UPGRADING LNG TERMINAL OPERATION CONTROL SYSTEM TO A SYSTEM ADAPTABLE TO FUTURE EXPANSION AT MINIMAL COST SYSTEM REPLACEMENT AT SENBOKU LNG TERMINAL I

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1 UPGRADING LNG TERMINAL OPERATION CONTROL SYSTEM TO A SYSTEM ADAPTABLE TO FUTURE EXPANSION AT MINIMAL COST SYSTEM REPLACEMENT AT SENBOKU LNG TERMINAL I RENOUVELLEMENT DU SYSTEME DE GESTION DE L EXPLOITATION DU TERMINAL DE GNL AVEC POUR OBJECTIF LA REDUCTION DU COUT ET LA REALISATION DE LA CAPACITE EVOLUTIVE UN EXEMPLE DU TERMINAL DE SENBOKU Hiroshi Fukumoto Hisato Inoue Yoshiki Matsushima Susumu Takebe* Haruhito Matsunami** System Replacement Project Team Senboku LNG Terminal I (*Engineering Dept., **Energy Technology Laboratories) Osaka Gas Co., Ltd. 4 Chikko-Hamadera-Cho, Sakai, Osaka , Japan ABSTRACT Osaka Gas Senboku LNG Terminal I produces city gas using LNG as a feedstock, and engages in the business of cold utilization systems. The computer system presently controlling terminal operation is outdated, having been operative for more than 15 years since entering use in The system is currently being upgraded. The upgraded system design focuses mainly on (1) drastic cost reduction, (2) realization of efficient operation control, and (3) adaptability to future system expansion. Unlike the traditional manner of upgrading, in which the entire system is replaced, this project employs a parts deterioration diagnostic program to determine the devices to be upgraded. The upgrading will integrate three systems (gas production processing, disaster prevention and power receiving/distribution) that at present are separately controlled, and will also minimize the number of computer units. The software currently in use will be automatically converted and input to the new system. These innovative measures have enabled upgrading of the existing system at the lowest possible cost and within a shorter period of time. In addition, operation screens and equipment layout at central control room have been ergonomically assessed to ensure optimal operability. The new system broadens the range of automatic operation control, unifies existing cold utilization system operation controls, and is adaptable to the system expansion that may be required when the current cold utilization business launches a new field in the future. PO-24.1

2 Upon full assessment of past experience, we will upgrade the existing system safely and without trouble, while keeping influences on terminal operation below the permissible level and ensuring continuous production and of city gas. RESUME L usine n 1 du Terminal de Senboku produit le gaz de ville à partir du GNL et fournit des services en profitant de l énergie cryogénique. Le système informatique pour la gestion de son exploitation qui a été mis en service en 1988 est à l heure actuelle renouvelé. La conception du nouveau système informatique a pour objectif principal de (1) réduire au maximum les coûts, (2) assurer une gestion efficace de l exploitation et de (3) de réaliser une capacité évolutive. Dans le cadre du renouvellement du système informatique qui signifie conventionnellement le remplacement du système entier, on a essayé cette fois-ci de limiter les interventions de renouvellement en diagnostiquant l état de dégradation de pièces et composants. Parallèlement, trois systèmes (procédés, lutte contre l incendie, réception/distribution électrique) qui étaient jusqu alors indépendants l un de l autre ont été intégrés dans un seul système, de même que leurs unités de commande qui ont été centralisées sur une seule unité de commande. Quant aux programmes, ils ont également été convertis systématiquement. Le renouvellement s est ainsi réalisé dans le meilleur délai aux moindres frais. Parmi les autres points à mentionner en particulier figurent l optimisation de la facilité d opérations atteinte avec prise en considération d un aspect ergonomique dans la conception de l écran de commande/contrôle et l agencement de la salle de commande centralisée, l élargissement du domaine de gestion automatique de l exploitation, l intégration de la gestion d exploitation des installations à énergie cryogénique dans le système renouvelé, la compatibilité avec l évolution des activités à énergie cryogénique dans l avenir. Le passage au nouveau système se réalisera en toute sécurité sans interrompre la production/distribution de gaz de ville tout en limitant son influence sur l exploitation à un niveau tolérable, compte tenu de l expérience acquise. 1. BRIEF DESCRIPTION OF BUSINESS Osaka Gas is engaged in the production, and sale of city gas using LNG as a main feedstock in the Kansai region located in the midwestern part of Japan. The number of city gas consumers in the business territory reaches approximately 6.6 million. The total volume of annual city gas sales is approximately 7.7 billion cubic meters when calculated in terms of the calorific power of 45 MJ/m 3. The company also supplies power generation fuel gas to H i m e j i L N G T e r m i n a l L E G E N D M a j o r t r u n k l i n e M a j o r p i p e l i n e T e r m i n a l / P l a n t S u p p l y d e p o t O s a k a B a y K o b e Kansai Airport Hokko Plant S e n b o k u L N G T e r m i n a l s W a k a y a m a 0 O s a k a S e r v i c e A r e a 10 km Figure 1. Osaka Gas business territory S h i g a K y o t o N a r a PO-24.2

3 electric power companies and engages in the cold utilization business. Furthermore, the company is actively expanding its electric power generation business in response to the deregulation of the energy sector. 2. OUTLINE OF THE SENBOKU LNG TERMINALS The Osaka Gas Senboku LNG Terminals are an important energy base in the Kansai region, producing approximately 70% of the total city gas production volume of the company and ing power generation fuel gas to power plants of electric power companies. At the Senboku LNG Terminals, Terminal I commenced operation in 1971 and has been receiving LNG since Terminal I receives 730,000 tons of LNG per year and produces city gas whose volume accounts for 13% of the total gas production volume of the company. This terminal forms an industrial complex with the neighboring plants of other companies (see Fig. 2). An annual total of approximately 2,300 tank truck services are operated to LNG from Terminal I to areas where no pipeline network has been constructed. This terminal is also responsible for various cold utilization businesses, including separation of air by liquefaction, production of liquefied carbon dioxide, production of high-purity methane, and low-temperature pulverization of industrial materials. A facility will be additionally installed in a few years to promote cascaded use of LNG cold energy. In addition, the capacity of the existing power generation plant will be increased from the current 18,000 kw to approximately 800,000 kw in the near future, in order to expand the business electric power. Low-temperature pulverization center generation facility Carbon dioxide Oil refining company LNG storage tanks Warm water Chemical company Pier Air liquefaction facility Liquefied carbon dioxide production facility Cold energy Figure 2. Senboku LNG Terminal I 3. OPERATION CONTROL SYSTEM UPGRADE PROJECT 3.1 Background The computer system presently controlling Senboku Terminal I operation is outdated, having been running for 15 years since it was first started in Because the Senboku Terminal I will become the base for various new businesses as previously described, it is necessary that its operation control system ensures a high level of cost competitiveness PO-24.3

4 through efficient operation control, as well as a high degree of adaptability for future expansion of new businesses. The existing system is currently being upgraded to meet these requirements. 3.2 Features of the Upgraded System The basic concepts of the upgraded system design are cost reduction, efficient operation control, and an ensured high degree of adaptability. Under the above design concepts, the practical measures shown in Fig. 3 are being taken. Basic upgrade concepts Practical design measures [1] Restriction of the replacement range (partial replacement) Replacing only those parts not capable of maintenance and end-of- service parts (1) Pursuit of cost reduction (Strengthening business competitiveness) (2) Efficient and highly reliable operation control (Construction of a system that is easy to operate using a minimum number of operators) (3) Ensuring adaptability for future system expansion (Ensuring adaptability for future expansion and modification of facilities) [2] Integration of three systems Simplification of the system by integrating three systems (gas production processing, disaster prevention, and power receiving/distribution systems) [3] Integration of s Reduction in the number of computer units by optimally grouping the facilities to be controlled [4] Automatic conversion of software Improvement of design, programming, and verification efficiencies through the automatic conversion of existing software for the upgraded system [5] Integrating operation with cold energy utilization facilities Unification of all control systems including those for air liquefaction, production of liquefied carbon dioxide, high-purity methane, etc.) [6] Control function enhancement Introduction of more automatic functions to achieve operation control using with a minimum number of operators [7] Usability Optimization of operationality Ergonomic assessment and design of the operation system to achieve more efficient operation control with fewer operation mistakes [8] Adaptation for future system expansion Adaptation of the system for cold utilization, power generation, and other new businesses without restriction Figure 3. Concept of system upgrading and practical measures (1) Restriction of the replacement range As shown in Fig. 4, the existing system to be upgraded consists of three independent systems (gas production processing, disaster prevention, and power receiving/distribution), which are each separately operated at present. Process data collected at production sites are transmitted to computer units (s) via signal converters. Based on the data, system operation is monitored and controlled on the consoles located in the Central Control Room (CCR). The signal converters remain unchanged since they are anticipated to continue functioning for quite some time. (Equipment enclosed by the dotted frames in Fig. 4 is being upgraded.) By limiting the replacement range as described above and by renewing only those parts not capable of maintenance and end-of-service parts, the cost of upgrading the system can be dramatically reduced. The duration for the system upgrade can also be reduced almost in half compared with the traditional manner. PO-24.4

5 For the signal converters to be used without replacement, test specimens were sampled for characteristics testing of life-limited parts and accelerated temperature resistance testing of circuit boards. Test results showed that the signal converters can continue working for another 10 years or so. Replacement range Figure 4. System architectures before and after upgrading (2) Integration of three systems and unification of s In the upgraded system, three systems (for gas production processing, disaster prevention, and power receiving/distribution) being separately controlled at present are integrated by linking them with one communication bus line, as shown in the bottom half of Fig. 4. This measure reduces the number of monitoring/operation consoles, thereby improving system operability. In addition, unifying the s aims for optimal grouping of existing facilities to reduce the number of s in half compared with the existing system (Fig. 5). PO-24.5

6 Equipment to be upgraded Equipment to be used continuously Equipment after upgrading Station 1 Station 2 Station 1 Station 2 Station 1-1 Station 1-2 Before upgrading During upgrade After upgrading Figure 5. Conceptual representation of unification (3) Automatic conversion of software In the conventional method of operation control system replacement, much time is consumed for the design, programming, and verification of the software. The functions of the upgraded system are basically the same as those of the existing system since the objective of upgrading is to improve software functionality without changing the process itself. An automatic software conversion technique is applied for the upgraded system. This technique automatically converts the software currently in use (source files) according to a specific conversion rule so that the converted software will conform to the specifications of the new system components and operating system (OS). The software currently in use includes a few portions that cannot be converted automatically due to architectural differences between the old and new systems and hence must be programmed manually. Application of this conversion technique is expected to reduce the design, verification, and other workloads on the user side to 60% compared with the traditional manner. (4) Integrating operation with cold energy utilization facilities The existing system bus line of cold energy utilization facilities will be integrated to enable the new system monitoring/operation console to operate both the city gas production systems and the air liquefaction system that is currently controlled separately from the gas production system. For integrating the system bus lines, an interface will be installed to enable data communication between the new system and the air liquefaction system and other systems. The system integration discussed above is expected to achieve reliable and efficient system monitoring/operation using a minimum number of operators. PO-24.6

7 (5) Control function enhancement The control system currently in operation at Terminal I is provided with various contingency functions to properly cope with the ever-fluctuating gas demand and to ensure safety and fast operation resumption in case of emergency. Examples of these functions are an automatic control of the number of equipment to be operated, automatic operation control of equipment during power failure and after recovery of power, and automatic operation of disaster prevention equipment when LNG or gas leakage is detected. The upgrade project aims to further improve system functions to achieve more efficient system operation while ensuring higher security using a minimum number of operators. In selecting the functions to be actually improved, detailed investigation of investment efficiency was required while paying attention to the fact that the existing system has various advanced automatic functions. A typical example of this improved functionality is described below. Improvement of LNG shipping operation on tank trucks. LNG is filled into approximately 2,300 tank trucks a year at six gates and shipped (Photo 1). Unlike highly automated gas production, LNG shipping operation requires many field workers. This has been a bottleneck in achieving terminal operation that uses the least possible number of workers/operators. a) Currently prevailing problems Automatic LNG weighing is impossible. The quantity of LNG to be filled into each tank truck has to be set from 2 to 11 tons. Since the computer system currently in use is unable to accurately measure the quantity of LNG to be filled into the tank truck, LNG is loaded manually in the field based on the past experiences of field operators. Pressure fluctuation in the main LNG discharge line The operator in charge must stabilize the line pressure manually while LNG is being pumped into the tank trucks. b) Procedures and practices for improvement Past data analysis During the past year we analyzed the quantity of LNG discharged from the six loading gates to find the relationship between the LNG quantity data collected by the control system and the quantity actually weighed on the truck scale. The results showed that both quantities are highly correlated with each other. Implementation of automatic filling function based on correlation We implemented an automatic LNG filling system having the following functions: Filling quantity setting: Filling quantity can be set in 0.1 ton increments on a digital setting device installed in the field (Photo 2). Filling practice: A series of sequences is fully automated. PO-24.7

8 Stabilization of LNG discharge line pressure in main pipes: Pressure fluctuation in LNG main pipes especially during simultaneous charging to two or more tank trucks is systematically controlled. c) Anticipated effects Realization of automatic measurement of LNG quantity and automatic stabilization control of LNG pressure in trunk pipes will dramatically reduce workloads in both the filling site and central control room. Reduced LNG filling time will improve work efficiency. Enhanced LNG quantity measuring accuracy will reduce the filling margin (resulting in a reduced number of delivery services on tank trucks). Photo 1. Shipping gates and LNG trucks Photo 2. Filling quantity field setting device (6) Usability optimization The pursuit of usability optimization uses an ergonomic approach to inquire into the principles of human behavior, in order to understand a system that ensures comfortable operation with minimized human error. We applied this approach to the computer graphic screens for controlling and monitoring we developed ourselves and to the equipment layout in the central control room. Our approach steps are shown in Fig. 6. Understanding user characteristics Understanding use conditions Defining specifications required by user Drawing up guidelines Building up system Verifying effectiveness User requirements Basic principles of ergonomics Restrictions on design Completing highly usable system Figure 6. Approach steps for improving usability Example of usability optimization. A conventional graphic screen and that prepared based on the above approach are shown in Figs. 7 and 8. In the upgraded graphic screen (Fig. 8), the font and size of characters, color scheme, information density, and number of groups of equipment in each screen page are optimized. PO-24.8

9 Figure 7. Before screen optimization Figure 8. After screen optimization (7) Adaptation for future system expansion The upgraded system design includes the following items to prepare for future system expansion. a) Equipment layout in the central control room The layout after the system upgrade is shown in Fig. 9. Integrating the three systems and integrated operation control of these systems with the cold utilization facilities have drastically reduced the number of monitoring/operation consoles. The new layout design was also assessed and improved from the viewpoint of usability. Entranc Maintenance space Entranc Drawing rack Printer/hard copier Central information panel Space for future Meeting table expansion Supervisor Chief operator Extra space for disaster countermeasures office Display unit Phone/Fax Maintenance generation generation output management system Truck system PDAs for patrol Space for additional equipment installation Drawing rack Drawing rack Drawing rack Drawing rack For gas production For cold utilization For power generation Figure 9. Equipment layout of central control room after system upgrade b) Surplus capacity of control system In the upgraded system, each control unit has a surplus capacity of at least 30% for software and at least 20% for hardware. Therefore, no additional device installation is required when completing small expansions or modifications of the system. In terms of the maximum allowable load on the communication bus lines, the number of the control units can be doubled or more. This shows that the upgraded system is adaptable to system expansions that may be required for further expansion of new businesses. PO-24.9

10 3.3 Cost Reduction Reducing investment costs is indispensable for strengthening cost competitiveness. As a result of employing various measures discussed above, we were able to reduce the system upgrade cost by almost half compared with the traditional methods. When taking into account the shortened system upgrade (switchover) time, improved design and verification efficiencies, upgrading the existing system will increase its effects even more. 4. UPGRADING SCHEDULE AND SWITCHING TO THE UPGRADED SYSTEM The upgrade schedule is shown in Table 1. Continuous production of city gas must be maintained even while the existing system is being upgraded. Switching to the new system will be carried out sequentially on the basis of each computer unit to avoid suspending any city gas production. Fiscal year Month Master plan Ordering Design and programming Table 1. System upgrade schedule Release of specification sheets Purchase order issuance Upgrading the existing system while ensuring continuous production of city gas Switching Replacement of trip boards, etc. Installation of power, ITV, etc. Switching start Gas production processing receiving/ distribution Switching end Disaster prevention Equipment removal and other tasks 5. CONCLUSION The operation control system in Senboku LNG Terminal I is currently being upgraded to a system adaptable for future system expansion. The new system design involves various innovative approaches to enable the upgrade to be done at the lowest possible cost. Since this terminal produces city gas, the system must be upgraded while ensuring continuous production and of city gas. We are continuously directing our attention to every detail to successfully complete this project by overcoming various difficulties. Upon completion of this project in the spring of 2005, Senboku Terminal I will be built up as the core of the cold utilization business complete with all necessary systems. PO-24.10