Air heated vaporizers (AHV), or ambient air vaporizers, are heat exchangers which vaporize liquified gas by using heat absorbed from the ambient air. Liquid gas like LNG passes through a number of interconnected tubes in various series and parallel paths. Extruded aluminum 'fins' allow ambient heat to be conducted into the cryogenic liquid stream. Due to this principle of operation these vaporizers do not require external power. It has been widely used for regasification of LNG, LOX, LIN etc.
Key Parameters of AHV
• Suitable for: LNG, LOX, LIN, LAR, LCO2, LC2H4, LNH3, LPG...
• Capacity per unit: 20 - 10,000 Nm3/h
• Working pressure: 0.1 - 40 Mpa
• Inlet/outlet temp.: -196 / 0-20 ℃
• Materials: Stainless steel for core tubes; Aluminum alloy for star-fins
A water bath vaporizer (WBV) is a heat exchanger designed to use warm water to transfer heat to cryogenic liquid via stainless steel coils submerged in the water. Means of heating the water includes: steam injection, circulating water from a heat source, electric heating, or gas fired / combustion heating.
A single unit of AHV has an operation time of approx. 8 hours, and for continuous operation, 2 or more sets should be used together, operating alternatively manually or automatically. Output gas via AHV normally has a temperature 10 ℃ lower than the ambient temperature. If the requirement on gas temperature is not high, then AHVs are ideal for the regasification for its zero energy consumption. Such applications are common in tropical and warm regions. The system can be supplemented with WBVs (as recuperators) during cold seasons.
Compared to AHV, a WBV is capable of 24 hours continuous operation, has a higher single-unit capacity, and suitable for flexible operation. At the same time, using water as the heating medium, the system is conducive to the operation of variable conditions. And the electrical heat source can be controlled, more conducive to the stability of the outlet temperature.
