The heating industry is endowed with huge opportunities, and intelligent transformation has become the new driving force for enterprise growth

At present, the boundary line of China’s heating industry is located at 33°N, near the Qinling Mountains and the Huai River. Including the northern fourteen provinces, municipalities and autonomous regions, the total heating area covers more than 20.6 billion m². Among them, the urban building heating area covers 14.1 billion m², while the rural area covers 6.5 billion m², and the "2+26" urban and rural buildings have a heating area of approximately 5 billion m².

According to public information, the total mileage of urban central heating pipe networks in China exceeded 312,000 km in 2017, of which the primary network is about 96,000 km long, and the secondary network is about 216,000 km. Central heating networks are mainly distributed in cities, and the total mileage of these central heating pipe networks is around 233,000 km, accounting for 74.6% of the total mileage of urban district central heating pipes. The total mileage of central heating pipe networks in county towns is close to 79,000 km, which accounts for 25.4%. In terms of heating time, due to geographical differences, the North China region is generally four months, and the Northeast and Northwest regions are generally between 5-7 months.

Such a huge heat pipe network structure and heating market data will inevitably affect the energy efficiency of enterprise management. With the maturity of IoT technology and the penetration of NB-IoT’s cellular-based technology in the industry, the concept of "universal connectivity" is widely used in the process of enterprise intelligent transformation. Monitoring of the heat exchange stations, temperature collection of the heat pipe networks and collection and analysis of the actual indoor temperatures of households have become key to improving the service efficiency of the heating enterprises.

Solving the pain points of enterprises, industrial wireless technology actively promotes the intelligent transformation of heat exchange stations

In order to improve the efficiency and accuracy of the work of the heat exchange stations, by analyzing the specific needs of the company’s pain points, especially the heat exchange stations, combined with the application of industrial wireless technology, the following functions can be added:

　　1) PC remote monitoring of field equipment;

　　2) Viewing device status at any time via mobile browser;

　　3) No additional network cable is required for field equipment, and the data is transmitted through the broadband cellular network;

　　4) Unattended, fully automatic control;

　　5) Simple maintenance and upgrade.

Structure diagram of heat exchange station system

The whole system adopts HMI touch screen for on-site workflow display, parameter alarm and data storage functions, and is connected to the intelligent gateway, I/O module and electric parameter acquisition module via standard Modbus. The I/O module is responsible for the analog and digital input and output, and the electrical parameter module is responsible for collecting the power consumption of the system. The final router connects to the server via 4G network, that is, the 4G cellular network provided by the SIM7600CE module, enabling the user to monitor the real-time situation of the site via mobile phone or computer.

Disassembly of industrial 4G router Click to learn about SIM7600CE

In order to ensure the reliability of the parameter monitoring of the heat exchange station, it must comply with a series of national specifications and industry standards, such as GBJ/232-90, 92 Specifications for Electrical Installation Engineering Construction and Inspection Acceptance, Engineering Design Regulations for Distributed Control Systems, etc. At the same time, the combination of remote and local control ensures the redundancy of the system. In management, the real-time alarm of the main station can be used for emergency treatment and timely maintenance of the sub-station, without the need for 24-hour manual monitoring, saving on maintenance costs, labor and time, and ensuring a stable and reliable operation of the system.

Real-time monitoring platform of heat exchange station

Wireless differential pressure transmitter monitors pipe network pressure to achieve heat network pressure balance

At present, the uneven distribution of secondary heating networks result in different distances from the heat exchange station. In order to obtain an ideal heating effect for the heat users within the jurisdiction of the heat exchange station, there are certain requirements for the secondary network water supply pressure. However, the long-term high temperature and high pressure will also affect the service life of the heating pipe networks. In some remote and sparsely populated areas where wired networks cannot be used to install monitoring equipment, and no effective power supply is available, the monitoring of the water supply and return pressure difference of the pipe networks is still a problem which needs to be addressed. With the popularization of IoT technology, especially the further improvement of the industrial wireless technology in the automatic detection and data acquisition system, the heat source delivered from the plant to each pipe network of the user can be detected in real-time, and the fault state can be reported, which achieves pressure balance of the pipe networks and greatly extends their service life.

Wireless differential pressure transmitter based on NB-IoT module customization Click to learn about SIM7000C

Combined with the demand analysis of the heating pipe network, aiming at the particularity of the heat conduction environment of the pipe networks, and based on the powerful and low-power NB-IoT core hardware, the fully functional software system platform and the customized design, through the transformation of traditional differential pressure transmitters, the following main functions are added:

　　1、Differential pressure sensor data is directly uploaded to the cloud server via NB-IoT technology;

　　2、The upper and lower limits of the pressure alarm can be set remotely, and the data will be reported in real time in case of exceeding pressure;

　　3、The data upload interval can be set remotely;

　　4、The field instrument data can be modified remotely;

　　5、Transmitter range is between 0 ~ 2MPa;

　　6、Measurement accuracy is between 0.1% FS ~ 0.25% FS;

　　7、Operating temperature range is between - 25 °C ~ 75 °C;

　　8、Protection class is IP67.

Wireless differential pressure transmitter monitoring platform

Through real-time monitoring by the wireless differential pressure transmitter, the enterprise can greatly improve the monitoring of the pipe networks, give an advanced warning, and effectively avoid uneven heating due to remoteness and environmental factors, and further increase the cost of heating and other problems. Through pressure feedback, the enterprise may also reduce the loss caused by the quality problems and reduce the heating costs.

Accurate collection of user data, forming data closed-loops by detecting energy-saving measures, and improving energy efficiency of enterprises

When heat energy is transmitted to the residential and office buildings through the pipe network, the outdoor heating system has to supply heat with a mass flow and excess load to comply with the heating standards, since the outdoor heating pipe networks currently running are mostly branched pipe networks and the heating system is generally unable to timely and effectively adjust the heating flow and water supply temperature based on changes of outdoor temperatures, resulting in large system leakage and high energy consumption.

At present, the energy saving measures in the industry include: installing a climate compensator, a matching electric valve in the heat exchange station, and an outdoor temperature sensor to improve the conduction and utilization of heat energy. However, the measures for energy conservation do not seem to answer the questions on whether energy is effectively utilized, whether the temperature difference is regulated, and whether the users are satisfied with their heating services. As we all know, the temperature and humidity sensors installed in the indoor space of office buildings and houses are the last layer of data for heating. If the enterprise can capture this layer of data, and cooperate with the differential pressure controller or the thermal transmitter, it can effectively solve the above problems. Compared with general temperature and humidity sensors, this equipment should meet the following characteristics:

　　1、It is sleek and smart-looking, and can be installed in the user's house;

　　2、The user does not need to set up networking (data is transmitted by NB-IoT);

　　3、The temperature and humidity are directly uploaded to the cloud server;

　　4、The acquisition frequency and cycle can be set remotely according to the heating time;

　　5、Guarantee one heating cycle (usually from the end of the autumn to the following spring) and reserve sufficient power to work.

Temperature and humidity monitoring based on NB-IoT through secondary development of modules

Click to learn about SIM7020C

Through this indoor temperature and humidity sensor, heating companies can obtain the analysis data of heating performance as soon as it allows, such as: the time for a single user to heat to a stable temperature and its average duration, single-user indoor temperature and average indoor temperature, etc. With the heat transmitter and adjustment of the speed of the water valve, the temperature difference can be stably regulated. This data can also be used to feedback the enterprise for maintenance and upgrade of the equipment, so that the service can form quantitative data, forming a closed loop of “service -> data -> upgraded data -> service”, improving enterprise efficiency and driving enterprise growth.

Conclusions

China has a huge potential demand for heating, and commercialization, socialization and marketization are also the main development trends of urban heating in the future. The eco-friendly cogeneration unit, with high thermal efficiency and a good energy saving performance, is one of the main development directions of urban heating technology. As the degree of automation of heating pipe network operation is increased, the indoor heating system will also realize room temperature control and household metering. Finally, through the use of industrial wireless technology, the wireless intelligent transformation of the heat exchange station, the wireless monitoring transformation of the pipe networks, and the collection and analysis of the end user data, the heating enterprises smarten the heating demand and solve the operational pain points. With the further penetration of industrial intelligent management, it is believed that enterprises can successfully break through operational bottlenecks and enhance value.

Note:

According to the Clean Winter Heating Plan for Northern China (2017-2021), “2+26” key cities include: Beijing, Tianjin; Shijiazhuang, Tangshan, Langfang, Baoding, Cangzhou, Hengshui, Xingtai, and Handan in Hebei Province; Taiyuan, Yangquan, Changzhi, and Jincheng in Shanxi Province; Jinan, Zibo, Jining, Dezhou, Liaocheng, Binzhou, and Heze in Shandong Province; Zhengzhou, Kaifeng, Anyang, Hebi, Xinxiang, Jiaozuo, and administrative region of Puyang in Henan Province.