Variable refrigerant flow, room air conditioner, and packaged air conditioner control systems with cost target optimization

Solution Overview

Problem

Existing building cooling systems face challenges in minimizing energy consumption without compromising occupant comfort, as precise temperature matching often leads to high energy costs and discomfort when energy consumption is reduced.

Innovation Solution

A controller system that uses a neural network to classify the building's state, determine temperature bounds, and adjust a cost function with penalty terms to optimize indoor air temperature setpoints, balancing energy efficiency and comfort by controlling cooling devices in variable refrigerant flow, room air conditioning, and packaged air conditioning systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the cooling system precisely matches occupant temperature preferences, then occupant comfort is improved, but energy consumption increases

Engineering Contradiction:

Improveoccupant comfortVSAvoidenergy consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary cooling by lowering the temperature setpoint before periods of high occupancy or high outdoor temperatures, storing cooling capacity in the building's thermal mass. This allows the system to reduce energy consumption during peak periods while maintaining comfort, as the pre-cooled environment can sustain comfortable temperatures without active cooling for extended periods.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts temperature setpoints based on real-time conditions including occupancy levels, outdoor temperature forecasts, and current building temperature. Rather than maintaining a fixed setpoint, the controller continuously optimizes the setpoint trajectory to balance comfort and energy consumption, allowing flexible response to changing conditions.

Inventive Principle:

Principle #15Dynamics

2Loss of energy

If the cooling system reduces energy consumption, then energy costs are reduced, but occupant comfort deteriorates

Engineering Contradiction:

Improveenergy costVSAvoidoccupant comfort

Core Design Contradiction:

Loss of energyVSEase of operation

Solution Approach 1:

The system performs preliminary cooling by lowering the temperature setpoint before periods of high occupancy or high outdoor temperatures, storing cooling capacity in the building's thermal mass. This allows the system to reduce energy consumption during peak periods while maintaining comfort, as the pre-cooled environment can sustain comfortable temperatures without active cooling for extended periods.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors actual indoor temperature, occupancy levels, and energy consumption, using this feedback to adjust future setpoint decisions. The controller learns from past performance and external conditions (weather forecasts, occupancy patterns) to optimize the trade-off between energy cost and comfort, ensuring that comfort requirements are met while minimizing energy expenditure.

Inventive Principle:

Principle #23Feedback

3Use of energy by moving object

If the system maintains comfortable temperatures without increased power, then energy consumption is reduced, but temperature control precision is compromised

Engineering Contradiction:

Improvepower consumptionVSAvoidtemperature control precision

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The system performs preliminary cooling by lowering the temperature setpoint before periods of high occupancy or high outdoor temperatures, storing cooling capacity in the building's thermal mass. This allows the system to reduce energy consumption during peak periods while maintaining comfort, as the pre-cooled environment can sustain comfortable temperatures without active cooling for extended periods.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts temperature setpoints based on real-time conditions including occupancy levels, outdoor temperature forecasts, and current building temperature. Rather than maintaining a fixed setpoint, the controller continuously optimizes the setpoint trajectory to balance comfort and energy consumption, allowing flexible response to changing conditions.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11002457B2Variable refrigerant flow, room air conditioner, and packaged air conditioner control systems with cost target optimization

Publication Date: 2021.05.11 TYCO FIRE & SECURITY GMBH

AI summary

A building cooling system includes a controller and a cooling device operable to affect indoor air temperature of a building. The controller is configured to obtain a cost function that characterizes a cost of operating the cooling device over a future time period, obtain a dataset relating to the building, determine a current state of the building by applying the dataset to a neural network, select a temperature bound associated with the current state, augment the cost function to include a penalty term that increases the cost when the indoor air temperature violates the temperature bound, and determine a temperature setpoint for each of a plurality of time steps in the future time period. The temperature setpoints achieve a target value of the cost function over the future time period. The controller is configured to control the cooling device to drive the indoor air temperature towards the temperature setpoint.