1, heating industry background

Wireless data transmission technology, such as flow, pressure and safety control in heating network, has won the good reputation of customers. With the rapid development of cogeneration, central heating throughout, and rising coal prices, charging a series of problems gradually appear, should the requirements of our customers, the company in 2002 began the development of prepaid system and after 2-3 years of gradual improvement, was applied to the market in 2005.

2, South control instrument prepayment system to solve the main problems

2.1, large loss of steam measurement

As the heating industry, from the power plant pipe exports began to measure to each household measurement, the total total difference is always great, the pipeline loss of large errors, mainly in the following aspects:

A. normal heat loss

The steam in the pipe, the temperature will gradually drop, produce a small amount of condensed water, this part of the condensate in the household metering instrument to measure, there is relationship between the flow velocity of condensed water and steam in the pipe, flow is large, the condensed water is less, the smaller the flow rate, the more condensed water. Belong to the normal loss.

B. metering instrument characteristic reasons, resulting in less count, leakage meter

At present, the steam measurement in the heating industry, because of its high temperature reasons, there are not many flow meters can be selected, mainly using vortex street, orifice, V, vertebral, bend four kinds of flow meters to measure. In addition to the vortex and V cone, the four flowmeters can reach the range of 1:10 to 1:15, and the range ratio of the orifice and elbow flowmeter is 1:3. Within the measuring range of the flowmeter, the instrument ensures the accuracy of the measurement, but when the flow rate is lower than the measuring limit of the flowmeter, the meter will leak even

When the flow in the pipeline exceeds the measuring range of the instrument, the fluid will appear the jet and the flow. The meter can not be measured, and the data measured by the instrument is much smaller than the actual flow. The following figure is a diagram of the range and range of the error of the DN100 vortex flowmeter:

When the number of users suddenly suddenly small, volatile, so the overall measurement error will increase, the performance is less, leakage, heating nature is the loss of the company, this phenomenon is most obvious in the production enterprise.

C. caused by malicious steam theft

Steam prices from 96 years, 60 yuan a ton, until now 300 yuan a ton, the user tried every means to steal steam more and more, the means are also multifarious, the main means of stealing steam have the following several kinds:

1) use a big head to puncture the instrument signal line, cause the temperature, pressure or flow signal line short circuit, so as to achieve the purpose of stealing steam. When the temperature signal is short circuited, the temperature shows the normal temperature, the vapor density decreases, and the instantaneous flow decreases several times. When the pressure and flow signals are short circuited, the measurement value is zero and the flow rate is ignored or the density is decreased.

2) make use of the flow measuring range characteristic of the flowmeter, make a false statement of the gas consumption, cause the error of the flowmeter selection of the heating company, and make the instrument work in the lower or lower flow or the upper limit flow for a long time. Use the instrument's error to steal steam.

3) bribe the heating company's meter reading or maintenance personnel, modify the instrument parameters, resulting in fewer meters, so as to achieve the purpose of stealing steam.

4) malicious to the metering instrument power failure, so that the instrument does not work in use, thereby stealing steam. High steam prices, large amount of use, once the phenomenon of malicious theft of steam, the amount of huge losses.

2.2 malicious arrears and cash flow problems

Steam unit price is high, the average user is hundreds of thousands of dollars per month, or even millions of fees, once encountered bad customers malicious arrears, heating companies will fall into a passive situation. On the one hand, coal, see the money delivery, on the other hand, gas charges can not be received, once the formation of baggage, there will be cash flow problems. The prepaid system can put the money in advance before, the side can organize coal inventory funds.

3, South control instrument prepayment system design and development basis

3.1. Design standards and specifications

Hardware and software technology the scheme provided are in line with national and local laws and regulations, and in strict accordance with the requirements of ISO9001 quality assurance system to organize production and provide technical services, implementation of the latest version of the international standards, national standards and industry standards and norms, comply with environmental requirements.

Technical conditions for site of GB 2887 calculation station

Site safety requirements for GB 9361 calculation station

GB 7260 uninterruptible power supply equipment

GB 50174 electronic computer room design rule

GB50343-2 building electronic information systems

GB 5007. Chinese coded character set

GBJ 93 construction and inspection of Industrial Automation Instrument Engineering

Quality inspection of GBJ 131 automatic instrument installation project

GB 18030 basic set of Chinese coded character sets for information interchange

All units of measurement are subject to the international system of units (SI system). The following are units of measurement for common parameters:

South control instrument anti-theft prepayment control box function brief introduction

Wireless remote transmission function:

Upload data: South control instrument security advance control box, built-in GPRS/CDMA wireless transmission module DTU, can easily be instantaneous flow, the user's cumulative flow, temperature and pressure, balance, valve opening, door opening and closing state information is uploaded to the monitoring computer room. At the same time, it can combine the configuration software of the upper computer to analyze the abnormity of temperature, pressure and flow, so as to judge the fault of the instrument, and avoid the customer to use the needle signal line to carry out the behavior of stealing steam, and realize the function of remote meter reading.

Instruction: through the monitoring computer, according to the accident occurred at the scene, remote valve closed, open, without any distance restrictions.

The alarm recording function of the out of doors alarm:

In order to avoid customer collusion overhaul, meter reader out of the box to modify the instrument coefficient, the control box is not only equipped with double locking facilities, but also has the function of unpacking alarm. Once the box door is opened, the system automatically uploads the time and state of the unpacking, and records it. At the same time, it can select the function of taking out the alarm and taking photos.

Historical curve storage function:

South control instrument anti-theft prepaid control instrument all Chinese picture, and can store temperature, pressure, flow 365 days history, once there is an unexpected dispute, you can easily query, while avoiding customer cheating, stealing steam.

Report function:

Control instrument has automatic reporting function, daily reports, monthly statements, annual cumulative, convenient inquiry, meter reading.

Recharge record display function:

Record each recharge record, convenient for customers to check and check on the spot.

• ultra range shutdown valve function:

According to the measurement range of field instruments can be set beyond the range of valve in the range beyond the upper limit, prepaid control instrument will automatically close the small valve, the flow control in the flow range; in the measuring range or less than zero flow, the valve can be closed automatically according to the set value. In order to prevent users from exceeding the scope of stealing steam behavior.

Ultra automatic range compensation function:

According to the measurement range of field instruments can be set beyond the range of automatic compensation of losses in excess of the upper limit and the lower limit range, prepaid control instrument can automatically set the required compensation; compensation for losses caused by excessive process.

Overdraft authorization function:

According to customer credit, you can arbitrarily set overdraft authorization limit, in order to avoid non working hours due to insufficient balance to close the valve, causing losses to customers.

Insufficient balance alarm function:

The amount of charge fees to customers according to the amount of alarm, sound and light alarm in advance by user, and uploaded to the host computer, inform the user through the heating company telephone service personnel, to avoid affecting the normal use of the client.

Power off time recording function:

In order to prevent users from stealing by means of power failure, the control device is provided with a power-off recording function, which can record the last 30 power failures and the power on time, so that the inquiry is convenient.

UPS backup power function:

System settings backup UPS power supply, can continuously maintain more than 24 hours of power supply time. And inform the host system in time to pay attention to.

System overall structure design

I. data monitoring system:

According to customer requirements can be integrated network, each site through the connection of 1 wireless transmission module, transmitted to the data center server. The monitoring system is constructed as shown in the following figure:

1, hardware:

Monitor host: use rack type U server, include 1 redundant data servers, 1 WEB servers. (configuration 22

Inch LCD) type: enterprise class: rack type structure: 4U

Processor: CPU type: Xeon E7420CPU frequency: 2130MHz, with 2 Xeon E7420 processors

Maximum number of processors: 4, process technology: 45 nm, three level cache: 8MB, CPU core: quad core (Dunnington)

Main board: FSB (bus): 1066MHz, expansion slot: 7 PCI-Express slots (4 x8,3 x4)

Memory: memory type: FB-DIMM, memory size: 2GB, maximum memory capacity: 128GB

Storage: hard disk size: 2*146GB, hard disk type: SAS, hard disk maximum capacity: 1.5TB

Network: network controller: 4 embedded Broadcom NetXtreme IITM 5708 Gigabit5 Ethernet card,

Interface type: standard interface: rear: 2 universal serial bus (USB) port 2, 9 pin serial port, video interface, Gigabit Ethernet interface for DRAC, with blue / orange lights LED ID button, the front 2: universal serial bus (USB) port 2, LCD panel with rolling system alarm the 15 pin of the video display, system interface, power on / off button, internal: 1 universal serial bus (USB)

Two 、 system software constitution:

When the user monitors the screen and data, the customer enters the user's own account number and password from the website. No matter when and where the customer is, as long as you can access the Internet, you can control the data at any time and place.

The main functions are:

24 - hour online operation, real-time acquisition of each user station temperature and pressure, flow and other operating parameters, operation of real-time monitoring of each acquisition meter, and the metering instrument malfunction can be found in a short period of time, and the failure time record record, to avoid the loss of measurement;

Carry on the operation analysis of the whole pipe network data, have powerful statistics and database inquiry function, can inquire the steam consumption situation of any user at any time; analyze the pipeline damage in real time and effectively;

• alarm the user, the city power outages, abnormal collection of parameters, and record for future reference;

• generate settlement bills (daily, monthly and annual reports) as required and print them directly;

The function of chart curve can reflect the steam consumption of each user intuitively;

Network design, support remote access function;

The combination of real time database and relational database ensures the stability and security of data.

Powerful software functions, combined with high-performance, low bit error rate data communication equipment, and UPS uninterrupted power supply design, to ensure the stability of the whole system performance.