Waste Heat Recovery System and Method of Operating the Same

摘要

A method of recovering waste heat includes pressurizing a flow of working fluid and transferring heat from a hot gas stream to the flow of working fluid in at least two successively arranged heat transfer sections. At least some of the working fluid is converted to a superheated vapor by the transfer of heat, and passes through an expander to recover useful work. A portion of the flow of working fluid is directed along a branch after having passed through at least one of the heat transfer sections, and bypasses the expander and at least one of the heat transfer sections before being recombined with the working fluid that has passed through the expander. The total flow rate of working fluid can be adjusted to regulate the temperature of the hot gas stream downstream of the heat transfer sections, and the amount of fluid that bypasses along the branch can be adjusted to regulate the temperature of the superheated vapor.

主权项

1. A method of recovering waste heat, the method comprising:
pressurizing a flow of liquid working fluid from a first pressure to a second pressure higher than the first pressure; transferring a first quantity of heat from a hot gas stream into the flow of liquid working fluid after having pressurized the flow of liquid working fluid to the second pressure; splitting the flow of liquid working fluid into a first portion and a second portion after having transferred the first quantity of heat into the flow of liquid working fluid; transferring a second quantity of heat from the hot gas stream into the first portion but not into the second portion, wherein transferring the second quantity of heat converts the first portion to a superheated vapor; non-adiabatically expanding the superheated first portion; and recombining the second portion with the expanded first portion after having non-adiabatically expanded the superheated first portion.