A shell-and-plate condenser, a method for removing oil from a refrigerant and use of a shell-and-plate condenser

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing shell-and-plate condensers face inefficiencies in oil separation, leading to reduced performance due to oil coating on plates, which affects refrigeration cycle efficiency.

Innovation Solution

An integrated oil separator unit is placed above the plate stack within the tubular outer shell, featuring a flow distribution chamber and demister elements, optimizing oil separation by distributing the refrigerant flow and utilizing gravitational separation to enhance efficiency without increasing the size of the oil separator unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oil separator elements are arranged inside the condenser to guide oil-containing refrigerant through them, then oil separation is achieved, but oil separation efficiency is insufficient

Engineering Contradiction:
Improveoil separation efficiencyVSAvoidrefrigeration cycle efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The oil separator unit is segmented into distinct functional zones: a flow distribution chamber with multiple exit holes, a flow guide channel, and a demister part with demister elements. This segmentation allows each zone to perform its specific function optimally - distributing flow evenly, guiding it through the demister, and separating oil efficiently - thereby resolving the contradiction between achieving sufficient oil separation and maintaining refrigeration efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flow distribution chamber acts as an intermediary component between the refrigerant inlet and the demister elements. It distributes the oil-containing refrigerant flow through multiple exit holes to ensure uniform flow distribution across the demister part, which enhances oil separation efficiency while preventing excessive pressure drop that would harm refrigeration cycle productivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the oil separator unit is placed above the plate stack, then space is optimized and refrigerant condensation is reduced, but the structure becomes more complex

Engineering Contradiction:
Improvecondenser space utilizationVSAvoidoil separator unit structure
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The oil separator unit merges multiple components - the flow distribution chamber, flow guide channel, and demister part - into a single integrated unit that is placed above the plate stack. This merging reduces the overall space required compared to separate components while the strategic placement above the plate stack utilizes the natural downward flow of condensed refrigerant, optimizing space utilization without excessive structural complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the flow distribution chamber extends in the longitudinal direction with multiple exit holes, then flow distribution is improved and oil separation efficiency increases, but the oil separator unit size increases

Engineering Contradiction:
Improveoil separation efficiencyVSAvoidflow distribution chamber length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

Instead of extending the flow distribution chamber only in the longitudinal direction, the invention utilizes the radial dimension by distributing exit holes around the circumference of the chamber. This dimensional change allows efficient flow distribution and oil separation without excessive longitudinal length, as the exit holes are arranged to provide uniform flow distribution in multiple directions simultaneously.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Reliability

If demister elements are arranged in the flow guide channel, then oil separation efficiency is enhanced, but pressure drop increases and energy consumption rises

Engineering Contradiction:
Improveoil separation efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention optimizes the parameters of the demister elements and their arrangement in the flow guide channel to achieve efficient oil separation while minimizing pressure drop. By carefully selecting demister element geometry, spacing, and orientation, the system achieves high oil separation efficiency without excessive energy consumption, resolving the contradiction between reliability and energy use.

Inventive Principle:
Principle #35Parameter changes

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 improves oil separation efficiency, reduces the risk of oil contacting the plate pack, and provides a more compact, cost-effective design that maintains refrigerant flow efficiency while minimizing pressure drop and energy consumption.

Implementation Method 1

the flow distribution chamber comprises at least one sidewall comprising a plurality of exit holes through which the oil-containing refrigerant leaves the flow distribution chamber in a direction substantially transversal to the longitudinal direction of the outer shell and flows out into a flow guide channel

Methodology Applied
Scientific EffectFlow distribution:

Implementation Method 2

Arranging the oil separating unit above the plate stack is advantageous in that in the condenser the refrigerant - that has changed from gaseous to liquid phase - will naturally seek downwards due to gravitational pull

Methodology Applied
Scientific EffectGravitational separation: Gravitation

Implementation Method 3

at least one outflow demister element arranged in a demister part of the flow guide channel

Methodology Applied
Scientific EffectDemister separation: Surface Tension

Implementation Method 4

flows out into a flow guide channel of the oil separator unit

Methodology Applied
Scientific EffectFluid flow guidance:

Implementation Method 5

in the condenser the refrigerant - that has changed from gaseous to liquid phase

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3034965B1A shell-and-plate condenser, a method for removing oil from a refrigerant and use of a shell-and-plate condenser
Publication Date: 2021.06.16 JOHNSON CONTROLS DENMARK APS
  • EP3034965B1 patent drawingFigure 1~2
  • EP3034965B1 patent drawingFigure 3~4
  • EP3034965B1 patent drawingFigure 5~6

AI summary

Disclosed is a shell-and-plate condenser (1) comprising a stack of corrugated heat transfer plates (5) arranged inside a tubular outer shell (8), wherein the outer shell (8) comprises at least one entrance hole (2) for leading oil-containing refrigerant into the condenser (1) and the condenser (1) further comprises an integrated oil separator unit (3) arranged above the plate stack. The oil separator unit (3) includes at least one flow distribution chamber (4) being connected to at least one of the entrance holes (2), wherein the flow distribution chamber (4) substantially extends in a longitudinal direction of the tubular outer shell (8) and wherein the flow distribution chamber (4) comprises at least one sidewall (6) comprising a plurality of exit holes (7) through which the oil-containing refrigerant leaves the flow distribution chamber (4) in a direction substantially transversal to the longitudinal direction of the outer shell (8) and flows out into a flow guide channel (9) of the oil separator unit (3). The oil separator unit (3) further includes at least one outflow demister element (10) arranged in a demister part (11) of the flow guide channel (9). A method for removing oil from a refrigerant by means of an oil separator unit (3) arranged inside a tubular outer shell (8) of a shell-and-plate condenser (1) and use of a shell-and-plate condenser (1) is also disclosed.