Help analyze the series-connected tubes of the heat exchanger
Thread Content
A lubricating oil cooler, with 32# turbine oil as the working medium in the shell side, at a pressure of 0.5 MPa; the safety valve of the oil pump is set at 0.88 MPa, ensuring cold oil circulation in case of an accident. The pipeline circulates water at a pressure of 0.45 MPa. Due to maintenance, oil circulation is carried out first before the heat exchanger is put into use. After circulating water was put into use for the operation of the equipment, lubricating oil entered the circulating water. Upon inspecting the oil cooler, it was found that the heat exchange tubes had been misaligned; the image shown depicts the side connected to the circulating water
The pressure of this safety valve should be 0.6 MPa; if this pressure is caused by low oil temperature, it indicates that overpressure occurred in the cooler, leading to this phenomenon. The root cause lies in operational issues and the setting of the safety valve. First, to start the oil pump at low temperatures, it is necessary to activate the electric heater in the fuel tank first in order to raise the oil temperature above 15°C before starting the pump. Additionally, before starting, the bypass valve for the oil circulation must be opened, and the oil pressure should be adjusted as required to maintain it at the designed value. The occurrence of such phenomena is purely a matter of operation. If this item is not included in the operating procedures, then it is a management issue. Also, check whether there is any blockage or deformation inside the tube that is causing it to move outward; otherwise, it would not move in that direction. For reference.
The pump was started during the day; currently, the temperature during the day here is above 15 degrees. The tube bundle has not been removed yet, and the lubricant used is L-TSA32
This post was last edited by CHANGBAISHI on 2020-4-12 at 06:30. It’s still necessary to rely on the actual oil temperature; oh, modern devices of this type all have trend charts that record the parameters, so it’s easy to know the value. Oh, one more thing to note: internally, the cause is investigated thoroughly, but externally it’s presented as a device issue. Just seal and weld up these gaps, and it can be used again. However, it is necessary to regularly check for any abnormalities in the water during normal use.
The leaders are also analyzing it; similar heat exchangers have been in use for five years without any problems
The maintenance site is so messy and untidy (ー_ー)!! Can oil be left on the floor? Does the HSE department not care? ! Copper tube heat exchange tubes? Still stainless steel? Is the expansion rate of the expansion joint plate appropriate? Has the pulling force been calculated?