【Major Equipment in the Chemical Equipment Industry】The key equipment of the 463-LNG receiving station is domestically produced

As can be seen from the description of the above processes, the key equipment in LNG receiving stations can be classified into five categories based on their functional roles: unloading, storage, BOG treatment and gasification for transmission, and transportation via tankers. The specific equipment included in each category is shown in Table 1:

Classification by equipment characteristics: Based on the classification by function mentioned above, it can be seen that the core equipment of LNG receiving stations, which are focused on low-temperature performance, includes unloading equipment, pumps, and vaporizers. Therefore, according to the characteristics of these devices, the following classification is possible: (1) Unloading equipment: unloading arms, loading/unloading skids； (2) Cryopump: tank pump, high-pressure transfer pump ； (3) Cryogenic compressor: Cryogenic BOG compressor ； (4) Vaporizer: ORV, SCV, IFV. Classifying in this way is closer to the conventional classification method for equipment, making it easier to conduct analyses on domestic production.

Unloading arms: The unloading arms used in large-scale LNG receiving stations are generally large-diameter (16 inches or 20 inches) low-temperature unloading arms. The traditional manufacturers include French company FMC, German company SVT, and Japanese company NIIGATA. With the rapid development of LNG receiving stations in China, domestic manufacturers specializing in fluid handling, such as Jiangsu Changleong, Lianyungang Yuanyang Fluid, and CSIC 716 Research Institute, began to conduct research on LNG unloading arms starting in 2011. They started with small-diameter, low-temperature unloading arms for ethylene, and gradually worked their way up to developing 16-inch, ultra-low-temperature, large-diameter unloading arms. In 2021, the 16-inch large-diameter unloading arms developed by CSIC 716 Research Institute were put into use at Sinopec’s Tianjin LNG receiving station. Jiangsu Changleong also received orders for LNG receiving stations in Zhangzhou and Chaozhou Huaying; the 16-inch unloading arms produced by Lianyungang Yuanyang Fluids will be utilized at the Jiaxing Pinghu LNG emergency peak-shaving station. This marks the full entry of domestically produced large-diameter unloading arms into practical application.

The core component of an LNG loading skid is the loading arm, and its key technology is similar to that of the LNG unloading arm – both rely on cryogenic rotary joints. Since 2009, Lianyungang Yuanyang Fluids Company and Dapeng LNG have been working together to develop domestic loading arms. These domestic loading arms are now quite mature; those produced by companies such as Lianyungang Yuanyang Fluids and Jiangsu Changleong have been used in various receiving stations, and new receiving stations built in recent years all utilize domestic loading arms.

Key materials for LNG receiving stations: When discussing domestically produced equipment, it is necessary to mention domestically produced materials as well. The key materials used in LNG receiving stations are also those with low-temperature properties, including low-temperature steel bars, low-temperature 9-nickel steel, and insulation materials. In recent years, the production of these materials within China has become possible, so no further details are needed here. The key materials in LNG receiving stations are primarily represented by the LNG storage tanks – standard 160,000 cubic meter tanks as well as super-large 270,000 cubic meter 9-nickel fully enclosed tanks. The design of these complete sets, the use of domestic materials, and the local construction techniques are all quite mature. However, it should be noted that film-type LNG storage tanks are increasingly favored by receiving stations due to their low cost and large storage capacity. The Beijing Gas Tianjin Nangang LNG storage project was the first to use 220,000 cubic meters of such storage tanks on a large scale; in the future, film-type LNG storage tanks might well become the trend. The Invar inner tank of film-type LNG storage tanks, as well as its unique insulation structure, are patented technologies from the French company GTT; there is still a long way to go before these technologies can be manufactured domestically. Progress in the localization of key equipment for LNG receiving stations: The key equipment for LNG receiving stations mentioned above has overcome the technical barriers related to low temperatures in terms of localization, and certain application results have been achieved. Some of this key equipment has moved from the research and development stage to the phase of application testing, with efforts ongoing to advance toward the important stages of technological maturity and increased scale based on the outcomes of these tests.

Key issues in the application of cryopumps; Technical characteristics of domestically produced tank pumps. Currently, domestically produced tank pumps are moving from the stage of being used in engineering applications to one where they gradually replace older models. In general, tank pumps with a capacity of 480 cubic meters per hour or 560 cubic meters per hour are used to replace those with a capacity of 3600 cubic meters per hour, or there is a shift from smaller to larger capacity pumps – the overall trend is an increase in flow rate. During the gradual replacement phase, the most critical issue to address is the problem of flow deviation. At the same flow rate, domestic pumps with a larger design flow rate tend to generate higher pressure, and under the same pressure conditions, domestic pumps also exhibit a higher flow rate. This requires adjusting the valve positions appropriately based on the design of the outlet pipeline of the pump inside the tank, and performing an organic fitting of the performance curves of the inlet pump and the domestic pump in order to reduce their mutual influence. There are currently two main design approaches for the outlet pipeline of the pump inside the tank: one involves installing a control valve on the outlet pipeline to directly regulate the flow rate ； Another method is to use a control valve on the return line for indirect regulation ； Overall, the first adjustment method yields better results. With the advancement of localization, domestic internal tank pumps will soon enter a stage of widespread use. Before that, an important issue that needs to be resolved is the choice of technical approach for localization. Currently, there are two types of technical approaches for localizing internal tank pumps: one involves the use of domestically produced components for all parts ； Another category involves the localization of some components, while other components such as cables are still imported. At present, the two technical approaches each have their own advantages, and those who decide to use them need to consider various factors such as cost-effectiveness, reliability, availability of spare parts, and subsequent maintenance.

Domestic high-pressure transfer pumps are currently in the stage of engineering application. Similar to domestic internal-tank pumps, the compatibility issue with the imported pumps that are already in use as well as their associated process systems represents the biggest challenge at present. At the same time, since the design pressure of high-pressure pumps is nearly an order of magnitude higher than that of pumps inside tanks, issues such as the dynamic and static balance of the pump body under high-pressure conditions, as well as the durability of key components like impellers, have become focal points in the performance testing of high-pressure pumps.

Stability analysis of domestically produced low-temperature compressors: Domestic BOG compressors are used less frequently in practice. In terms of overall performance, their BOG processing capacity, energy consumption, and operational efficiency are comparable to those of imported compressors. Based on practical experience, domestic BOG compressors require special attention to two aspects: first, the quality of key components such as cylinders, piston rods, and unloading valves; relevant quality defects were observed in the actual use of a certain project ； Second is the durability issue of worn components such as support rings and bearing shells; practical experience shows that domestic compressors require shorter maintenance intervals compared to imported compressors.

There are significant differences in the applications of gasifiers. The three domestically produced gasifiers exhibit notable differences in their performance in practical use, each with its own characteristics. The performance of domestic ORVs is comparable to that of imported ORVs. In actual use, domestic ORVs demonstrate good performance in terms of vaporization capacity, fin icing, and scaling removal ； Localization addresses the issue of spare parts being able to serve as substitutes for imported products. Additionally, thanks to the on-site support provided by domestic manufacturers, it is possible to effectively resolve any problems that arise with either domestic ORVs or imported ORVs. Domestic IFVs perform better than imported ones. Domestic IFVs are being used on a large scale at Sinopec’s Tianjin LNG receiving station, and their performance in terms of gasification capacity and seawater temperature difference is significantly superior to that of imported products. At the designed processing capacity, the seawater temperature difference can be reduced to 1°C, which demonstrates their high gasification capacity. Compared to ORVs, IFVs have a stronger vaporization capacity, but require periodic cleaning of their internal tubes. There is significant room for improvement in domestic SCVs. Due to their more complex structure and intricate manufacturing process compared to ORVs and IFVs, these SCVs face numerous issues during the localization process. Notable problems include difficulties in adjusting the combustion ratio, ignition failures, fan malfunctions, high noise levels, and excessive emissions. Both the control systems and the physical equipment require continuous optimization at the installation site. The extensive on-site tuning required takes up a large amount of fuel gas, which constitutes a burden for the users in the initial stages. Through continuous tuning, domestic SCVs are operating more and more normally, and they have begun to play a key role in ensuring supply during winter. Therefore, the key issue to focus on in the localization of SCVs is the stability of their operation. Unlike the localization of other critical equipment, where more attention is paid to the manufacturing quality of the equipment itself and its durability at low temperatures, the localization of SCVs should emphasize system control, optimizing control logic to ensure the orderly integration of various complex components such as fans, fuel gas systems, gasification units, and circulating water systems.