Vapor Compression Adsorption Cycle for Engine-Off Cabin Cooling
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Solution Overview
Problem
Existing vehicle air-conditioning systems fail to maintain prolonged cooling in the operator's cabin when the engine is off, leading to battery drain and potential starting issues due to reliance on engine power for compressor operation.
Innovation Solution
A cooling system comprising a compressor, condenser, accumulator, pressure reducer, evaporator, and adsorption bed with adsorbent material that stores high-pressure refrigerant when the engine is off, allowing for extended cabin cooling by releasing refrigerant to the evaporator and adsorbing it with the adsorption bed to maintain a pressure gradient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the engine is kept on to power the air-conditioning system, then cooling is maintained, but fuel consumption increases and the vehicle cannot be turned off
Solution Approach 1:
The system pre-charges the accumulator with high-pressure refrigerant during engine operation. When the engine is turned off, this stored refrigerant is automatically released to the evaporator to maintain cabin cooling without requiring the engine to remain running, thus resolving the contradiction between maintaining cooling and reducing fuel consumption.
2Temperature
If the battery is used to power the air-conditioning system when the engine is off, then cooling is maintained, but battery drain occurs and the vehicle may not start
Solution Approach 1:
The accumulator is pre-charged with high-pressure refrigerant during engine operation. When the engine stops, this stored refrigerant provides continuous cooling without requiring battery power, eliminating battery drain and ensuring the vehicle can start reliably when needed.
Solution Approach 2:
The system extracts the refrigerant storage function into a separate accumulator component that can be independently charged during engine operation and then discharge to provide cooling without engine or battery involvement, separating the cooling function from both engine and battery dependencies.
3Use of energy by moving object
If the compressor is stopped to save energy, then fuel consumption decreases, but cooling stops and the cabin temperature rises
Solution Approach 1:
The accumulator is pre-filled with high-pressure refrigerant before the compressor stops. When the compressor is shut off to save energy, the accumulator automatically releases this stored refrigerant to the evaporator, maintaining cabin cooling without requiring the compressor to remain operational.
Solution Approach 2:
The system operates in periodic cycles where the compressor runs to charge the accumulator, then stops to conserve energy while the accumulator provides cooling. This periodic operation pattern allows the system to alternate between energy consumption and energy-free cooling periods.
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
Enables continuous cooling of the operator cabin for several minutes after the engine is turned off, preventing battery drain and ensuring the vehicle can start again, with the option for rapid cooling when the engine restarts.
Implementation Method 1
an adsorption bed having an adsorption material that adsorbs refrigerant from the heat exchanger
Implementation Method 2
a pressure reducer configured to decrease refrigerant pressure and to meter an amount of refrigerant that is received by the evaporator
Implementation Method 3
an evaporator configured to remove heat from an operator cabin with the refrigerant
Implementation Method 4
a condenser configured to remove heat from the refrigerant to convert the refrigerant from the gas state to a liquid state
Implementation Method 5
a compressor configured to compress a refrigerant in a gas state
Data Source
AI summary
A cooling system is disclosed so that an operator cabin can be cooled even if the engine is off. An accumulator can be used to store high-pressure refrigerant until its release. When the compressor is off, the accumulator can release the high pressure refrigerant through the pressure reducer and to the evaporator where heat in the operator cabin can be removed by the refrigerant. An absorption bed with activated carbon can be used to adsorb the refrigerant from the evaporator in order to create a pressure gradient in A/C system. The refrigerant in the accumulator can also be used to subcool a refrigerant in the condenser through a heat exchanger. This allows the operator cabin to be cooled faster up on engine start up. The adsorption bed can also be used to create a pressure gradient in the cooling system.