Heat Pump Refrigerant Injection Control for Compressor Cooling

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Solution Overview

Problem

The existing heat pump devices have limited application and efficiency due to the fixed refrigerant injection method, which restricts the expansion of their operational capabilities.

Innovation Solution

The refrigerant line is designed with an adjustable inflow opening that can open either above or below the refrigerant level in the collector, allowing for the selective injection of pure vapor, liquid, or wet refrigerant vapor into the compressor, controlled by the expansion valve, enabling improved efficiency and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a fixed refrigerant inflow opening below the refrigerant level is used, then liquid refrigerant is discharged to cool the compressor, but the application limits and efficiency cannot be further expanded

Engineering Contradiction:
Improvecompressor coolingVSAvoidapplication limits
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The refrigerant line is designed with a movable section that can be positioned vertically to adjust the refrigerant inflow opening location. This dynamic positioning allows the system to switch between different refrigerant discharge modes (liquid, vapor, or wet) by changing the relative position of the inflow opening to the refrigerant level, thereby resolving the contradiction between compressor cooling and expanded application limits.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the physical parameter of the refrigerant inflow opening position relative to the refrigerant level. By adjusting this position parameter, the system can control whether liquid, vapor, or wet refrigerant is discharged, enabling adaptation to different application requirements while maintaining compressor cooling capability when needed.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If a refrigerant collector is added to enable intermediate injection, then the efficiency and application limits are expanded, but the device complexity increases

Engineering Contradiction:
ImproveefficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The refrigerant collector is designed to serve multiple functions: it acts as a storage vessel for refrigerant, provides a interface for intermediate injection, and enables control over refrigerant phase through the adjustable inflow opening. This multi-functionality allows the system to achieve improved efficiency and expanded application limits without adding proportionally complex components, as the same collector structure supports various operational modes.

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

3Device complexity

If the refrigerant inflow opening is fixed, then the device structure is simple, but the vapor-to-liquid ratio cannot be controlled

Engineering Contradiction:
Improvedevice structureVSAvoidvapor-to-liquid ratio control
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The refrigerant line incorporates a movable section that enables dynamic adjustment of the inflow opening position. This dynamic feature allows control over the vapor-to-liquid ratio by positioning the opening at different heights relative to the refrigerant level, achieving adaptability without excessive structural complexity through a straightforward mechanical adjustment mechanism.

Inventive Principle:
Principle #15Dynamics

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 solution enhances the heat pump's efficiency and expands its application limits by allowing targeted control of the vapor-to-liquid ratio, improving performance and enabling both heating and cooling functions effectively.

Implementation Method 1

the state of aggregation in which the refrigerant is injected into the compressor can be determined via the controllable expansion valve and thus via the refrigerant level in the refrigerant collector. Injection of vapor refrigerant improves the efficiency and performance of the heat pump device. Injection of liquid refrigerant offers the possibility of cooling the compressor

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

Injection of vapor refrigerant improves the efficiency and performance of the heat pump device. Injection of liquid refrigerant offers the possibility of cooling the compressor, lowering the hot gas temperature

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2812638B1Heat pump device
Publication Date: 2018.04.11 VIESSMANN GRP GMBH & CO KG
  • EP2812638B1 patent drawingFigure 1~2
  • EP2812638B1 patent drawingFigure 3~4
  • EP2812638B1 patent drawingFigure 5~6

AI summary

The invention relates to a heat pump apparatus, comprising a compressor (1), downstream of which a liquefier (2) is connected, downstream of which a refrigerant collector (3) is connected that, for the intermediate injection of refrigerant into the compressor (1), is connected to the compressor via a refrigerant line (4). According to the invention, in order to set the refrigerant level in the refrigerant collector (3), a controllable expansion valve (5) is arranged between the liquefier (2) and the refrigerant collector (3) and, depending on the setting of the expansion valve (5), the refrigerant line (4) has a refrigerant feed opening (6) opening above and/or below the refrigerant level during the operation of the heat pump apparatus.