Cascade Heat Pump Compressor Bypass for Higher Compression Ratio

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Solution Overview

Problem

Cascade heat pumps face reduced efficiency due to decreased compression ratio when using a single compressor for both refrigerant cycles, leading to increased power consumption.

Innovation Solution

Implementing a cascade heat pump system with a first and second refrigerant cycle, where the second refrigerant is compressed in two stages using both the second compressor and the first compressor, with a flow rate regulating part to control the flow direction and bypass the first compressor, allowing for high compression ratios and improved efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If one compressor is used to compress the refrigerant circulating in the refrigerant cycle, then the device complexity is reduced, but the compression ratio decreases and efficiency is reduced

Engineering Contradiction:
Improvecompressor configurationVSAvoidefficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent divides the compression function into two separate compressors: a first compressor for the first refrigerant cycle and a second compressor for the second refrigerant cycle. This segmentation allows each compressor to be optimized for its specific refrigerant and operating conditions, thereby improving compression ratio and efficiency while maintaining manageable system complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If one compressor is used to compress the refrigerant circulating in the refrigerant cycle, then the device complexity is reduced, but the power consumption increases

Engineering Contradiction:
Improvecompressor configurationVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent segments the compression system into two independent compressors, each optimized for specific refrigerant cycles. This allows for more efficient compression processes tailored to each refrigerant's properties, reducing overall power consumption compared to a single通用 compressor that must handle both cycles with compromised efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first compressor is designed with multi-functionality to handle both the first refrigerant cycle and assist in compressing the second refrigerant. This universal capability allows the system to optimize power consumption by routing refrigerant flows dynamically, ensuring that each compressor operates in its most efficient range under different operating conditions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 enhances the compression ratio and reduces power consumption by optimizing refrigerant flow and compression, especially during high external temperatures, thereby improving the overall efficiency of the heat pump system.

Implementation Method 1

a first refrigerant cycle in which a first refrigerant circulates and a second refrigerant cycle in which a second refrigerant circulates to heat-exchange the first refrigerant with the second refrigerant through a refrigerant heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

an evaporator for evaporating the refrigerant expanded by the expander

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

a condenser for condensing the refrigerant discharged from the compressor

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP2615392B1Cascade heat pump
Publication Date: 2019.03.06 LG ELECTRONICS INC
  • EP2615392B1 patent drawingFigure 1
  • EP2615392B1 patent drawingFigure 2
  • EP2615392B1 patent drawingFigure 3

AI summary

Provided is a cascade heat pump. The cascade heat pump includes a first refrigerant cycle including a first compressor and a first indoor heat exchanger, a second refrigerant cycle including a second compressor and a second indoor heat exchanger, an outdoor heat exchanger in which a refrigerant compressed in the first compressor or the second compressor is condensed, a bypass tube allowing the refrigerant compressed in the second compressor to bypass the first compressor, thereby flowing into a discharge side of the first compressor, and a first flow rate regulating part disposed on a discharge side of the second compressor to introduce the refrigerant discharged from the second compressor into one of the first compressor and the bypass tube.