Flooded Evaporator Refrigerant Distribution With Level-Feedback Control

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Solution Overview

Problem

Conventional vapor compression systems in heating, ventilation, and air conditioning (HVAC) systems face inefficiencies in thermal energy transfer and refrigerant management, particularly in evaporators where the distribution and regulation of refrigerant can lead to suboptimal heat transfer and refrigerant level control.

Innovation Solution

The vapor compression system incorporates a shell with a first tube bundle, a hood, a distributor, a supply line with a valve, and a level sensor to regulate refrigerant flow, ensuring efficient thermal energy transfer and refrigerant distribution, with the distributor positioned above the tube bundle and the valve controlling the flow based on sensed refrigerant levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If refrigerant distribution is improved by adding control mechanisms, then heat transfer efficiency is improved, but device complexity increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements feedback control by using a level sensor to detect refrigerant levels in the evaporator and automatically adjusting the refrigerant supply valve accordingly. This closed-loop system maintains optimal refrigerant distribution without requiring complex manual intervention or overly complicated control mechanisms, thereby improving heat transfer efficiency while keeping device complexity manageable.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The refrigeration system performs self-regulation of refrigerant distribution through the automatic control mechanism. The level sensor continuously monitors refrigerant levels and the control valve automatically adjusts supply without external intervention, allowing the system to self-optimize its performance and maintain efficient heat transfer while avoiding the need for additional complex external control systems.

Inventive Principle:
Principle #25Self-service

2Use of energy by moving object

If refrigerant level control is enhanced with sensing and regulation, then thermal energy transfer is improved, but device complexity increases

Engineering Contradiction:
Improvethermal energy transferVSAvoiddevice complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The system employs feedback control where the level sensor continuously monitors refrigerant levels and provides real-time data to the control valve, which automatically adjusts refrigerant supply to maintain optimal levels. This ensures efficient thermal energy transfer in the evaporator while using a relatively simple and elegant control architecture rather than complex multi-component systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex mechanical refrigerant level control mechanisms with a sensing and automatic valuation system. Instead of using elaborate mechanical float valves or complex linkage systems, the invention uses electronic or electromagnetic sensors and control valves that respond automatically to level changes, simplifying the overall device while improving thermal energy transfer efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 heat transfer efficiency by optimizing refrigerant distribution and level management, improving the overall performance and efficiency of the vapor compression system in HVAC applications.

Implementation Method 1

The sensor is configured and positioned to sense a level of liquid refrigerant in the shell

Methodology Applied
Scientific EffectLevel sensing:

Implementation Method 2

The valve is configured and positioned to regulate flow in the second supply line in response to a sensed level of liquid refrigerant from the level sensor

Methodology Applied
Scientific EffectFlow regulation:

Implementation Method 3

The distributor is positioned above the first tube bundle

Methodology Applied
Scientific EffectRefrigerant distribution:

Implementation Method 4

the refrigerant is brought into contact with the outer or exterior surfaces of the tube bundle inside the shell, resulting in a transfer of thermal energy between the liquid to be cooled and the refrigerant

Methodology Applied
Scientific EffectThermal energy transfer: Heat Exchanger

Implementation Method 5

As a result of the thermal energy transfer with the liquid, the refrigerant is heated and converted to a vapor state

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2232166B1Vapor compression system
Publication Date: 2012.04.18 JOHNSON CONTROLS TECHNOLOGY CO
  • EP2232166B1 patent drawingFigure 1
  • EP2232166B1 patent drawingFigure 2
  • EP2232166B1 patent drawingFigure 3

AI summary

An evaporator (168) in a vapor compression system (14) (168) includes a shell (76), a first tube bundle (78); a hood (86); a distributor (80); a first supply line (142); a second supply line (144); a valve (122) positioned in the second supply line (144); and a sensor (150). The distributor (80) is positioned above the first tube bundle (78). The hood (88) covers the first tube bundle (78). The first supply line (142) is connected to the distributor (80) and an end of the second supply line (144) is positioned near the hood (88). The sensor (150) is configured and positioned to sense a level of liquid refrigerant (82) in the shell. The valve (122) regulates flow in the second supply line in response to the level of liquid refrigerant (82) from the sensor (150).