Variable Accumulator HVAC Design for DC Power Efficiency in Vehicles
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Solution Overview
Problem
Conventional DC heating and cooling systems for vehicles and remote structures face inefficiencies due to limited battery capacity, size, and weight constraints, leading to suboptimal performance and increased energy consumption, especially when utility power is unavailable.
Innovation Solution
A HVAC system utilizing a variable accumulator with a piston and actuator, along with a control system that adjusts the system's characteristics to optimize compressor performance, allowing for efficient operation using DC power by varying the flow of refrigerant through multiple coils and using sensors to measure and control temperature and pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a large battery array is used to provide sufficient power for heating and cooling systems, then the power availability is improved, but the size and weight increase significantly
Solution Approach 1:
The patent applies dynamics by making the accumulator volume variable rather than fixed. The accumulator can dynamically adjust its storage capacity based on real-time system needs, allowing the system to optimize between power storage and physical space/weight constraints. This resolves the contradiction by enabling the battery array to provide sufficient power when needed while minimizing its physical footprint during normal operation.
Solution Approach 2:
The patent changes the parameter of accumulator volume from a fixed value to a variable parameter that can be adjusted. By using an expandable accumulator design, the system can change its effective storage capacity based on operational requirements, thereby providing sufficient power for heating and cooling without permanently increasing the battery array's size and weight.
2Power
If the internal combustion engine is operated in idle mode to provide power for heating and cooling when parked, then the power availability is improved, but energy efficiency deteriorates and pollution increases
Solution Approach 1:
The patent extracts the heating and cooling function from the internal combustion engine, separating these functions so that the engine is no longer required to idle solely to provide power for climate control. The DC-powered heating and cooling system operates independently using the battery array and expandable accumulator, eliminating the energy waste and pollution associated with engine idling.
Solution Approach 2:
The system enables self-service by allowing the DC-powered heating and cooling system to operate autonomously without requiring the internal combustion engine to run. The expandable accumulator provides sufficient power storage capacity for the climate control system to function independently, freeing the engine from idle operation and its associated energy losses.
3Device complexity
If a fixed-volume accumulator is used in the DC heating and cooling system, then the device complexity is reduced, but the adaptability to varying power demands deteriorates
Solution Approach 1:
The patent applies dynamics by transforming the fixed-volume accumulator into a variable-volume accumulator. This dynamic design allows the accumulator to adjust its storage capacity in response to varying power demands of the heating and cooling system, thereby improving adaptability without introducing excessive complexity. The expandable design provides a straightforward mechanism to match power supply with demand.
Solution Approach 2:
The expandable accumulator design provides multi-functionality by serving both as a power storage device and as an adaptive element that responds to varying system demands. This universal design approach allows the same component to handle different operating conditions (varying power demands) without requiring separate fixed-capacity accumulators for each scenario, thereby improving adaptability while maintaining reasonable system complexity.
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
Enhances the efficiency and performance of DC heating and cooling systems by optimizing compressor operation, reducing energy consumption, and minimizing the need for engine idling or excessive battery drain.
Implementation Method 1
The variable accumulator is arranged between the evaporator and the compressor. The control system operates the actuator to displace the piston to alter at least one characteristic of the HVAC system.
Data Source
AI summary
A HVAC system for a vehicle has a condenser, an evaporator, a compressor, a variable accumulator comprising a piston and an actuator, and a control system operatively connected to the actuator. Fluid flows in a circuit from the condenser, to the evaporator, to the compressor, and to the condenser. The variable accumulator is arranged between the evaporator and the compressor. The control system operates the actuator to displace the piston to alter at least one characteristic of the HVAC system.