Compressor Heat Recuperation Control Using Motor Drive Current
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Solution Overview
Problem
In compressor devices with heat recuperation systems, controlling the temperature of heated coolant to a predefined level is challenging, especially under varying load conditions, and traditional methods require expensive flow meters for accurate control.
Innovation Solution
A compressor device with a control unit that adjusts the coolant flow rate based on the actual drive current of the electric motor or gas flow rate, eliminating the need for a flow meter by using a characteristic relationship to determine the desired flow rate and control the adjustable valve position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional flow meters are used to control coolant flow rate for accurate temperature control, then temperature control precision is improved, but device cost and complexity increase
Solution Approach 1:
The invention extracts and eliminates the flow meter component from the control system. Instead of using a flow meter to directly measure coolant flow rate, the system uses the electric motor's drive current as a proxy indicator, which correlates with the required coolant flow rate based on heat generation. This removes the expensive and complex flow meter while maintaining control capability through the existing current sensing infrastructure.
Solution Approach 2:
The invention introduces an intermediary relationship between drive current and coolant flow rate control. The drive current serves as an intermediate parameter that indirectly indicates the thermal load and required coolant flow. The control unit uses this intermediary signal to adjust the coolant flow rate via the control means, establishing a control chain: drive current → inferred thermal load → required coolant flow → actual coolant flow adjustment.
2Use of energy by moving object
If multiple components are cooled using the same cooling circuit, then system efficiency is improved, but temperature control stability deteriorates
Solution Approach 1:
The invention implements dynamic control of the coolant flow rate based on real-time drive current conditions. Instead of using a fixed flow rate that would be difficult to optimize for multiple components with varying thermal loads, the system continuously adjusts the coolant flow rate to match the actual thermal demand indicated by the drive current. This dynamic adjustment maintains temperature stability even as different components require different cooling levels under varying operating conditions.
3Adaptability or versatility
If coolant flow rate is adjusted to compensate for varying load conditions, then adaptability is improved, but control complexity increases
Solution Approach 1:
The invention implements a feedback control mechanism where the drive current serves as the feedback signal indicating thermal load conditions. The control unit continuously monitors the drive current and adjusts the coolant flow rate accordingly through the control means. This closed-loop feedback system enables the cooling system to automatically adapt to varying load conditions without requiring complex external sensors or manual intervention, as the drive current already contains the necessary information about thermal demand.
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 solution allows for precise control of coolant temperature without the need for expensive flow meters, simplifying and cost-reducing the control mechanism while maintaining accurate temperature regulation across varying load conditions.
Implementation Method 1
a heat recuperation system for recuperating heat from a compressed gas resulting from the compression of the suctioned gas, the heat recuperation system comprising a piping network having an inlet and an outlet for a coolant
Implementation Method 2
the compressor element is driven by an electric motor
Implementation Method 3
at least one compressor element for compressing a suctioned gas
Data Source
AI summary
The present invention relates to a compressor device (1) comprising:a compressor installation (2) having at least one compressor element (3a, 3b, 3c) for compressing a suctioned gas,the compressor element (3a, 3b, 3c) being driven by an electric motor (4);a heat recuperation system (6) for recuperating heat from a compressed gas resulting from the compression of the suctioned gas,the heat recuperation system (6) comprising a piping network (7) having an inlet (8) and an outlet (9) for a coolant, said piping network (7) being provided at this inlet (8) or outlet (9) with control means with a flow rate control state variable for modifying a first flow rate of the coolant in the piping network (7); anda control unit (13) which adjusts the flow rate control state variable of the control means on the basis of a drive current of the electric motor (4) or on the basis of a second flow rate of the suctioned gas such that a temperature Tw,out at the outlet (9) of the piping network (7) is driven to a predefined level.