The plate heat exchanger is composed of plates, sealing gaskets, fixed compression plates, movable compression plates, compression studs, nuts, upper and lower guide rods, and front pillars. Tubular oil cooler is composed of shell, tube bundle, upper and lower water chamber, end cover and other components. A core composed of a red copper tube and a multi-layer partition is installed in a circular shell, and both ends of the copper tube are bulged on the tube plate. So what are the performances of these two types of oil coolers?
1. Comparison of heat transfer effect.
(1) When lubricating oil flows in the shell side of the tube-type oil cooler, there are many laminar parts, and the tendency to fouling is high. The bypass between baffle and shell, baffle and heat exchange tube, tube bundle and shell. The oil passing through these bypasses does not fully participate in heat exchange. There is no bypass in the plate heat exchanger, and the corrugation of the plate can cause the fluid to produce strong turbulence at a small flow rate. It has a self-cleaning effect to prevent the ability to generate dirt, and improves the heat exchange effect of the lubricating oil.
(2) The plate of the plate-type oil cooler is made of stainless steel, and the plate thickness is only 0.5 mm. The cooling tube of the tube-type oil cooler is made of red copper with a thickness of about 2.0 mm. Therefore, the plate heat exchanger has a better heat exchange effect than the tubular oil cooler. When the heat exchange is the same, the plate heat exchanger requires a much smaller heat exchange area than the tubular oil cooler.
(3) Lubricating oil and cooling water flow countercurrently in the plate heat exchanger. The lubricating oil and cooling water of the tubular oil cooler flow in the shell side and the tube side respectively. It is a cross-flow flow method as a whole, which reduces the logarithmic average temperature difference. Plate heat exchangers can achieve temperature crossover, and the end temperature difference can reach 1℃; shell-and-tube oil coolers cannot achieve temperature crossover, and the end temperature difference can only reach 5℃.
2. Comparison of convenience for maintenance.
(1) The compact structure of the plate-type oil cooler provides convenient space for maintenance. Under the condition of equal heat exchange, the space occupied is only 1/2 of the shell-and-tube oil cooler. The disassembly of the plate heat exchanger only needs to loosen the clamping screw, and 100% of the surface of the inverted heat exchange plate can be contacted within the original space, and the disassembly and assembly are very convenient.
(2) The plates of the plate heat exchanger do not need to be mechanically cleaned during minor repairs of the unit, and the inner wall of the copper tube of the tubular oil cooler is cleaned by brushing. During the overhaul of the unit, the entire core of the tubular oil cooler needs to be lifted out for chemical cleaning. There is a dead angle between the inner copper tube and the partition, which cannot be thoroughly cleaned. After the clamping bolts of the plate-type oil cooler are removed, the plates are removed for mechanical cleaning, which is convenient for cleaning and there is no dead corner during cleaning.
(3) After the copper pipe of the large-tube oil cooler leaks, the plugging method is used to plug the leakage. If the blocking rate exceeds 10%, it needs to be completely replaced, and the cooling area is decreasing. Plate heat exchanger plates can get the most suitable heat transfer effect and capacity by adjusting the number of plates or changing the process.