Is it feasible to integrate LNG pumps and tanks?
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This post was last edited by Yuanhong07 on 2015-10-26 at 16:39. To reduce heat losses in the pipeline from the LNG storage tank to the submersible pump, which could lead to BOG release and thus waste of resources, integrated LNG pump-tank gas stations were proposed. What is the feasibility of this? Is the amount of residual liquid too high? The submersible pump is placed inside the storage tank; gas stations typically use horizontal tanks with a capacity of 60 m3 or 30 m3, and the diameter of such tanks ranges from 2.5 to 3 meters. What are the typical dimensions of LNG submersible pumps? (I’ve seen a pump pool with a height of around 1 meter.) I saw online that a certain company’s LNG pump-tank integrated refueling station has a residual liquid rate of only 5%, which makes me highly skeptical. Alternatively, a groove can be designed at the bottom of the storage tank to house the submersible pump, thereby using a double-wall tank structure in place of a pump chamber. Such storage tanks need to be custom-made. What is the practical feasibility of using a custom pump-tank integrated unit to replace a 1m pipeline? Everyone is welcome to discuss! Share valuable experience!
It is feasible in LNG plants; the equipment requirements are relatively high. However, it’s unclear whether it’s feasible for gas filling stations – small tanks are not cost-effective, while large tanks face difficulties in passing safety approvals
The plan is feasible; it depends on whether the LNG storage tank manufacturers are willing to do this. It would be best if the manufacturers could handle everything in a integrated manner
For such customized products, manufacturers generally are reluctant to produce them
We are manufacturing pump skids; you can get in touch with us
Could the poster send over your plan drawings? The pump in our unit is of the skid-mounted type outside the tank, similar to the installation style of liquid oxygen pumps.
This is a common design; the several sets we have made also feature external pumps
Are your LNG storage tanks manufactured in-house or purchased from external suppliers?
It would be ideal to install the pump inside the tank, but currently, due to various factors, equipment manufacturers are reluctant to do so at LNG refueling stations. It’s mainly a cost issue. Since domestic producers of LNG storage tanks manufacture tanks with capacities of 50 to 300 cubic meters (tanks with capacities of 300 to 1,000 cubic meters are less common and not often seen). Currently, small LNG tank manufacturers only produce connection ports; asking them to create a pump port is something they find difficult to accomplish from a technical standpoint. This is different from the on-site construction of larger tanks with capacities of 3,000 to 5,000 cubic meters in LNG receiving stations and liquefaction plants. Moreover, facilities such as maintenance platforms, boom lifts, and electric hoists are also needed, which is impractical in a small space like an air filling station. Moreover, those who are responsible for the practical design and construction of CNG stations in municipal projects, as well as those who establish the relevant standards, may not have seen this type of structure before; once you create it, they are likely to say that you’re not professional and that what you’ve built is some kind of aberration. Therefore, the ideal process and equipment solution depends on the specific project and industry in use. To take the simplest example, consider the LNG pump skids, which are considered very mature in the LNG refueling station industry today. Upon closer inspection, however, it can be seen that there are many unreasonable aspects that need improvement. Yet equipment manufacturers and clients often focus on whether the equipment can function properly; they may complain about severe gasification issues or difficulties in refueling. In fact, many of these problems stem from the design of the pump skids themselves. But in China’s industry, this has become the status quo, and it is now considered acceptable by everyone. So, whether it’s the standards or the actual situation, it’s basically like this.
The point is that gas stations generally have small tanks, and most manufacturers are unwilling to install pumps inside such tanks.
This technology already exists; it’s a mature design! :)