Parallel Heat Recovery Refrigeration Circuit for Demand Matching

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Solution Overview

Problem

Existing refrigeration systems face challenges in efficiently managing heat recovery and controlling heat transfer to meet varying and changing heat demands, leading to complex and inefficient operations.

Innovation Solution

A refrigeration circuit with a three-way regulation valve and multiple heat rejecting heat exchangers, allowing for precise control of refrigerant flow through a heat recovery heat exchanger and heat rejecting heat exchangers to match heat demand, while avoiding throttling effects that reduce efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If refrigerant flow is controlled by switching between cooling mode and heat recovery mode, then heat demand can be met, but system complexity and control difficulty increase

Engineering Contradiction:
Improveheat demand matchingVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by using a continuously adjustable three-way regulation valve instead of discrete mode switching. The valve can be positioned at any opening degree between fully closed and fully open, allowing continuous modulation of refrigerant flow to the heat recovery heat exchanger. This dynamic control enables smooth adjustment of heat delivery to match varying heat demands without the complexity of switching between discrete cooling and heat recovery modes, resolving the contradiction between adaptability and device complexity.

Inventive Principle:
Principle #15Dynamics

2Power

If refrigerant flow through heat recovery heat exchanger is increased, then heat transfer capability is improved, but system stability decreases due to continuously changing operation

Engineering Contradiction:
Improveheat transfer capabilityVSAvoidsystem operational stability
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

The patent implements feedback control by using a controller that receives temperature signals from temperature sensors and adjusts the three-way regulation valve position accordingly. The controller compares the actual temperature of the fluid to be heated with the desired set point temperature and continuously modulates the valve opening degree to maintain the temperature within a specified band. This closed-loop feedback system provides both high heat transfer capability and operational stability by making real-time adjustments rather than continuous switching, resolving the contradiction between power and stability.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If three-way valve is used for controlling refrigerant flow, then heat delivery precision is improved, but device complexity increases

Engineering Contradiction:
Improveheat delivery precisionVSAvoidvalve system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies the universality principle by designing the three-way regulation valve to perform multiple functions: it controls refrigerant flow to the heat recovery heat exchanger, adjusts the mixing ratio between refrigerant from the heat recovery heat exchanger and refrigerant from the receiver, and regulates the overall refrigerant flow to the expansion device. This multi-functional valve consolidates what would otherwise require multiple separate components, achieving precise heat delivery control while minimizing device complexity.

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

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 enables stable, energy-efficient heat recovery and transfer, reducing the need for complex control systems and minimizing energy waste by adjusting heat delivery to match user demands, thus enhancing operational stability and cost-effectiveness.

Implementation Method 1

at least one heat recovery heat exchanger (12) having a refrigeration circuit side (12a) and heat recovery system side (12b) and being configured to transfer heat between the refrigeration circuit side (12a) and the heat recovery system side (12b)

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

at least one regulation valve which is switchable between an open position, in which the regulation valve is completely open, a closed position, in which the regulation valve is completely closed, and at least one intermediate position, in which the regulation valve is partially open

Methodology Applied
Scientific EffectFlow control: Valve

Implementation Method 3

at least one compressor for compressing the refrigerant gas

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

at least one expansion device for expanding the refrigerant liquid

Methodology Applied
Scientific EffectThrottling: Pressure Drop

Data Source

PatentEP2751500B1Refrigeration circuit and refrigeration method providing heat recovery
Publication Date: 2019.08.28 CARRIER CORP
  • EP2751500B1 patent drawingFigure 1
  • EP2751500B1 patent drawingFigure 2
  • EP2751500B1 patent drawingFigure 3

AI summary

A refrigeration circuit is circulating a refrigerant and comprises in the direction of flow of the refrigerant at least one compressor (4a, 4b, 4c); at least one heat rejecting heat exchanger (6); at least one expansion device (8); and at least one evaporator (10). The refrigeration circuit further comprises at least one heat recovery heat exchanger (12) having a refrigeration circuit side (12a) and heat recovery system side (12b) and being configured for transferring heat between the refrigeration circuit side (12a) and the heat recovery system side (12b), wherein the refrigeration circuit side (12a) is fluidly connected in parallel to the at least one heat rejecting heat exchanger (6) for flowing circulating refrigerant through the refrigeration circuit side (12a); and at least one regulation valve (16), which is configured for regulating the flow of refrigerant flowing through the refrigeration circuit side (12a) of the at least one heat recovery heat exchanger (12). The at least one regulation valve (16) is switchable between an open position, in which the regulation valve (16) is completely open; a closed position, in which the regulation valve (16) is completely closed; and at least one intermediate position, in which the regulation valve (16) is partially open.