A waste heat utilization device (2) for an internal combustion engine has a Rankine cycle (8) that recovers waste heat from an internal combustion engine (4), a generator (30) that is rotationally driven by an expander (14) and converts a rotational drive force into electric power, a converter (32) that controls the rotational speed of the expander (14) through the generator (30), refrigerant-condition detecting means (22, 24, 26, 28) that detects the pressure and temperature of a refrigerant passing through the expander (14), and a controller (34) that calculates pressure ratio Rp of the refrigerant in the immediate upstream and downstream of the expander (14) and specific heat ratio K of the refrigerant passing through the expander (14) on the basis of the pressure and temperature of the refrigerant, which have been detected by the refrigerant-condition detecting means (22, 24, 26, 28), calculates a preset pressure ratio Rps of the pressure ratio Rp by multiplying predetermined volume ratio Rv of the expander (14) by the specific heat ratio K, and specifies rotational speed N of the expander (14) to the converter (32) on the basis of the pressure ratio Rp and the preset pressure ratio Rps.

Waste Heat Utilization Device for Internal Combustion Engine

The waste heat recovery system includes a Rankine cycle device in which working fluid circulates through a pump, a boiler, an expander and then through a heat exchanging device, heat exchange occurs in the boiler between the working fluid and intake fluid that is introduced into an internal combustion engine while being cooled. The heat exchanging device includes a condenser condensing the working fluid, a receiver connected downstream of the condenser and storing liquid-phase working fluid, a subcooler connected downstream of the receiver and subcooling the liquid-phase working fluid, and a selector device serving to change the ratio of the condenser to the subcooler. The waste heat recovery system further includes a determination device for determining required cooling load for the intake fluid, and a controller for controlling the selector device depending on the required cooling load determined by the determination device.

Waste heat recovery system

A method and system for operating a cascaded organic Rankine cycle (ORC) system (100) utilizes two waste heat sources from a positive-displacement engine (106), resulting in increased efficiency of the engine (106) and the cascaded ORC system (100). A high temperature waste heat source from the positive-displacement engine (106) is used in a first ORC system (102) to vaporize a first working fluid (118). A low temperature waste heat source from the positive-displacement engine (106) is used in a second ORC system (104) to heat a second working fluid (130) to a temperature less than the vaporization temperature. The second working fluid (130) is then vaporized using heat from the first working fluid (118). In an exemplary embodiment, the positive-displacement engine (106) is a reciprocating engine. The high temperature waste heat source may be exhaust gas and the low temperature waste heat source may be jacket cooling water.

Cascaded organic rankine cycle (orc) system using waste heat from a reciprocating engine

The present invention relates to a system and method for cooling a combustion gas charge prior. The combustion gas charge may include compressed intake air, exhaust gas, or a mixture thereof. An evaporator is provided that may then receive a relatively high temperature combustion gas charge and discharge at a relatively lower temperature. The evaporator may be configured to operate with refrigeration cycle components and/or to receive a fluid below atmospheric pressure as the phase-change cooling medium.

System And Method For Cooling A Combustion Gas Charge

In a dual-source organic Rankine cycle (DORC), the condensed and slightly sub-cooled working fluid at near ambient temperature (~300 K) and at low-side pressure (0.1 to 0.7 MPa) is (1) pumped to high-side pressure (0.5-5 MPa), (2) pre-heated in a low-temperature (LT) recuperator, (3) boiled using a low-grade heat source, (4) super-heated in a high-temperature (HT) recuperator to a temperature close to the expander turbine exhaust temperature using this exhaust vapor enthalpy, (5) further super-heated to the turbine inlet temperature (TIT) using a mid-grade heat source, (6) expanded through a turbine expander to the low-side pressure, (7) cooled through the HT recuperator, (8) cooled through the LT recuperator, (9) mostly liquefied and slightly subcooled in a condenser, and (10) the condensed portion is returned to the pump to repeat this cycle.

High-temperature dual-source organic rankine cycle with gas separations

In a waste heat recovery system wherein a heat exchanger derives heat from an engine exhaust, a venturi is fluidly connected to an engine exhaust port so as to thereby increase the flow rate and reduce the pressure in a manifold which is fluidly connected between the venturis and the heat exchanger A fan is provided downstream of the heat exchanger to draw hot gases from the manifold, through the heat exchanger and discharge it to ambient But when the fan is not operating during periods in which the engine is operating, the lower pressure manifold will draw ambient air in through the fan and through the heat exchanger, with the ambient air then being entrained in the exhaust gases being discharged from an exhaust channel downstream of the venturi In one embodiment, a plurality of heat sources are provided with each having its own venturi connected to the common low pressure manifold

Thomas D. Radcliff

Papers

Apparatus for extracting exhaust heat from waste heat sources while preventing backflow & corrosion