Flowrate Valve Control Using Planned-Flow Feedback

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Solution Overview

Problem

Existing flowrate control devices using flowrate regulating valves face challenges in stably changing flowrates due to non-linear behavior, particularly with three-way valves, which can lead to heat shock issues when abrupt changes occur.

Innovation Solution

A flowrate control device that includes a storing unit for opening degree characteristics, an inputting unit for target flowrate and change velocity, a detecting unit for fluid flowrate, and an opening-degree regulating unit that calculates and adjusts the opening degree of the valve using feedback control based on detected and planned flowrates to achieve stable flowrate changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a flowrate regulating valve with linear characteristic is used, then precise flow control is improved, but non-linear behavior still occurs making it difficult to change flowrate as desired

Engineering Contradiction:

Improveflow control precisionVSAvoidflowrate change stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The control device uses feedback control by continuously detecting the actual flowrate with a flowmeter and comparing it with the target flowrate. The opening degree of the flowrate regulating valve is adjusted based on the difference between detected and target flowrates, enabling stable flowrate control that overcomes non-linear valve characteristics.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The control device calculates the required opening degree by referencing stored opening degree characteristic data that defines the relationship between opening degree and Cv value. By dynamically adjusting the opening degree parameter based on detected flowrate and target flowrate, the system achieves stable flowrate control despite valve non-linearity.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If a flowrate regulating valve with non-linear characteristic is used, then adaptability is improved, but flowrate change stability deteriorates causing abrupt changes and heat shock risk

Engineering Contradiction:

Improvevalve characteristic adaptabilityVSAvoidflowrate change stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system employs feedback control where the actual flowrate is continuously detected and compared with the target flowrate. The opening degree is adjusted based on the flowrate difference, ensuring stable flowrate changes even when using valves with non-linear characteristics.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The control device stores opening degree characteristic data in advance, defining the relationship between opening degree and Cv value. This pre-stored characteristic information is used to calculate the appropriate opening degree for achieving the target flowrate, enabling smooth and controlled flowrate transitions.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If flowrate is changed rapidly to reach target flowrate, then productivity is improved, but heat shock risk increases due to abrupt flowrate changes

Engineering Contradiction:

Improveflowrate response speedVSAvoidheat shock risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The detecting unit detects flowrate at predetermined cycles, and the control device updates the opening degree calculation based on these periodic detections. This periodic control approach allows for controlled flowrate changes that balance response speed with stability, preventing abrupt changes that could cause heat shock.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS12436549B2Flowrate control device, flowrate control method, and fluid supply system

Publication Date: 2025.10.07 SHINWA CONTROLS

AI summary

A flowrate control device includes: a storing unit that stores opening degree characteristic of a flowrate regulating valve; an inputting unit that inputs a target flowrate of the fluid flowing out from the flowrate regulating valve, and a flowrate change velocity to reach the target flowrate; a detecting unit that detects, from when the control of the flowrate to the target flowrate is started, the flowrate of the fluid flowing out from the flowrate regulating valve at a predetermined cycle; and an opening-degree regulating unit that regulates an opening degree of the flowrate regulating valve. The opening-degree regulating unit determines a difference between a detected flowrate detected by the detecting unit and a planned flowrate in the course of achieving the target flowrate, the planned flowrate corresponding to the detected flowrate and being defined by the flowrate change velocity and the number of detection executed by the detecting unit.