Auxiliary Sub-Cooler Coil for Dispenser Condensation Control
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Solution Overview
Problem
Existing refrigerated ice or beverage dispensers face issues with condensation on the protective metal casing due to low temperatures, leading to moisture collection, potential damage to electrical components, and reduced refrigeration performance, as the hot gas from the compressor can overheat the foam pack and evaporator coils.
Innovation Solution
An auxiliary sub-cooler is introduced in the refrigerant line after the condenser but before the expansion valve, using warm liquid refrigerant to dissipate heat and prevent condensation on the foam pack, while also increasing the cooling capacity by further cooling the refrigerant before its expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If hot gas from the compressor is used to warm the foam pack, then condensation is prevented, but the evaporator coils are overheated and performance is reduced
Solution Approach 1:
A sub-cooler coil is introduced as an intermediary component in the refrigerant line between the condenser and expansion valve. This coil transfers heat from the warm liquid refrigerant to the foam pack enclosure, preventing condensation without directly heating the evaporator coils. The sub-cooler acts as a mediator that separates the heating function from the cooling function, allowing independent control of each.
Solution Approach 2:
The patent changes the temperature parameter of the refrigerant by introducing a sub-cooling stage. The liquid refrigerant is sub-cooled below its condensation temperature before entering the expansion valve, creating a temperature gradient that allows heat transfer to the foam pack without affecting evaporator temperature. This parameter change enables the foam pack to be warmed while maintaining evaporator cooling efficiency.
2Productivity
If the foam pack temperature is lowered to increase cooling capacity, then refrigeration efficiency improves, but condensation and moisture collection increase
Solution Approach 1:
The sub-cooler coil serves as a thermal intermediary between the refrigerant system and the foam pack enclosure. It allows the foam pack to be maintained at a higher temperature (preventing condensation) while the refrigerant is sub-cooled to increase cooling capacity. The intermediary decouples the temperature requirements of the two systems.
Solution Approach 2:
The patent segments the thermal management functions by separating the foam pack temperature control from the refrigerant temperature control. The sub-cooler coil creates an independent thermal zone around the foam pack, allowing differential temperature management where the enclosure can be warmer than the refrigerant, preventing condensation while maximizing cooling capacity.
3Reliability
If a drip pan and drain line are added to manage condensate, then condensation damage is prevented, but device complexity and maintenance requirements increase
Solution Approach 1:
Instead of managing condensation as a harmful byproduct, the patent converts the thermal energy that would otherwise cause condensation into a useful resource. The warm liquid refrigerant from the condenser is redirected through the sub-cooler coil to provide intentional heating of the foam pack, preventing condensation before it forms. This transforms a potential problem (excess heat in refrigerant) into a beneficial function (condensation prevention).
Solution Approach 2:
The sub-cooler coil performs preliminary heating action on the foam pack enclosure before condensation can occur. By warming the enclosure surfaces in advance through the sub-cooling process, the system prevents the temperature conditions that would lead to condensation, eliminating the need for downstream condensation management systems like drip pans and drain lines.
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 effectively reduces condensation on the foam pack, prevents damage to electrical components, and enhances the cooling capacity of the freeze chamber by maintaining the foam pack's bottom temperature above the dew point, ensuring efficient refrigeration performance.
Implementation Method 1
transfer heat from the liquid refrigerant to the protective enclosure, usually metal, of the foam pack to prevent or reduce condensation of humidity on the same
Implementation Method 2
further cool the compressed or liquid refrigeration before its expansion and to also transfer heat from the liquid refrigerant to the protective enclosure
Implementation Method 3
the condenser is responsible for removing the heat off the hot gas refrigerant (coming from the compressor)
Data Source
AI summary
A freeze type dispenser having a refrigeration system including a compressor, condenser, expansion means and evaporator in the form of one or more freeze chambers in an enclosure is provided with a sub-cooler or auxiliary coil. The sub-cooler is located downstream of the condenser but upstream of the expansion means and is supplied with condensed refrigerant liquid. The sub-cooler is located adjacent the freeze chamber enclosure to prevent or reduce condensation of the same, without adversely affecting, and in fact increasing cooling performance or capacity.