Rankine Cycle Engine Cooling System Weight Reduction
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Solution Overview
Problem
The implementation of a Rankine cycle in vehicles to recover waste heat and improve fuel economy leads to increased vehicle weight due to the need for additional cooling components, which can counterbalance the fuel economy benefits and result in insufficient temperature differences for cooling water.
Innovation Solution
An engine cooling system that integrates a Rankine cycle with a water-cooled air conditioner cooling cycle, utilizing the outlet-side cooling water from a sub-radiator to liquefy vaporized coolant, eliminating the need for an air-cooled condenser and allowing for a downsized system that reduces vehicle weight and enhances cooling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a Rankine cycle is employed to recover waste heat and improve fuel economy, then fuel economy is improved, but vehicle weight increases due to additional cooling components
Solution Approach 1:
The patent combines the Rankine cycle system with the air conditioner cooling cycle into an integrated system. The condenser of the air conditioner serves dual purposes: condensing refrigerant and cooling the first coolant from the Rankine cycle. This merging eliminates the need for separate air-cooled condensers for both systems, reducing component count and vehicle weight while maintaining fuel economy benefits from waste heat recovery
Solution Approach 2:
The water-cooled condenser is designed to perform multiple functions simultaneously: it acts as the condenser for the air conditioner cooling cycle and also serves as the cooler for the first coolant in the Rankine cycle. This multi-functionality reduces the number of required cooling components, thereby suppressing vehicle weight increase while preserving the fuel economy improvement from waste heat recovery
2Temperature
If air-cooled condensers are disposed at the front surface of the vehicle, then cooling function is provided, but air flow resistance increases and temperature difference for cooling water becomes insufficient
Solution Approach 1:
The patent extracts and eliminates the air-cooled condenser from the front surface of the vehicle. By removing this component, air flow resistance is reduced and the radiators can operate more efficiently with improved air flow, resulting in sufficient temperature difference for cooling water without the blocking effect of front-mounted air-cooled condensers
Solution Approach 2:
The patent transitions from air-cooled to water-cooled condensation system. The water-cooled condenser uses circulating water instead of air flow for heat dissipation, eliminating the need for air-cooled condensers at the front surface. This hydraulic approach reduces air flow resistance while maintaining effective cooling function and sufficient temperature difference for the Rankine cycle
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration suppresses the increase in vehicle weight, improves the Rankine cycle performance by maintaining sufficient temperature differences, and reduces air flow resistance, resulting in a more efficient engine cooling system.
Implementation Method 1
some of inlet-side cooling water of the radiator is used as a heating source for the evaporator
Implementation Method 2
a first coolant circulates through a cooling pump, an evaporator, an expander, and a condenser
Implementation Method 3
a Rankine cycle configured such that a first coolant circulates through a cooling pump, an evaporator, an expander, and a condenser
Implementation Method 4
some of outlet-side cooling water of the sub-radiator is used as a cooling source for the condenser
Implementation Method 5
a first coolant circulates through a cooling pump, an evaporator, an expander, and a condenser
Implementation Method 6
a cooling cycle for an air conditioner configured to cool a vehicle by utilizing a vaporization of a liquid second coolant
Implementation Method 7
the vaporized second coolant is cooled and again liquefied by using some of the outlet-side cooling water of the sub-radiator in the condenser
Data Source
AI summary
An engine cooling system, capable of reducing vehicle weight caused by employing a Rankine cycle and capable of improving Rankine cycle performance, including some inlet-side cooling water of a radiator is used as a heating source for a first evaporator and some outlet-side cooling water of a sub-radiator is used as a cooling source for a condenser, a coolant that has passed through an expander, a second evaporator, and a compressor in a cooling cycle for an air conditioner, vaporized, cooled and liquefied by passing through a side to be cooled of the condenser in the Rankine cycle.