Cyclic dewfall system of low-temperature liquid cargo ship

Abstract

The invention discloses a cyclic dewfall system of a low-temperature liquid cargo ship. The system comprises a ship drying and humidity-reduction device, wherein one air outlet of the ship drying and humidity-reduction device is connected to each cargo cabin and each dry insulation cabin by pipelines; emptying holes of the cargo cabins and the dry insulation cabins are connected to a cargo cabin air return header pipe and a dry insulation cabin air return header pipe by branch pipe systems; the cargo cabin air return header pipe and the dry insulation cabin air return header pipe are connected to an air return adjustment device; the air return adjustment device is connected to an inlet end of the ship drying and humidity-reduction device; a bypass conversion valve is disposed between the ship drying and humidity-reduction device and the air return adjustment device; and one inlet of the bypass conversion valve is connected to a bypass new air pipe. According to the invention, gas cabin charging pipes and discharge pipelines of the cargo cabins / dry insulation cabins of the low-temperature liquid cargo ship are in sealed connection with a compressed drying system; air is absorbed and supplemented by the air return adjustment device based on a venturi tube; and the gas dew point at the inlet of the ship drying and humidity-reduction device can be reduced continuously and cyclically.

Description

technical field [0001] The invention relates to a dry dew reduction technology in the loading process of a low-temperature liquid cargo ship, in particular to a circulating dew reduction system for a low-temperature liquid cargo ship. Background technique [0002] For LNG, LEG and other cryogenic liquid cargo ships, it is very important to reduce and maintain the low dew point value of the liquid cargo tank / dry compartment (such as the dry compartment of type C independent cargo tank). If there is excessive moisture before loading, it will not only affect the cargo tank Affect the quality of the cargo. During the cooling process of the cold cabin, the water condenses into micro-ice to affect the operation of the liquid cargo pump, and even cause damage to the shaft seal and other components of the pump. If the dew point of the dry compartment is too high and there is moisture, it will affect the insulation layer. The heat preservation effect will seriously cause the heat pre...

AI Technical Summary

Problems solved by technology

[0004] If the drying process exceeds the processing capacity of the dryer, or the ambient air intake humidity is too high, the ship is limited by the processing capacity of its own gas dew drying equipment. For LNG and LEG ships with medium and large tank capacity, the dew process operation needs to be continued Longer time, unstable dew effect, LNG, LEG ship dew point test value has strict standards, the ship often seriously affects the ship's operation time and loading efficiency due to the long operation of the ship dew process

At the same time, this kind of gas drying mostly adopts the form of adsorption dryer (or combination mode of suction and drying), and due to long-term use, it is also faced with the limitation of energy consumption of equipment and service life of adsorption filters.

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