Chiller system with serial flow evaporators

Solution Overview

Problem

Existing chiller systems with multiple refrigerant circuits often suffer from higher evaporator approach temperatures, leading to reduced heat transfer, increased energy consumption, and lower capacity due to suboptimal configurations.

Innovation Solution

The evaporators in multiple refrigerant circuits are arranged in a serial flow configuration, where the conditioning fluid flows through one evaporator and then another, reducing evaporator approach temperatures and enhancing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If multiple refrigerant circuits are arranged in traditional parallel configurations, then system capacity is maintained, but evaporator approach temperatures increase leading to reduced heat transfer efficiency

Engineering Contradiction:

Improveevaporator approach temperatureVSAvoidheat transfer efficiency

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent inverts the traditional parallel configuration of multiple refrigerant circuits by arranging evaporators in series. Instead of conditioning fluid flowing through multiple evaporators simultaneously in parallel, the fluid flows sequentially through evaporators in series, allowing each evaporator to operate at optimized temperature differentials and reducing overall approach temperatures.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the operational parameters of the refrigerant circuits by implementing series flow configuration, which alters the temperature and pressure profiles across evaporators. This parameter change enables lower evaporator approach temperatures and improved heat transfer efficiency compared to traditional parallel arrangements.

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If traditional parallel refrigerant circuit configurations are used, then system simplicity is maintained, but energy consumption increases due to higher evaporator approach temperatures

Engineering Contradiction:

Improveenergy consumptionVSAvoidrefrigerant circuit configuration

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent inverts the traditional parallel configuration of multiple refrigerant circuits by arranging evaporators in series. Instead of conditioning fluid flowing through multiple evaporators simultaneously in parallel, the fluid flows sequentially through evaporators in series, allowing each evaporator to operate at optimized temperature differentials and reducing overall approach temperatures.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the potential disadvantage of increased system complexity from series configuration into a benefit by demonstrating that the additional circuit arrangement delivers significant energy savings through reduced evaporator approach temperatures and improved heat transfer efficiency, making the added complexity worthwhile.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If series flow configuration is implemented, then heat transfer efficiency is improved, but system complexity increases

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidrefrigerant circuit configuration

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent inverts the traditional parallel configuration of multiple refrigerant circuits by arranging evaporators in series. Instead of conditioning fluid flowing through multiple evaporators simultaneously in parallel, the fluid flows sequentially through evaporators in series, allowing each evaporator to operate at optimized temperature differentials and reducing overall approach temperatures.

Inventive Principle:

Principle #13The other way round (Inversion)

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 arrangement reduces refrigerant pressure lift, decreases energy consumption by compressors, and lowers operational costs while allowing for cost-effective manufacturing and improved performance in HVAC&R systems.

Implementation Method 1

a first evaporator configured to place a first refrigerant in a heat exchange relationship with a conditioning fluid

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a second evaporator configured to place a second refrigerant in a heat exchange relationship with the conditioning fluid

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentUS20230392828A1Chiller system with serial flow evaporators

Publication Date: 2023.12.07 JOHNSON CONTROLS BUILDING EFFICIENCY TECH WUXI

AI summary

A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a first refrigerant circuit having a first evaporator configured to place a first refrigerant in a heat exchange relationship with a conditioning fluid, where the first evaporator includes a first set of first tubes and a second set of first tubes configured to direct the conditioning fluid through the first evaporator. The HVAC&R system also includes a second refrigerant circuit having a second evaporator configured to place a second refrigerant in a heat exchange relationship with the conditioning fluid, where the second evaporator includes a first set of second tubes and a second set of second tubes configured to direct the conditioning fluid through the second evaporator. The HVAC&R system further includes a conditioning fluid circuit configured to circulate the conditioning fluid serially through the first set of first tubes, the second set of first tubes, the first set of second tubes, and the second set of second tubes.