Method for operating a linear concentrator solar power plant, and linear concentrator solar power plant

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Solution Overview

Problem

Linearly concentrating solar power plants face challenges in maintaining safe operation during transitional periods and preventing heat transfer medium freezing, especially with molten salts, due to temperature differences and solidification issues in pipeline systems.

Innovation Solution

A method that ensures a high flow rate of the heat transfer medium through pipeline loops to maintain turbulent flow, with part of the medium being recirculated and mixed with newly supplied medium to prevent stratification and freezing, using a mixing device connected to the pipeline loop to maintain a stable temperature above the solidification point.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the flow rate of heat transfer medium is reduced during low solar irradiance, then energy consumption is decreased, but temperature differences within the pipe loop increase causing receiver damage

Engineering Contradiction:
Improveenergy consumptionVSAvoidreceiver integrity
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The mixing device pre-heats the heat transfer medium by mixing hot medium from the storage tank with cold medium before it enters the pipe loop, ensuring that even at reduced flow rates during low solar irradiance, the temperature difference within the pipe loop remains acceptable and receiver damage is prevented

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mixing device acts as an intermediary between the storage tank and the pipe loop, combining hot and cold heat transfer medium to create a pre-heated mixture that maintains safe temperature gradients in the receiver during part-load operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If molten salt is used as heat transfer medium to achieve higher operating temperatures, then plant efficiency is improved, but freezing risk in pipeline systems increases

Engineering Contradiction:
Improveplant efficiencyVSAvoidpipeline operation safety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The mixing device pre-heats the cold molten salt from the storage tank by mixing it with hot molten salt before it enters the pipeline system, ensuring that the temperature remains above the freezing point even during night operation or periods of low solar irradiance

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses temperature sensors to monitor the heat transfer medium temperature and adjusts the mixing ratio accordingly, ensuring that the temperature in the pipeline system remains above the freezing point of the molten salt under all operating conditions

Inventive Principle:
Principle #23Feedback

3Reliability

If the heat transfer medium temperature is maintained high to prevent freezing, then freezing risk is reduced, but heat losses to the environment increase

Engineering Contradiction:
Improvefreezing preventionVSAvoidheat loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system dynamically adjusts the temperature parameter of the heat transfer medium by controlling the mixing ratio of hot and cold salt, maintaining the minimum temperature required to prevent freezing while minimizing heat losses to the environment

Inventive Principle:
Principle #35Parameter changes

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 prevents damage from temperature differences, ensures continuous operation, and minimizes heat losses by maintaining the heat transfer medium temperature close to the solidification control temperature, reducing the risk of freezing and extending the operational lifespan of pipeline systems.

Implementation Method 1

The absorption of solar thermal radiation is subject to fluctuating energy flow during operation

Methodology Applied
Scientific EffectAbsorption of solar thermal radiation: Absorption (EM radiation)

Implementation Method 2

The flow must be turbulent to ensure that the pipe is heated sufficiently and evenly

Methodology Applied
Scientific EffectTurbulent flow: Turbulence

Implementation Method 3

at least a portion of the heat transfer medium which has flowed through the pipe loop is mixed with heat transfer medium which is to be supplied to the pipe loop

Methodology Applied
Scientific EffectMixing: Stirring

Data Source

PatentEP3102890B1Method for operating a linear concentrator solar power plant, and linear concentrator solar power plant
Publication Date: 2019.09.25 BASF SE
  • EP3102890B1 patent drawingFigure 1~2
  • EP3102890B1 patent drawingFigure 3~4
  • EP3102890B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for operating a linear concentrator solar power plant (1), in which method a heat exchange medium flows through a pipeline loop (47) with at least one receiver, wherein the heat exchange medium has a flow velocity which is so great that the flow in the pipeline loop (47) is turbulent, wherein at least part of the heat exchange medium is removed upon exit from the pipeline loop (47) and is guided back into the pipeline loop (47). Furthermore, the invention relates to a linear concentrator solar power plant having at least one pipeline loop (47) with at least one receiver, in which a heat exchange medium which flows through the pipeline loop (47) is heated by incoming solar energy, wherein a mixing device (27) is included, in which at least part of the heat exchange medium which flows through the pipeline loop (47) is mixed with heat exchange medium to be fed in.