Central heating is an important measure to save energy and improve the environment. It is also an important infrastructure for urban economic and social development, and its development level is the symbol of urban modernization. And the continuous development of social economy and the improvement of the comfort requirements of human settlements have driven the rapid development of central heating industry and become the main heating mode for people. Energy saving, environmental protection, cost reduction and efficiency improvement have become the primary problems to be solved in the heating industry. The optimal design of central heating system and the progress of heating technology are prerequisites to ensure the sustainable development of central heating, so as to achieve the best environment with the most economical energy consumption.

It is an important energy-saving measure to adopt advanced technical equipment, high-tech materials and products with high power, high efficiency and low energy consumption. THT has been paying close attention to the progress and development of the heating industry. For more than 20 years, it has devoted itself to strengthening the research and popularization of heat transfer technology, constantly creating value and benefits for users, not only saving a lot of energy, but also greatly reducing the metal consumption. From providing high-efficiency plate heat exchanger products to providing the design and service of fully automatic unattended preassembled integrated heat exchange station, from 1991, the patent product of unequal cross-section plate heat exchanger was developed to the successful application of high-pressure plate heat exchanger in pressure insulation heat exchange station, which provided technical progress for central heating.

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Unequal cross-section plate heat exchangers are widely used in central heating industry. The heat transfer plates are designed into herringbone corrugations with different cross-sectional areas of fluid channels on both sides, so that adjacent plates with large cross-sectional areas form wide channels, while those with small cross-sectional areas form narrow channels. The ratio of cross-sectional areas is 2: 1, and the angular holes on the plates are divided into two types, namely, large-angle holes and wide channels, and small-angle holes and narrow channels. In addition to the characteristics of the plate heat exchanger with equal cross section, the plate heat exchanger with unequal cross section has the following remarkable characteristics:

Improve heat exchange capacity: because of the special structure of the heat exchanger, it is especially suitable for the working condition of hot and cold side throughput ≥2:1. Because the cross-sectional area ratio of the runner is 2:1, in the case of single flow, the flow rate between the plates of cold and hot media is close to or equal, thus improving the heat transfer coefficient, that is,to improving the heat exchange capacity of the plate heat exchanger.

Reduce the investment cost: when the treatment capacity of cold and hot media is ≥2:1, the heat transfer coefficient of unequal cross-section heat exchanger can be increased by 20-30% and the heat exchange area can be reduced by 20-30%, thus reducing the equipment investment cost.

Low pressure loss: Because the unequal cross-section plate heat exchanger is usually a single process, and the unequal cross-section diversion distribution is adopted on the heat transfer plate, the large and small treatment capacities are different, and the flow rate between plates is more reasonable than the equal cross-section type, which effectively reduces the pressure loss.

More convenience to use: Because the plate heat exchangers with unequal cross-sections are usually single-flow, the nozzles are on one side of the fixed plate, and the movable plate is not restricted, which greatly facilitates the installation, commissioning, combination change, cleaning and maintenance of users.

Now, more and more central heating projects are beginning to recycle the waste heat generated in thermal power plants, and cogeneration has become a universally recognized energy-saving way. As one of the main equipment of cogeneration, the network heater uses the steam extracted from the steam turbine as the heat source (generally, the steam extracted from the fourth or fifth stage, and the steam pressure is 0.2-0.6Mpa) to heat the network water. Therefore, the operation reliability, advanced design rationality and investment economy of heating network heaters have always been the goals pursued by manufacturers.