A method for controlling suction pressure based on a most loaded cooling entity
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Solution Overview
Problem
Vapor compression systems face a challenge in balancing sufficient heat transfer in evaporators with minimal energy consumption, as low suction pressure enhances heat transfer but increases compressor work, while high suction pressure reduces energy efficiency.
Innovation Solution
A method to control suction pressure by identifying the most loaded cooling entity and adjusting it to the maximum required suction pressure level, ensuring sufficient heat transfer without excessive energy consumption, by determining the required change in suction pressure based on the current load of each entity and controlling the compressor capacity accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If low suction pressure is selected to ensure good heat transfer in evaporators, then heat transfer efficiency is improved, but energy consumption of the compressor unit increases
Solution Approach 1:
The invention dynamically adjusts the suction pressure setpoint based on the identified most loaded cooling entity's requirements. Instead of using a fixed suction pressure, the system continuously monitors cooling needs of multiple entities and adapts the suction pressure in real-time, allowing the system to operate at optimal pressure levels that balance heat transfer efficiency and compressor energy consumption.
Solution Approach 2:
The invention changes the suction pressure parameter dynamically based on the load conditions of different cooling entities. By identifying which cooling entity is most loaded and adjusting the suction pressure accordingly, the system optimizes the balance between maintaining sufficient temperature difference for heat transfer and limiting the pressure difference across the compressor to reduce energy consumption.
2Use of energy by moving object
If high suction pressure is selected to limit energy consumption, then energy efficiency is improved, but heat transfer in evaporators deteriorates
Solution Approach 1:
The system dynamically determines the suction pressure setpoint based on real-time monitoring of cooling entity loads. When cooling demand is low, the system can operate at higher suction pressures to improve energy efficiency. When cooling demand increases, the system automatically adjusts to lower suction pressures to maintain adequate heat transfer, thus dynamically optimizing the trade-off between energy efficiency and heat transfer performance.
Solution Approach 2:
The invention adjusts the suction pressure parameter based on the identified most loaded cooling entity's requirements. By changing the suction pressure setpoint according to actual cooling needs rather than using a fixed high pressure, the system ensures adequate heat transfer when required while maintaining energy efficiency during lower demand periods.
3Reliability
If suction pressure is optimized for one cooling entity, then that entity's cooling need is met, but other cooling entities may not receive sufficient cooling
Solution Approach 1:
The invention makes the suction pressure control system universal by considering the requirements of multiple cooling entities simultaneously. The system identifies the most loaded entity among all connected cooling entities and sets the suction pressure to meet that entity's requirements, thereby ensuring that all entities receive adequate cooling service through a single optimized control parameter.
Solution Approach 2:
The system performs preliminary identification of the most loaded cooling entity before finalizing the suction pressure setpoint. By proactively determining which entity has the highest cooling demand based on monitored parameters, the system can pre-adjust the suction pressure to ensure adequate cooling for all entities, preventing any single entity from being under-cooled.
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 ensures efficient heat transfer in evaporators while minimizing energy consumption by maintaining the suction pressure at a level that meets the requirements of all cooling entities, reducing the energy needed for compression and optimizing system efficiency.
Implementation Method 1
heat exchange takes place in a heat rejecting heat exchanger and one or more evaporators, respectively
Implementation Method 2
The evaporating temperature is determined by the properties of the refrigerant and by the pressure prevailing in the evaporator
Implementation Method 3
a fluid medium, such as a refrigerant, is alternatingly compressed and expanded
Data Source
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AI summary
A method for controlling suction pressure in a vapour compression system (1) comprising one or more cooling entities (5) is disclosed. For each cooling entity (5), a maximum required suction pressure and/or a required change in suction pressure for maintaining a target temperature in the refrigerated volume is obtained. A most loaded cooling entity (5) among the one or more cooling entities (5) is identified, based on the maximum required suction pressures and/or the required changes in suction pressure. The suction pressure of the vapour compression system (1) is controlled in accordance with the maximum required suction pressure and/or required change in suction pressure for the identified most loaded cooling entity (5).