Multi-Zone VRF Coil Control for Simultaneous Heating and Cooling

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Solution Overview

Problem

Conventional multi-zone air conditioning systems are inefficient in providing simultaneous heating and cooling to individual zones without using additional heat mediums and often require extensive refrigerant and electrical infrastructure, leading to higher costs and maintenance challenges.

Innovation Solution

A multi-zone variable refrigerant flow (VRF) unit that consolidates refrigerant piping and electrical wiring, using a mode control unit to manage refrigerant flow to evaporating coils, allowing for independent heating or cooling of zones and reducing the need for additional heat sources, while containing refrigerant within a housing to comply with safety standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional multi-zone air conditioning systems are used to provide simultaneous heating and cooling to individual zones, then heating and cooling functionality is achieved, but extensive refrigerant piping and electrical wiring are required leading to higher costs and maintenance challenges

Engineering Contradiction:

Improvesimultaneous heating and cooling capabilityVSAvoidrefrigerant piping and electrical wiring infrastructure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple evaporating coils serving different zones into a single integrated system with a shared refrigerant circuit. The mode control unit manages refrigerant distribution to multiple coils simultaneously, enabling heating and cooling in different zones without requiring separate extensive piping infrastructure for each zone.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The refrigerant system is designed to serve multiple functions simultaneously - it can provide cooling to multiple zones through evaporating coils, and provide heating through the same system by reversing the refrigerant flow direction. This multi-functionality eliminates the need for separate heating and cooling infrastructure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Temperature

If conventional multi-zone systems use zone dampers to mix heated and chilled air, then temperature regulation for each zone is achieved, but the flow of mixed air to each zone is kept approximately constant reducing system efficiency

Engineering Contradiction:

Improvezone temperature controlVSAvoidair flow efficiency

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The patent replaces the mechanical zone damper mixing system with a refrigerant-based thermal control system. Instead of mechanically mixing heated and chilled air streams with dampers, the system uses refrigerant flow control through expansion valves to directly condition the air in each zone, eliminating the need for constant mixed air flow and improving overall system efficiency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If refrigerant is contained within a housing to comply with safety standards, then safety compliance is improved, but access to refrigerant components for maintenance becomes more difficult

Engineering Contradiction:

Improvesafety standards complianceVSAvoidrefrigerant component accessibility

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The patent divides the refrigerant system into modular segments within the housing, with accessible service ports and removable components. The evaporating coils and expansion valves are positioned and configured to allow maintenance access through designated openings in the housing, enabling technicians to service refrigerant components without completely disassembling the unit while maintaining safety containment.

Inventive Principle:

Principle #1Segmentation

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

The solution enables efficient, cost-effective, and maintenance-friendly simultaneous heating and cooling of multiple zones with reduced refrigerant and electrical requirements, improving compliance with safety standards and minimizing condensate issues within the conditioned space.

Implementation Method 1

The coils may allow heat transfer between supply air from a supply fan and the refrigerant in the coils to reduce the temperature of the supply air for various zones in a cooling mode of operation

Methodology Applied

Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

The mode control unit may supply refrigerant from the VRF unit to two or more evaporating coils ('coils') through a thermal or thermostatic expansion valve

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10161640B2Multi-zone variable refrigerant flow heating/cooling unit

Publication Date: 2018.12.25 MJC

AI summary

An air conditioning that includes a housing. The housing encloses a mode control unit that switches a zone coil associated with a zone from a cooling mode to a heating mode by switching from a cooling medium to a heating medium flowing through the zone coil. The zone coil receives the heating or cooling medium and conditions incoming air from a supply fan to be exhausted in a zone associated with the zone coil. A variable refrigerant flow cooling/heating unit provides a cooling medium or a heating medium at varying rates to control a temperature of a zone.