Economizer injection in a reciprocating compressor

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Solution Overview

Problem

Multi-stage compressors used in vapor compression systems with economizers are bulky, complex, and costly due to the need for separate compressor stages, where refrigerant from the economizer is only compressed in the second stage, bypassing the first stage and increasing system size and complexity.

Innovation Solution

A reciprocating compressor design with a cylinder block and head featuring distinct regions for suction, economizer, and discharge, equipped with valves that allow controlled fluid communication, including an economizer valve operated by a controller based on pressure and piston movement sensors to integrate economizer flow into the compression process, potentially eliminating the need for a second compressor stage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a multi-stage compressor is used to compress economizer refrigerant in a separate second stage, then the refrigerant can be properly compressed, but the system size, complexity, and cost increase

Engineering Contradiction:
Improverefrigerant compression capabilityVSAvoidcompressor stage configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the compression of both regular suction refrigerant and economizer refrigerant into a single compression stage. The cylinder head is divided into a suction bore and an economizer bore, both communicating with a common compression chamber. This allows one compression stage to perform the work that traditionally required two separate stages, reducing system complexity while maintaining proper refrigerant compression capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single compression stage is designed to handle multiple functions: it compresses both the regular suction refrigerant flow and the economizer refrigerant flow. The common compression chamber serves as a universal space that receives and compresses refrigerant from both bores, eliminating the need for dedicated compression chambers for each refrigerant source

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

2Reliability

If separate compressor stages are used for suction and economizer refrigerant, then proper compression is achieved, but the compressor footprint and manufacturing cost increase

Engineering Contradiction:
Improvecompression performanceVSAvoidcompressor footprint
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the compression functions into a single stage with a common compression chamber that receives refrigerant from both the suction bore and economizer bore. This consolidation eliminates the need for separate compression chambers and reduces the overall compressor footprint while maintaining effective compression of both refrigerant streams

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If economizer refrigerant is injected into the conduit between compressor stages, then compression is achieved, but the system requires additional valves and control mechanisms increasing complexity

Engineering Contradiction:
Improvecompression functionVSAvoidvalve and control system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent eliminates the need for separate injection valves by providing direct communication between the economizer bore and the common compression chamber through an opening in the piston. This direct pathway allows economizer refrigerant to enter the compression chamber without requiring complex injection valve mechanisms, reducing system complexity while maintaining compression functionality

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent removes the intermediate conduit and injection valve components from the system by establishing direct communication between the economizer bore and compression chamber. This extraction of unnecessary components simplifies the valve and control system while preserving the essential compression function

Inventive Principle:
Principle #2Taking out (Extraction)

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 design reduces system size, complexity, and cost by integrating the economizer flow into the compression process within a single compressor stage, enhancing efficiency and reducing the footprint of the compressor.

Implementation Method 1

moving a piston within the cylinder to increase a pressure within the cylinder, moving the piston to further increase the pressure within the cylinder

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

a suction valve selectively operable to fluidly couple the suction region and the first bore

Methodology Applied
Scientific EffectPressure differential flow: Pressure Gradient

Implementation Method 3

an economizer valve selectively operable to fluidly couple the economizer region and the first bore

Methodology Applied
Scientific EffectPressure differential flow: Pressure Gradient

Data Source

PatentEP4130472A1Economizer injection in a reciprocating compressor
Publication Date: 2023.02.08 CARRIER CORP
  • EP4130472A1 patent drawingFigure 1
  • EP4130472A1 patent drawingFigure 2
  • EP4130472A1 patent drawingFigure 3

AI summary

A compressor 20 includes a cylinder block 28 having a first bore 30 and a cylinder head 32 overlapping the cylinder block. The cylinder head 32 has a second bore 34 aligned with the first bore 30. The second bore 34 is separated into a plurality of distinct regions including a suction region 42 and an economizer region 46. A plurality of valves includes a suction valve 50 selectively operable to fluidly couple the suction 42 region and the first bore 30, and an economizer valve 54 selectively operable to fluidly couple the economizer region 46 and the first bore 30.