Compressor Output Control Using Variable Evaporator Temperature Limits

Solution Overview

Problem

Conventional cooling systems with fixed evaporator temperature ranges can lead to inefficient operation and potential freezing issues, as the compressor remains on or off based on static temperature limits, failing to adapt to varying conditions.

Innovation Solution

A method and system that dynamically adjust the compressor's operation by calculating a variable temperature limit based on the difference between the target and actual evaporator temperatures, considering factors like ambient temperature, user settings, and sun load, allowing for adaptive operation within a range that balances efficiency and prevents freezing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed temperature range is used for evaporator control, then the compressor operation is simple and reliable, but the cooling system efficiency deteriorates under varying conditions

Engineering Contradiction:

Improvecompressor operation reliabilityVSAvoidcooling system efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic temperature limits that automatically adjust based on operating conditions such as ambient temperature, vehicle speed, and engine load. Instead of fixed temperature thresholds, the system calculates variable temperature limits that adapt to changing environmental and operational parameters, thereby maintaining optimal cooling efficiency across diverse conditions while preserving system reliability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the temperature parameter thresholds dynamically based on multiple input factors including ambient temperature, sun load, and vehicle operating mode. By modifying the temperature limit parameters in response to varying conditions, the system optimizes compressor operation efficiency without compromising reliability, directly addressing the contradiction between fixed simplicity and variable performance.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If the compressor operates continuously within a fixed temperature range, then the control logic is simple, but energy consumption increases and fuel savings are reduced

Engineering Contradiction:

Improvecontrol logic complexityVSAvoidfuel consumption

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent implements dynamic temperature limits that automatically adjust based on operating conditions such as ambient temperature, vehicle speed, and engine load. Instead of fixed temperature thresholds, the system calculates variable temperature limits that adapt to changing environmental and operational parameters, thereby maintaining optimal cooling efficiency across diverse conditions while preserving system reliability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system changes the temperature parameter thresholds dynamically based on multiple input factors including ambient temperature, sun load, and vehicle operating mode. By modifying the temperature limit parameters in response to varying conditions, the system optimizes compressor operation efficiency without compromising reliability, directly addressing the contradiction between fixed simplicity and variable performance.

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If a fixed temperature limit is used, then the system is easy to operate, but adaptability to different environmental conditions deteriorates

Engineering Contradiction:

Improvesystem operation simplicityVSAvoidadaptability to environmental conditions

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The system automatically determines appropriate temperature limits by processing input data from various sensors and pre-programmed algorithms. The controller self-adjusts the temperature thresholds based on ambient conditions, sun load, and vehicle operating parameters without requiring manual intervention, thereby maintaining ease of operation while achieving high adaptability to varying environmental conditions.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system changes the temperature parameter thresholds dynamically based on multiple input factors including ambient temperature, sun load, and vehicle operating mode. By modifying the temperature limit parameters in response to varying conditions, the system optimizes compressor operation efficiency without compromising reliability, directly addressing the contradiction between fixed simplicity and variable performance.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8682527B2Cooling system compressor with variable operating range

Publication Date: 2014.03.25 DENSO INTERNATIONAL AMERICA INC

AI summary

A method of operating an air conditioning system includes changing output of the compressor based on a temperature limit of the evaporator. The temperature limit is one of a predetermined fixed temperature limit and a variable temperature limit. The method also includes determining the variable temperature limit by determining a target air outlet temperature for conditioned air in a control space, detecting an actual evaporator temperature, calculating a difference between the target air outlet temperature and the actual evaporator temperature, finding a predetermined first temperature adjustment that correlates to the difference, finding a predetermined second temperature adjustment that correlates to another condition, and calculating the variable temperature limit by adjusting the fixed temperature limit by one of the first and second temperature adjustments.