Heating system for empty fuel cabin of LNG (liquefied natural gas) dual-fuel ship

Abstract

The utility model relates to the field of dual-fuel container ships, and provides an empty fuel cabin heating system of an LNG dual-fuel ship. Comprising an empty bin surrounding a fuel bin, a heat exchange circulating unit is installed in the empty bin, the heat exchange circulating unit comprises a heat exchange medium generating device, a heat exchange circulating pipe network and a heat exchange medium heating system, the heat exchange medium heating system comprises a plurality of heat exchange units, and each heat exchange unit comprises a liquid supply pump and an electric heater which are connected in series through a pipeline. A heat exchange medium in the expansion tank sequentially passes through the liquid supply pump and the electric heater and then is fed into the heat exchange circulating pipe network; the heat exchange medium generating device and the heat exchange medium heating system equipment are arranged in the area outside the void, the heat exchange circulating pipe network is arranged in the void, and the occupied space is small; automatic control is achieved through linkage of the sensor and the three-way valve. The technical scheme is simple in equipment composition, high in integration level and convenient to operate, and the internal environment temperature of the empty bin is balanced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of dual-fuel container ship, specifically relates to LNG dual-fuel ship fuel tank empty cabin heating system. BACKGROUND

[0002] LNG dual-fuel ship uses fuel oil and LNG as fuel, and LNG fuel is stored in the fuel tank in liquid form. Since the storage temperature of liquefied natural gas is-163 DEG C, although the fuel tank is subjected to heat insulation treatment, the temperature of the surrounding cabin is usually below-5 DEG C, and the problems such as gas condensation, pipe blockage and freezing are prone to occur in the cabin, in order to ensure the stable operation of the equipment in the cabin, the empty cabin is arranged around the LNG fuel tank, and the temperature in the cabin is stabilized by heating and temperature control of the empty cabin.

[0003] The common empty cabin hot air heating mode of LNG ship includes hot air heating, electric heating and steam heating. The hot air heating includes a heating fan, a damper, an air duct pipeline and a control system. The electric heating utilizes the heat source generated by the built-in electric heating element. The steam heating is to arrange heating coils in the empty cabin by using the steam generated by the boiler on the ship. The hot air heating has the advantages of simple structure, but the disadvantages are large volume occupation, the need to arrange large-diameter air pipes in limited space, and great influence by environmental temperature. The electric heating has fast response speed, but high energy consumption. The steam heating has the advantages of high energy efficiency and utilization of existing energy, but the disadvantages are occupation of steam resources on the ship and increase of boiler energy consumption. SUMMARY

[0004] In order to meet the temperature control requirements of LNG fuel tank, save equipment space and reduce energy consumption, the utility model provides LNG dual-fuel ship fuel tank empty cabin heating system.

[0005] The technical scheme adopted by the utility model is as follows:

[0006] The LNG dual-fuel ship fuel tank empty tank heating system comprises an empty tank surrounding the fuel tank, a heat exchange circulating unit installed in the empty tank, and a heat exchange medium passing through the heat exchange circulating unit. The heat exchange circulating unit comprises a heat exchange medium generating device, a heat exchange circulating pipe network, and a heat exchange medium heating system. The heat exchange medium generating device is installed in the auxiliary equipment room on the upper building, comprising an expansion tank. The output pipeline of the expansion tank is connected to the heat exchange medium heating system. The heat exchange medium heating system comprises a plurality of heat exchange units, each heat exchange unit comprising a liquid supply pump and an electric heater connected in series through a pipeline. The heat exchange medium in the expansion tank is sequentially sent to the heat exchange circulating pipe network after passing through the liquid supply pump and the electric heater. The circulating pipe network comprises heat exchange pipelines distributed in the bow and stern of the empty tank, a main liquid supply pipeline, and a main liquid return pipeline. The heat exchange unit is connected to the input end of each heat exchange pipeline through the main liquid supply pipeline. The output end of each heat exchange pipeline is connected to the main liquid return pipeline. The main liquid return pipeline is connected to the input end of the heat exchange unit to form a heat exchange cycle. A three-way valve is installed on the main liquid supply pipeline. The three-way valve is connected to a standby loop pipeline, which is connected to the input end of the heat exchange unit. Temperature sensors are installed in the bow and stern of the empty tank. The opening state of the three-way valve is related to the feedback value of the temperature sensor.

[0007] Further, the expansion tank is connected to a glycol pneumatic pump. The input end of the glycol pneumatic pump is connected to a mixing tank. The mixing tank is connected to a glycol input and a water input. The glycol input is a glycol storage tank. The glycol storage tank and the expansion tank are respectively provided with a breather pipe, which extends to the open-air safety area of the ship.

[0008] Further, the mixing tank is provided with an overflow port and a discharge port. The output end of the expansion tank is provided with a relief port. The overflow port, the discharge port, and the relief port are respectively connected to a sewage pipeline.

[0009] Further, the heat exchange medium heating system comprises two heat exchange units arranged side by side. The input ends of the two heat exchange units are connected to the output end of the expansion tank, the main loop pipeline, and the standby loop pipeline through a distribution pipeline and a valve. The output end of one of the heat exchange units is connected to the main liquid supply pipeline. The output end of the other heat exchange unit is connected to a standby heat exchange unit.

[0010] Further, the standby heat exchange unit comprises a standby liquid supply pipeline, a standby heat exchange pipeline, and a standby liquid return pipeline. The standby liquid supply pipeline, the standby heat exchange pipeline, the standby loop pipeline, and the heat exchange unit form a heat exchange cycle.

[0011] Further, five sensors are respectively installed in the bow and stern of the empty tank. The five sensors are distributed at the four corners and the middle of the corresponding cabin.

[0012] Further, the main liquid supply pipeline, the main liquid return pipeline, the standby heat exchange pipeline, and the standby liquid return pipeline are respectively connected to a top exhaust port.

[0013] After adopting the above technical solution, the beneficial effects of this utility model are as follows:

[0014] Using water-glycol as the heat exchange medium, it is less prone to crystallization at low temperatures, exhibiting good antifreeze properties; its increased boiling point helps maintain liquid stability at high temperatures; it is environmentally friendly, with the heat exchange medium generator and heating system located outside the empty chamber, while the heat exchange circulation network is arranged inside the empty chamber, occupying minimal space; automatic control is achieved through the linkage of sensors and three-way valves. When the temperature inside the chamber is within the set range, the heat exchange medium does not enter the heat exchange pipes, and the heater does not heat, circulating only externally, resulting in low energy consumption. This technical solution features simple equipment composition, high integration, convenient operation, and uniform temperature within the empty chamber. Attached Figure Description

[0015] Fig. 1 This is a schematic diagram of a heat exchange medium generating device.

[0016] Fig. 2 This is a schematic diagram of the heat exchange cycle unit.

[0017] Fig. 3 This is a schematic diagram of a heat exchange medium heating system.

[0018] In the diagram: 1. Heat exchange medium generating device; 11. Ethylene glycol storage tank; 12. Mixing tank; 13. Ethylene glycol-water pneumatic pump; 14. Expansion tank; 15. Vent pipe; 2. Heat exchange medium heating system; 21. Liquid supply pump; 22. Electric heater; 23. Bypass branch; 3. Heat exchange circulation network; 31. Heat exchange pipe; 32. Auxiliary heat exchange pipe; 33. Main liquid supply pipe; 34. Backup liquid supply pipe; 35. Main liquid return pipe; 36. Backup liquid return pipe; 37. Three-way valve; 4. Empty chamber bow; 5. Empty chamber stern; 6. Sensor; 7. Sewage pipe. Detailed Implementation

[0019] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings:

[0020] like Figs. 1-3 As shown, the empty fuel tank heating system of an LNG dual-fuel ship is used to heat the empty tank and achieve temperature control. The empty tank surrounds the LNG fuel tank, and the temperature is increased by heat exchange in the empty tank when the temperature inside the tank is lower than the set value. It consists of a heat exchange medium generating device 1, a heat exchange medium heating system 2, a heat exchange circulation network 3, and an electrical control system. The heat exchange medium generating device 1 and the heat exchange medium heating system 2 are installed in the auxiliary equipment room built on the superstructure to avoid occupying the space of the fuel tank. The heat exchange circulation network 3 is installed in the empty tank bow 4 and empty tank stern 5.

[0021] The heat exchange medium generating device 1 is used for providing heat exchange medium for the whole heating system. The technical scheme adopts water glycol as the heat exchange medium. The water glycol as the heat exchange medium is not easy to crystallize in a low temperature environment and has good anti-freezing property. The heat exchange medium generating device comprises a glycol storage tank 11, a mixing tank 12, a glycol water pneumatic pump 13 and an expansion tank 14. The water system of the ship and the glycol storage tank 11 input into the mixing tank 12 to form a 45% concentration water glycol medium. The glycol water pneumatic pump 13 extracts the medium from the mixing tank 12 and sends it into the expansion tank 14. The expansion tank 14 provides the medium into the whole system and timely supplements the medium when the medium in the system is lost, so as to ensure the stable pressure in the pipeline of the system. The glycol storage tank 11 and the expansion tank 14 are respectively provided with a breather pipe 15 extending to the open air safety area of the ship.

[0022] The heat exchange medium heating system 2 comprises two parallel heat exchange units. Each heat exchange unit comprises a liquid supply pump 21 and an electric heater 22 connected in series by a pipeline. The liquid supply pump 21 is used for sending the medium in the expansion tank 14 or the backflow in the heat exchange circulation pipeline network 3 into the electric heater 22 for heating and then sending it back into the heat exchange circulation pipeline network 3 for heat exchange circulation.

[0023] The heat exchange circulation pipeline network 3 comprises heat exchange pipelines 31 distributed in the bow and stern of the empty cabin, auxiliary heat exchange pipelines 32, a main liquid supply pipeline 33, a backup liquid supply pipeline 34, a main backflow pipeline 35 and a backup backflow pipeline 36. The heat exchange unit sends the heated heat exchange medium into the heat exchange pipeline 31 through the main liquid supply pipeline 33 or sends the heated heat exchange medium into the auxiliary heat exchange pipeline 32 through the backup liquid supply pipeline 34. Remote control valves are respectively arranged on each pipeline. The auxiliary heat exchange pipeline 32 is a backup of the heat exchange pipeline 31. The heated medium returns to the heat exchange unit through the main backflow pipeline 35 and the backup backflow pipeline 36, so as to complete the heat exchange circulation. A three-way valve 37 is arranged on the main liquid supply pipeline 33. The third passage of the three-way valve 37 is communicated with the backup backflow pipeline 36. When the temperature of the empty cabin is in a set range, the heat exchange medium returns to the heat exchange unit through the three-way valve 37 and the backup backflow pipeline 36 without entering the heat exchange pipeline 31 for heat exchange. The main liquid supply pipeline 33, the main backflow pipeline 35, the backup liquid supply pipeline 34 and the backup backflow pipeline 36 are respectively connected with top exhaust ports.

[0024] The heat exchange medium heating system 2 comprises two parallel heat exchange units. The input ends of the two heat exchange units are connected with the output end of the expansion tank 14, the main backflow pipeline 35 and the backup backflow pipeline 36 through a distribution pipeline and a valve. The output end of one of the heat exchange units is connected with the main liquid supply pipeline 33, and the output end of the other heat exchange unit is connected with the backup liquid supply pipeline 34. Each electric heater is respectively connected with a bypass branch 23. The bypass branch 23 can realize the passage when the medium does not need to be heated.

[0025] The electric control system is used to control the work of various kinds of three-way valves, remote control valves, heating systems, liquid supply pumps and other elements in the system, and collect data through sensors. Five sensors 6 are installed in the empty cargo bow and stern respectively, and the five sensors 6 are distributed in the four corners and the middle of the corresponding cabin. When the temperature of one of the sensors 6 is lower than the set value, the bypass branch 23 of the electric heater is closed, and the medium is sent into the empty cargo after being heated by the electric heater 22 under the action of the liquid supply pump 21 to complete the heat exchange cycle. When the temperature of all sensors reaches the set range, the valves on both sides of the electric heater 22 are closed, the bypass branch 23 is opened, the three-way valve switches the passage, and the medium completes the circulation of sequentially passing through the liquid supply pump 21, the bypass branch 23, the main liquid supply pipeline 33, the standby liquid return pipeline 36 and finally returning to the liquid supply pump 21.

[0026] The mixing tank 12 is provided with an overflow port and a discharge port, and the output end of the expansion tank 14 is provided with a discharge port, and the overflow port, the discharge port and the discharge port are connected with the sewage pipeline 7 respectively, and the electric heater 22 is provided with an overflow port, and the overflow port is also connected with the sewage pipeline 7.

Claims

1. LNG dual-fuel ship fuel tank emptying heating system, comprising an emptying tank surrounding a fuel tank, a heat exchange circulating unit is installed in the emptying tank, and a heat exchange medium is circulated in the heat exchange circulating unit, characterized in that, The heat exchange circulating unit comprises a heat exchange medium generating device, a heat exchange circulating pipe network and a heat exchange medium heating system, the heat exchange medium generating device is installed in an auxiliary equipment room of the ship, and comprises an expansion tank, an output pipeline of the expansion tank is connected with the heat exchange medium heating system; the heat exchange medium heating system comprises a plurality of heat exchange units, each heat exchange unit comprises a liquid supply pump and an electric heater connected in series through pipelines, heat exchange medium in the expansion tank is sequentially sent into the heat exchange circulating pipe network after passing through the liquid supply pump and the electric heater; the circulating pipe network comprises heat exchange pipelines distributed in the bow and the stern of the empty cabin, a main liquid supply pipeline and a main liquid return pipeline, the input ends of the heat exchange pipelines are connected with the main liquid supply pipeline through the heat exchange units, the output ends of the heat exchange pipelines are connected with the main liquid return pipeline, and the input ends of the heat exchange units are connected with the main liquid return pipeline to form a heat exchange circulation; a three-way valve is installed on the main liquid supply pipeline, a standby loop pipeline is connected with the three-way valve, and the input ends of the heat exchange units are connected with the standby loop pipeline; temperature sensors are installed in the bow and the stern of the empty cabin, and the opening state of the three-way valve is related to the feedback value of the temperature sensors.

2. The LNG dual-fuel ship fuel tank airless heating system of claim 1, wherein, The expansion tank is connected with a glycol pneumatic pump, an input end of the glycol pneumatic pump is connected with a mixing tank, the mixing tank is connected with a glycol input and a water input, the glycol input is a glycol storage tank, air pipes are respectively installed on the top of the glycol storage tank and the expansion tank, and the air pipes extend to a safety area of the ship exposed to the air.

3. The LNG fueled ship fuel tank empty tank heating system according to claim 2, characterized in that, The mixing tank is provided with an overflow port and a discharge port, an output end of the expansion tank is provided with a blowdown port, and the overflow port, the discharge port and the blowdown port are respectively connected with a sewage pipeline.

4. The LNG fueled ship fuel tank empty tank heating system of claim 1, wherein, The heat exchange medium heating system comprises two heat exchange units arranged side by side, input ends of the two heat exchange units are connected with an output end of the expansion tank, the main loop pipeline and the standby loop pipeline through a distribution pipeline and a valve, an output end of one of the heat exchange units is connected with the main liquid supply pipeline, and an output end of the other heat exchange unit is connected with a standby heat exchange unit.

5. The LNG fueled ship fuel tank empty tank heating system according to claim 4, characterized in that, The standby heat exchange unit comprises a standby liquid supply pipeline, a standby heat exchange pipeline and a standby liquid return pipeline, and the standby liquid supply pipeline, the standby heat exchange pipeline, the standby loop pipeline and the heat exchange unit form a heat exchange circulation.

6. The LNG fueled ship fuel tank airless heating system of claim 1, wherein, Five sensors are respectively installed in the bow and the stern of the empty cabin, and the five sensors are distributed at four corners and a middle part of corresponding cabins.

7. The LNG fueled ship fuel tank empty tank heating system of claim 1, wherein, The main liquid supply pipeline, the main liquid return pipeline, the standby heat exchange pipeline and the standby liquid return pipeline are respectively connected with top exhaust ports.

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