A device that transfers heat from one fluid to another
Heat exchanger is a device that transfers heat from one fluid to another. All heating equipment can be shared by the whole plant, or can be set up together with the steam turbine. In order to prevent scaling and corrosion of equipment and pipes, the incoming water of evaporator and make-up water of circulating water of heating network also need to be softened and deoxidized to varying degrees, but the requirements are far lower than boiler feed water.
- Chinese name
- Heat exchanger
- Category
- Mixed and surface
- Concept
- A device for transferring heat from one fluid to another
- Scope of use
- All heating equipment can be shared by the whole plant
Device classification
A device that transfers heat from one fluid to another. It is divided into mixed type and surface type. The heat transfer process in hybrid heat exchanger is through direct mixing of hot fluid and cold fluid. Hybrid condenser It is a kind of hybrid heat exchanger. Heat in surface heat exchanger is transferred from one fluid to another through solid wall. Used in thermal power plants Steam heater Evaporator, heat supply network water heater and surface condenser of steam turbine are all surface heat exchange devices. The utility model relates to a surface type heat exchange device. There are two types: vertical and horizontal. The movement of water depends on the natural circulation formed by the different specific gravity of water and soda water mixture. In order to reduce secondary steam carrying water, in addition to ensuring a certain steam space, the steam outlet is also equipped with Steam water separation device 。 When the secondary steam supply is large, the number of evaporators can be increased in parallel. A surface heat exchanger similar to a low-pressure regenerative heater (see feedwater heater). Water flows in the pipe and heating steam condenses outside the pipe. Heating network heaters can be divided into base load heaters and peak load heaters according to their functions. The base load heater shall use the steam turbine of 0.12-0.25 MPa to adjust the steam extraction (see cogeneration) as the heat source, which can heat the water in the heating network to above 95 ℃, meeting the general heating needs. The peak load heater uses higher pressure steam turbine extraction to heat the water to 130~150 ℃ or higher. It only runs in series with the base load heater in the coldest short term. The purpose of this staged heating is to save high-pressure steam extraction and improve thermal economy. In addition, in order to save the investment of heat supply network pipeline and heat supply network water circulating pump Some countries widely use heating systems that use high temperature water and large temperature difference throughout the heating period. For example, most of Europe uses 200/70 ℃, most of the United States 160/80 ℃, and the Soviet Union 150/70 ℃. 
