CN103436650B - Thermal load wireless detection system of high precision blast furnace and detection method thereof - Google Patents

Abstract

The invention discloses a thermal load wireless detection system of a high precision blast furnace and a detection method thereof, belonging to the field of thermal load detection of blast furnaces. The system disclosed by the invention comprises a wireless thermodetector, a temperature acquisition terminal and an upper computer, wherein the wireless thermodetector detects temperature and flow of a cooling wall of the blast furnace in real time and transmits temperature and flow signals to the temperature acquisition terminal. The temperature acquisition terminal collects the temperature and flow signals transmitted by the wireless thermodetector through a ZigBee wireless transceiving module and transmits the collected temperature and flow signals to the upper computer. The upper computer comprises a serial communication interface program and configuration software, wherein the serial communication interface program is used for extracting the temperature and flow signals transmitted by the temperature acquisition terminal and carrying out data format conversion, and the configuration software is used for displaying in a graphical manner and storing historical data. According to the system disclosed by the invention, the measurement precision of thermal load and the stability are improved, and data are transmitted through a ZigBee wireless network without paving high temperature cables, so that the cost is greatly saved.

Description

A kind of high precision blast furnace thermal load wireless detecting system

Technical field

The invention belongs to blast furnace thermal load detection field, the particularly fusion of the wireless technology based on Zigbee protocol and blast furnace cooling stave thermal load detection technique, mainly completes the transmission over radio of blast furnace cooling stave thermal load signal.

Background technology

The long-lived high yield of the application of blast furnace cooling system thermal load online measuring technique to blast furnace, accident potential avoid very important.Blast furnace thermal load determines by blast-furnace cooled water water temperature difference and Inlet and outlet water flow, and thermal load has directly reflected the distribution of Gas Flow in blast furnace cooling system and stove, belongs to the core Monitoring systems of blast furnace realtime monitoring.If can understand in time the variation of each position thermal load in stove, and can take corresponding treatment measures to maintain rational cooling system (as improved hydraulic pressure, increase cooling water inflow, reducing cooling stave series connection piece number etc.), just can ensure by thermal load control in allowed limits, this has very important practical significance for stablizing blast furnace cooling system, guarantee blast furnace safety high yield, reinforcing blast furnace smelting, prolongation blast furnace work-ing life and reducing blast furnace accident potential.Blast furnace must keep rational cooling system, and the water consumption at the each position of blast furnace and its thermal load are adapted.The production of blast furnace and studies confirm that, after the thermal load at the each position of blast furnace is designed to determine, when thermal load designs when excessive, certainly will strengthen the service discharge of water coolant, that is to say that can to cause cooling intensity excessive, cause the symptoms such as furnace lining knot is thick, thereby affect the rational cooling system of blast furnace; If thermal load design is too little, mean that service discharge reduces, can cause cooling performance poor, in stove, can not form slag crust, cause lining erosion to be accelerated, cooling stave is damaged too early.Along with the strengthening of blast-furnace smelting, restoration of lower stack corrodes serious, the thermal load on-line detecting system of therefore installing, can monitor in real time the thermal load at shaft position variation, keep rational blast furnace operating system.

Domestic iron-smelting blast furnace cupola well burnt accident in rapid succession in recent years, in August, 2010 husky steel 1#(2500M ³) hearth breakout, heavy steel 1200M ³cinder monkey below stove skin burns, the new 1# stove of in January, 2011 Anshan iron and steel plant (3200M ³) hearth breakout, in October, 2011 5# of Nangang stove, and all there is relevant accident in Ma Gangyi iron 10# stove, causes the person, the property heavy losses that are difficult to make up.Tracing it to its cause is all there is no perfect cupola well Monitoring systems, cannot find in time the position of hearth erosion, adopts an effective measure in time.Blast-furnace cooled water Monitoring systems is made up of several parts of water temperature detection, flow detection, data processing centre (DPC), system software and communication, and wherein most crucial part is water temperature detection system.The stability of water temperature detection system, precision have directly determined performance and the validity of blast-furnace cooled water Monitoring systems.

The most wired measuring modes that adopt of at present domestic traditional thermal load detection system sensor front end, the defect that also has some to be difficult to overcome in actual use, make a concrete analysis of as follows:

(1) expending greatly of high-temperature cable.Because general blast furnace throat envrionment temperature is higher, must use high-temperature cable temperature measurement node is powered and communicate by letter, traditional thermal load metering system, each temperature measurement node at least will consume three high-temperature cables.According to Field Research, a horse steel blast furnace has more than 800 coolant water temperature detection node need consume more than 2400 high-temperature cable altogether, and now the high-temperature cable on market is very expensive, so traditional thermal load metering system cost is very high, and make a large amount of metallic substance and high-temperature insulation material that high-temperature cable need expend, in the situation that China's existing resource is in short supply, adopt wired measuring mode to be unfavorable for the continuity of industrial chain.

(2) construction is complicated.Traditional thermal load metering system, adopt high-temperature cable power and communicate by letter, and blast furnace cooling stave environment is severe, manually places very inconvenience of high-temperature cable, so the construction of traditional thermal load metering system is complicated, brings great inconvenience to site operation.

(3) network management and maintenance difficulties are large.Due to traditional thermal load metering system, adopt high-temperature cable power and communicate by letter, while breaking down, to expend a large amount of human and material resources investigations and again lay high-temperature cable, so traditional thermal load metering system is to the next inconvenience greatly of administering and maintaining of network.According to investigation, the coolant water temperature of Ma Gangyi seat large blast furnace detects annual maintenance expense and usually reaches more than hundreds of thousands of, if can upgrade temp measuring system technology, makes the network of communication can self, with 9 blast furnace measuring and calculating of whole horse steel, the maintenance expense under saving is just millions of.

(4) network structure is single, network communication reliability is low.Traditional thermal load metering system, in order to reduce the interference on transmission route, can only adopt single network topology structure, and under severe site environment, is difficult to lay high-temperature cable according to single network topology.And traditional thermal load metering system adopts unibus mode to carry out data transmission more, node and node influence each other, and a node breaks down, and probably affects whole communication network, and this just reduces the reliability of network communication.

(5) blast furnace iron notch place environment is severe, and temperature is high, and high temperature liquid iron often can be splashed to around on cable, cable is melted, and blast furnace iron notch place adopts wired measuring mode to be also unfavorable for site operation.If adopt wireless measurement mode fundamentally to address these problems.

By patent retrieval, the existing detection that adopts wireless technology to realize blast furnace water temperature system in prior art.As Chinese Patent Application No.: 201210265426.0, the applying date: on July 30th, 2012, invention and created name is: a kind of wireless blast-furnace cooled water temperature difference on-line measurement system, and this application case comprises the webserver, industrial computer, data transducer, receiving station and transmitting node; Wherein, the water temperature information detecting is sent to receiving station by described transmitting node; Described receiving station sends to described industrial computer by the described temperature information receiving by described data transducer; Described industrial computer is for sending to the described webserver by the described temperature information receiving, and the each point for measuring temperature of this system all adopts Digital Measurement of Temperature chip, wireless digital transmission mode, makes point for measuring temperature without any the cable being connected with the external world.But point for measuring temperature all adopts Digital Measurement of Temperature chip in this application case, the defect that digital temperature sensor also has some to be difficult to overcome in actual use.As not high in temperature monitor meter accuracy, water temperature difference often differs 0.1 DEG C, and thermic load value will affect 10%, and cupola well layer because of resistance to material thicker, that is to say if temperature monitor meter accuracy do not reach ± 0.1 DEG C, thermal load may occur that negative value will be shown as zero, also just lose the meaning of its monitoring.For this application case, be described as follows:

(1) precision of digital temperature sensor is lower, the DS18B20 digital temperature sensor that market is used now, its minimum resolution can reach 0.0625 DEG C, precision is ± 0.5 DEG C, and the turnover thermal load of general blast furnace throat water coolers requires to be controlled at 0.3～0.7 DEG C, exceeding this working range staff will take some measures, and mean and will occur accident if exceed 0.9 DEG C, and personnel may will withdraw.Therefore, use digital temperature sensor still to have sizable accident potential.

(2) digital temperature sensor is three pin chip structures, generally be equipped with 51 or AVR micro-chip form system for detecting temperature, owing to being encapsulated in water-tight and air-tight airtight sleeve pipe, when blast furnace work simultaneously, sensor environment of living in is severe, all kinds of interference are very large, so its stability is not high, while running into sensor damage, need often to change detection probe.

(3) digital temperature sensor adopts single wire transmission pattern, and the input and output of signal are single line, and this often needs equipment vendors to send slip-stick artist to carry Special Equipment to carry out scene and reset while just having caused detection probe to be changed, and then generation maintenance expense.

The present invention is at the design initial stage, this blast furnace thermal load wireless detecting system intends adopting the wireless communication mode based on Zigbee protocol, pass through powered battery, without high-temperature cable, ZigBee is a kind of wireless network protocol of low speed short-distance transmission, and the principal feature of ZigBee is: (1) ZigBee module, by powered battery, is carried out data transmission by ZigBee wireless network, use at the scene without cable laying, saved a large amount of costs.(2) reduce power consumption.Under normal power supply pattern, No. 5 drying battery of 2 joints can be supported 1 node work several months, even longer.This is the outstanding advantage of ZigBee.Compare, bluetooth can be worked and can be worked a few hours several weeks, WiFi.(3) low cost.By significantly simplify agreement (less than bluetooth 1/10), reduced the requirement to communication controller, by forecast analysis, with 8051 8 8-digit microcontroller measuring and calculating, Full Featured major joint needs 32KB code, and subfunction node is few to 4KB code, and ZigBee exempts from agreement patent royalty.The price of every chip block is approximately 2 dollars.(4) heavy body.ZigBee can adopt multiple network topological framework, manages some child nodes by a major joint, and maximum major joints can be managed 254 child nodes; Major joint also can, by last layer network node control, can form at most the large net of 65000 nodes simultaneously.(5) high safety.ZigBee provides three level security patterns, comprise without security settings, use access control inventory (Access Control List, ACL) symmetric cryptography that prevents illegally obtaining data and adopt Advanced Encryption Standard (AES128), to determine flexibly its security attribute.(6) ZigBee-network self-organization, under the coordination of Zigbee protocol, ZigBee-network can be identified newly-increased node automatically, automatically excises malfunctioning node simultaneously.The maintenance and management of network all automatically carries out under the coordination of Zigbee protocol, without labor management and maintenance.

Although the wireless measurement mode based on Zigbee protocol of employing, compared with traditional wired measuring mode, has significant advantage, the maximum difficult point that adopts the wireless measurement mode of Zigbee protocol to exist in thermal load fields of measurement is:

(1), if a node breaks down, will cause its attached child node cannot proper communication;

(2) work-ing life not long, although ZigBee module dissipation is low, common batteries can supply a temperature instrumentation work several months, blast furnace environment is severe, changes very inconvenience of battery, requires temperature instrumentation work-ing life in actual production more than 2 years.These are to be all badly in need of for radio detection technology the technical problem solving, and in addition, in prior art, the reliability and stability of blast furnace cooling stave thermal load detection system need further to improve.

Summary of the invention

1. the technical problem that invention will solve

The object of the invention is to overcome the deficiency of blast furnace cooling stave thermal load wired measuring mode in prior art, a kind of high precision blast furnace thermal load wireless detecting system and detection method thereof are provided, adopt technical scheme of the present invention, wireless communication technique based on Zigbee protocol is applied to blast furnace cooling stave thermal load detection field, construction complexity, network management and maintenance difficulty are reduced, promoted the diversity of network topology structure, the reliability of network communication simultaneously.

2. technical scheme

For achieving the above object, technical scheme provided by the invention is:

A kind of high precision blast furnace thermal load wireless detecting system of the present invention, comprises wireless thermodetector, temperature acquisition terminal and upper computer, described wireless thermodetector comprises Pt1000 temperature sensor, flow sensor, temperature and flow signal treatment circuit, low power processor, ZigBee radio receiving transmitting module and power module, described Pt1000 temperature sensor is intake for detection of blast-furnace cooled water, temperature at discharging condensate, described flow sensor is for detection of blast-furnace cooled water flow, above-mentioned Pt1000 temperature sensor, the signal output part of flow sensor is connected to temperature and flow signal treatment circuit, temperature and flow signal treatment circuit, ZigBee radio receiving transmitting module is connected with low power processor respectively, described power module respectively with Pt1000 temperature sensor, flow sensor, temperature and flow signal treatment circuit, low power processor, ZigBee radio receiving transmitting module is connected, and this power module is for powering to wireless thermodetector, and described power module is battery, and wireless thermodetector detects temperature and the flow of blast furnace cooling stave in real time, and sends temperature and flow signal to temperature acquisition terminal,

Described temperature acquisition terminal comprises ZigBee radio receiving transmitting module, treater, sound and light alarm and state display module, RS485 communication module and power module, described ZigBee radio receiving transmitting module, RS485 communication module is connected with treater respectively, described treater output terminal is connected with sound and light alarm and state display module, this sound and light alarm and state display module are for monitoring in real time the running status of each wireless thermodetector, and carry out sound and light alarm, described power module respectively with sound and light alarm and state display module, RS485 communication module, treater is connected, this power module is for powering to temperature acquisition terminal, this power module is wired power supply form, temperature acquisition terminal gathers by ZigBee radio receiving transmitting module temperature and the flow signal that wireless thermodetector transmits, and be sent to upper computer by gathering the temperature and the flow signal that come, above-mentioned wireless thermodetector is the sensor node of system, temperature acquisition terminal is the aggregation node of system, several temperature acquisition terminals are connected in series successively by RS485 bus, the communication bus two ends of last temperature acquisition terminal are connected to terminal resistance, wireless thermodetector and temperature acquisition terminal composition MESH network, and adopt interrupter duty pattern, this wireless thermodetector and temperature acquisition terminal communication mode are the cableless communication based on Zigbee protocol, and the agreement that wireless thermodetector relates to is Zigbee protocol,

Described upper computer comprises serial communication interface routine and configuration software, this serial communication interface routine is for extracting temperature and the flow signal that temperature acquisition terminal transmission comes and carrying out Data Format Transform, and described configuration software is for graphically showing and carrying out storage of history data P; Above-mentioned upper computer is system coordination device, and the communication modes of upper computer and temperature acquisition terminal is RS485 balanced type differential communication.

Furthermore, described temperature and flow signal treatment circuit comprise processes temperature signal circuit and flow signal treatment circuit, wherein processes temperature signal circuit comprises Pt1000 treatment circuit and AD converter, described Pt1000 treatment circuit comprises three-wire system Pt1000, subtractor one, subtractor two and measuring bridge circuit, and described measuring bridge circuit comprises the first zero-regulator resistor R1, the second zero-regulator resistor R2, Rt, reference resistance R _refwith current-limiting resistance Ri, above-mentioned the first zero-regulator resistor R1, the second zero-regulator resistor R2, Rt and reference resistance R _refseries connection successively, an end of current-limiting resistance Ri is connected on the first zero-regulator resistor R1 and reference resistance R _refbetween, the other end of current-limiting resistance Ri is connected to power supply, three pins of described three-wire system Pt1000 respectively with reference resistance R _ref, the second zero-regulator resistor R2 with ground be connected; Described subtractor one is got reference resistance R _refthe voltage at two ends is as the reference voltage of AD converter, the output terminal of subtractor one is connected with the reference voltage input terminal of AD converter, "+" end of subtractor two is connected with the positive pole of three-wire system Pt1000, "-" end of subtractor two is connected with one end of the second zero-regulator resistor R2, the output terminal of subtractor two is connected with the input end of analog signal of AD converter, and the digital signal output end of AD converter is connected with low power processor.The processes temperature signal circuit of the present invention's design is in order to improve thermometric precision and stability.

Furthermore, described wireless thermodetector adopt degree of protection higher than the housing of IP67 as guard shield, described temperature acquisition terminal adopt degree of protection higher than the housing of IP66 as guard shield.

A kind of high precision blast furnace thermal load method for wirelessly testing of the present invention, the steps include:

Step 1:

Temperature and the flow of a blast furnace cooling stave detected at wireless thermodetector interval for 2 minutes, and send temperature and flow signal to temperature acquisition terminal, described wireless thermodetector adopts interrupter duty pattern, be that wireless thermodetector makes all chips in instrument in holding state under normal circumstances, after only receiving the request instruction of father node, just all chips are waken up, after waking up, carry out AD sampling and medium filtering processing, and the temperature collecting and flow signal are sent, after being sent out, temperature and flow signal get back to again holding state, wherein: described wireless thermodetector comprises Pt1000 temperature sensor, flow sensor, temperature and flow signal treatment circuit, low power processor, ZigBee radio receiving transmitting module and power module, described Pt1000 temperature sensor is intake for detection of blast-furnace cooled water, temperature at discharging condensate, described flow sensor is for detection of blast-furnace cooled water flow, above-mentioned Pt1000 temperature sensor, the signal output part of flow sensor is connected to temperature and flow signal treatment circuit, temperature and flow signal treatment circuit, ZigBee radio receiving transmitting module is connected with low power processor respectively, described power module respectively with Pt1000 temperature sensor, flow sensor, temperature and flow signal treatment circuit, low power processor, ZigBee radio receiving transmitting module is connected, this power module is for powering to wireless thermodetector, described power module is battery,

Step 2:

Temperature acquisition terminal gathers by ZigBee radio receiving transmitting module temperature and the flow signal that wireless thermodetector transmits, and be sent to upper computer by gathering the temperature and the flow signal that come, wherein: described temperature acquisition terminal comprises ZigBee radio receiving transmitting module, treater, sound and light alarm and state display module, RS485 communication module and power module, described ZigBee radio receiving transmitting module, RS485 communication module is connected with treater respectively, described treater output terminal is connected with sound and light alarm and state display module, this sound and light alarm and state display module are for monitoring in real time the running status of each wireless thermodetector, and carry out sound and light alarm, described power module respectively with sound and light alarm and state display module, RS485 communication module, treater is connected, this power module is for powering to temperature acquisition terminal, this power module is wired power supply form, above-mentioned wireless thermodetector is the sensor node of system, temperature acquisition terminal is the aggregation node of system, several temperature acquisition terminals are connected in series successively by RS485 bus, the communication bus two ends of last temperature acquisition terminal are connected to terminal resistance, wireless thermodetector and temperature acquisition terminal composition MESH network, this wireless thermodetector and temperature acquisition terminal communication mode are the cableless communication based on Zigbee protocol, the agreement that wireless thermodetector relates to is Zigbee protocol,

Step 3:

Upper computer calculates blast furnace thermal load Q:Q=Δ T × F × CPn by following formula, wherein: Δ T=∑ 0T _{temperature at discharging condensate}/ n-T _{inflow temperature}, Δ T is water temperature difference; F: cooling water flow; CPn: tuning coefficient, CPn=4.1817/10=0.41817; Wherein: described upper computer comprises serial communication interface routine and configuration software, this serial communication interface routine is for extracting temperature and the flow signal that temperature acquisition terminal transmission comes and carrying out Data Format Transform, and described configuration software is for graphically showing and carrying out storage of history data P; Above-mentioned upper computer is system coordination device, and the communication modes of upper computer and temperature acquisition terminal is RS485 balanced type differential communication.

3. beneficial effect

Adopt technical scheme provided by the invention, compared with existing known technology, there is following unusual effect:

(1) a kind of high precision blast furnace thermal load wireless detecting system of the present invention, wireless thermodetector wherein passes through powered battery, carry out data transmission by ZigBee wireless network, without laying high-temperature cable, save a large amount of costs, fundamentally solved the defect that traditional thermal load metering system cannot be measured at iron notch; Difficulty of construction reduces greatly simultaneously, has saved a large amount of human and material resources.

(2) a kind of high precision blast furnace thermal load wireless detecting system of the present invention, its ZigBee-network self-organization, under the coordination of Zigbee protocol, ZigBee-network can be identified newly-increased node automatically, automatically excise malfunctioning node simultaneously, the maintenance and management of network all automatically carries out under the coordination of Zigbee protocol, without labor management and maintenance, has saved a large amount of maintenance expenses; Simultaneously, ZigBee adopts MESH networking, manage some child nodes by a major joint, maximum major joints can be managed 254 child nodes, major joint also can, by last layer network node control, can form at most the large net of 65000 nodes simultaneously, and each node has own distinctive channel, a node breaks down and can not affect whole communication network, thereby improves the reliability of network communication.

(3) a kind of high precision blast furnace thermal load wireless detecting system of the present invention, adopt Pt1000 RTD as temperature sensor, and adopt the processes temperature signal circuit of innovative design of the present invention, thermal load measuring accuracy and stability are improved, specifically comprise following three aspects:: a) high resolving power, Pt1000 temperature factor is TCR=3850ppm/K, coordinates processes temperature signal circuit of the present invention, 0.001 DEG C of resolution; B) high precision, adopt Pt1000 as temperature sensor, coordinate the novel ratio electric bridge temperature-compensation circuit of the present invention's design, the resolving power that equals 10～20 times with measuring accuracy is calculated, measuring accuracy can reach 0.02 DEG C, meets the requirement of blast furnace thermal load to measuring accuracy completely; C) high stability, the present invention adopts Pt1000 RTD as temperature sensor, coordinates the processes temperature signal circuit of innovative design of the present invention to make the digital quantity of AD converter output only with pt1000 zero degree resistance R ₀with reference resistance R _refrelevant, so the blast furnace thermal load wireless detecting system of the present invention design is adapted at carrying out under rugged environment measurement steady in a long-term.

(4) a kind of high precision blast furnace thermal load method for wirelessly testing of the present invention, the work of its wireless thermodetector adopts interrupter duty pattern can greatly extend battery, adopt interrupter duty pattern of the present invention to make the wireless thermodetector most of the time in holding state, and the power consumption of chip under holding state is extremely low, can ignore.Temperature instrumentation is 30mA in the maximum power dissipation sending when state, and 2min gathers once, gathers that once institute is time-consuming is: 1.5s, one saves the 8500mAh spendable life-span of battery and is: and the use of existing technology battery can only reach the several months, so adopt interrupter duty pattern greatly to extend battery.

(5) a kind of high precision blast furnace thermal load method for wirelessly testing of the present invention, adopt MESH networking mode, MESH network is a kind of mesh network topology, except allowing the communication between father node and child node, also allow the asking of neighbor node within communication range with the non-set membership of routing capabilities to communicate, it is to realize on tree network basis, different from tree network is, MESH network is a kind of special, the point-to-point network structure of transmitting by relay mode, its route can automatically be set up and safeguard, and there is powerful self-organization, self-healing function, network can be communicated by letter by the mode of " multistage jumping ", can form very complicated network, there is the very large route degree of depth and node of network scale, the advantage of this topological framework is to have reduced message delay, reliability and stability are strengthened, the present invention has thoroughly solved the defect that traditional thermal load metering system and existing patent cannot overcome.

Brief description of the drawings

Fig. 1 is the communication schematic diagram of a kind of high precision blast furnace thermal load wireless detecting system of the present invention;

Fig. 2 is the hardware design block diagram of wireless thermodetector in the present invention;

Fig. 3 is wireless thermodetector programflow chart in a kind of high precision blast furnace thermal load method for wirelessly testing of the present invention;

Fig. 4 is the hardware design block diagram of temperature acquisition terminal in the present invention;

Fig. 5 is upper computer design frame chart in the present invention.

Fig. 6 is the design frame chart of processes temperature signal circuit in the present invention, wherein: 1, Pt1000 treatment circuit; 2, AD converter.

Embodiment

For further understanding content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.

Embodiment 1

In conjunction with Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5, further illustrate as follows to a kind of high precision blast furnace thermal load wireless detecting system of the present invention and detection method thereof.A kind of high precision blast furnace thermal load wireless detecting system of the present embodiment, comprises wireless thermodetector, temperature acquisition terminal and upper computer.As shown in Figure 2, in the present embodiment, wireless thermodetector comprises Pt1000 temperature sensor, flow sensor, temperature and flow signal treatment circuit, low power processor, ZigBee radio receiving transmitting module and power module, described Pt1000 temperature sensor is intake for detection of blast-furnace cooled water, temperature at discharging condensate, described flow sensor is for detection of blast-furnace cooled water flow, above-mentioned Pt1000 temperature sensor, the signal output part of flow sensor is connected to temperature and flow signal treatment circuit, temperature and flow signal treatment circuit, ZigBee radio receiving transmitting module is connected with low power processor respectively, described power module respectively with Pt1000 temperature sensor, flow sensor, temperature and flow signal treatment circuit, low power processor, ZigBee radio receiving transmitting module is connected, and this power module is for powering to wireless thermodetector, and described power module is battery, and wireless thermodetector detects temperature and the flow of blast furnace cooling stave in real time, and sends temperature and flow signal to temperature acquisition terminal.Because the temperature measurement node number of blast furnace cooling stave is many, adopt the wireless network of Zigbee protocol to communicate, greatly reduce difficulty of construction, save a large amount of human and material resources.Wireless thermodetector is arranged on blast furnace cooling stave point for measuring temperature, and environment is the most severe, and there was dampness in the air, low visibility, so select degree of protection higher than the housing of IP67 the guard shield as wireless temperature measurement instrument.In order to extend the work-ing life of wireless temperature measurement instrument, select high capacity cell (8500mAh left and right).In order to extend battery, all chips of wireless thermodetector are selected low-power chip, and can by microprocessor control its in standby mode.

The present invention adopts magnetic flow meter as flow sensor, magnetic flow meter can be measured by first-class to blast furnace, an a certain section cooling water flow like clockwork, so blast furnace thermal load accuracy of detection depends primarily on Furnace Water Temperature Difference accuracy of detection, and Furnace Water Temperature Difference high-acruracy survey depends on processes temperature signal circuit, temperature detecting precision is mainly determined by temperature resolution.So designing a set of rational processes temperature signal circuit has great importance for improving blast furnace thermal load accuracy of detection.The present invention is considering on the basis of conventional P t1000 processes temperature signal circuit defect, has designed novel ratio electric bridge temperature-compensation circuit, i.e. Pt1000 processes temperature signal circuit in the present invention.

Traditional Pt1000 processes temperature signal circuit adopts common bridge diagram or constant current source driving circuit.Wherein, the major defect of common bridge diagram has: 1. because the reference voltage of the AD converter in common bridge diagram is by high precision reference voltage source independently, so digital quantity and the Pt1000 resistance of AD converter output are nonlinear relationship; 2. common bridge diagram is measured the necessary high precision reference voltage source that uses in order to realize high-precision temperature, and high precision reference voltage source price is high, and its magnitude of voltage is subject to the impact of envrionment temperature larger, so common bridge diagram is unfavorable for using under severe site environment; 3. common bridge diagram can only use two wire system Pt1000, so that measuring accuracy is affected by wire resistance is larger.

Constant current source driving circuit makes to flow through the current constant of Pt1000 by constant current source, digital quantity and the Pt1000 resistance of AD converter output are nonlinear relationship, and constant current source driving circuit can adopt three-wire system Pt1000 to offset the impact of wire resistance.But constant current source driving circuit itself exists and is difficult to overcome one's shortcomings: 1. thermometric resolution is low, and constant current source driving circuit need to be compromised between resolving power and Pt1000 spontaneous heating, and this has just limited the raising of thermometric resolving power; 2. Pt1000 spontaneous heating is large, can only improve in order to improve resolving power the current value that flows through Pt1000, and this just makes Pt1000 spontaneous heating large, thereby affects Pt1000 measuring accuracy; 3. constant current source driving circuit is measured the necessary high precision reference voltage source that uses in order to realize high-precision temperature, and high precision reference current source price is high, and its current value is subject to the impact of envrionment temperature larger, so constant current source driving circuit is also unfavorable for using under severe site environment.

The present invention adopts novel ratio electric bridge temperature-compensation circuit, has both combined common bridge diagram and constant current source driving circuit advantage separately, has overcome again both defects.Temperature Treatment circuit using novel ratio electric bridge temperature-compensation circuit as Pt1000, has great importance to improving blast furnace thermal load accuracy of detection, and the circuit topology of novel ratio electric bridge temperature-compensation circuit as shown in Figure 6.Temperature in the present embodiment and flow signal treatment circuit comprise processes temperature signal circuit and flow signal treatment circuit, wherein processes temperature signal circuit comprises Pt1000 treatment circuit 1 and AD converter 2, described Pt1000 treatment circuit 1 comprises three-wire system Pt1000, subtractor one, subtractor two and measuring bridge circuit, and described measuring bridge circuit comprises the first zero-regulator resistor R1, the second zero-regulator resistor R2, Rt, reference resistance R _refwith current-limiting resistance Ri, above-mentioned the first zero-regulator resistor R1, the second zero-regulator resistor R2, Rt and reference resistance R _refseries connection successively, an end of current-limiting resistance Ri is connected on the first zero-regulator resistor R1 and reference resistance R _refbetween, the other end of current-limiting resistance Ri is connected to power supply, three pins of described three-wire system Pt1000 respectively with reference resistance R _ref, the second zero-regulator resistor R2 with ground be connected; Described subtractor one is got reference resistance R _refthe voltage at two ends is as the reference voltage of AD converter 2, the output terminal of subtractor one is connected with the reference voltage input terminal of AD converter 2, "+" end of subtractor two is connected with the positive pole of three-wire system Pt1000, "-" end of subtractor two is connected with one end of the second zero-regulator resistor R2, the output terminal of subtractor two is connected with the input end of analog signal of AD converter 2, and the digital signal output end of AD converter 2 is connected with low power processor.R1, r2 in Fig. 6, r3 are three-wire system Pt1000 wire equivalent resistance, and current-limiting resistance Ri is excessive for preventing from flowing through the electric current of Pt1000, causes Pt1000 spontaneous heating, causes measuring result to occur larger error.In order to reduce the impact of Pt1000 spontaneous heating on measuring result as far as possible, take into account again the input range of reference voltage simultaneously, the resistance span of current-limiting resistance Ri is: 15K～20K.I is the electric current that flows through Pt1000, and subtractor one, subtractor two can consist of amplifier, also can use the AD converter that both are integrated together, as the AD7705 of ADI company.Can be obtained by Fig. 6:

V _in+＝I(Rt+r2)+U ₀…………………………………………………………(1)

$V_{\mathrm{in}-}=I(\mathrm{Rt}+r2+R_{\mathrm{ref}})\×\frac{R2+r1}{R1+R2+r1}+U_0\·\·\·\left(2\right)$

Above-mentioned formula (1) and (2) can be by U after subtracting each other ₀cancellation obtains:

$V_{\mathrm{in}}=V_{\mathrm{in}+}-V_{\mathrm{in}-}=I(\mathrm{Rt}+r2)-I(\mathrm{Rt}+r2+R_{\mathrm{ref}})\×\frac{R2+r1}{R1+R2+r1}\·\·\·\left(3\right)$

Know again: V _ref=V _ref+-V _ref-=I × R _ref

${\mathrm{AD}}_{\mathrm{out}}=\frac{V_{\mathrm{in}}}{V_{\mathrm{ref}}}=\frac{I(\mathrm{Rt}+r2)-I(\mathrm{Rt}+r2+R_{\mathrm{ref}})\×\frac{R2+r1}{R1+R2+r1}}{I\×R_{\mathrm{ref}}}\×2^N\·\·\·\left(4\right)$

Wherein: N is the figure place of AD converter 2, r1, r2, r3 are the equivalent resistance of tri-lead-in wires of three-wire system Pt1000, and I is the electric current that flows through Pt1000, U ₀for the voltage at Pt1000 lead resistance r3 two ends, R1 is the first zero-regulator resistor, and R2 is the second zero-regulator resistor, R _reffor reference resistance, Rt is Pt1000 RTD resistance.

In formula (4), molecule denominator all contains electric current I, electric current I is divided out:

${\mathrm{AD}}_{\mathrm{out}}=\frac{V_{\mathrm{in}}}{V_{\mathrm{ref}}}=\frac{(\mathrm{Rt}+r2)-(\mathrm{Rt}+r2+R_{\mathrm{ref}})\×\frac{R2+r1}{R1+R2+r1}}{R_{\mathrm{ref}}}\×2^N\·\·\·\left(5\right)$

There is following relation:

Rt＝R ₀+ΔRt

R ₀=R2

………………………………………………………………(6)

R _ref＝R1

r1＝r2＝r3=r

Wherein: R ₀for the resistance of Pt1000 0 DEG C time, R ₀=1000 Ω, Δ Rt is Pt1000 RTD resistance and R ₀difference:

ΔRt=Rt-R ₀。

For people, with co-relation, formula (5) can turn to:

${\mathrm{AD}}_{\mathrm{out}}=\frac{V_{\mathrm{in}}}{V_{\mathrm{ref}}}=\frac{(\mathrm{\ΔRt}+R_0+r)-(\mathrm{\ΔRt}+R_0+r+R_{\mathrm{ref}})\×\frac{R_0+r}{R_{\mathrm{ref}}+R_0+r}}{R_{\mathrm{ref}}}\×2^N\·\·\·\left(7\right)$

Abbreviation obtains:

${\mathrm{AD}}_{\mathrm{out}}=\frac{\mathrm{\ΔRt}}{R_{\mathrm{ref}}+R_0+r}\×2^N\·\·\·\left(8\right)$

Wherein: wire resistance r is in denominator position, and r<1 Ω, much smaller than R ₀and R _refso, can ignore, in traditional bridge diagram, wire resistance r, in molecule position, can cause larger measuring error in the time surveying low temperature.

Formula (7) further abbreviation is:

${\mathrm{AD}}_{\mathrm{out}}=\frac{\mathrm{\&Delta;Rt}}{R_{\mathrm{ref}}+R_0}\&times;2^N\&CenterDot;\&CenterDot;\&CenterDot;\left(9\right)$

$\frac{{\mathrm{\&Delta;Rt}}_{\max }}{R_{\mathrm{ref}}+R_0}\&le;\frac{1}{16}\&CenterDot;\&CenterDot;\&CenterDot;\left(10\right)$

The temperature-measuring range of blast-furnace cooled water: 0～70 DEG C, the standard meter of looking into Pt1000 calibration table Pt1000 resistance and vs. temperature is known, and under 70 DEG C of conditions, the resistance of Pt1000 is: 1270.751 Ω, Δ Rt _max=1270.751-1000=270.751 Ω, the low speed AD converter of N=20, low price, as the AD7799 of ADI company, so the figure place of AD converter is chosen as N=20.According to the inequality relation of formula (10), can obtain: R _ref>=Δ Rt _max× 16-R ₀=270.751*16-1000=3332.016 Ω, gets R _ref=3.6K, the temperature factor of Pt1000 be TCR=3.85 Ω/DEG C, can be obtained by formula (9):

$\mathrm{\&Delta;Rt}=\frac{(R_{\mathrm{ref}}+R_0)\&times;{\mathrm{AD}}_{\mathrm{out}}}{K\&times;2^N}\&CenterDot;\&CenterDot;\&CenterDot;\left(11\right)$

$\mathrm{\&Delta;T}=\frac{\mathrm{\&Delta;Rt}}{\mathrm{TCR}}\&CenterDot;\&CenterDot;\&CenterDot;\left(12\right)$

Make AD in formula (11) _out=1, can obtain the thermometric resolving power of novel ratio electric bridge temperature-compensation circuit for people's formula (12):

Coefficient N=16, TCR=3.85 Ω/DEG C, so R0=1000 Ω can be made as definite value thermometric resolving power only with reference resistance R _refrelevant, irrelevant with reference voltage, the feature according to the known novel ratio electric bridge temperature-compensation circuit of above analysis: 1. resolving power is high, according to the thermometric resolving power thermometric Measurement Resolution of the known novel ratio electric bridge temperature-compensation circuit of formula (13) up to 0.001 DEG C; 2. greatly reduced the impact of wire resistance on measuring accuracy, can have been obtained to the derivation of formula (9) by formula (8); 3. circuit is simple, and on market, many AD converters are integrated together the programmable amplifier of K=2n, subtractor, AD converter now, as the AD7799 of ADI company, and AD7799 low price, performance is good.AD7799 is 24 bit A/D converters, and when application, desirable AD value is high 20, loses low 4.If adopt such AD converter, can greatly simplify circuit, this is also the adaptable Another reason of novel ratio electric bridge temperature-compensation circuit; 4. temperature is floated littlely, adopts integrated AD converter, and from formula (9), the digital quantity ADout of AD converter output is only with R0 and reference resistance R _refrelevant, R0 drift is less than or equal to 0.04%, and temperature is floated the fixed value resistance low price that is less than or equal to 0.025%, has easily bought, so novel ratio electric bridge temperature-compensation circuit is adapted at can carrying out measurement steady in a long-term under rugged environment; 5. digital quantity ADout and the Pt1000 resistance of AD converter output are linear, from formula (9); 6. do not need to use high-precision reference voltage source, formula (9) is known, and the digital quantity ADout of AD converter output is irrelevant with the precision of reference voltage, as long as common service voltage is provided; 7. Pt1000 spontaneous heating is little, from formula (13), the thermometric resolving power of novel ratio electric bridge temperature-compensation circuit is irrelevant with the electric current that flows through Pt1000, constant current source driving circuit will reach high resolving power must improve constant current source electric current, this just causes Pt1000 to produce spontaneous heating (Pt1000 spontaneous heating critical electric current value is 0.5mA), with Ri=15K measuring and calculating, in novel ratio electric bridge temperature-compensation circuit, the electric current that flows through Pt1000 is $I_{\mathrm{pt}1000}=\frac{5}{(2.3+15)\&times;2}=0.145\mathrm{mA},$ Spontaneous heating reduces greatly.

Than digital temperature sensor, the present invention can reach the digital temperature sensor index that is beyond one's reach: 1) high precision, adopt Pt1000 as temperature sensor, coordinate the novel ratio electric bridge temperature-compensation circuit of the present invention's design, the resolving power that equals 10～20 times with measuring accuracy is calculated, measuring accuracy can reach 0.02 DEG C, meets the requirement of blast furnace thermal load to measuring accuracy completely; 2) high stability, Pt1000 is platinum resistance temperature sensor, its characteristic is subject to the impact of external environment little, can be obtained the digital quantity AD of AD converter output by formula (9) _outonly with R ₀and R _refrelevant, R ₀drift is less than or equal to 0.04%, and temperature is floated the fixed value resistance low price that is less than or equal to 0.025%, has easily bought.Novel ratio electric bridge temperature-compensation circuit is adapted at carrying out measurement steady in a long-term under rugged environment, and this is that digital temperature sensor cannot be accomplished.

As shown in Figure 4, in the present embodiment, temperature acquisition terminal comprises ZigBee radio receiving transmitting module, treater, sound and light alarm and state display module, RS485 communication module and power module, described ZigBee radio receiving transmitting module, RS485 communication module is connected with treater respectively, described treater output terminal is connected with sound and light alarm and state display module, this sound and light alarm and state display module are for monitoring in real time the running status of each wireless thermodetector, and carry out sound and light alarm, described power module respectively with sound and light alarm and state display module, RS485 communication module, treater is connected, this power module is for powering to temperature acquisition terminal, this power module is wired power supply form, temperature acquisition terminal gathers by ZigBee radio receiving transmitting module temperature and the flow signal that wireless thermodetector transmits, and be sent to upper computer by gathering the temperature and the flow signal that come, above-mentioned wireless thermodetector is the sensor node of system, temperature acquisition terminal is the aggregation node of system, several temperature acquisition terminals are connected in series successively by RS485 bus, because adopting RS485 bus and upper computer, temperature acquisition terminal carries out communication, in order to reduce the reflection wave producing on communication bus, whole RS485 network is impacted, in the end the communication bus two ends of a temperature acquisition terminal connect the terminal resistance (as shown in Figure 1) of 120 Ω, the communication bus two ends of last temperature acquisition terminal are connected to the terminal resistance of 120 Ω, wireless thermodetector and temperature acquisition terminal composition MESH network, and adopt interrupter duty pattern, this wireless thermodetector and temperature acquisition terminal communication mode are the cableless communication based on Zigbee protocol, the agreement that wireless thermodetector relates to is Zigbee protocol.Temperature acquisition terminal should select suitable place to install according to the position of temperature instrumentation, so that carry out reliable communicating with wireless temperature measurement instrument.The environment for use of temperature acquisition terminal is more random, but also must select degree of protection higher than the housing of IP66 the guard shield as temperature acquisition terminal, to ensure the steady running of temperature acquisition terminal.Temperature acquisition terminal environment for use is relatively better, without using high-temperature cable, uses common shielding cable power supply and communicates by letter.

As shown in Figure 5, in the present embodiment, upper computer comprises serial communication interface routine and configuration software, this serial communication interface routine is for extracting temperature and the flow signal that temperature acquisition terminal transmission comes and carrying out Data Format Transform, and described configuration software is for graphically showing and carrying out storage of history data P; Above-mentioned upper computer is system coordination device, and the communication modes of upper computer and temperature acquisition terminal is RS485 balanced type differential communication.The layered structure of upper computer comprises applied layer and transport layer, the function of applied layer comprise the foundation of database, graphically show and storage of history data P; The function of transport layer comprises data extraction and Data Format Transform.

In conjunction with a kind of high precision blast furnace thermal load wireless detecting system structure of the present embodiment, the concrete steps of its detection method are as follows:

Step 1: temperature and the flow of a blast furnace cooling stave detected at wireless thermodetector interval for 2 minutes, and send temperature and flow signal to temperature acquisition terminal, described wireless thermodetector adopts interrupter duty pattern, be that wireless thermodetector makes all chips in instrument in holding state under normal circumstances, after only receiving the request instruction of father node, just all chips are waken up, after waking up, carrying out AD adopts and medium filtering processing, and will collect temperature and flow signal sends, after being sent out, temperature and flow signal get back to again holding state; In the present invention, the interrupter duty pattern of wireless thermodetector, for saving electric energy, extends battery very crucial, and programflow chart as shown in Figure 3;

Step 2: temperature acquisition terminal gathers by ZigBee radio receiving transmitting module temperature and the flow signal that wireless thermodetector transmits, and be sent to upper computer by gathering the temperature and the flow signal that come; A temperature acquisition terminal can gather temperature and the flow signal that more than 16 wireless thermodetector sends, so the temperature acquisition terminal quantity using in blast furnace thermal load wireless detecting system of the present invention is few more a lot of than wireless thermodetector, and the power consumption of temperature acquisition terminal is larger, be not suitable for passing through powered battery.So temperature acquisition terminal is by wired power supply, and carries out communication by RS485 bus and upper computer, reliable more economically;

Step 3: upper computer calculates blast furnace thermal load Q:Q=Δ T × F × CPn by following formula, wherein: Δ T=∑ 0T _{temperature at discharging condensate}/ n-T _{inflow temperature}, Δ T is water temperature difference; F: cooling water flow; CPn: tuning coefficient, CPn=4.1817/10=0.41817.As shown in Figure 5, the major function of upper computer is that blast furnace cooling stave thermal load situation is graphically shown to upper computer design frame chart, and saves historical data.

Below schematically the present invention and embodiment thereof are described, this description does not have restricted, and shown in accompanying drawing is also one of embodiments of the present invention, and actual structure is not limited to this.So, if those of ordinary skill in the art is enlightened by it, in the situation that not departing from the invention aim, without the creationary frame mode similar to this technical scheme and the embodiment of designing, all should belong to protection scope of the present invention.

Claims (2)

1. a high precision blast furnace thermal load wireless detecting system, comprises wireless thermodetector, temperature acquisition terminal and upper computer, it is characterized in that:

Described wireless thermodetector comprises Pt1000 temperature sensor, flow sensor, temperature and flow signal treatment circuit, low power processor, ZigBee radio receiving transmitting module and power module, described Pt1000 temperature sensor is intake for detection of blast-furnace cooled water, temperature at discharging condensate, described flow sensor is for detection of blast-furnace cooled water flow, above-mentioned Pt1000 temperature sensor, the signal output part of flow sensor is connected to temperature and flow signal treatment circuit, temperature and flow signal treatment circuit, ZigBee radio receiving transmitting module is connected with low power processor respectively, described power module respectively with Pt1000 temperature sensor, flow sensor, temperature and flow signal treatment circuit, low power processor, ZigBee radio receiving transmitting module is connected, and this power module is for powering to wireless thermodetector, and described power module is battery, and wireless thermodetector detects temperature and the flow of blast furnace cooling stave in real time, and sends temperature and flow signal to temperature acquisition terminal, wherein: described temperature and flow signal treatment circuit comprise processes temperature signal circuit and flow signal treatment circuit, wherein processes temperature signal circuit comprises Pt1000 treatment circuit (1) and AD converter (2), described Pt1000 treatment circuit (1) comprises three-wire system Pt1000, subtractor one, subtractor two and bridge diagram, and described bridge diagram comprises the first zero-regulator resistor R1, the second zero-regulator resistor R2, Rt, reference resistance R _refwith current-limiting resistance Ri, above-mentioned the first zero-regulator resistor R1, the second zero-regulator resistor R2, Rt and reference resistance R _refseries connection successively, an end of current-limiting resistance Ri is connected on the first zero-regulator resistor R1 and reference resistance R _refbetween, the other end of current-limiting resistance Ri is connected to power supply, three pins of described three-wire system Pt1000 respectively with reference resistance R _ref, the second zero-regulator resistor R2 with ground be connected, described subtractor one is got reference resistance R _refthe voltage at two ends is as the reference voltage of AD converter (2), the output terminal of subtractor one is connected with the reference voltage input terminal of AD converter (2), "+" end of subtractor two is connected with the positive pole of three-wire system Pt1000, "-" end of subtractor two is connected with one end of the second zero-regulator resistor R2, the output terminal of subtractor two is connected with the input end of analog signal of AD converter (2), and the digital signal output end of AD converter (2) is connected with low power processor,

Described temperature acquisition terminal comprises ZigBee radio receiving transmitting module, treater, sound and light alarm and state display module, RS485 communication module and power module, described ZigBee radio receiving transmitting module, RS485 communication module is connected with treater respectively, described treater output terminal is connected with sound and light alarm and state display module, this sound and light alarm and state display module are for monitoring in real time the running status of each wireless thermodetector, and carry out sound and light alarm, described power module respectively with sound and light alarm and state display module, RS485 communication module, treater is connected, this power module is for powering to temperature acquisition terminal, this power module is wired power supply form, temperature acquisition terminal gathers by ZigBee radio receiving transmitting module temperature and the flow signal that wireless thermodetector transmits, and be sent to upper computer by gathering the temperature and the flow signal that come, above-mentioned wireless thermodetector is the sensor node of system, temperature acquisition terminal is the aggregation node of system, several temperature acquisition terminals are connected in series successively by RS485 bus, the communication bus two ends of last temperature acquisition terminal are connected to terminal resistance, wireless thermodetector and temperature acquisition terminal composition MESH network, and adopt interrupter duty pattern, this wireless thermodetector and temperature acquisition terminal communication mode are the cableless communication based on Zigbee protocol, and the agreement that wireless thermodetector relates to is Zigbee protocol,

Described upper computer comprises serial communication interface routine and configuration software, this serial communication interface routine is for extracting temperature and the flow signal that temperature acquisition terminal transmission comes and carrying out Data Format Transform, and described configuration software is for graphically showing and carrying out storage of history data P; Above-mentioned upper computer is system coordination device, and the communication modes of upper computer and temperature acquisition terminal is RS485 balanced type differential communication.

2. a kind of high precision blast furnace thermal load wireless detecting system according to claim 1, it is characterized in that: described wireless thermodetector adopt degree of protection higher than the housing of IP67 as guard shield, described temperature acquisition terminal adopt degree of protection higher than the housing of IP66 as guard shield.