Technical Development for Large Storage of Liquid Hydrogen in WE-NETKAWASAKI HEAVY INDASTRIES.LTD. 118,Futatsuzuka,Noda,Chiba,278 Japan
AbstractIn Japan, International Clean Energy Network Using Hydrogen Conversion System while simultaneously preserving the environment. WE-NET project which extends over until 2020, is divided into three phases. Liquid Natural Gas (LNG), and further, it is estimated that the scale of the liquid hydrogen facilities will be fairly larger than existing ones. liquid hydrogen storage in subtask 5. classified into two R&D items ; <1> Design of the total system for the large-scale system, peripheral technologies for in-ground storage tank and underground bedrock system,we made the basic process flow of liquid hydrogen storage plants. In the item <2>, we investigated the material and structure of the thermal insulation for the large liquid hydrogen storage tank. And we conducted the conceptual report of thermal insulation, and their capacity is the final target capacity, 50,000m3 per unit tank.1. IntroductionWE-NET project with the following three major R&D phases have being carrying out since 1993. Phase$B-5(J(1993-1996), survey on key technologies, the basic research and the elemental technologies Phase$B-6(J(1996-2003), a pilot-scale plants will be constructed by using the elemental technologies developed in Phase$B-5(J demonstrated plants will be constructed on an international scale in order to deploy the system for actual use. Development for Phase$B-5(J is divided into nine subtasks as shown in Table-1, and working-group of technical development for large-scale liquid hydrogen storage is included in the subtask 5. In the subtask 5, liquid hydrogen having the advantage Natural Gas (LNG) and further, it is estimated that the scale of the liquid hydrogen facilities will be fairly larger than existing ones. The subtasks and working-groups are in progress in the form of collaboration collaborated report in the working-group.2. Results2.1 Design of the total system for the large-scale liquid hydrogen storage(1) Study of similar large liquid storage systemequipment of loading, vaporization, BOG disposal, return gas equipment, exhaust gas disposal, and so on. The number of investigated LNG receiving terminals are 12 typical terminals in Japan and overseas. installed, and 2) gas is returned to the LNG tanker by the storage tank pressure in some terminals when receiving from the LNG tanker. As other equipments, there is temperature is lower than LNG, many equipments (loading arm, vaporization equipment, cryogenic compressor, liquid hydrogen pump, etc.) must be developed.
(2) Research of existing liquid hydrogen storage equipment
(3) Research of peripheral technologies for in-ground storage tank
(4) Study of basic process flow for a large amount of liquid hydrogen storage 2.2 Research of the storage equipment(1) Thermal insulation material and structureWe investigated the similar large cryogenic storage tanks such as LNG storage tanks and so on. The investigation has revealed that the application of the thermal insulation structure for LNG directly to the liquid hydrogen is difficult, and it insulation structure for the liquid hydrogen temperature. And we have studied the existing liquid hydrogen storage tanks. The result of the study has revealed that the largest capacity of the existing liquid hydrogen storage tank in Japan is 540m3 at the Tanegashima Space Center, outside Japan, 3218m3 at J.F.Kennedy Space Center of NASA, largest tank with perlite vacuum insulation in the world. As a result, the perlite vacuum insulated storage tank is used for the large capacity because of relatively stable performance and excellent workability,in case of allowing site space. On the other hand, the multilayer vacuum insulated storage tank is used in the smaller storage tank because of its capability of making an effective use of storage tank space and minimizing the thermal insulation and heat capacity. However, the large liquid hydrogen storage system planned in the WE-NET requires development of technologies such as thermal insulation support structure of the internal tank (liquid storage), and so on.
(2) Conceptual report of large storage tank for liquid hydrogen 3. ConclusionWe have studied the current technologies for cryogenic liquid storage in wide scope. In the result of the study, the problems in the case of application of the current technologies to the large-scale liquid hydrogen storage system have been storage tanks with various thermal insulation structures, and got the realizable dimensions from the viewpoint of storage tank strength. In the next step, we will carry out the elemental experiment of the insulation material and structure, which are needed for designing the large liquid hydrogen storage tank. The activities reported here have been carried out by the working group members. The participants are MITSUBISHI HEAVY INDUSTRIES,LTD.,4. Literature Reference1) M.Murase, "R&D Plans for WE-NET (World Energy Network)", International Hydrogen and Clean Energy Symposium 1995.2) K.Fukuda, "Current R&d Activities in WE-NET Project", International Hydrogen and Clean Energy Symposium 1995. |