58 Why are high-level fuel tanks installed on various machines?

Ensure that all areas are filled with oil.

The high-level oil tank is one of the safety protection devices for the machine set. During normal operation of the machine set, the lubricating oil enters from the bottom and exits from the top, flowing directly back into the oil tank ； In the event of a power outage or machine shutdown, and if the auxiliary oil pump cannot start to supply oil in a timely manner, the lubricating oil in the high-level oil tank will flow through the oil pipelines, pass through each bearing, and then return to the oil pipes, thereby ensuring that the machine can continue to operate with the necessary lubrication.

When the lubricating oil pump stops suddenly, especially when the unit is running at high speeds, it is very likely to cause bearing burnout. With a high-level tank in place, in the event of a sudden power outage that prevents the lubricating oil pump from starting and results in a disruption in the supply of lubricating oil, it ensures that the necessary lubrication is available for all components of the unit during shutdown, thus preventing the bearings from being damaged.

A high-level oil tank is provided to prevent power outages; when the pump stops operating, the oil in this tank is used to lubricate the various bearing surfaces of the unit.

In emergency situations, ensure that the unit has sufficient lubrication and buffering time:lol

Functions of the high-level oil tank: 1. In the event of a power outage or damage to the oil pump, it can supply sufficient oil to the bearing shells, ensuring that the centrifuge can stop urgently without the bearing shells suffering from dry friction due to a lack of oil. Function of the high-level oil tank: 2. The high-level oil tank serves to ensure that, in the event of production accidents such as power outages or pump failures, the gravitational potential energy resulting from the height difference can be used to supply lubricating oil to the machinery, thereby enabling lubrication and cooling. To prevent the shaft bearings from being damaged, it provides lubrication for the equipment bearings during the period when the unit is running at idle speed, thereby protecting the shafts and bearings after the low lubricating oil pressure interlock is activated. Under normal conditions, the lubricating oil enters the high-level oil tank through a flow-limiting orifice plate, and then returns to the tank via a high-level overflow pipe, thereby ensuring the renewal of the lubricating oil in the high-level oil tank. In an emergency situation, the lubricating oil in the upper oil tank flows back to the bearings through check valves to lubricate them. Generally, the oil storage capacity of the upper oil tank should be sufficient to last for about 5 minutes. In the event of a power outage, voltage fluctuations, or oil pump failures, the gravitational potential energy resulting from the height difference is used to supply lubricating oil to the machine temporarily, thereby lubricating the equipment bearings during the machine’s idle operation and protecting the shafts. This prevents dry friction between the bearings from causing damage to the bearing shells. Before the unit starts operating, the oil circuit system is activated first. The oil inlet line in the high-level tank is relatively thin and equipped with a flow control orifice, while the oil return line is thicker. When the power to the system is cut off, the oil supply system in the high-level tank stops functioning as well due to the shutdown of the oil pump; at this point, no oil flows out through the return line. Instead, the oil in the high-level tank is forced into the compressor system by the difference in pressure. The tank in our facility can supply oil for ten minutes, and there are also two sets of accumulators, which provide enough time to use the emergency stop button to ensure the safe shutdown of the unit. The function of the high-level oil tank is to ensure that the centrifuge shuts down in case the centrifugal oil pump loses power and the emergency oil pump does not start; the oil in the high-level oil tank is used to lubricate the bearings, thereby preventing bearing burnout. The difference between a centrifugal compressor and a reciprocating compressor is that it does not stop rotating immediately after shutdown; due to inertia, it continues to spin for a while longer, a phenomenon known as coasting. When the electric pump at the fuel station stops operating for some reason (usually the compressor shuts down automatically due to low oil pressure), or when there is a fault in the lubrication system for other reasons (such as leaks at the lowest points), and the lubrication system cannot function properly while the unit is still running (whether it is stopped or not), this measure is taken to prevent bearing wear and damage to the bearing shells. There should be requirements regarding the height and capacity of the high-position fuel tank

The installation height of the high-level fuel tank must meet the minimum oil pressure requirements in case of an accident, and it must allow access to the bearing shells. The volume requirement must be sufficient to meet the coasting time of the compressor unit.