1. Application Environment Overview A thermal power company is mainly responsible for providing energy services to businesses and residents in the region. After the system is fully operational, it can meet
Within 1.8Km2, there are nearly 2 million m2 of steam for production, living, heating and cooling of various buildings. The saturated steam of 0.6MPa is used as the basic thermal working medium: as the heat source of the heating system of each user in winter, the circulating water of the heating system is brought to a controlled temperature through the work of heat exchangers (mostly plate heat exchangers); The saturated steam of MPa can meet the user's comfort and the requirements of air conditioning through the working cycle of the lithium bromide refrigerator (mostly steam type double effect type).
1. Heat source The company's heating field boiler room includes 4 sets of 35 tons / hour, 1.57MPa saturated steam boiler and 3 sets of 10 tons / hour,
1.25MPa saturated steam single-layer assembled saturated steam boiler, with a total installed capacity of 170 tons / hour. The main and auxiliary boiler rooms are equipped with blower fan, feed water pump, dust collector and water treatment equipment.
2. Regional heating pipe network A set of district heating pipe network is arranged in a ring shape in the area, with a total length of 5.2Km. Due to the adaptability of the two steam pipes to heating (cooling) load changes, it is still in terms of improving the reliability of gas supply. Both are more advantageous, so the steam adopts double parent control. In order to save energy and ensure the recovery of steam condensate water, a condensate return water pipe is also arranged in the heat pipe network. Each steam user is required to use a closed return water system to use the condensate water pump to return the condensate water and ensure the condensate return water rate. Not less than 80%.
3. The steam from the heat exchange refrigeration station enters the heat exchange refrigeration station and is sent to the heat exchange refrigeration equipment through the decompression valve. In summer, the cold water produced by the lithium bromide absorption refrigeration unit is 7-12 ° C, and the chilled water pump is used to supply the air conditioning unit or fan coil through the pipeline. And new fan units and other terminal devices, the site is equipped with condensate pumps, make-up pumps, condensate water tanks, make-up water tanks and softened water devices, and a cooling tower is set on the roof of the building; 55 ~ 70 ℃ hot water is prepared by plate heat exchangers in winter and heated The circulating water pump is supplied to the fan coil unit and the new fan group through the pipeline (the radiator is used at the end of some systems). The heat exchange station is equipped with a demineralized water device to store the demineralized water for the circulating water of the heating system. The expansion water tank is set on the top floor. Insufficient water pressure in the system (mainly manifested as a decrease in the level of the expansion tank) needs to start the make-up pump to make up water from the make-up water tank (some systems make up the water tank and the condensate tank) to make up water. Heat the net for condensate return.
In this way, the entire base only needs a single thermal medium production and transportation system to cooperate with the secondary system of each heating and cooling station to meet the various needs of enterprises and residents of the living area. According to the difference between the heating and cooling load in winter and summer Each type of furnace is operated separately, the utilization rate of the boiler is high, and it is also convenient for each other to ensure safe operation. The equipment types and operation processes of different heating and cooling stations are different. Inappropriate design and selection of equipment will cause difficulties in operation management. The difficulties in operation management directly affect the service life of equipment, the safety and stability of operation, etc. In the case of imperfections of each heating and cooling station, analyze and solve it, improve the use efficiency of equipment in operation management, and make the equipment safe and reliable, and efficient operation for a long time has become an important issue for base energy service personnel. Therefore, the company automated the system.
Second, the system principle This system is a real-time on-site measurement and control system and a remote monitoring system. Its processing of measurement data and control algorithms are based on digital calculations and implemented through software. Like most computerized monitoring systems, the main body is composed of sensors, on-site acquisition modules, GPRS modules, industrial tablet computers, main control computers, and remote monitoring centers.
1. Industrial tablet computer, main control computer: It is the core of the computer monitoring system, and its main characteristics are as follows:
1) The working process of the main control computer is completely determined by the pre-programmed software, and the conventional instrument is realized by electronic logic circuit or other mechanical hardware logic. Whether the control management function is realized by software or hardware is the main control of computer control and conventional instrument control the difference.
2) The system runs a program compiled with VC, and directly connects various input signals to the computer input port through the data bus.
In order to achieve data acquisition, control, management and protection functions, instead of the conventional instrument controller consisting of independent one-to-one single-loop control or protection circuits, the main control computer may fully consider various parameters of the control object. It carries out unified and systematic control, protection and management.
3) Industrial tablet computers are portable, simple and practical, and are mostly used near industrial sites. Built-in WinCE, Linux embedded operating system, stable performance, temperature resistance, humidity resistance, strong anti-interference ability. With touch screen, touch operation, independent operation, real-time display monitoring!
2. Sensors Sensors sense various physical quantities that need to be monitored and controlled and turn them into electrical signals to the computer, which is equivalent to the eyes of the main control computer. This system transmits the status of various parameters to the field module in the form of voltage and switching signals, mainly including temperature sensor, pressure sensor, liquid level sensor and current sensor.
3. Field module The DAM-3046 series field module completes the data collection and control signal transmission to the actuator, and then transmits the signal to the conversion module DAM-3210 through the RS485 communication method, and converts it into an RS232 communication method that can be connected to the computer serial port.
4. The actuator can be controlled by various switches and valves directly controlled by the computer. The computer can realize the control function by adjusting the actuator, which is equivalent to the hands and feet of the master computer. The controller is connected to the actuator through two types of output channels of the field module:
1) Digital output channel (DO). It can set the output channel to high or low frequency by the control software, can drive the relay or other switch components through the drive circuit, and can also drive the indicator light to display the status;
2) Emulation output channel (AO). The output signal is a voltage of 0 ~ 10V, the value of which is determined by the control software,
Because the signals processed inside the computer are all digital signals, this continuously variable analog signal is generated by a digital-simulation conversion circuit (D / A).
5. GPRS module
1) Brief description: GPRS is the abbreviation of General Packet Radio Service (General Packet Radio Service). It is a new bearer service developed on the existing GSM system. The purpose is to provide packet data services for GSM users. GPRS uses the same wireless modulation standard, the same frequency band, the same burst structure, the same frequency hopping rule and the same TDMA frame structure as GSM. This new packet data channel is very similar to the current circuit-switched voice traffic channel. . Therefore, the existing base station subsystem (BSS) can provide comprehensive GPRS coverage from the beginning. GPRS allows users to send and receive data in an end-to-end packet transfer mode without using network resources in circuit-switched mode. Thus, an efficient and low-cost wireless packet data service is provided. The heat network remote monitoring system based on GPRS network has the following characteristics:
â—‡ Always-on GPRS DTU will automatically attach to the GPRS network when it is turned on, and establish a communication link with the data center to send and receive data from user data devices at any time, with high real-time performance;
â—‡ The GPRS DTU is always online according to the flow rate, and charges according to the number of data packets received and sent. There is no charge when there is no data flow;
â—‡ The transmission speed of the high-speed transmission GPRS network will reach 160Kbps at the fastest, and the rate depends on the network settings of the mobile operator. According to the network situation of China Mobile, it can currently provide stable data transmission of 20-40Kbps;
â—‡ Simple, rapid and flexible networking GPRS wireless system can build a virtual mobile data communication dedicated network covering all of China through the Internet network anytime, anywhere, providing access convenience for the majority of small and medium-sized users and saving access investment;
â—‡ The communication link is maintained by a professional operator. Because China Mobile's GPRS data service is used, the link maintenance is also the responsibility of China Mobile, eliminating the worries of communication link maintenance;
◇ Lightning protection Because of the use of China Mobile ’s GPRS data service, the transmission power of GPRS DTU is very small, the antenna is very short, and no overhead is required without affecting the Internet access, which overcomes the possibility of lightning damage caused by cable transmission and radio station transmission. Disadvantages of the device.
2) The GPRS module is connected to the tablet computer or the main control computer through the serial port. When configuring the GPRS communication module, enter the necessary parameters such as the fixed IP address of the data center, the data collection command, and the collection time interval in advance. At the same time, the relevant parameters can also be set remotely. After receiving the data sent by the controller, the GPRS communication module sends the data to the IP address network server set above, and forwards it to the data center server through port mapping. The process of sending data by GPRS is as follows: the data is sent to China Mobile's GPRS network, then through the Internet, and finally received in the data center through a server connected to a dedicated line or broadband dial-up network. The receiving server completes a series of data processing, database writing, forwarding and other jobs.
3. Composition of the automatic control system
1. Hardware main body: The various sensors are described as follows:
(1) The temperature sensor uses a thermal resistance temperature sensor. The thermal resistance is a temperature-measuring component that changes with temperature. Its resistance value increases as the temperature rises. The heated part (temperature-sensing component) is evenly wound around the insulation with thin metal wires. On the skeleton made of materials, there are two major types of industrial thermal resistance: platinum thermal resistance and copper thermal resistance. This system uses platinum thermal resistance, the index number is Pt100, and the applicable temperature range is-
200 ～ 850 ℃, the basic structure of common thermal resistance is not only temperature-sensitive components, but also protection sleeves, installation fixtures, junction boxes, etc.
(2) Pressure sensor
The 4040PC pressure sensor is the first single-chip pressure transmitter developed by Honeywell. Its package is suitable for harsh environments, the operating temperature is -45 ~ 125 ℃, the structure is made of stainless steel, glass, flux, silicon And brass. Full correction and temperature compensation are used to provide linearly amplified output. The single-chip technology based on resistance characteristics greatly improves long-term reliability.
(3) Liquid level sensor Honeywell LL series liquid level switches can provide very accurate liquid level measurement. 1 LED and 1 photoelectric receiver are placed in a plastic semi-spherical ball. According to the principle of internal reflection of light, when When there is no liquid, most of the LED light will be received by the photoelectric receiver. When the liquid covers the surface of the ball, the refractive index of the interface between the dome and the liquid changes, and the photoelectric receiver receives
The LED light will decrease, so the output will change. The on / off output signal is connected to the digital input of the field module to read it regularly for the computer.
2 The hardware frame diagram is shown in the figure:
Picture one:
Data transmission path 1: Collect the signal from the sensor through the DAM-3000 series 485 module, and send the collected signal to the tablet computer through the 485 interface for real-time monitoring. Or output external signals to regulate and execute the device's actions. Please refer to Figure 1 for the specific process.
Picture two
Data transmission path 2: Collect the signal from the sensor through the DAM-3000 series 485 module, and then convert the 485 signal into a 232 signal by the DAM-3210 module and send it to the main control computer. The main control computer then passes GPRS
The module transmits the signal to the remote monitoring center. Please refer to Figure 2 for the specific process.
3. Field module The system uses DAM-3000 series field modules, which are briefly described as follows:
(1) DAM-3046 module
6-channel thermal resistance input module function: collect temperature of supply and return water through temperature sensor Address: 01-19
Sense0-59: Water supply temperature, a total of 60 temperature measurement points, requires 10 DAM-3046 modules
Sense60-119: return water temperature, a total of 60 temperature measurement points, need 10 channels DAM-3046 module
(2) DAM-3058F module
8-channel analog input function: collect various pressure signals through pressure sensor Address: 20
Vin0: water supply pressure
Vin1: outlet pressure of make-up pump
Vin2: outlet pressure of circulating pump
Vin3: outlet pressure of condensate pump
Vin5: return water pressure after decontamination
Vin6: steam pressure at the inlet of the heat exchanger
Vin7: Home steam pressure (3) DAM-3013
16-channel isolated digital input module function: collect the liquid level signal of the condensate tank through the liquid level sensor, and start the condensate pump when there is water in the high liquid level according to the liquid level status,
Stop condensate pump when there is no water in low liquid level Address: 21
In0-7: Collect 8 high level signals
In8-15: Collect 8 low level signals (4) DAM-3014
16-channel isolated open collector output module function: control the start and stop address of condensate pump and make-up water pump by liquid level: 22
Out0-7: Control 8-way condensate pump
Out8-15: Control 8-channel makeup water pump (5) DAM-3210
Isolated RS-232 to RS-485 conversion module function: convert 485 signal to 232 signal
4. Actual operation effect Since the automatic control system was put into operation, the operation condition is good, which ensures the safe and stable operation of the heat exchange system, and there is no failure. There are no more operating personnel in the heat exchange station, which improves efficiency. Through the tablet computer and GPRS module, the dual monitoring of on-site monitoring and remote monitoring is realized.
Within 1.8Km2, there are nearly 2 million m2 of steam for production, living, heating and cooling of various buildings. The saturated steam of 0.6MPa is used as the basic thermal working medium: as the heat source of the heating system of each user in winter, the circulating water of the heating system is brought to a controlled temperature through the work of heat exchangers (mostly plate heat exchangers); The saturated steam of MPa can meet the user's comfort and the requirements of air conditioning through the working cycle of the lithium bromide refrigerator (mostly steam type double effect type).
1. Heat source The company's heating field boiler room includes 4 sets of 35 tons / hour, 1.57MPa saturated steam boiler and 3 sets of 10 tons / hour,
1.25MPa saturated steam single-layer assembled saturated steam boiler, with a total installed capacity of 170 tons / hour. The main and auxiliary boiler rooms are equipped with blower fan, feed water pump, dust collector and water treatment equipment.
2. Regional heating pipe network A set of district heating pipe network is arranged in a ring shape in the area, with a total length of 5.2Km. Due to the adaptability of the two steam pipes to heating (cooling) load changes, it is still in terms of improving the reliability of gas supply. Both are more advantageous, so the steam adopts double parent control. In order to save energy and ensure the recovery of steam condensate water, a condensate return water pipe is also arranged in the heat pipe network. Each steam user is required to use a closed return water system to use the condensate water pump to return the condensate water and ensure the condensate return water rate. Not less than 80%.
3. The steam from the heat exchange refrigeration station enters the heat exchange refrigeration station and is sent to the heat exchange refrigeration equipment through the decompression valve. In summer, the cold water produced by the lithium bromide absorption refrigeration unit is 7-12 ° C, and the chilled water pump is used to supply the air conditioning unit or fan coil through the pipeline. And new fan units and other terminal devices, the site is equipped with condensate pumps, make-up pumps, condensate water tanks, make-up water tanks and softened water devices, and a cooling tower is set on the roof of the building; 55 ~ 70 ℃ hot water is prepared by plate heat exchangers in winter and heated The circulating water pump is supplied to the fan coil unit and the new fan group through the pipeline (the radiator is used at the end of some systems). The heat exchange station is equipped with a demineralized water device to store the demineralized water for the circulating water of the heating system. The expansion water tank is set on the top floor. Insufficient water pressure in the system (mainly manifested as a decrease in the level of the expansion tank) needs to start the make-up pump to make up water from the make-up water tank (some systems make up the water tank and the condensate tank) to make up water. Heat the net for condensate return.
In this way, the entire base only needs a single thermal medium production and transportation system to cooperate with the secondary system of each heating and cooling station to meet the various needs of enterprises and residents of the living area. According to the difference between the heating and cooling load in winter and summer Each type of furnace is operated separately, the utilization rate of the boiler is high, and it is also convenient for each other to ensure safe operation. The equipment types and operation processes of different heating and cooling stations are different. Inappropriate design and selection of equipment will cause difficulties in operation management. The difficulties in operation management directly affect the service life of equipment, the safety and stability of operation, etc. In the case of imperfections of each heating and cooling station, analyze and solve it, improve the use efficiency of equipment in operation management, and make the equipment safe and reliable, and efficient operation for a long time has become an important issue for base energy service personnel. Therefore, the company automated the system.
Second, the system principle This system is a real-time on-site measurement and control system and a remote monitoring system. Its processing of measurement data and control algorithms are based on digital calculations and implemented through software. Like most computerized monitoring systems, the main body is composed of sensors, on-site acquisition modules, GPRS modules, industrial tablet computers, main control computers, and remote monitoring centers.
1. Industrial tablet computer, main control computer: It is the core of the computer monitoring system, and its main characteristics are as follows:
1) The working process of the main control computer is completely determined by the pre-programmed software, and the conventional instrument is realized by electronic logic circuit or other mechanical hardware logic. Whether the control management function is realized by software or hardware is the main control of computer control and conventional instrument control the difference.
2) The system runs a program compiled with VC, and directly connects various input signals to the computer input port through the data bus.
In order to achieve data acquisition, control, management and protection functions, instead of the conventional instrument controller consisting of independent one-to-one single-loop control or protection circuits, the main control computer may fully consider various parameters of the control object. It carries out unified and systematic control, protection and management.
3) Industrial tablet computers are portable, simple and practical, and are mostly used near industrial sites. Built-in WinCE, Linux embedded operating system, stable performance, temperature resistance, humidity resistance, strong anti-interference ability. With touch screen, touch operation, independent operation, real-time display monitoring!
2. Sensors Sensors sense various physical quantities that need to be monitored and controlled and turn them into electrical signals to the computer, which is equivalent to the eyes of the main control computer. This system transmits the status of various parameters to the field module in the form of voltage and switching signals, mainly including temperature sensor, pressure sensor, liquid level sensor and current sensor.
3. Field module The DAM-3046 series field module completes the data collection and control signal transmission to the actuator, and then transmits the signal to the conversion module DAM-3210 through the RS485 communication method, and converts it into an RS232 communication method that can be connected to the computer serial port.
4. The actuator can be controlled by various switches and valves directly controlled by the computer. The computer can realize the control function by adjusting the actuator, which is equivalent to the hands and feet of the master computer. The controller is connected to the actuator through two types of output channels of the field module:
1) Digital output channel (DO). It can set the output channel to high or low frequency by the control software, can drive the relay or other switch components through the drive circuit, and can also drive the indicator light to display the status;
2) Emulation output channel (AO). The output signal is a voltage of 0 ~ 10V, the value of which is determined by the control software,
Because the signals processed inside the computer are all digital signals, this continuously variable analog signal is generated by a digital-simulation conversion circuit (D / A).
5. GPRS module
1) Brief description: GPRS is the abbreviation of General Packet Radio Service (General Packet Radio Service). It is a new bearer service developed on the existing GSM system. The purpose is to provide packet data services for GSM users. GPRS uses the same wireless modulation standard, the same frequency band, the same burst structure, the same frequency hopping rule and the same TDMA frame structure as GSM. This new packet data channel is very similar to the current circuit-switched voice traffic channel. . Therefore, the existing base station subsystem (BSS) can provide comprehensive GPRS coverage from the beginning. GPRS allows users to send and receive data in an end-to-end packet transfer mode without using network resources in circuit-switched mode. Thus, an efficient and low-cost wireless packet data service is provided. The heat network remote monitoring system based on GPRS network has the following characteristics:
â—‡ Always-on GPRS DTU will automatically attach to the GPRS network when it is turned on, and establish a communication link with the data center to send and receive data from user data devices at any time, with high real-time performance;
â—‡ The GPRS DTU is always online according to the flow rate, and charges according to the number of data packets received and sent. There is no charge when there is no data flow;
â—‡ The transmission speed of the high-speed transmission GPRS network will reach 160Kbps at the fastest, and the rate depends on the network settings of the mobile operator. According to the network situation of China Mobile, it can currently provide stable data transmission of 20-40Kbps;
â—‡ Simple, rapid and flexible networking GPRS wireless system can build a virtual mobile data communication dedicated network covering all of China through the Internet network anytime, anywhere, providing access convenience for the majority of small and medium-sized users and saving access investment;
â—‡ The communication link is maintained by a professional operator. Because China Mobile's GPRS data service is used, the link maintenance is also the responsibility of China Mobile, eliminating the worries of communication link maintenance;
◇ Lightning protection Because of the use of China Mobile ’s GPRS data service, the transmission power of GPRS DTU is very small, the antenna is very short, and no overhead is required without affecting the Internet access, which overcomes the possibility of lightning damage caused by cable transmission and radio station transmission. Disadvantages of the device.
2) The GPRS module is connected to the tablet computer or the main control computer through the serial port. When configuring the GPRS communication module, enter the necessary parameters such as the fixed IP address of the data center, the data collection command, and the collection time interval in advance. At the same time, the relevant parameters can also be set remotely. After receiving the data sent by the controller, the GPRS communication module sends the data to the IP address network server set above, and forwards it to the data center server through port mapping. The process of sending data by GPRS is as follows: the data is sent to China Mobile's GPRS network, then through the Internet, and finally received in the data center through a server connected to a dedicated line or broadband dial-up network. The receiving server completes a series of data processing, database writing, forwarding and other jobs.
3. Composition of the automatic control system
1. Hardware main body: The various sensors are described as follows:
(1) The temperature sensor uses a thermal resistance temperature sensor. The thermal resistance is a temperature-measuring component that changes with temperature. Its resistance value increases as the temperature rises. The heated part (temperature-sensing component) is evenly wound around the insulation with thin metal wires. On the skeleton made of materials, there are two major types of industrial thermal resistance: platinum thermal resistance and copper thermal resistance. This system uses platinum thermal resistance, the index number is Pt100, and the applicable temperature range is-
200 ～ 850 ℃, the basic structure of common thermal resistance is not only temperature-sensitive components, but also protection sleeves, installation fixtures, junction boxes, etc.
(2) Pressure sensor
The 4040PC pressure sensor is the first single-chip pressure transmitter developed by Honeywell. Its package is suitable for harsh environments, the operating temperature is -45 ~ 125 ℃, the structure is made of stainless steel, glass, flux, silicon And brass. Full correction and temperature compensation are used to provide linearly amplified output. The single-chip technology based on resistance characteristics greatly improves long-term reliability.
(3) Liquid level sensor Honeywell LL series liquid level switches can provide very accurate liquid level measurement. 1 LED and 1 photoelectric receiver are placed in a plastic semi-spherical ball. According to the principle of internal reflection of light, when When there is no liquid, most of the LED light will be received by the photoelectric receiver. When the liquid covers the surface of the ball, the refractive index of the interface between the dome and the liquid changes, and the photoelectric receiver receives
The LED light will decrease, so the output will change. The on / off output signal is connected to the digital input of the field module to read it regularly for the computer.
2 The hardware frame diagram is shown in the figure:
Picture one:
Data transmission path 1: Collect the signal from the sensor through the DAM-3000 series 485 module, and send the collected signal to the tablet computer through the 485 interface for real-time monitoring. Or output external signals to regulate and execute the device's actions. Please refer to Figure 1 for the specific process.
Picture two
Data transmission path 2: Collect the signal from the sensor through the DAM-3000 series 485 module, and then convert the 485 signal into a 232 signal by the DAM-3210 module and send it to the main control computer. The main control computer then passes GPRS
The module transmits the signal to the remote monitoring center. Please refer to Figure 2 for the specific process.
3. Field module The system uses DAM-3000 series field modules, which are briefly described as follows:
(1) DAM-3046 module
6-channel thermal resistance input module function: collect temperature of supply and return water through temperature sensor Address: 01-19
Sense0-59: Water supply temperature, a total of 60 temperature measurement points, requires 10 DAM-3046 modules
Sense60-119: return water temperature, a total of 60 temperature measurement points, need 10 channels DAM-3046 module
(2) DAM-3058F module
8-channel analog input function: collect various pressure signals through pressure sensor Address: 20
Vin0: water supply pressure
Vin1: outlet pressure of make-up pump
Vin2: outlet pressure of circulating pump
Vin3: outlet pressure of condensate pump
Vin5: return water pressure after decontamination
Vin6: steam pressure at the inlet of the heat exchanger
Vin7: Home steam pressure (3) DAM-3013
16-channel isolated digital input module function: collect the liquid level signal of the condensate tank through the liquid level sensor, and start the condensate pump when there is water in the high liquid level according to the liquid level status,
Stop condensate pump when there is no water in low liquid level Address: 21
In0-7: Collect 8 high level signals
In8-15: Collect 8 low level signals (4) DAM-3014
16-channel isolated open collector output module function: control the start and stop address of condensate pump and make-up water pump by liquid level: 22
Out0-7: Control 8-way condensate pump
Out8-15: Control 8-channel makeup water pump (5) DAM-3210
Isolated RS-232 to RS-485 conversion module function: convert 485 signal to 232 signal
4. Actual operation effect Since the automatic control system was put into operation, the operation condition is good, which ensures the safe and stable operation of the heat exchange system, and there is no failure. There are no more operating personnel in the heat exchange station, which improves efficiency. Through the tablet computer and GPRS module, the dual monitoring of on-site monitoring and remote monitoring is realized.
Circular Emergency Ceiling Light is according to the type can be divided into maintenance or non-maintenance . It is made of solid polycarbonate material , with protection rating of IP65 , suitable for indoor and outdoor use . It comes with a premium rechargeable lithium-ion battery with automatic monthly and annual detection .
Emergency Ceiling Light
Emergency Light Ceiling,Industrial Emergency Light,Led Emergency Ceiling Lights,Ceiling Mounted Emergency Lights
Jiangmen City Pengjiang District Qihui Lighting Electrical Appliances Co., Ltd , https://www.qihuilights.com