Ejector-type heat exchangers in the air conditioning in transport

In the modern world, the air conditioning systems have become the most widespread application and have become an everyday part of everyday life. However, due to the complexity of the construction during the designing of the air conditioning systems and the development of modern technologies, there are still many system’s assemblies that can be upgraded and improved. Along with such parameters as ergonomics and weight and size characteristics, a significant role is played by such parameters of the operation of the air conditioning systems as efficiency, reliability, resource. These parameters are particularly relevant in the context of miniaturization and work on a closed cycle in mobile transport vehicles (automotive, aircraft and ship equipment), since efficiency, mass and resource exert a determinative influence on the total cost of vehicles and the costs of its maintenance and operation. The main parameters that regulate the air conditioning systems are the temperature, flow rate and humidity of the supplied air. The article studies and compares the methods of primary cooling of hot air supplied to the helicopter's air conditioning systems, when the cabin is heated at low temperatures. Often this is done using air-to-air heat exchangers. In the materials of the article, it is proposed to consider the option of replacing one of such heat exchanger with an ejector-type heat exchanger, a description and comparison of the existing and proposed options for the modernization of the air conditioning system’s schemes, and estimate the acceptability of their implementation on the helicopter. Also, a comparative work was conducted to estimate the advantages and disadvantages of such a replacement. The primary estimated calculations of the change in the system’s parameters were implemented in the case of introduction of a replacement in all conventional load modes of a typical helicopter model. Specific features of the application of this replacement are given and additional innovations which are necessary for its implementation are pointed out. For calculations, the software complex ANSYS CFX, MathCAD, Solid Edge ST8 was used. In the course of the work, a construction and a method were revealed that provided the optimal parameters and method of implementation for the introduction of the ejector into the composition of the air conditioning system.

air-to-air heat exchanger, heat mixer, ejector, air conditioning system, service life, aircraft transport, consumption, temperature control, thermal stresses, efficiency, reliability