Apparatus, system and method for the capture, utilization and sendout of latent heat in boil off gas onboard a cryogenic storage vessel
An apparatus, system and method for capture, utilization and sendout of latent heat in boil off gas (“BOG”) onboard a cryogenic storage vessel is described. A liquefied gas vessel comprises a cryogenic cargo tank onboard a liquefied gas vessel, the cargo tank comprising a liquefied gas and a BOG, a latent heat exchanger fluidly coupled to a stream of the liquefied gas and a stream of the BOG, wherein the latent heat exchanger transfers a heat between the BOG stream and the liquefied gas stream to produce a condensed BOG, means for combining the condensed BOG and the liquefied gas stream to obtain a combined stream, the means for combining the condensed BOG and the liquefied gas stream fluidly coupled to the latent heat exchanger, and a liquefied gas regasifier onboard the vessel and fluidly coupled to the combined stream, wherein the liquefied gas regasifier regasifies the combined stream.
1. A liquefied gas vessel comprising:
a cryogenic cargo tank onboard a liquefied gas vessel, the cargo tank comprising a liquefied gas and a boil off gas (“BOG”);
a latent heat exchanger fluidly coupled to a stream of the liquefied gas and a stream of the BOG, wherein the latent heat exchanger transfers a heat between the BOG stream and the liquefied gas stream to produce a condensed BOG;
means for combining the condensed BOG and the liquefied gas stream to obtain a combined stream, the means for combining the condensed BOG and the liquefied gas stream fluidly coupled to the latent heat exchanger;
a liquefied gas regasifier onboard the vessel and fluidly coupled to the combined stream, wherein the liquefied gas regasifier regasifies the combined stream; and
an uncondensed gas vent fluidly coupling a fuel gas and an uncondensed BOG from the latent heat exchanger.
2. The vessel of claim 1 , wherein the latent heat exchanger comprises the uncondensed gas vent.
3. The vessel of claim 1 , wherein the means for combining the condensed BOG and the liquefied gas stream is an eductor.
4. The vessel of claim 1 , wherein the means for combining the condensed BOG and the liquefied gas stream is at least one drain pump.
5. The vessel of claim 1 , further comprising a condensate drain pot fluidly coupled between the latent heat exchanger and the means for combining the condensed BOG and the liquefied gas stream, wherein the condensate drain pot further comprises:
a condensed BOG inlet fluidly coupled to an outlet of the latent heat exchanger;
a liquefied gas inlet fluidly coupled to the cryogenic cargo tank; and
a condensed BOG outlet fluidly coupled to the condensed BOG inlet.
6. The vessel of claim 5 , wherein the condensate drain pot comprises the uncondensed gas vent.
7. The vessel of claim 1 , further comprising a suction drum fluidly coupled between the means for combining the condensed BOG and the liquefied gas stream and the regasifier.
8. The vessel of claim 1 , wherein the latent heat exchanger comprises a BOG inlet that receives compressed BOG from a discharge side of a compressor, wherein the compressor regulates a discharge pressure of the BOG stream entering the latent heat exchanger.
9. The vessel of claim 1 , wherein the vessel is an LNG carrier and the liquefied gas is LNG.
10. The vessel of claim 1 , wherein there are a plurality of cryogenic cargo tanks and the BOG stream fluidly couples a first cryogenic cargo tank of the plurality of cryogenic cargo tanks and the latent heat exchanger and the liquefied gas stream fluidly couples a second cryogenic cargo tank of the plurality of cryogenic cargo tanks and the latent heat exchanger.