This type of plant serves two purposes, one for production of electrical power and the other for desalination. These combine vapor compression with multi-stage flash evaporators. For this process to be economical there are restrictions to a relatively low output of water compared with energy. There has been research done to allow the ratio to shift to a higher production of water and a possibility is specially designed low-pressure nuclear reactors.
Vapor compression evaporation is important to single- and dual-purpose processes for desalination because it has relatively low heat-transfer surface requirements and energy demands. There are three major points of interest that are known for vapor compression evaporation:
1) The energy required needs to be in the form of work. (It can make use of the energy from nuclear reactors.) 2) The separation process of evaporation is well developed. 3) The heat-transfer surface area requirements are lower than most other processes.
A comparison with other processes such as MSF, multi-stage flash, and LTV, long tube vertical can be done with the corresponding heat-cycle efficiencies as a discussion of the third point of interest.