System and method of controlling a variable-capacity compressor

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Solution Overview

Problem

Climate-control systems, such as heat-pump and refrigeration systems, face inefficiencies in energy usage due to the inability to dynamically adjust compressor capacity based on varying outdoor air temperatures and thermal loads, leading to suboptimal heating and cooling performance.

Innovation Solution

A climate-control system with a variable-capacity compressor and a control module that switches between low and high capacity modes based on demand signals, outdoor air temperature, and temperature slope, using a lookup table to determine runtime settings and account for relative humidity and thermal loads, allowing for adaptive operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the compressor operates in high-capacity mode continuously, then the heating or cooling speed is improved, but energy efficiency deteriorates

Engineering Contradiction:

Improveheating or cooling speedVSAvoidenergy efficiency

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The compressor capacity is made dynamic rather than fixed, allowing it to adjust between high-capacity and low-capacity modes based on real-time outdoor temperature conditions and thermal load requirements, thereby optimizing both cooling speed and energy efficiency

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the compressor by switching between different capacity modes (high-capacity and low-capacity) based on outdoor temperature slopes and accumulated runtime, allowing optimal energy efficiency while maintaining adequate cooling performance

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If the compressor operates in low-capacity mode continuously, then energy efficiency is improved, but the heating or cooling speed deteriorates

Engineering Contradiction:

Improveenergy efficiencyVSAvoidheating or cooling speed

Core Design Contradiction:

Use of energy by moving objectVSSpeed

Solution Approach 1:

The system dynamically adjusts compressor capacity based on environmental conditions, switching to high-capacity mode when outdoor temperature slopes indicate rapidly changing conditions that require faster response, while operating in low-capacity mode during stable conditions

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The control module uses feedback from outdoor temperature sensors and runtime accumulation to determine when to switch between capacity modes, ensuring the system responds appropriately to changing thermal loads while maintaining energy efficiency

Inventive Principle:

Principle #23Feedback

3Productivity

If the compressor runtime in high-capacity mode is extended, then the thermal load is reduced faster, but energy consumption increases

Engineering Contradiction:

Improvethermal load reduction rateVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The system changes the operational parameters by setting specific runtime thresholds for high-capacity mode based on outdoor temperature slopes, allowing the compressor to operate at high capacity only when the environmental conditions justify the additional energy consumption for faster thermal load reduction

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10436491B2System and method of controlling a variable-capacity compressor

Publication Date: 2019.10.08 COPELAND LP

AI summary

A climate-control system includes a variable-capacity compressor unit and a control module. The variable-capacity compressor unit is operable in a first capacity mode and in a second capacity mode that is higher than the first capacity mode. The control module may be configured to switch the variable-capacity compressor unit between the first capacity mode and the second capacity mode based on a demand signal, a current outdoor air temperature, an outdoor-air-temperature slope, and a previous runtime of the variable-capacity compressor unit in the second capacity mode.