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The connection methods between the external heating network and heat users are generally divided into two types: indirect connection and direct connection. A common form of indirect connection is the use of plate heat exchanger units for heat exchange at heat exchange stations or at the entrances to end-users; this approach requires the construction of specialized heat exchange station buildings, resulting in high costs in terms of equipment and civil works. Direct connection is further divided into three types: applications in level transmitters, distributed hot water mixing units for heating, and traditional heating systems. Type 1 involves no mixing device – the hot water from the external supply enters the heating system directly before being delivered to consumers’ homes. This approach is suitable for small heating systems, but its application is limited by certain conditions ； Direct connection of 2-water jet injectors; this method is simple in design, but it requires a certain pressure difference between the supply water and the return water ； Direct connection of 3-pump mixing water pumps; this setup requires the use of additional mixing water pumps, which consumes a certain amount of electrical energy. With the widespread use of variable-frequency water pumps, the advantages of this approach are becoming evident; currently, many heating systems in China employ this type of connection. The direct connection of mixed water pumps is also known as a mixed water system. Principle of the mixing system: The mixing system is generally installed in the basement at the thermal inlet of each building unit. Its principle is to mix the return water coming from the users with the secondary water supply from the heating network, using a mixing bypass pipe. Applications of level transmitters: Distributed mixing units in heating systems versus traditional heating systems. The main advantages of using level transmitters: http://www.xahuaheng.cn/uploadfile/20200312_090054417.png 1. Level transmitters feature reliability in operation and stable performance ； 2. Dedicated V/I integrated circuits with few peripheral components, high reliability, simple and easy maintenance, small size and light weight, making installation and debugging extremely convenient ； 3. Aluminum alloy die-cast housing with three-terminal isolation and an electrostatic spray paint protective layer for durability ； 4. 4-20mA DC two-wire signal transmission, with strong interference resistance and long transmission distance ； 5. Three types of indicator displays – LED, LCD, and pointer – for very convenient on-site reading. Can be used to measure viscous, crystalline, and corrosive media ； 6. High accuracy, high stability. In addition to the imported original sensors being laser-adjusted, comprehensive compensation is provided for the overall temperature drift and non-linearity of the device within its operating temperature range. The traditional design method for circulating water pumps involves selecting such pumps based on the farthest and most disadvantaged users, and placing them at the heat source to overcome the resistances in the heat source, heat distribution network, and end-user systems. This traditional design creates excessive head loss for heat users at the proximal end of the heating system (near the heat source). To meet the circulation flow rate of the heat users at the proximal end, a flow control valve must be installed to dissipate the excess head pressure. This unnecessary throttling loss is caused by the traditional design method for circulating water pumps themselves. With a distributed variable-frequency circulation pump system, the electrical power supplied by the heat source main circulation pump, the primary circulation pump, and the secondary circulation pump is all effectively consumed within their respective operating ranges, with no unnecessary power loss. Applications of level transmitters: Distributed mixing units in heating systems versus traditional heating systems. In traditional circulation systems, most users employ control valves to dissipate excess head pressure, resulting in the total power of the heat source’s main circulation pump being wasted on reactive losses. Its total power consumption N is definitely greater than that of the distributed cycling method’s total power N. The distribution circulation method involves installing a circulation water pump with a low head at the heat source, in addition to a primary circulation pump at the end of the external network. Multiple primary circulation pumps along the route work together, using a \"segmented relay circulation\" method to facilitate the transfer of the heat medium. Although the pressure drop across each external network segment is equal to that of the corresponding segments in the traditional approach, the power N required for these two methods is different. Applications of level transmitters: Distributed mixing units in heating systems versus traditional heating systems. In traditional systems, the circulation pumps are located at the heat source, and the power supplied is designed for the maximum total circulation flow rate. In the distributed variable-frequency design, the circulation pump at the heat source only needs to overcome the internal resistance within the heat source; the resistance in the external network is overcome by the flow rates provided by the circulation pumps distributed along the system. According to the Heating Information Network, it is obvious that the total pumping power of circulation pumps designed in this way is lower than that of circulation pumps designed using traditional methods. According to relevant data, the use of distributed variable-frequency circulation pumps can save 30-40% in energy consumption. By adopting a distributed variable-frequency pump solution, the system has low unnecessary power consumption and lower operating costs. For each user, the operation of the circulation pump only needs to meet the head pressure required for the operation of that facility. Under design conditions, the minimum power that each user’s circulation pump needs to provide per cycle is sufficient; at part load, due to the varying loads of different users, it is still possible to adjust the pump speed to meet the requirements of the pipeline network, with virtually no throttling losses caused by valves. Secondly, with the distributed variable-frequency pump approach, the pump has low power and low head, as well as a strong ability to adapt to changes in heat load. In the early stages of development of urban heat load, when remote users fail to reach the designed load, primary circulation pumps with lower head can be used in those remote users who have insufficient pressure head ； Once the heat network load has developed fully, and the distribution of heat load often deviates from what was anticipated during design, primary circulation pumps with lower head can be moved to users located closer to the heat source, while primary circulation pumps with higher head can be installed at remote users. If the changes in the system’s operating conditions are fully taken into account when selecting water pumps, ensuring that each pump can operate at its high-efficiency point during adjustment, the energy-saving benefits are self-evident. Applications of level transmitters: Distributed mixing units in heating systems versus traditional heating systems. Industrial automatic transmitter manufacturers are those that monitor, display, record, or control process parameters during industrial production. Monitoring the industrial production process is a fundamental means of understanding and controlling it. Only by being able to accurately understand the overall situation of the process at all times and exercise control over it can production proceed smoothly, resulting in high productivity and the manufacture of qualified products. Applications of level transmitters: distributed mixing units for heating, as well as traditional heating systems. Huaheng Transmitter Manufacturer has developed two key technologies: sensors and intelligent circuit boards. This ensures full control over the core components of all its products, while also improving the accuracy of its industrial automatic transmitters, from 0.2 grade to 0.1 grade. Other products for measuring flow rate and temperature can also be developed by extending the core technologies already in use. The information was collected and compiled by Xi’an Huaheng Level Transmitter Manufacturer.