Reciprocating compressor and fluid injection system

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Solution Overview

Problem

Existing reciprocating compressors face challenges in efficiently injecting fluid at an intermediate pressure into multiple compression mechanisms, leading to suboptimal energy consumption and performance.

Innovation Solution

A reciprocating compressor design that includes a system for injecting fluid at intermediate pressure into each compression mechanism from a single source, utilizing a housing cover with intermediate-fluid passages and a fluid storage plenum to which the intermediate-fluid passages and storage plenums are in fluid communication, allowing selective fluid communication with the cylinders.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If fluid injection system is added to reciprocating compressor, then energy efficiency is improved, but device complexity increases

Engineering Contradiction:
Improveenergy consumptionVSAvoidsystem complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The fluid injection system is nested within the existing compressor housing structure. The intermediate-fluid passages are integrated into the housing cover, and the fluid storage plenum is positioned within the housing, allowing the injection system to utilize the existing structural space rather than adding external components.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The housing cover serves multiple functions: it encloses the compression mechanisms and simultaneously contains the intermediate-fluid passages and fluid storage plenum. This multi-functional design reduces the need for separate dedicated injection system housings or additional structural components.

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

2Productivity

If multiple compression mechanisms are used, then productivity is improved, but ease of operation worsens

Engineering Contradiction:
Improvedischarge-pressure refrigerant supplyVSAvoidfluid injection control
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The fluid injection system combines multiple intermediate-fluid passages into a single housing cover structure that serves all compression mechanisms. The fluid storage plenum provides a common source for all passages, allowing centralized fluid supply to multiple cylinders through a unified control architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system segments the fluid distribution into separate intermediate-fluid passages for each compression mechanism, allowing independent control and optimization of fluid injection timing and quantity for each cylinder while maintaining a unified storage plenum.

Inventive Principle:
Principle #1Segmentation

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 energy efficiency by minimizing energy consumption and ensuring reliable operation of the compressor, effectively providing a cooling and/or heating effect on demand, efficiently providing sufficient discharge-pressure refrigerant to the system.

Implementation Method 1

The intermediate-fluid port is in fluid communication with the first fluid storage plenum via a first intermediate-fluid passage and the second fluid storage plenum via a second intermediate-fluid passage

Methodology Applied
Scientific EffectFluid communication:

Data Source

PatentEP4667744A1Reciprocating compressor and fluid injection system
Publication Date: 2025.12.24 COPELAND LP
  • EP4667744A1 patent drawingFigure 1
  • EP4667744A1 patent drawingFigure 2
  • EP4667744A1 patent drawingFigure 3A~3B

AI summary

A compressor includes a housing, a first compression mechanism and a second compression mechanism disposed in the housing, and a valve. Both the first compression mechanism and the second compression mechanism are configured to compress a working fluid from a suction pressure to a discharge pressure. The first compression mechanism includes a first cylinder housing having a first fluid storage plenum. The second compression mechanism includes a second cylinder housing having a second fluid storage plenum. An intermediate-fluid port is in selective fluid communication with the valve. The intermediate-fluid port is in fluid communication with the first fluid storage plenum via a first intermediate-fluid passage and the second fluid storage plenum via a second intermediate-fluid passage. Working fluid at an intermediate pressure enters the intermediate-fluid port through the valve. The intermediate pressure is greater than the suction pressure and less than the discharge pressure.