Propane Refrigerated Shelf Modules for Safety and Capacity
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Solution Overview
Problem
Current refrigeration systems using natural refrigerants like hydrocarbons face limitations in higher cooling capacities due to safety regulations, leading to increased complexity and costs, while conventional fluorinated refrigerants have environmental drawbacks.
Innovation Solution
A refrigerated shelf design utilizing a single refrigerant circuit with propane, optimized by spacing components and using a glycol/water mixture, which allows for efficient cooling with reduced complexity and enhanced safety features to manage propane's ignitability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydrocarbons are used as refrigerant in higher cooling capacities, then environmental friendliness and thermodynamic properties are improved, but safety requirements and system complexity increase due to flammability regulations
Solution Approach 1:
The refrigerated display case is divided into multiple shelf modules, each with its own refrigeration unit and refrigerant circuit. This segmentation allows each module to operate independently with limited refrigerant charge, reducing safety concerns while maintaining high cooling capacity at system level. The modular design enables complex systems to be built from simpler, safer units.
Solution Approach 2:
The patent transitions from horizontal placement of refrigeration units to vertical stacking of shelf modules. This dimensional change allows multiple refrigeration circuits to be arranged vertically, reducing the refrigerant charge in each horizontal plane while achieving high total cooling capacity through vertical integration.
2Reliability
If multiple refrigerant circuits are used to meet safety requirements, then safety is improved, but device complexity and installation effort increase
Solution Approach 1:
Each shelf module contains a complete refrigeration unit with compressor, condenser, and evaporator, segmented into modular assemblies. This segmentation allows independent operation and simplifies installation while meeting safety requirements through distributed refrigerant containment.
Solution Approach 2:
Multiple shelf modules are combined to form a complete refrigerated display case system. The modular design allows standardised components to be merged into different configurations, reducing overall system complexity while maintaining safety through replicated safe units.
3Power
If larger refrigerant charge is used to achieve higher cooling capacities, then cooling performance is improved, but safety requirements and regulatory compliance become more difficult
Solution Approach 1:
The total cooling capacity is distributed across multiple segmented refrigeration units, each with small refrigerant charge. This segmentation achieves high system-level cooling capacity while each unit remains within safe refrigerant charge limits, simplifying regulatory compliance.
Solution Approach 2:
The system changes the parameter of refrigerant charge distribution from concentrated to distributed. By using multiple circuits with small charges instead of one large charge, the system achieves high cooling capacity while maintaining safety compliance through parameter optimization.
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
Enables efficient operation of larger refrigerated shelves with higher cooling capacities using propane, reducing complexity and costs while ensuring safety and environmental friendliness.
Implementation Method 1
an evaporator, a condenser and an expansion device which are integrated into the shelf modules
Implementation Method 2
the evaporator is integrated into the rear wall section, in particular into the inner cover
Implementation Method 3
a compressor and a condenser are spaced apart and arranged in different wall sections
Implementation Method 4
an expansion device which are integrated into the shelf modules
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a cooling shelf (1) having at least one unit composed of a plurality of wall groups, namely a base group (11), a rear wall group (12) and a top group (13), which delimit a cooling space (4) from below, the rear and above, and having a cooling device (5) with a refrigerant circuit, which comprises, as components, at least one compressor (51), an evaporator (50), a condenser (52) and an electric control device (55). An environmentally friendly, efficient and hence safely operable cooling shelf is obtained in that propane is contained as a coolant in the refrigerant circuit with a filling amount of more than 150 g.