Ship operation management system
An LNG carrier which uses natural gas generated by vaporization of LNG as propulsive fuel and including cargo tank, spray apparatus, and carrier communication device; land-based equipment including land-based communication device and processing device; processing device including: first vapor quantity estimating section which estimates total quantity of natural vapor generated from the LNG remaining in the cargo tank in a case where the LNG carrier is traveling on planned ballast course, based on sea weather data; a second vapor quantity estimating section which estimates a total quantity of spray vapor generated by performing spraying operations in a case where the LNG carrier is traveling on planned ballast course, based on the sea weather data; and heel quantity calculating section which calculates required heel quantity, by summing the total quantity of natural vapor and spray vapor, and the land-based communication device transmits the required heel quantity to the carrier communication device.
1. A ship operation management system comprising:
a liquefied natural gas (LNG) carrier which uses a natural gas generated by vaporization of LNG, as propulsive fuel, the LNG carrier including a cargo tank which stores the LNG therein, a spray apparatus which performs spraying operations for spraying the LNG to an inner surface of the cargo tank, and a carrier communication device; and
land-based equipment including a land-based communication device which is capable of communicating with the carrier communication device, and a processing device,
wherein the processing device includes:
a first vapor quantity estimating section which estimates a total quantity of a natural vapor generated from the LNG remaining in the cargo tank in a case where the LNG carrier is traveling on a planned ballast course, based on sea weather data;
a second vapor quantity estimating section which estimates a total quantity of a spray vapor generated by performing the spraying operations in a case where the LNG carrier is traveling on the planned ballast course, based on the sea weather data; and
a heel quantity calculating section which calculates a required heel quantity, by adding up the total quantity of the natural vapor which is estimated by the first vapor quantity estimating section and the total quantity of the spray vapor which is estimated by the second vapor quantity estimating section,
wherein the land-based communication device transmits the required heel quantity to the carrier communication device, while the LNG carrier is on a laden voyage.
2. The ship operation management system according to claim 1 ,
wherein the processing device includes an optimal course deriving section which derives an optimal ballast course with which a fuel consumption quantity is minimum, based on the sea weather data, and
wherein the planned ballast course is the optimal ballast course.
3. The ship operation management system according to claim 1 ,
wherein the first vapor quantity estimating section estimates the total quantity of the natural vapor by deriving a generation quantity of the natural vapor per unit time based on the sea weather data so that the generation quantity changes due to influences of rolling and pitching of the LNG carrier, and by adding up generation quantities of the natural vapor per unit time for a ballast voyage period.
4. The ship operation management system according to claim 1 ,
wherein the second vapor quantity estimating section estimates the total quantity of the spray vapor by deciding timings of the spraying operations based on the sea weather data so that a temperature of the cargo tank on a reference point is kept at a predetermined temperature or lower, and by adding up generation quantities of the spray vapor in the spraying operations for a ballast voyage period.
5. The ship operation management system according to claim 2 ,
wherein the first vapor quantity estimating section estimates the total quantity of the natural vapor by deriving a generation quantity of the natural vapor per unit time based on the sea weather data so that the generation quantity changes due to influences of rolling and pitching of the LNG carrier, and by adding up generation quantities of the natural vapor per unit time for a ballast voyage period.
6. The ship operation management system according to claim 2 ,
wherein the second vapor quantity estimating section estimates the total quantity of the spray vapor by deciding timings of the spraying operations based on the sea weather data so that a temperature of the cargo tank on a reference point is kept at a predetermined temperature or lower, and by adding up generation quantities of the spray vapor in the spraying operations for a ballast voyage period.
7. The ship operation management system according to claim 3 ,
wherein the second vapor quantity estimating section estimates the total quantity of the spray vapor by deciding timings of the spraying operations based on the sea weather data so that a temperature of the cargo tank on a reference point is kept at a predetermined temperature or lower, and by adding up generation quantities of the spray vapor in the spraying operations for a ballast voyage period.
8. The ship operation management system according to claim 5 ,
wherein the second vapor quantity estimating section estimates the total quantity of the spray vapor by deciding timings of the spraying operations based on the sea weather data so that a temperature of the cargo tank on a reference point is kept at a predetermined temperature or lower, and by adding up generation quantities of the spray vapor in the spraying operations for a ballast voyage period.