A real-time monitoring system and method for concrete mixture outlet temperature

Abstract

A system and method for real-time monitoring of the temperature at the outlet of a concrete mixture, the system includes a temperature sensing device arranged at a receiving hopper, the temperature sensing device is connected to a measurement and control unit, and the measurement and control unit is connected to a front-end host. The system also includes a discharge sensing device, the discharge sensing device is used to sense the phase current of the mixing motor, the discharge sensing device is connected to the front-end host; the front-end host is connected to a server. The system also includes a client, the client accesses the server, performs basic data setting and information query on the system; the server is used to store the basic data of the system and the data uploaded by the front-end host, and performs calculations, processing and display on the data. Through a system and method for real-time monitoring of the temperature at the outlet of a concrete mixture, the outlet temperature of the concrete mixture can be obtained in real time, data support can be provided to ensure that the outlet temperature is qualified, and it is convenient for the concrete mixing system to take temperature control measures in a timely manner. Compared with the existing methods, the monitoring method of the present invention is more convenient and has a higher monitoring frequency.

Description

Technical Field

[0001] The invention relates to the field of concrete mixture outlet temperature monitoring, and in particular to a concrete mixture outlet temperature real-time monitoring system and method. Background Art

[0002] During the production and operation of a concrete mixing plant, for concrete with temperature control requirements, it is usually necessary to monitor its temperature when it leaves the mixer. In the prior art, it is monitored manually, which is divided into contact and non-contact methods. The contact method is: take a concrete sample, insert a thermometer into it, and read the temperature; the non-contact method is: when the mixer is discharging, aim a temperature gun at the discharged concrete and read the temperature. Both methods require manual supervision, which is time-consuming and labor-intensive. There is a lot of dust at the machine outlet, which is not good for health. The detection frequency is low and the temperature feedback is not timely.

[0003] Timely acquisition of the temperature of the concrete mixture at the outlet is a prerequisite for ensuring that the concrete meets the temperature control requirements. According to the measured concrete temperature, timely measures can be taken to prevent the outlet temperature from exceeding the control range. For example, in order to prevent the occurrence of cracks after the concrete hardens and reduce the temperature entering the warehouse, a certain project needs to control the concrete outlet temperature to no more than 7°C. According to the measured outlet temperature, the amount of ice chips in the concrete batching, the mixing water temperature, and the aggregate precooling temperature can be adjusted in time.

[0004] In addition, with the development of today's sensor technology, computer technology and Internet of Things technology, the foundation has been laid for the real-time monitoring of the concrete mixture outlet temperature. Summary of the invention

[0005] The present invention provides a real-time monitoring system and method for the temperature of a concrete mixture outlet. Through the system and method, the temperature of the concrete mixture outlet can be obtained in real time, providing data support for ensuring that the outlet temperature is qualified, and facilitating the concrete mixing system to take temperature control measures in a timely manner. Compared with the existing method, the monitoring method of the present invention is more convenient and has a higher monitoring frequency.

[0006] The technical solution adopted by the present invention is:

[0007] A real-time monitoring system for the temperature of a concrete mixture outlet, the system comprising:

[0008] A temperature sensing device is arranged at the receiving hopper, the temperature sensing device is connected to the measurement and control unit, and the measurement and control unit is connected to the front host;

[0009] The system also includes a discharge sensing device, which is used to sense the phase current of the mixing motor. The discharge sensing device is connected to a front-end host; the front-end host is connected to a server.

[0010] The temperature sensing device comprises a dust-blocking valve, and the dust-blocking valve is connected to the front host.

[0011] The temperature sensing device includes a fixing frame, a temperature sensor, a fixing ring, a pipe head, a pipe body and a pipe tail; the fixing ring is provided with an internal thread, and a flange-shaped protrusion is provided at one end of the fixing ring; the temperature sensor is screwed into the fixing ring through the thread and is installed in the pipe body together with the fixing ring; the flange-shaped protrusion of the fixing ring is exposed at one end of the pipe body and is in close contact with the end; one end of the pipe body is screwed into the joint with the internal thread of the dust block valve and is connected to one end of the dust block valve, and the pipe head is connected to the other end of the dust block valve; the pipe tail is at the other end of the pipe body, and the power supply and data cables of the temperature sensor pass through the center hole of the pipe tail; the pipe head and the pipe body are installed on the upper edge of the receiving hopper through a fixing frame.

[0012] The unloading sensing device is a mixer working current acquisition module, which senses the phase current of the mixer motor through the current acquisition module and transmits the sensing result to the front host.

[0013] The measurement and control unit includes a temperature signal processing module, a data transmission module and a control module. The measurement and control unit receives the temperature signal collected by the temperature sensing device, converts the data and transmits it to the front host, receives the opening and closing instructions of the dust barrier valve sent by the front host, and controls the opening and closing of the dust barrier valve.

[0014] The front host downloads data from the server, receives and stores data from the unloading sensing device and the measurement and control unit, calculates the data, generates control instructions, sends valve opening and closing and temperature collection instructions to the measurement and control unit, and uploads the collected temperature and current data to the server in a timely manner.

[0015] The system also includes a client, which accesses a server to set basic data and query information for the system; the server is used to store basic system data and data uploaded by a front-end host, and to perform calculations, processing and display on the data.

[0016] A method for real-time monitoring of the temperature of a concrete mixture outlet is provided. The working current value of the mixer is collected at intervals and recorded. The process line of the current value changing with time is recorded. The median of the latest a1 current values ​​is calculated, which is recorded as I0. The median of the previous a2 current values ​​adjacent to the latest measured value is calculated, which is recorded as I -1 , assuming the critical current of mixer unloading is I s , when I0 s -1 ​​If the condition is established, it is considered that the mixer has started to discharge. At this time, send the dust valve opening command, wait for the dust valve to be fully opened, start recording the measured value of the temperature sensor, record once at a certain interval, record a3 times, stop recording, and close the dust valve; take the median of the a4 measured temperature values ​​as the representative value of the outlet temperature of the batch of concrete mixture. When the current measurement value meets the discharge judgment condition again, the temperature measurement of the next batch of concrete begins.

[0017] Mixer unloading critical current I s The critical current determination method is: observe the operating status of the mixer, correspond to the specific concrete type and single-plate mixing volume, record the working current value of the mixer at the start of unloading, record no less than a5 values, and take the middle value as the unloading critical current I s .

[0018] The present invention discloses a system and method for real-time monitoring of the temperature of a concrete mixture outlet, and has the following beneficial effects: 1) A front-end host is provided in the system composition of the present invention, and is located near a temperature sensing device, a discharge sensing device, and a measurement and control unit. The front-end host directly receives and stores the current data collected by the discharge sensing device, calculates and generates instructions by itself, and sends instructions to the measurement and control unit, receives, stores and processes the collected temperature data, and then communicates with the server through the front-end host, rather than directly communicating with the server and the discharge sensing device and the measurement and control unit. This architecture enables the front-end host to communicate with nearby on-site facilities in a more stable close-range manner, ensures the stability and real-time performance of temperature monitoring, and can continue data collection when the front-end host and the server are temporarily disconnected from communication. Long-distance wireless network communication can be used between the front-end host, the server, and the client. In this way, the system can achieve data monitoring in a wider geographical span and stable collection of on-site data. 2) The temperature sensor uses an infrared thermometer, which can realize non-contact temperature measurement of the object being measured, avoiding the wear of the temperature sensor and the slowness of temperature perception caused by the contact measurement method. 3) The structural setting of the temperature sensing device, the fixed ring, the dust valve, the pipe head, the pipe body and the pipe tail together form a closed space, so that the temperature sensor is isolated from the outside world during the non-temperature measurement period, reducing the pollution of the optical probe in the temperature sensor by the dust and water vapor in the production environment of the mixing station. During the unloading period, the dust valve can be opened, and the light enters the sensor, so that the device can measure the temperature normally. 4) The unloading sensing device determines the unloading state by monitoring the working current of the mixer, so that when the system is built, only a current transformer needs to be looped on the power supply line of the mixer, avoiding deep intervention in the circuit of the mixing system, reducing interference with the mixing system, and improving the convenience of system construction. 5) The present invention uses the method of taking the median instead of the average value when judging the unloading state, calculating the representative value of the machine outlet temperature, and determining the critical current of unloading, which can effectively avoid the adverse effects of abnormal values ​​collected in the complex electromagnetic environment on the results on the site, and improve the accuracy of the value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the monitoring system of the present invention.

[0020] Figure 2 This is the curve diagram of the working current change process of the mixer.

[0021] Figure 3 It is a real-time temperature process curve chart.

[0022] Figure 4 This is the process curve diagram of the representative value of the outlet temperature. DETAILED DESCRIPTION

[0023] like Figure 1As shown, a real-time monitoring system for the temperature of a concrete mixture outlet is provided, and the system comprises a temperature sensing device 1, a discharge sensing device 2, a measurement and control unit 3, a front-end host 4, a server 5, and a client 6.

[0024] The temperature sensing device 1 is arranged at the upper edge of the receiving hopper 14, and is composed of a fixing frame 7, a temperature sensor 8, a fixing ring 9, a dust-proof valve 10, a pipe head 11, a pipe body 12, and a pipe tail 13. Among them, the temperature sensor 8 is a cylindrical infrared thermometer, and the optical resolution (ratio of the measuring distance to the target diameter) is not less than 20, and the column body is provided with an external thread; the fixing ring 9 is a section of plastic pipe, provided with an internal thread, and a flange-shaped protrusion is provided at one end; the dust-proof valve 10 is an electric ball valve, and the tubular joints at both ends of the valve body are provided with internal threads; the pipe head 11 is a section of metal pipe, and one end is provided with an external thread; the pipe body 12 is a section of metal pipe, and both ends are provided with external threads; the pipe tail 13 is a metal end cover, provided with an internal thread, and the center of the end cover is provided with a wire outlet hole. The fixing frame 7 is a section of bent steel plate, and two pipe clamps are welded on it in parallel.

[0025] The temperature sensor 8 is screwed into the fixing ring 9 through threads and installed into the pipe body 12 together; the flange-shaped protrusion of the fixing ring 9 is exposed at one end of the pipe body 12 and is in close contact with the end, and this end of the pipe body 12 is screwed into the joint with internal threads of the dust valve 10 and connected to one end of the dust valve 10; the pipe head 11 is connected to the other end of the dust valve 10 through threads; the pipe tail 13 is connected to the other end of the pipe body 12 through threads, and the power supply and data lines of the temperature sensor 8 pass through the center hole of the pipe tail 13. The fixing frame 7 clamps the pipe body 12 and the pipe head 11 through two pipe clamps, and its bent steel plate part is fixed at a suitable position on the upper edge of the receiving hopper 14, and the fixed angle can make the longitudinal axis of the temperature sensor 8 intersect with the concrete 15 in the receiving hopper 14.

[0026] The unloading sensing device 2 is a mixer working current acquisition module, which senses the phase current of the mixer motor through a current transformer and transmits the sensing result to the front host 4.

[0027] The measurement and control unit 3 includes a temperature signal processing module, a data transmission module and a control module, which is connected to the temperature sensing device 1 and the front host 4, receives the temperature signal collected by the temperature sensing device 1, transmits the data to the front host 4 after data conversion, receives the opening and closing instructions of the dust barrier valve 10 sent by the front host 4, and controls the opening and closing of the dust barrier valve 10.

[0028] The front-end host 4 downloads data from the server 5, receives and stores data from the unloading sensing device 2 and the measurement and control unit 3, calculates the data, generates control instructions, sends valve opening and closing and temperature collection instructions to the measurement and control unit 3, and uploads the collected temperature and current data to the server 5 in a timely manner; the client 6 accesses the server 5 to set basic data and query information for the system; the server 5 is used to store the system basic data and the data uploaded by the front-end host 4, and calculates and displays the data.

[0029] Implementation and data processing methods:

[0030] 1) Build a real-time monitoring system for the temperature of the concrete mixture outlet, so that the temperature sensing device 1, the discharge sensing device 2, the measurement and control unit 3, the front host 4, the server 5 and the client 6 can be connected and communicated smoothly;

[0031] 2) When installing the temperature sensing device 1, make the center of the concrete mixture to be measured be on the longitudinal axis of the temperature sensor 8, and make the ratio of the distance between the concrete mixture and the temperature sensor 8 to the projected diameter of the concrete mixture on the vertical plane of the longitudinal axis of the temperature sensor 8 less than 20;

[0032] 3) Collect the working current value of the mixer at a time interval of 1 to 2 seconds, record the process line of the current value changing with time, calculate the median of the latest 5 current values, recorded as I0, calculate the median of the previous 5 current values ​​adjacent to the latest measured value, recorded as I -1 , assuming the critical current of mixer unloading is I s , when I0 s -1 If the condition is established, it is considered that the mixer has started to discharge. At this time, send the dust valve 10 opening command, wait for the dust valve to be fully opened, start recording the measured value of the temperature sensor 8, record once every 2 seconds, record 20 times, stop recording, and close the dust valve 10. Take the median of the 20 measured temperature values ​​as the representative value of the outlet temperature of the batch of concrete mixture. When the current measurement value meets the discharge judgment condition again, the temperature measurement of the next batch of concrete begins.

[0033] 4) Critical current I of mixer unloading s The critical current determination method is: observe the operating status of the mixer, correspond to the specific concrete type and single-plate mixing volume, record the working current value of the mixer at the start of unloading, record no less than 10 values, and take the middle value as the unloading critical current I s .

[0034] Example:

[0035] ​​There is a concrete mixing station at a hydropower station site. On the second floor of the station, there is a receiving hopper under the mixer outlet. The concrete mixture discharged from the mixer falls into the receiving hopper 14 and stays for a short time before continuing to fall into the transport vehicle. The temperature sensing device 1 is welded and fixed on the upper edge of the receiving hopper 14 and the supporting steel column of the mixer, so that its probe is aimed at the position at the bottom of the receiving hopper 14 where more concrete is received. The measurement and control unit 3 is tied and fixed on the railing inside the station. The front host 4 and the unloading sensing device 2 are placed on the top surface of the control cabinet in the central control room, and the current transformer of the unloading sensing device 2 is buckled on the power supply line of the mixer in the distribution cabinet.

[0036] The temperature sensor 8 uses a CK-01A infrared temperature sensor with an output signal of 4-20mA.

[0037] The unloading sensing device 2 uses the DAM3505N current acquisition module.

[0038] The temperature signal processing module in the measurement and control unit 3 uses the DAM4502 analog-to-485 module, the data transmission module uses the WF5010 WIFI-DTU, and the control module uses the DAM0100 serial port relay control board.

[0039] The front host 4 is an industrial computer. The server 5 is a cloud server.

[0040] C25 concrete, 3 cubic meters per tray, corresponding unloading critical current I s Determined to be 125A. After the real-time monitoring system for the temperature at the outlet of concrete mixture is built, it starts to run. The unloading sensing device 2 sends the collected working current of the mixer to the front host 4 in real time. The front host 4 receives and stores the current data, and analyzes and judges. When it is found that it meets the unloading conditions, it sends a temperature collection instruction to the measurement and control unit 3. The measurement and control unit 3 receives the instruction and instructs the temperature sensing device 1 to open the dust valve 10. The temperature starts to be collected 4 seconds after the valve opening instruction is sent and is stored in the front host 4. Each time the dust valve 10 is opened, 20 temperature values ​​are collected, and the value is taken as the representative value of the outlet temperature of the current plate of concrete, which is also stored in the front host 4. The client 6 can access the cloud server remotely through the Internet. The server 5 retrieves data from the front host 4 and displays it on the client 6.

[0041] Typical mixer working current change process curve is as follows Figure 2 The real-time temperature process curve of the corresponding period is shown in Figure 3 The process curve of the representative value of the outlet temperature in the corresponding period is shown in Figure 4 shown.

[0042] Figure 2This is the curve chart of the working current change process of the mixer of "Unit 2, Building 2". The time range is: 2021-07-28 16:40 to 2021-07-28 16:54. The horizontal axis is time and the vertical axis is the current value. Figure 2 The middle horizontal line with arrows corresponds to the current of 125 A. It can be seen that during this period, the current process line crosses the 125 A current line three times, corresponding to three times of unloading. Figure 3 There are 3 temperature sequences in Figure 2 3 times of unloading.

[0043] The statistical result of the absolute error range of temperature measurement of the real-time monitoring system for the temperature of the concrete mixture outlet is ±0.6℃, which can meet the accuracy requirements of dynamically sensing the temperature of the outlet in concrete production.

[0044] The present invention discloses a real-time monitoring system and method for the temperature of a concrete mixture outlet. The system uses a light-sensitive temperature sensor to sense the temperature of the concrete mixture discharged from the mixer outlet in real time. The temperature sensor 8 is fixed in a metal pipe with an electric ball valve to reduce the pollution of dust and water vapor to the optical probe of the temperature sensor. The system uses a real-time sensing method for the working current of the mixer to judge the mixer discharge, so as to open the electric ball valve on time, open the optical path, and implement temperature measurement. The system uses a front-end host 4 plus a server 5 architecture to implement data management. The system realizes real-time monitoring of the concrete outlet temperature in a harsh environment. The system runs stably and is easy to use, which lays a foundation for real-time control of the outlet temperature in concrete production.

Claims

1. A real-time monitoring system for the temperature of a concrete mixture outlet, characterized in that The system includes: A temperature sensing device (1) is arranged at the receiving hopper (14), the temperature sensing device (1) is connected to a measurement and control unit (3), and the measurement and control unit (3) is connected to a front-end host (4); The system also includes a discharge sensing device (2), the discharge sensing device (2) is used to sense the phase current of the mixing motor, the discharge sensing device (2) is connected to a front-end host (4), and the front-end host (4) is connected to a server (5); The temperature sensing device (1) comprises a fixing frame (7), a temperature sensor (8), a fixing ring (9), a pipe head (11), a pipe body (12), and a pipe tail (13); The fixing ring (9) is provided with an internal thread, and one end of the fixing ring (9) is provided with a flange-shaped protrusion. The temperature sensor (8) is screwed into the fixing ring (9) through the thread and is installed in the pipe body (12) together with the fixing ring (9). The flange-shaped protrusion of the fixing ring (9) is exposed at one end of the pipe body (12) and is in close contact with the end. One end of the pipe body (12) is screwed into a joint with an internal thread of the dust-blocking valve (10) and connected to one end of the dust-blocking valve (10), and the pipe head (11) is connected to the other end of the dust-blocking valve (10); The tube tail (13) is at the other end of the tube body (12), and the power supply and data lines of the temperature sensor (8) pass through the central hole of the tube tail (13); The pipe head (11) and the pipe body (12) are mounted on the upper edge of the receiving hopper (14) via a fixing frame (7); The temperature sensing device (1) comprises a dust-blocking valve (10), and the dust-blocking valve (10) is connected to the front host (4); The fixing ring (9), the dust blocking valve (10), the pipe head (11), the pipe body (12) and the pipe tail (13) together form a closed space for isolating the temperature sensor (8) from the outside during non-temperature measurement periods.

2. A real-time monitoring system for concrete mixture outlet temperature according to claim 1, characterized in that: The unloading sensing device (2) is a mixer working current acquisition module, which senses the phase current of the mixer motor through the current acquisition module and transmits the sensing result to the front host (4).

3. A real-time monitoring system for concrete mixture outlet temperature according to claim 1, characterized in that: The measurement and control unit (3) comprises a temperature signal processing module, a data transmission module and a control module. The measurement and control unit (3) receives the temperature signal collected by the temperature sensing device (1), performs data conversion and transmits the data to the front-end host (4), receives the opening and closing instructions of the dust-blocking valve (10) sent by the front-end host (4), and controls the dust-blocking valve (10) to open and close.

4. The real-time monitoring system for concrete mixture outlet temperature according to claim 1, characterized in that: The front host (4) downloads data from the server (5), receives and stores data from the discharge sensing device (2) and the measurement and control unit (3), performs operations on the data, generates control instructions, sends valve opening and closing and temperature collection instructions to the measurement and control unit (3), and uploads the collected temperature and current data to the server (5) in a timely manner.

5. The real-time monitoring system for concrete mixture outlet temperature according to claim 1, characterized in that: The system also includes a client (6), which accesses a server (5) to set basic data and query information for the system; the server (5) is used to store basic system data and data uploaded by a front-end host (4), and to perform computational processing and display on the data.

6. A method for real-time monitoring of concrete mixture outlet temperature using a real-time temperature monitoring system according to any one of claims 1 to 5, characterized in that: Collect the working current value of the mixer at regular intervals, record the process line of the current value changing with time, calculate the median of the latest a1 current values, recorded as I0, calculate the median of the previous a2 current values ​​adjacent to the latest measured value, recorded as I -1 , assuming the critical current of mixer unloading is I s , when I0 s -1 When the condition a is established, it is considered that the mixer has started to discharge. At this time, an instruction to open the dust-blocking valve (10) is sent. When the dust-blocking valve (10) is fully opened, the measured value of the temperature sensor (8) is recorded once at a certain interval, and a3 times are recorded. The recording is stopped and the dust-blocking valve (10) is closed. The median of the a4 measured temperature values ​​is taken as the representative value of the outlet temperature of the batch of concrete mixture. When the current measurement value meets the discharge judgment condition again, the temperature measurement of the next batch of concrete is started.​​ 7. The method for real-time monitoring of concrete mixture outlet temperature according to claim 6, characterized in that: Mixer unloading critical current I s Determine in advance and correct it in time. The critical current determination method is: observe the operating status of the mixer, correspond to the specific concrete type and single-plate mixing volume, record the working current value of the mixer at the start of unloading, record no less than a5 values, and take the middle value as the unloading critical current I s .

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