Hybrid heat exchanger
Hybrid heat exchanger relys on the direct contact of cold and hot fluids to conduct heat transfer. This heat transfer method avoids the fouling resistance between the heat transfer wall and its two sides. As long as the contact between fluids is good, there is a large heat transfer rate. Therefore, where fluid mixing is allowed, mixed heat exchangers can be used, such as gas washing and cooling, cooling of circulating water, steam-water mixing heating, steam condensation and so on. It is widely used in chemical and metallurgical enterprises, power engineering, air conditioning engineering and many other production sectors. According to the different uses, the hybrid heat exchanger can be divided into the following types.
1. Cooling tower (or cold water tower). In this equipment, by the method of natural ventilation or mechanical ventilation, the production has been raised in the temperature of water cooling after recycling, in order to improve the economic efficiency of the system. For example, the circulating water of thermal power plant or nuclear power plant and the cooling water of ammonia synthesis production are recycled after the cooling tower. This method has been widely used in practical engineering.
2. Gas scrubbers (or scrubbers). It is used in industry to scrub gases for various purposes, such as absorbing certain components of gas mixtures with liquids, removing dust from gases, humidifying or drying gases, etc. But the most widely used use is cooling gas, and the liquid used for cooling is mostly water. The spray room widely used in air conditioning engineering can be regarded as a special form. The spray chamber can not only cool the air like a gas scrubber, but also heat it. However, it also has the shortcomings of high water quality requirements, large floor area, energy consumption of pumps and so on. Therefore, in general buildings, sprinkler chamber is not often used or only used as humidification equipment. However, a large number of textile and cigarette factories still use jet heat exchangers for the purpose of regulating humidity.
3. Jet heat exchanger. In this equipment, the high pressure fluid is ejected from the nozzle to form a high speed, and the low pressure fluid is introduced into the mixing chamber and directly contacted with the jet for heat transfer, and enters the diffusion tube together. After the outlet of the diffuser reaches the same pressure and temperature, it is delivered to the user.
4. Mixed condenser. This equipment is generally water and steam in direct contact with the method of condensation of steam.