Heat exchanger (also known as heat exchanger or heat exchanger) is a device used to transfer heat from hot fluid to cold fluid to meet specified process requirements. It is an industrial application of convection heat transfer and heat transfer. Heat exchangers can be classified in different ways. According to its operation process can be divided into three categories: interwall type, mixed type, reheat type (or reheat type); According to its surface compact degree can be divided into compact type and non-compact type.
The hybrid heat exchanger relies on direct contact between cold and hot fluids to conduct heat transfer. This heat transfer mode avoids thermal resistance of heat transfer wall and dirt on both sides. As long as the contact between fluids is good, the heat transfer rate will be higher. Therefore, where fluid is allowed to mix with each other, hybrid heat exchanger can be used, such as gas washing and cooling, circulating water cooling, vapor-water mixed heating, steam condensation and so on. It is used in chemical and metallurgical enterprises, power engineering, air conditioning engineering and many other production sectors. The mixed heat exchanger can be divided into several types according to different USES: (1) cooling tower (or cold water tower) in this equipment, use natural ventilation or mechanical ventilation to cool and cool the water already raised in production and then recycle it to improve the economic benefit of the system. For example, circulating water in thermal power plants or nuclear power plants, cooling water in ammonia production, etc. are recycled after cooling by water cooling towers. This method has been widely used in practical engineering. Gas scrubbers (or scrubbers) are used in industry for a variety of purposes, such as absorbing certain components of the gas mixture with liquid, removing dust from the gas, humidifying or drying the gas, etc. But its most extensive use is to cool the gas, which is mostly water. The sprinkler chamber widely used in air conditioning engineering can be considered as a special form of it. The spray chamber not only cools the air like a gas scrubber, but also heats it. But, it also has to water quality requirement is high, cover an area greatly, pump energy is much wait for a shortcoming: so, in general building, spray chamber already used infrequently or use as humidification equipment only. However, in the main purpose of humidity control textile mills, cigarette factories, etc. are still in use! (3) in this equipment, the high-pressure fluid is ejected by the nozzle, forming a high speed. The low-pressure fluid is introduced into the mixing chamber to conduct heat transfer in direct contact with the jet flow, and enters the diffusion tube together, and is sent to the user after the outlet of the diffusion tube reaches the same pressure and temperature. (4) the hybrid condenser is generally used to condense the steam by direct contact with water.
