Chiller system, method for obtaining middle water temperature and control method thereof

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Solution Overview

Problem

In cooler systems with multiple units connected in series, monitoring middle water temperature is challenging due to space constraints and high material costs associated with traditional water temperature sensors, requiring innovative methods to accurately acquire and control middle water temperature without significant layout modifications.

Innovation Solution

A cooler system utilizing current sensors, water temperature sensors, and virtual temperature sensors to calculate middle water temperature based on temperature differences, refrigeration capacities, and working currents, with a controller adjusting refrigeration capacities to maintain set values, eliminating the need for additional physical sensors and reducing material costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If water temperature sensors are arranged to monitor middle water temperature, then measurement precision is improved, but device complexity and material costs increase

Engineering Contradiction:
Improvemiddle water temperature monitoringVSAvoidsensor arrangement and layout modification
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses existing water temperature sensors to detect entering and leaving water temperatures, then creates a virtual copy of the temperature monitoring function through calculation. The middle water temperature is computed based on the ratio relation among temperature differences, rated refrigeration capacities, and working currents, eliminating the need for physical sensor installation at intermediate positions.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent introduces working current as an intermediary parameter to establish the relationship between compressor output and temperature change. By using the ratio of working currents and rated refrigeration capacities, the system mediates the calculation of middle water temperature without direct physical measurement, bridging the gap between easily measurable parameters and the desired temperature value.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If water temperature sensors are arranged to monitor middle water temperature, then measurement precision is improved, but material costs increase

Engineering Contradiction:
Improvemiddle water temperature monitoringVSAvoidmaterial cost
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent creates a virtual temperature sensor through calculation rather than using physical sensors. By computing middle water temperature from existing measurements (entering and leaving water temperatures, working currents), the system avoids the material cost of additional temperature sensors while maintaining measurement precision.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system uses its own existing components (water temperature sensors and current sensors) to generate the middle water temperature information. The calculation method leverages parameters already being measured for other control purposes, making the system self-sufficient and avoiding additional material expenses.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If physical sensors are installed for middle water temperature monitoring, then measurement precision is improved, but ease of manufacture deteriorates due to layout modification requirements

Engineering Contradiction:
Improvemiddle water temperature monitoringVSAvoidlayout modification complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces physical sensor installation with a computational approach. The virtual temperature sensor is implemented through software calculation using existing sensor data, completely avoiding the need for physical modifications to the cooler system layout and eliminating installation complexity.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent substitutes the mechanical/physical approach of installing sensors with an electronic/computational approach. Instead of physically placing sensors in the water flow path, the system uses electronic sensors already present and performs calculations to derive middle water temperature, replacing mechanical installation requirements with computational processing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3446052B1Chiller system, method for obtaining middle water temperature and control method thereof
Publication Date: 2022.06.15 CARRIER CORP
  • EP3446052B1 patent drawingFigure 1
  • EP3446052B1 patent drawingFigure 2
  • EP3446052B1 patent drawingFigure 3

AI summary

A cooler system includes a plurality of cooler units; a condensed water flow path, an aqueous medium in the condensed water flow path sequentially flowing through each of the cooler units; a cooling water flow path, an aqueous medium in the cooling water flow path sequentially flowing through each of the cooler units in a flow direction opposite to a flow direction of the aqueous medium in the condensed water flow path; a plurality of current sensors used for detecting working currents of the cooler units; water temperature sensors used for detecting an entering water temperature and a leaving water temperature of the cooling water flow path; at least one virtual temperature sensor arranged between the cooler units and used for acquiring a middle water temperature between the cooler units; and a controller.