Hybrid heat exchanger
Hybrid heat exchangers rely on direct contact between cold and hot fluids for heat transfer. This heat transfer method avoids the thermal resistance of the heat transfer partition and its sides. As long as the contact between the fluids is good, there will be a large Heat transfer rate. Therefore, where fluids are allowed to mix with each other, hybrid heat exchangers can be used, such as gas washing and cooling, circulating water cooling, steam-water mixing heating, steam condensation, etc. It is used in chemical and metallurgical enterprises, power engineering, air conditioning engineering, and many other production departments.
According to different uses, the hybrid heat exchanger can be divided into the following different types:
(1) Cooling tower (or cold water tower)
In this kind of equipment, the water whose temperature has been raised in the production is cooled and cooled down by natural ventilation or mechanical ventilation to improve the economic benefit of the system. For example, circulating water in thermal power plants or nuclear power plants, cooling water in the production of synthetic ammonia, etc. are recycled after cooling by water cooling towers. This method has been widely used in practical projects.
(2) Gas scrubber (or scrubber)
There are various purposes for using this equipment to scrub gas in industry, such as absorbing certain components in a gas mixture with a liquid, removing dust from the gas, and humidifying or drying the gas. But its ultra-wide use is for cooling gas, and the liquid used for cooling is mostly water. The spray room widely used in air conditioning engineering can be considered as a special form of it. The spray chamber can not only cool the air like a gas scrubber, but also heat it. However, it also has shortcomings such as high water quality requirements, large floor area, and high energy consumption by pumps. Therefore, in general buildings, spray rooms are not often used or only used as humidification equipment. However, it is still widely used in textile factories and cigarette factories whose main purpose is to regulate humidity!
(3) Jet heat exchanger
In this equipment, the fluid with higher pressure is ejected from the nozzle to form a very high speed. The low-pressure fluid is introduced into the mixing chamber to directly contact the jet for heat transfer, and enters the diffusion tube together. The same pressure and temperature will be sent to users.
(4) Hybrid condenser
This kind of equipment generally uses water and steam in direct contact to condense the steam.
Regenerative heat exchanger
Regenerative heat exchangers are used for regenerative heat exchange equipment. Built-in solid filler to store heat. Refractory bricks are generally used to form fire lattices (sometimes with metal corrugated tape, etc.). The heat exchange is carried out in two stages. At this stage, the hot gas passes through the fire lattice and transfers the heat to the fire lattice to be stored. In the second stage, the cold gas passes through the fire lattice and is heated by receiving the heat stored in the fire lattice. These two stages alternate. Usually two regenerators are used alternately, that is, when hot gas enters one device, cold gas enters the other device. It is commonly used in the metallurgical industry, such as the regenerator of steel-making open hearth furnaces. It is also used in the chemical industry, such as air preheaters or combustion chambers in gas stoves, and regenerative cracking furnaces in artificial oil plants.
Regenerative heat exchangers are generally used in applications where the requirements for medium mixing are relatively low.