Steam prepaid system

1. Background of the heating industry

The wireless data transmission technology in terms of flow, pressure, and safety control of the heating pipe network has won a good reputation from customers. With the rapid development of cogeneration and central heating in various places, as well as the rising price of coal, a series of metering and charging problems have gradually emerged, in response to the requirements of our customers, the company began to develop a prepayment system in 2002 and after 2-3 years of gradual improvement, it was officially applied to the market in 2005.

2. The main problems solved by the prepaid system of Nankong instruments

2.1 The problem of large steam metering loss

As a heating industry, the total from the outlet of the power plant pipeline to the measurement of each sub-household is always very different, and the large error of pipeline loss mainly appears in the following aspects:

a. Normal heat loss

When the steam is transported in the pipeline, the temperature will gradually drop, producing a small amount of condensate, this part of the condensate can not be measured by the instrument in the household metering, the amount of condensate is related to the flow rate of steam in the pipeline, the larger the flow rate, the less condensate, the smaller the flow rate, the more condensate is produced, which is a normal loss.

b. Undercounting or omission caused by the characteristics of the meter

At present, in the steam measurement of the heating industry, there are not many flow meters to choose from because of its high temperature, and four flow meters are mainly used for measurement. In addition to the range of 1:10-1:15 for vortex street and V-cone, the flow measurement range ratio of orifice plate and bend pipe is 1:3. Within the measurement range of the flow meter, the meter can ensure the accuracy of the measurement, but when the flow rate is lower than the lower limit of the flow meter, the meter will miss the meter or even not

Count; When the flow in the pipeline exceeds the measurement range of the instrument, the fluid will appear jet, and the flow meter cannot be measured, and the data measured by the instrument is far less than the actual flow. The following figure is the relationship between the error and the range of a DN100 vortex flow meter:

When the user's usage fluctuates greatly, then the overall measurement error will increase, and the manifestation is undercounting, missing time, which is naturally the loss of the heating company, which is the most obvious phenomenon in the production enterprise.

c. Caused by malicious steam theft

The price of steam has increased from 60 yuan a ton in 96 to 300 yuan a ton now, and there are more and more cases where users try their best to steal steam, and the means are also varied, and the main means of stealing steam are as follows:

1) Use a big head needle to prick the instrument signal line to cause a short circuit in temperature, pressure or flow signal line to achieve the purpose of stealing steam. When the temperature signal is short-circuited, the temperature shows normal temperature, the vapor density decreases, and the instantaneous flow rate drops several times. When the pressure and flow signals are short-circuited, the measured value is directly displayed as zero, resulting in the flow rate not being counted or the density dropping.

2) Use the flow meter to measure the range characteristics and falsely report the gas consumption, resulting in the wrong selection of the flow meter of the heating company, so that the meter works at the low limit flow rate or high upper limit flow for a long time. Use the error of the instrument to steal steam.

3) Bribe the meter reading or maintenance personnel of the heating company to modify the meter parameters and cause the meter to be undercounted, so as to achieve the purpose of stealing steam.

4) Maliciously cut off the power to the meter, so that the instrument does not work during use, so as to steal steam. The price of steam is high, the usage is large, and once there is a malicious phenomenon of stealing steam, the amount of loss is huge.

2.2 Malicious arrears and capital turnover problems

The unit price of steam is high, and ordinary users spend hundreds of thousands or even millions of dollars every month. On the one hand, coal is shipped on the spot, and on the other hand, the automobile fee cannot be recovered, and once the burden is formed, there will be capital turnover problems. The prepaid system can collect the money in advance, and the funds can be used to organize coal inventory.

3. The basis for the design and development of the prepaid system of Nankong Instrumentation

3.1. The standards and specifications on which the design is based

The software and hardware equipment and technology provided by this program comply with national and local laws and regulations, and organize production and provide technical services in strict accordance with the requirements of the ISO9001 quality assurance system, implement the latest version of international standards, national standards, industry standards and related specifications, and meet environmental protection requirements.

All units of measurement follow the International System of Units (SI system). The following are the units of measurement for commonly used parameters:

Introduction to the functions of the anti-theft prepaid control box of Nankong Instrument

●Wireless remote transmission function:

Data upload:The anti-theft prepaid control box of Nankong Instrument has a built-in GPRS/CDMA wireless transmission DTU module, which can easily upload the user's instantaneous flow, cumulative flow, temperature, pressure, balance, valve opening, box door opening and closing status and other information to the computer in the monitoring room. At the same time, it can be combined with the configuration software of the upper computer to analyze the abnormality of temperature, pressure and flow to judge the instrument fault, and at the same time avoid customers from using needle punch signal lines to steal steam, and realize the remote meter reading function.

Instructions are transmitted:The valve can be closed and opened remotely by monitoring the computer according to the unexpected situation on site, without any distance limitation.

●Unboxing door alarm recording function:

In order to avoid customer collusion in maintenance and meter reading personnel to open the box to modify the instrument coefficient, the control box is not only equipped with double lock facilities, but also has the function of opening the box. Once the box door is opened, the system automatically uploads the unpacking time and status, and records it, and at the same time, you can choose the unboxing alarm and photo function to automatically upload the captured photos or notify the management via short message.

●History curve storage function:

The anti-theft prepaid controller of Nankong Instrument is full Chinese screen, and can store 365 days of historical records of temperature, pressure, and traffic, which can be easily inquired in case of unexpected disputes, and at the same time avoid customers from cheating and stealing steam.

● Reporting functions:

The controller has automatic report function, daily report, monthly report, and annual accumulation, which is convenient for query and reading.

● Deposit record display function:

Record each recharge record to facilitate customers to check and query on site.

● Over-range shut-off function:

According to the measurement range of the on-site instrument, the valve can be set to close the range beyond the range, and when the upper limit range is exceeded, the prepaid controller will automatically close the small valve to control the flow within the flow range. When the measurement range is less than the measuring range or when the flow rate is zero, the valve can be automatically closed according to the set value. To prevent users from maliciously stealing automobiles from over-range.

● Over-range automatic compensation function:

According to the measurement range of the on-site instrument, the loss can be set to automatically compensate for the loss beyond the range range, and when the upper limit and lower limit range are exceeded, the prepaid controller will automatically compensate according to the set requirements; It is used to compensate for losses caused by over-range.

● Overdraft Authorization Features:

According to the customer's creditworthiness, the overdraft authorization limit can be set arbitrarily to avoid losses caused to customers by closing the valve due to insufficient balance during non-working hours.

● Insufficient balance alarm function:

The charging amount sets the alarm value according to the customer's usage, prompts the user through sound and light alarm in advance, and uploads it to the upper computer at the same time, and informs the user through the phone number of the service staff of the heating company to avoid affecting the normal use of the customer.

● Power Loss Time Recording Function:

In order to prevent users from stealing through power off, the controller is equipped with a power failure record function, which can record the last 30 power outages and power-on times, which is convenient for query.

● UPS backup power function:

The system is equipped with a backup UPS power supply, which can maintain a continuous power supply time of more than 24 hours. And inform the superior system to pay attention in time.

Overall structure design of the system

1. Data monitoring system part:

According to customer requirements, the network can be networked as a whole, and each site is connected to a wireless transmission module to transmit to the data center server. The monitoring system is composed as follows:

1. Hardware part:

Monitoring host: Rack-mounted U-shaped server is selected, including one redundant data server and one WEB server. (Configuration 22.)

LCD monitor) Type: Enterprise Category: Rack Structure: 4U

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

Maximum number of processors: 4, process process: 45nm, L3 cache: 8MB, CPU core: quad-core (Dunnington)

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

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

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

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

Interface type: Standard Interfaces: Rear: 2 Universal Serial Bus (USB) 2.0 Ports, 9-Pin Serial Port, Video Interface, Gigabit Ethernet Interface for DRAC, ID Button with Blue/Orange LED Indicator, Front: 2 Universal Serial Bus (USB) 2.0 Ports, LCD Panel with System Alarm Scrolling Display, 15-Pin Video Interface, System Power On/Off Button, Internal: 1 Universal Serial Bus (USB)

2. System software composition:

When monitoring the screen and data, the customer only needs to enter the account number and password specified by the user from the website to log in. Customers can control their monitoring data anytime, anywhere, as long as they have access to the Internet.

The main functions are:：

● 24-hour online operation, real-time collection of temperature, pressure, flow and other operating parameters of each user sub-station, real-time monitoring of the operation of each collection meter, and the failure of the on-site collection and metering instrument can also be found in a short time, and the failure time record is filed to avoid the loss of measurement;

● Carry out operation analysis of the entire pipeline network data, with powerful statistical and database query functions, which can query the steam consumption of any user in any time period; Analyze the pipeline damage in real time and effectively;

● Alarm the situation of power outage and abnormal collection parameters at the user's end, and record it for future reference;

● Generate settlement statements (daily, monthly and annual statements) as needed, and can print them out directly;

● Chart curve function, which can intuitively reflect the steam consumption of each user;

● Network design, support remote access function;

● The combination of real-time and relational databases ensures data stability and security.

The powerful software functions combined with high-performance, low-bit error rate data transmission communication equipment and UPS uninterruptible power supply design ensure the stability and reliability of the entire system performance。