of smoke, water vapor, and background gas. It also eliminates the influence of measurement system fluctuations on the measurement results, ensuring the accuracy and stability of the measurement.

Technical indicators

SO2: 0～100～1000ppm (can be customized according to buyer's needs)

NO: 0～100～1000ppm (can be customized according to buyer's needs)

Accuracy: ≤±2%

Linear error: ≤±2%FS

Zero drift: ≤±2%FS/7D

Range drift: ≤±2%FS/7D

Response time: ≤30s

other

O2 measurement electrochemical, 0～25%, ≤±2%FS

Power supply: 220VAC, 50Hz

Ambient temperature limit: -10～40℃

Communication interface: 1 RS232; 1 RS485/RS232

Digital interface: 4 relay outputs, 2 binary inputs

Analog interface: 5-way 4~20mA output, 2-way 4~20mA input

Instrument features

ØHigh reliability

It uses a pulse xenon lamp with a service life of 10 years as the light source and a solidification spectrometer, with no moving parts and high reliability.

ØCombined gas chamber design

The combined gas chamber design makes spectrum adjustment easy and improves spectrum intensity.

ØHigh measurement accuracy and good stability

Using DOAS (Differential Optical Absorption Spectroscopy) algorithm, the measurement results are not affected by factors such as smoke, dust, moisture, etc., and the measurement accuracy is high; at the same time, the DOAS algorithm also eliminates the errors caused by instrument aging, and the measurement stability is good.

ØHighly intelligent and digital

It has multiple high-performance processors built in, and the processors use high-speed data bus communication technology. Each module has powerful digital configuration and detection functions; it is simple to operate and easy to use.

ØRich user interface

Provides a variety of interfaces, can be easily integrated into various control and monitoring systems. Through RS485 and RS232 communication methods to build a wireless or wired network, to facilitate the daily operation, maintenance and management of the instrument.

ØComparison with common analyzers

3.1.3 Analysis system

The analysis system consists of:

ØSampling unit (probe, filter, thermostat);

The sampling unit of the FT-CEMS-A system is mainly composed of a sampling probe and a heating pipeline. The sampling probe is installed at an appropriate position of the flue (or chimney) in accordance with national standards to collect gas in the flue and transport the gas to the heating box inside the cabinet through the heating pipeline. To ensure the accuracy of the measurement results, the sampling probe and the heating pipeline are both electrically heated, which can keep the gas at a set temperature to prevent moisture condensation in the gas. The length of the heating pipeline can be customized according to the actual needs of the buyer.

ØPretreatment unit (sampling pump, dehumidification, fine filtration, drainage, etc.);

The flue gas reaches the pretreatment system through the high-temperature sampling probe and the heating pipe. The pretreatment system switches to the condenser through the sampling ball valve for steam-water separation. The condensed water is discharged in time through the peristaltic pump, condensed and dehydrated by the condenser, and then dust-removed and filtered through the three-stage fine filter. The clean, dust-free and water-free sample gas after treatment enters the flue gas analyzer for analysis and measurement.

ØAnalytical unit (SO2, NO, NO2, O2);

ØSignal output (SO2, NO, NO2, O2 concentration, range conversion, calibration status, fault status, etc.);

ØOthers (gas circuit, circuit, etc.);

ØAnalytical instrument cabinet: 2000×700×800MM (height*depth*width).

3.2 Particle monitoring

Instrument: Smoke (dust) measuring instrument

Model: LSS2004

Measurement principle: Laser backscattering method

Technical parameter table:

Implementation standard: HJ/T 76-2007 Technical requirements and detection methods for continuous monitoring system of flue gas emissions from fixed pollution sources.

Product performance characteristics:

The integrated probe for speed measurement and sampling at the same point is adopted to support accurate isokinetic sampling.

Supports simultaneous output of four parameters: flue temperature, flue pressure, flue flow rate, and flue concentration.

The instrument adopts a variety of advanced technologies, including: correlation noise cancellation technology, laser emission power stabilization technology, extremely low noise TIA, interference control and signal integrity design, and anti-harsh environment design technology, to provide fast, reliable and accurate quantitative smoke emission data.

3.3 Flue gas parameter monitoring

3.3.1 Temperature, pressure and flow integrated probe (temperature, pressure and flow rate)

The structure of the temperature-pressure-flow integrated probe measurement device mainly includes micro differential pressure transmitter, static pressure sensor, thermal resistor (or thermocouple), pitot tube, back-blowing solenoid valve, temperature and pressure compensation, etc. Its measurement principle is: the primary pressure taking element adopts the traditional pitot tube measurement method. After correct installation, the full pressure and back pressure taking tubes of the pitot tube will transmit the detected dynamic pressure and static pressure to the differential pressure transmitter respectively. The differential pressure transmitter converts the difference between dynamic pressure and static pressure into 4~20mA square root proportional current and transmits it to the distribution box data acquisition module, and the computer in the CEMS cabinet processes the data.

The inner and outer surfaces of the pitot tube are specially treated to effectively avoid flue gas corrosion and reduce dust adhesion. The backflush solenoid valve is mainly used for system backflush when measuring dirty gases (such as flue gas discharged from boilers): when dust and dirt are adhered to and accumulated in the probe detection hole, the solenoid valve is opened at a fixed time or according to a predetermined program, and compressed air is connected to the two pressure pipes at the same time for blowing and removal. During normal measurement, the solenoid valve is in the closed state.

Technical features

l It can measure the temperature, pressure and flow rate of flue gas in real time, and output it through 3-way analog signal 2-wire 4~20mA.

l Automatically and regularly backflush the dynamic and static pressure ends of the pitot tube.

lHigh measurement accuracy, good reliability, and long-term continuous operation.

lEasy to install and wire, low maintenance.

Technical indicators

ØRange: linear output 0-40m/s, effective measuring range: 5~30 m/s;

ØOutput signal: 4~20mA two-wire system;

ØMeasurement accuracy: ±2%FS;

ØCalibration frequency: 12 months;

ØResponse time: <1s;

ØDifferential pressure (temperature, pressure) transmitter power supply: 24VDC, two-wire;

ØOverpressure limit of differential pressure transmitter: 4.0MPa;

Ø Pitot tube material: 304, 316L stainless steel;

Ø Normally closed back-blowing solenoid valve power supply: 220VAC, 50Hz;

Ø Pitot tube insertion length: 500~2000mm optional;

ØPressure transmitter range: -10~10kPa;

ØTemperature transmitter range: 0~300℃;

Ø Medium temperature range: -40~500℃;

ØAmbient temperature: -40~85℃;

ØStorage temperature: 0~50℃;

ØStorage humidity: 0~85%RH.

ØMounting flange: DN50;

ØMaterial: SUS316L

Choose an installation location

The installation location of the temperature-pressure-flow integrated probe should be selected as a straight pipe section with stable and uniform flue gas flow rate. For details, please refer to the relevant requirements in HJ/T 75-2001 "Technical Specifications for Continuous Monitoring of Flue Gas Emissions from Thermal Power Plants" or HJ/T 76-2001 "Technical Requirements and Detection Methods for Continuous Monitoring Systems of Flue Gas Emissions from Stationary Pollution Sources".

Butt flange welding and embedding

Before installing the temperature, pressure and flow integrated probe, a DN50 butt flange pipe must be pre-buried or welded at the selected flue opening. When installing the flange, pay attention to the installation direction (as shown in the figure below). There must be a 100mm wrench space between the flange and the flue. The flange size is shown in the figure below. When welding the flange, pay attention to the direction of the flange, as shown in the figure below.

Instrument Installation

The on-site installation is based on the direction of the flue gas flow, so that the dynamic pressure port (H port) of the Pitot tube faces the direction of the airflow, and the static pressure port (L port) faces the opposite direction of the airflow. Then, connect the instrument to the installed flange and tighten it with screws and nuts.

The ports of the Pitot tube are defined as: the positive pressure port in the positive airflow direction and the static pressure port in the reverse airflow direction, which are respectively inserted into the quick-connect connectors of the dynamic pressure port (H) and the static pressure port (L).

Gas connection

There is an 8mm quick-connect connector at the bottom of the temperature and pressure flow, which is used to connect an external purge gas source. The back-blowing gas must be oil-free and dust-free, with a pressure of 0.4~0.7MPa.

The connected 220VAC power cables and signal cables all use crimping terminals, and the three 4~20mA signal cables are all connected to the distribution box using shielded cables.

Maintenance cycle

It is recommended that users check the instrument for the first time 3 days after system installation, and check it again 15 days later. If there are no problems, it can be checked every 3 months.

The backflush pressure of the Pitot tube is 0.2-0.7MPa. The backflush time is adjusted according to the smoke concentration, temperature, moisture, etc. of the working conditions. Generally, it is backflush once every 12 hours, and the backflush time is 1-3 minutes.

Maintenance content

Check whether the instrument power supply and instrument gas source are normal, and observe whether the flue gas temperature, pressure, flow rate, etc. displayed by the host computer are within a reasonable range. A simple judgment can be made based on the on-site environment and unit operation conditions.

3.3.2 Humidity measurement (optional)

Instrument: Flue gas moisture meter

Instrument model: HF-SD-100

Measuring principle: High temperature capacitive humidity sensor

Measuring range: 0～100% (can be customized according to buyer's needs)

Measurement accuracy: ±2%

Input voltage: 220VAC

Output current: 4～20mA

3.4 Data collection and processing

ØData collector (optional)

Analog input: 8 input channels

Output: analog output 8 channels or GPRS

ØIntegrated industrial computer

Windows XP operating system, 6 232 serial ports, providing 232 interface for data acquisition instrument data upload

ØSplitter (optional)

One 4-20mA channel is reserved to upload data to the enterprise DCS

ØSystem software: HFMonitor1.0, an online monitoring and management system for pollution sources

The system is developed based on national and local air pollutant emission standards, implements the government's decision on controlling air pollution and improving air quality, implements online continuous monitoring of air stationary pollution sources, and provides timely and effective data for pollution declaration, total amount control, and pollution fee collection. It can be used for continuous monitoring systems of individual pollution sources, and can also be widely used in environmental monitoring stations at all levels and large and medium-sized enterprises to conduct air quality monitoring and evaluation and daily air quality reports.

ØFeatures:

²It has complete data collection, processing and transmission functions. It supports LAN distributed operation.

²The system works in real time. Real-time data collection is rapid and stable, and the transmission speed is fast. The real-time status of air pollution can be quickly and timely grasped through remote communication; it has a high time resolution.

²The system has the functions of timed automatic calibration, automatic diagnosis and automatic alarm; it operates under strict quality control procedures, and the data obtained has good comparability and traceability.

²The long-term and continuous operation of the system can not only obtain a large amount of data, adapt to the monitoring requirements of various pollution sources, and fully reflect the actual situation of pollution source emissions and treatment facility operations, but also derive the law of pollution changes, providing a detailed and reliable technical basis for pollution prediction and environmental assessment.

²The system provides good parameter modification functions according to different situations, which can help system administrators and maintenance personnel diagnose the working status of various measuring instruments and sensors.

²The system provides real-time data display and real-time curves, and can automatically generate various reports.

4. Gas Monitoring System Features

ØThe core instrument uses ultraviolet spectroscopy to measure flue gas, which has high measurement accuracy, good reliability, little impact from dust and moisture, and low maintenance cost.

ØHigh temperature sampling and high temperature heating (120℃～180℃) transmission, dust removal and anti-condensation.

Ø Rapid condensation and rapid water removal are adopted in the pretreatment system to ensure that the gas composition remains unchanged. Directly measure the dry basis value of flue gas, which meets the requirements of national standards.

ØThe system cabinet can be fully opened, greatly improving the convenience of system maintenance.

ØSystem Control

²PLC can be used for calibration and system purge. The sampler temperature, heating pipe temperature and condenser temperature are all involved in system control to ensure that the system is in the best operating state.

²The system can also use various shortcuts for calibration and system purging, etc., to provide convenience for operators. The shortcut method reduces the requirements for operators.

²The system control also displays various statuses in the system online so that the system operation status can be understood in real time.

5. Gas Monitoring System Engineering Installation

5.1 Common conditions to be provided by the purchaser

ØPower supply: 220VAC, 50Hz, 2kW, excluding heating pipes and air conditioners. Heating pipes 60W/m, air conditioners (if necessary) 1000W.

ØInstrument air: 0.4～0.7MPa, clean oil-free compressed air, dew point -30℃.

ØMain tools used during installation:

²Drill and matching tools, water pipes, etc.; drill bit diameter: 60mm, 75mm, 100mm. (for brick flues)

² Impact drill; drill bit diameter 10mm.

² Common tools;

ØInstallation materials:

²Ordinary expansion bolt (metal): M8mm;

²Pipe clamp expansion bolt (metal): 8mm; fixed pipe size: 20mm, 50mm.

²Ordinary expansion bolts (plastic): 6mm, 8mm;

²Cable conduit and other commonly used materials.

5.2 Basic operating costs

5.3 Design Division

The purchaser shall provide the environmental parameters of the sampling point, including the sampling point temperature, dust content, flue gas content and other design data, as well as the flue diameter, wall thickness, height from the ground, flue structural materials, annual average ambient temperature, maximum and minimum temperatures, atmospheric pressure, etc. Based on the on-site data, the supplier shall select and design the best solution to meet the use requirements, and the supplier shall propose a construction plan as a design reference.

5.4 System Installation and Implementation

5.4.1 Opening location

The sampling point is usually located on the center line of the horizontal flue of the brick or steel structure before the smoke enters the chimney; it can also be installed on the chimney. It is best to combine the project requirements and have professionals specify the installation location to meet the needs.

See Appendix 1 for the schematic diagram of the opening positions

5.4.2 Installation Platform

The height of the guardrail of the installation platform is 1.2m, and the bottom surface of the platform should use anti-slip steel plates; at the bottom of the platform, a 150mm wide steel plate is welded along the perimeter of the guardrail to prevent the installation parts from falling off the platform.

The bottom of the platform is 1.4m away from the center of the flue, and the height of the guardrail is 1.2m. The platform is supported by a steel frame structure and fixed to the flue. A ladder for going up and down the platform is built on one side of the platform.

See Appendix 2 for a schematic diagram of the platform

5.4.3 Requirements for instrument rooms

Ø Location: As close to the measurement position on the flue as possible (it can be considered below the flue).

ØBuilding size: The usable area of the instrument room should be no less than 6m2 (single system). The indoor clear height should be no less than 2.6m.

ØIndoor environment requirements: temperature between 10 and 35°C, relative humidity below 80%, ventilation, no vibration, and no strong magnetic field interference.

ØPower supply: The power cord enters the bottom of the instrument cabinet through the cable trench. The distance between the instrument and the wall should not be less than 500mm.

See Appendix 3 for a schematic diagram of the analysis hut.

5.5 Opening and flange welding

ØSampling probe opening size: Ø60mm;

See Appendix 4 for the embedded flange of the sampling probe

Ø Pitot tube flow meter measuring hole: Ø60 mm;

See Appendix 4 for the embedded flange of the sampling probe

ØDust monitor sampling hole: Ø75mm;

See Appendix 5 for the embedded flange of dust monitor

Ø Reference hole: (The reference hole is reserved for environmental protection data comparison, and the enterprise needs to provide it by itself. Generally, it can be between DN80 and DN120)

For reference hole embedded flange, see Appendix 6

Note: The hole spacing on the flue should be greater than 500mm; if it is a brick flue, it is recommended to pre-embed the steel pipe and then weld it to the flange.

Directly above the instrument in the instrument room, at a height of 2.5m from the ground, there are openings for the sample gas pipeline and exhaust pipe. The opening size is φ60~80mm, and there are two openings.

5.5 Layout of power lines and signal lines:

The purchaser shall provide: the working platform shall be equipped with a 220VAC, 50Hz power supply with a power of approximately 2000W; the power cord shall be laid to 0.5m directly below the gas sampling hole (entering the power box provided by the supplier); in addition, a signal cable shall be laid from the analysis cabinet in the instrument room to the power box.

See Appendix 7 for the system wiring and layout diagram

5.6 Arrangement and Fixing of Gas Sampling Tubes

ØThe sampling pipeline above the instrument room can be directly fixed on the wall and platform support column, and finally enter the instrument room. Starting from the sampling probe, the sampling pipe should be inclined downward to the instrument room with a slope of not less than 1%;

Ø Or fix the sampling tube on the steel cable, and fix the steel cable to the flue and chimney wall (also needs to be tilted). However, it must be ensured that there will be no scratches between the sampling tube and the wall at any time.

5.7 On-site installation guidance, commissioning and acceptance

Under the guidance of the on-site technical service personnel, the equipment of this project was installed and debugged according to the technical data, inspection standards, drawings and instructions provided by us. The installation and debugging process is arranged as follows:

After the contract equipment is installed, we will send people to guide the debugging and solve the equipment problems that occur during the debugging as soon as possible. The performance acceptance is carried out after all equipment is installed and debugged. Both the buyer and the seller participate in this acceptance. After the acceptance is completed and all performance indicators meet the indicators, the buyer signs the equipment acceptance certificate for this project.

Training Program

The specific contents of the training, such as time, number of participants, and location, shall be agreed upon by both the supply and demand parties.

6.Quality assurance and after-sales service

(1) Our company provides a 12-month quality assurance period for the entire system. During the warranty period, the company regularly performs free maintenance on the system and replaces spare parts free of charge. If the system fails, we will respond within 24 hours. If necessary, a technical engineer will arrive at the site within 48 hours.

(2) After the warranty period expires, our company will provide lifetime paid repair and maintenance services and offer the most favorable prices for spare parts.

(3) Free upgrade of system software.

(4) Provide free training to factory personnel.