Condenser Assembly and Control Method For Use With Rankine Power System

A waste heat recovery system in thermal communication with an exhaust conduit of an internal combustion engine of a vehicle, the waste heat recovery system comprising:

• a working fluid loop fluidly connecting a working fluid pump, an evaporator and an expander and allowing a volume of working fluid to flow therethrough;
• a condenser assembly fluidly connected to the working fluid loop between the expander and the working fluid pump, the condenser assembly including:
• a coolant fluid conduit configured to connect to a coolant fluid loop of a coolant system of the vehicle, the coolant fluid conduit including a coolant fluid inlet and a coolant fluid outlet wherein a volume of coolant fluid of the coolant system flows from the coolant fluid inlet to the coolant fluid outlet when the coolant fluid conduit is connected to the coolant fluid loop;
• and
• a coolant fluid bypass fluidly connected between the coolant fluid inlet and the coolant fluid outlet, the coolant fluid bypass including a coolant fluid control valve, the coolant fluid control valve configured to vary a portion of the volume of coolant fluid that flows through the coolant fluid bypass;
• a temperature sensor positioned downstream of the condenser assembly and operable to output a signal indicative of a temperature of the working fluid before the working fluid enters the working fluid pump;
• and
• a control unit in communication with the temperature sensor and the coolant fluid control valve, wherein the control unit selectively controls the coolant fluid control valve to vary the portion of the volume of coolant fluid that flows through the coolant fluid bypass based on the signal from the temperature sensor.

A method of controlling a temperature of a working fluid in a waste heat recovery system, the method comprising:

• operating a coolant fluid pump to cause coolant fluid to flow at a constant flow rate through a coolant fluid conduit in a condenser assembly;
• receiving a signal from a temperature sensor indicative of a temperature of a working fluid in a working fluid loop, wherein the working fluid loop is in thermal communication with an exhaust conduit of an internal combustion engine;
• comparing the temperature of the working fluid in the working fluid loop to one or more predetermined thresholds;
• and
• adjusting a portion of coolant fluid flowing through a coolant bypass based on the temperature of the working fluid in the working fluid loop.