RU2498555C1 - Temperature control system of mound of fine materials - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to devices of temperature control of bulk materials during their prolonged storage and can be used in devices that control the temperature conditions in silage warehouses. The system comprises the M-1 temperature measurement device, each of which comprises thermal hanger with N temperature sensors located in the local control zones, and also a computer connected to the actuator. The input and output of each of the M temperature measurement devices are output bi-directional communication line and are connected to the respective inputs of the bi-directional bus driver connected to the computer system bus, which output is connected to the display device.

EFFECT: invention provides increased operation speed and accuracy of determining the focal points of danger in the mound, as well as simplification of installation and repair of the device.

9 cl, 2 dwg

Description

The invention relates to devices for controlling the temperature of bulk materials during their long-term storage and can be used in devices that control the temperature regime in silo-type warehouses.

Known devices for measuring the temperature of bulk materials, for example.with. USSR No. 972262 in class G01K 7/16 "Device for measuring the temperature of bulk materials", and.with. USSR No. 1071267 for class A01F 25/00 "Device for monitoring the temperature regime of the embankment in elevators", application for invention RU 94023973 A1 and RU 2002108028 A1 in class G01K 13/10.

Known devices include devices for processing measurement results, a display and suspension unit with successive resistance thermometers made in the form of sections of a multi-turn coil wound on a support cable running along the entire height of the controlled material and enclosed in a flexible shell, and a measuring circuit. The cable with resistance thermometers form a suspension streamlined by bulk material.

A disadvantage of the known devices is the low accuracy of temperature measurement, since resistance thermometers have low resistance, which changes slightly with temperature. Due to the serial connection of switching, measuring and connecting communication lines, various resistances are added to the resistances of resistance thermometers, which leads to the summation of the total measurement error, which is often unacceptable. The connecting wires have parameters close to the values of the resistance thermometers and depend on the length and transition resistance of the contacts. To correct the measured temperature, corrections are often made that do not provide the necessary accuracy.

The closest in technical essence to the proposed is a device for controlling the temperature of bulk fine materials according to the patent for utility model 51453, A01F 25/00, taken as a prototype.

Figure 1 presents a diagram of a prototype device, where it is indicated:

1 - thermal suspension; 1 ₁ ÷ 1 _N - temperature sensors; 5 - register of movement of the temperature field; 8 - computers; 10 - actuator; 12 - unit for measuring the dynamics of the temperature field; 13 - block calculating the coordinates of the heat sources; 14 is a block for processing information and generating control commands; 15 - block interference protection.

The prototype device contains a thermal suspension 1 with temperature sensors 1 ₁ ÷ 1 _N located in local zones, a computer 8, including a block of interference protection 15, a unit for measuring the dynamics of the temperature field 12, a register of movement of the temperature field 5, a block for calculating the coordinates of the heating sources 13, a unit for processing information and generating control commands 14, as well as an actuator 10.

Temperature sensors 1 ₁ ÷ 1 _{N are} divided into groups I, II, etc. Four temperature sensors 1 ₁ ÷ 1 _N are placed in each local zone, the distance between the sensors should be at least ten times less than the distance between the centers of the control zones.

The prototype device operates as follows.

In the initial state, the signals from the temperature sensors 1 ₁ ÷ 1 _{N are} continuously supplied to the computer 8. In the computer 8, the initial processing of signals from the temperature sensors 1 ₁ ÷ 1 _N takes place, as a result of which the initial temperature field is formed in the information processing unit and the formation of control commands 14 With the further functioning of the device in block 12, the dynamics of the temperature field of the embankment is recorded, and in block 13 the coordinates of the resulting heat sources are calculated. The distance between the temperature sensors 1 ₁ ÷ 1 _N in the local control zone is not less than ten times less than the distance between the centers of the control zones. This allows you to record minor relative temperature changes in the controlled area and not respond to large, but smooth temperature changes in the entire embankment.

The received signals from the temperature sensors 1 ₁ ÷ 1 _N in blocks 15 and 12 are compared with the reference values, and when deviating from the set value in blocks 5 and 13, the temperature gradient is recorded and the location coordinates of the resulting heat sources are calculated. The signals from the computer blocks 15, 12, 5, 13 are sent to block 14. In the computer block 14, all the information received from the blocks 15, 12, 5, 13 is processed, after which a signal is issued to the actuator 10 to eliminate hot spots.

The disadvantage of the prototype device is the low speed measurement of foci of danger.

The objective of the proposed technical solution is to increase the speed of measuring foci of danger.

To solve this problem, a temperature control system for bulk materials containing a temperature measuring device, including a thermal suspension with N temperature sensors located in local control zones, the distance between the sensors must be at least ten times less than the distance between the centers of the local control zones, as well as a computer connected to an actuator, according to the invention, (M-1) temperature measuring devices are introduced, wherein the input and output of each of the M tempo measuring devices The temperatures are an output bidirectional communication line and are connected to the corresponding inputs of a bi-directional bus driver connected to a computer system bus, the output of which is connected to an indication device.

The scheme of the proposed temperature control system for the bulk of bulk materials is shown in FIG. 2, where indicated:

1 - thermal suspension; 1 ₁ ÷ 1 _N - temperature sensors; 2 - analog-to-digital converter (ADC); 3 - direct current source; 4 - decoder; 5 - universal register; 6 - universal asynchronous transceiver; 7 - bidirectional bus driver; 8 - computers; 9 - indication device; 10 - actuator; 11 ₁ ÷ 11 _M - temperature measuring devices.

The proposed temperature control system contains M temperature measuring devices 11 ₁ -11 _M , each of which is connected to the corresponding inputs of the bi-directional bus driver 7 connected to the computer system bus 8, the outputs of which are connected to the indicating device, by a corresponding bi-directional communication line (for example, a current loop) 9 and actuator 10, respectively. Each temperature measuring device 11 includes a thermal suspension 1 and an mounting head including an ADC 2, a DC source 3, a decoder 4, a universal register 5 and a universal asynchronous transceiver 6. Moreover, the thermal suspension 1 consists of N temperature sensors 1 ₁ -1 _N.

The input of the decoder 4 is connected to the first output of the universal register 5, the second output of which is connected to the input of the DC source 3; the input of the universal register 5 is connected to the output bus of the universal transceiver 6, the input and output of which are a bi-directional communication line of the temperature measuring device 11. In addition, the outputs of the decoder 4 are connected to the inputs of the corresponding temperature sensors 1 ₁ ÷ 1 _N , the outputs of which are combined and connected to the output DC source 3 and the input of the ADC 2, the output of which is connected to the input of the universal transceiver 6 via the bus.

As temperature sensors, resistance thermometers can be used, for example, both copper (TCM-Cu) and platinum (TSP-Pt), thermocouples, for example, TPP (Platinum - 13% rhodium / platinum), as well as temperature sensors, for example , Heraeus companies: semiconductor temperature sensors (semiconductor thermistors) info@sensorica.ru).

In this case, as a temperature measuring device 11, a Dallas Semiconductor temperature sensor (www.maxim-ic.co) can be used.

Indication device 9 is used to monitor the dynamics of temperature changes in the silo (embankment), allows the use of animation elements for greater clarity, can be made in the form of an indicator panel and connected in parallel with the computer monitor 8.

The ability to connect the ZVM 8 to the Internet allows you to monitor the status of the silos, being at a remote distance from their location, which extends the functionality of the proposed device. As a computer can be used, for example, a laptop, communicator.

The actuator is known from the prior art and can be performed, for example, as described in RF patent 2425304.

The work of the proposed system is provided in two main modes: settings and automatic.

The proposed system in configuration mode works as follows.

In the setup mode, the proposed system, using a computer signal 8, turns on the system and then polls the temperature sensors 1 ₁ ÷ 1 _N in order to calibrate their temperature characteristics. In this case, the choice of a temperature measuring device 11 with thermal suspensions 1 and installed temperature sensors 1 ₁ ÷ 1 _N.

The number (M) of temperature measuring devices with thermal suspensions in the storage tank (silo, embankment) depends on its geometric dimensions (cross-sectional area) and the thermophysical characteristics of the controlled bulk material

, $$\text{M}=\left\{\left[\frac{\text{S}\cdot \text{<figure-callout id="9" label="δ" filenames="00000006.png" state="{{state}}">δ</figure-callout>}}{\text{9}}+\text{one}\right]\right\}$$

,

where S is the cross-sectional area of the silo (embankment);

δ is the coefficient that determines the thermal conductivity of the controlled material.

So, for example, with a silo cross-sectional area equal to S = 25 m ² and δ = 1

, при δ=0,2, М≈2. $$\text{M}=\left\{\left[\frac{\text{25}\cdot \text{one}}{\text{9}}+\text{one}\right]\right\}\approx \text{four}$$

, with δ = 0.2, M≈2.

The number of temperature sensors in the suspension 1 of the temperature measuring device 11 is calculated based on the height of the embankment (silo, capacity) of the controlled material.

, где L - высота силоса (насыпи). $$\text{M}=\left\{\left[\frac{\text{<figure-callout id="9" label="L" filenames="00000006.png" state="{{state}}">L</figure-callout>}}{\text{9}}+\text{one}\right]\right\}$$

where L is the height of the silo (embankment).

For example, with a silo height of L = 14 m

$$\text{N}=\left[\frac{\text{fourteen}}{\text{2}}\right]+\text{one}=\text{8}$$

The measurement results are sent to computer 8, where they are processed and stored. Based on the calculations performed in computer 8, a map of the temperature field in the silo (embankment) is compiled. This card is the source for working in supervisor and automatic modes.

In supervisor mode, the results of mathematical processing are reflected on the screen of the monitor (display device) and serve as a source of information for the operator. Automatic mode involves the issuance of control commands from the computer 8 directly to the actuator 9 to prevent emergency situations.

After the setup mode, the computer 8 enters the operating mode. In this mode, sequential continuous measurement of the temperature in the embankment takes place, processing of the measurement results and comparison with data stored in the computer 8. Based on the comparison and processing, the computer 8 provides information to the indicating device 9.

In the event that foci of elevated temperature are detected, caused, for example, by self-heating processes, an actuator 10 receives a command from the computer 8. The actuator 10 gives a command to eliminate the emergency. The result of this command can be, for example, an urgent unloading of a silo or a signal to the emergency fire extinguishing system about the need to suppress the self-heating zone.

The proposed solution meets the criterion of industrial applicability, because can be carried out by known technical means. For example, a bi-directional bus former 7 can be made as shown in Fig. 14.11, C.313; universal asynchronous transceiver 6 - on C.260; current loop - on С.270, fig. 12.18 of the book of C. Gilmore. "Introduction to microprocessor technology", M., Mir, 1984.

Compared with the prototype, the proposed device can improve the speed and accuracy of determining the foci of danger in the embankment due to the fact that in the prototype there is an alternate interrogation of each temperature sensor, and this process takes a long time, and several thermal suspensions 1 are interrogated immediately (in parallel) in the proposed system, data arrive faster via a two-wire communication line and processed by a computer, and when displayed on the display panel, the whole picture of the temperature field in the mound from all temperature measuring devices is visible, ystvovannyh in each mound.

In addition, installation and repair of the device are simplified by reducing the number of wires in the communication line and using modern semiconductor multifunction devices based on micro- and nanoelectronics.

Claims (9)

1. A temperature control system for bulk materials containing a temperature measuring device including a thermal suspension with N temperature sensors located in local control zones, and the distance between the sensors should be at least ten times less than the distance between the centers of the local control zones, as well as a computer connected to the actuator, characterized in that M-1 temperature measuring devices are introduced, while the input and output of each of the M temperature measuring devices are output double The pressure line connection and are connected to respective inputs of a bidirectional bus driver associated with the computer system bus, the output of which is connected to the display device. 2. The system according to claim 1, characterized in that each temperature measuring device includes a thermal suspension with N temperature sensors, the outputs of which are combined and connected to the output of the DC source and the ADC input, the output of which is connected by a bus to the input bus of the universal asynchronous transceiver, one output whose bus is connected to the input of the universal register, the first output of which is connected to the input of the decoder by the bus, the outputs of which are connected to the inputs of the corresponding temperature sensors, in addition, the second the course of the universal register is connected to the input of a DC source, and the other output bus of the universal transceiver is an output bidirectional communication line of the temperature measuring device. 3. The system according to claim 2, characterized in that the number of sensors in the temperature measuring device is determined based on the height of the embankment. 4. The system according to claim 1, characterized in that the number of temperature measuring devices is calculated based on the cross-sectional area of the storage tank and the thermophysical characteristics of the controlled bulk material. 5. The system according to claim 1, characterized in that the display panel is used as an indication device. 6. The system according to claim 1, characterized in that the computer is configured to connect to the Internet. 7. The system according to claim 1, characterized in that the communicator is used as a computer. 8. The system according to claim 1, characterized in that the current loop is used as a communication line. 9. The system according to claim 1, characterized in that a radio line is used as a communication line.

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