Patent ID: 8931275
Filing Date: 2015-01-13
Classification: F02G,F28D,F28F,G05D,Y02T

Abstract:
1. A waste heat recovery system comprising: a plurality of system fluid lines; a first heat exchanger receiving heat from a low grade heat source; a second heat exchanger receiving heat from a high grade heat source; a pump for pumping a phase changing fluid through the plurality of fluid lines; an expander receiving the fluid in a gas phase from the second heat exchanger on one of the plurality of fluid lines; an economizer heat exchanger receiving the fluid in the gas phase from the expander on one of the plurality of fluid lines; a condenser receiving the fluid in the gas phase from the economizer heat exchanger on one of the plurality of fluid lines; and a plurality of valves configured to control the flow of the fluid through the plurality of fluid lines in different flow modes as determined by a power ratio that is a ratio of heat power provided by the second heat exchanger to heat power provided by the first heat exchanger, wherein the system is put in an economizer heat exchanger after first heat exchanger mode when the power ratio is a predetermined low power ratio where the fluid from the pump flows to the economizer heat exchanger after the fluid flows to the first heat exchanger and an economizer heat exchanger before first heat exchanger mode when the power ratio is a predetermined high power ratio where the fluid from the pump flows to the economizer heat exchanger before the first heat exchanger.