Instant Water Cooling System (Tube-In-Tube Evaporator)

This research paper presents the design, development, and performance evaluation of an instant water-cooling system using a tube-in-tube (double-pipe) evaporator integrated with a vapor compression refrigeration cycle. The system is designed to deliver drinking water cooled to 5–10°C within 60 seconds of activation, eliminating the need for pre-chilled storage tanks. A food-grade stainless steel inner tube carries the water while refrigerant R-134a circulates through the annular space in a counter-flow arrangement. The fixture was fabricated from mild steel (IS 2062) for structural support. Experimental results demonstrated a maximum coefficient of performance (COP) of 3.84, thermal effectiveness of 0.87, and cooling capacity of 1.8 kW under optimal conditions. The system reduces inspection and assembly time compared to conventional plate evaporator designs and achieves superior pressure drop characteristics.