Thermal model creation device, method, and program of building
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Solution Overview
Problem
Creating a highly accurate thermal model representing temperature changes in zones defined by air conditioning zoning is challenging due to the large number of parameters that need to be determined, which often results in parameter combinations that cancel each other out, reducing the model's accuracy.
Innovation Solution
A thermal model creation device and method that sets constraint conditions for parameters and determines their values using a parameter estimation method, such as the least squares method, to prevent cancellations and improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If parameter estimation method is used to determine parameter values in thermal model, then the thermal model can be created automatically, but combinations of parameter values that cancel each other are derived, reducing model accuracy
Solution Approach 1:
The patent transforms the parameter estimation problem by changing the estimation target from individual parameters to the product of parameters (e.g., K11 = k11 × C11). This parameter transformation allows the estimation to capture the effective thermal characteristics directly, avoiding the cancellation issue that occurs when estimating individual parameters separately. The constraint conditions are applied to the transformed parameters to ensure physical meaningfulness.
Solution Approach 2:
The patent applies constraint conditions preliminarily during the parameter estimation process to guide the optimization toward physically meaningful solutions. By pre-defining constraints such as positivity requirements and relationships between parameters, the estimation algorithm is directed away from spurious solutions where parameters cancel each other out, ensuring accurate thermal model creation from the outset.
2Adaptability or versatility
If the number of zones in the building increases, then the coverage of the thermal model increases, but the number of parameters that need to be determined increases, making model creation more difficult
Solution Approach 1:
The patent segments the thermal model creation process into modular components: (1) defining zones and their thermal characteristics, (2) establishing constraint conditions based on zone relationships, (3) performing parameter estimation with constraints, and (4) validating the model. This segmentation allows the model to scale to any number of zones without proportionally increasing complexity, as each zone can be processed independently following the same methodology.
Solution Approach 2:
The patent reduces the effective number of parameters by transforming them into products (e.g., Kij = kij × Cij) that can be estimated directly. This parameter transformation, combined with constraint conditions, reduces the degrees of freedom in the system, allowing the model to handle any number of zones without a proportional increase in the complexity of parameter determination.
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 approach enables the creation of a highly accurate thermal model, allowing for precise prediction of zone temperatures and efficient control of air conditioning systems, leading to improved energy efficiency and savings.
Implementation Method 1
a parameter determination means for determining all unknown values of parameters in the thermal model under the constraint conditions
Data Source
AI summary
There is provided a thermal model creation device capable of creating a highly accurate thermal model. A constraint-condition setting means 72 sets constraint conditions of parameters in the thermal model. A parameter determination means 73 determines all unknown values of parameters in the thermal model under the constraint conditions.