Heat-to-Power Expansion System with Electrical Speed Sensing
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Solution Overview
Problem
Determining the generator's rotational speed accurately is crucial for matching the frequency of the alternating voltage generated by the generator with the network frequency to enable effective feeding of electrical energy into a supply network.
Innovation Solution
Incorporating a speed sensor designed as an electrical sensor generator coupled to the generator's shaft, which generates a voltage signal proportional to the rotational speed, allowing direct measurement without significant current flow, and using a control system to regulate the generator's operation for optimal feed-in.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a current-based sensor signal is used to measure generator speed, then the sensor can detect rotational speed, but the signal evaluation becomes complex due to current flow through consumers and loss of speed proportionality
Solution Approach 1:
The patent replaces current-based sensing with voltage-based sensing. The sensor generator produces a voltage signal proportional to rotational speed, eliminating the need for current flow through consumers. This substitution simplifies signal evaluation while maintaining measurement accuracy, as voltage can be measured directly without additional circuitry.
2Ease of manufacture
If the sensor generator is exposed to lubricant and working medium for easy integration, then integration is simplified, but the sensor may be damaged by environmental conditions
Solution Approach 1:
The patent employs sealing measures including seals and protective coatings on the sensor generator. These flexible barriers allow the sensor to be exposed to lubricant and working medium for easy integration while protecting internal components from damage. The seals create a protective interface between the sensor and harsh environmental conditions.
3Measurement precision
If a high voltage range sensor generator is used to improve speed measurement accuracy, then measurement precision improves, but the cost and complexity of electrical components increases
Solution Approach 1:
The patent optimizes the voltage range of the sensor generator to produce signals between 30-48 V at generator speeds corresponding to mains frequency. This parameter optimization improves measurement precision while keeping electrical components within standard, cost-effective voltage ranges. The sensor generator is specifically designed to output sufficient voltage for accurate measurement without requiring high-voltage components.
4Device complexity
If the sensor rotor is directly coupled to the shaft without bearings, then the structure is simplified, but precise centering becomes more difficult to achieve
Solution Approach 1:
The patent employs self-centering mechanisms where the sensor rotor is directly coupled to the shaft without additional bearings. The design incorporates features that automatically ensure proper centering during assembly, eliminating the need for complex bearing arrangements while maintaining manufacturing precision. The direct coupling leverages the shaft's inherent geometry to achieve accurate alignment.
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
Ensures precise measurement of generator speed, enabling efficient and stable connection to the power grid while avoiding complex current evaluations and protecting the sensor from environmental conditions.
Implementation Method 1
the sensor generator has a sensor rotor with permanent magnetization, which interacts with a stator having stator windings, wherein, when the sensor rotor rotates, a voltage dependent on the rotational speed of the sensor rotor occurs at the stator windings of the stator
Data Source
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AI summary
According to the invention, to improve an expansion system (30) for producing electrical energy from heat, by means of a thermodynamic cycle, comprising an expansion device (32), operated by an expanding work medium of the thermodynamic cycle, and a generator (34), which is driven by the expansion device, the expansion system has a speed sensor (120), which is coupled to a shaft (98) of the expansion system, said shaft rotating proportionally to a rotor of the generator, and which is formed as an electrical sensor generator (122), which generates an electrical sensor signal.