Apparatus and method for carrying out a cold steam process

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Solution Overview

Problem

Existing cold steam processes using carbon dioxide as a refrigerant face complexity in frequency control for high-pressure management, making them difficult to regulate efficiently.

Innovation Solution

A device and method that incorporate a motor-driven main compressor, high-pressure heat exchanger, expander, subcooler, and high-pressure compressor to control and regulate the cold steam process, allowing for simplified management of high pressure through a high-pressure control valve and expander-compressor unit, enabling efficient subcooling and heat absorption across multiple pressure levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a complex frequency control system is used to influence high pressure in CO2 cold vapor processes, then the coefficient of performance can be improved, but the device complexity increases

Engineering Contradiction:
Improvecoefficient of performanceVSAvoidfrequency control system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the complex frequency control system from the CO2 cold vapor process by replacing it with a simple on/off control mechanism for the high-pressure compressor, thereby reducing device complexity while maintaining energy efficiency through alternative means (subcooling and work-performing expansion)

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The high-pressure compressor serves dual functions: it maintains high pressure in the system and provides subcooling of the refrigerant through its discharge line, eliminating the need for separate control systems and additional components

Inventive Principle:
Principle #25Self-service

2Use of energy by moving object

If work-performing expansion is used to increase the coefficient of performance, then energy efficiency improves, but the device complexity increases due to additional control requirements

Engineering Contradiction:
Improvecoefficient of performanceVSAvoidcontrol system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The invention merges the expansion mechanism with the high-pressure compressor by using the compressor's discharge line to provide both pressure maintenance and subcooling functions, thereby implementing work-performing expansion without requiring separate complex control systems

Inventive Principle:
Principle #5Merging (Combining)

3Stress or pressure

If a hydraulic pressure intensifier is used for pressure control, then high pressure management is achieved, but the device complexity increases

Engineering Contradiction:
Improvehigh pressure controlVSAvoidpressure control device complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The invention removes the hydraulic pressure intensifier from the system and replaces it with a mechanically driven high-pressure compressor that directly provides both pressure control and subcooling functions, thereby simplifying the overall device architecture

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 solution enhances the coefficient of performance by 15% compared to traditional cold steam processes, reducing exergy losses and allowing for space-saving design, while maintaining comparable high-pressure values, and can be further optimized with two-stage compression and multiple-stage expansion.

Implementation Method 1

A high-pressure heat exchanger is provided to cool the mass flow of the fluid at high pressure, thereby increasing its density and reducing its temperature

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

This allows the fluid to then absorb heat in the subcooler at medium pressure in a counterflow, thereby subcooling the high-pressure mass flow within the subcooler

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

The evaporator is configured to absorb heat, causing the fluid's density to decrease and the temperature of the mass flow from the expander, at evaporator pressure, to increase

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Data Source

PatentEP3329191B1Apparatus and method for carrying out a cold steam process
Publication Date: 2024.06.05 BITZER KUEHLMASCHINENBAU GMBH
  • EP3329191B1 patent drawingFigure 1~2
  • EP3329191B1 patent drawingFigure 3~4
  • EP3329191B1 patent drawingFigure 5~7

AI summary

The present invention relates to an apparatus and to a method for carrying out a cold steam process. The apparatus has a motor-operated primary compressor (C1) which is designed to draw in a mass flow of a fluid, serving as refrigerant, at evaporator pressure and to compress this mass flow to high pressure, and a high-pressure heat exchanger (H) which is designed to cool the mass flow of the fluid at high pressure, to increase the density and to reduce a temperature of the fluid. Also provided is an expander (E) which is designed to expand to evaporator pressure, so as to perform work, the mass flow of the fluid coming from the high-pressure heat exchanger (H), and an evaporator (V) which is designed to take up heat such that the density of the fluid decreases as it passes through the evaporator and the temperature of the mass flow coming from the expander (E) at evaporator pressure, and of the fluid guided through the evaporator (V), increase. Finally, there is a sub-cooler (U), which is connected downstream of the high-pressure heat exchanger (H) and upstream of the expander (E), wherein downstream of the sub-cooler (U) and upstream of the expander (E) part of the fluid can be diverted from the mass flow and can be expanded by means of a high-pressure control valve (TH) to an intermediate pressure, such that the fluid then, at intermediate pressure, absorbs heat in counter-flow in the sub-cooler (U), and thus additionally sub-cools the mass flow which is at high pressure, and a high-pressure compressor (C2) which is mechanically directly connected to the expander (E) and is designed to compress, to high-pressure, only that part of the fluid that is diverted upstream of the expander (E) in the sub-cooler (U) and guided in counter-flow, and to mix this fluid, upstream of the high-pressure heat exchanger (H) with the mass flow coming from the motor-operated primary compressor (C1).