Explain the relevant regulations of the Heat Exchanger Unit in detail
Expansion joint Expansion joint is the primary form of Copper Heat Exchanger tube and steel tube sheet connection in the current manufacturing process of heat exchangers. The quality of the expansion mouth during expansion joints is related to the radial gap, surface roughness, and expansion ratio of the heat exchange tube and the tube sheet. In order to obtain excellent and stable expansion quality, it is necessary to strictly control the processing accuracy of the tube sheet, properly select the expander, the expansion power and the control method to ensure the appropriate expansion degree and adopt a reasonable expansion sequence. Nevertheless, leakage and leakage problems often occur during pressure tests and need further repair. And similar problems will occur during the equipment work cycle, which will bring some trouble to users and manufacturing enterprises.
The new process of bonding and expanding the steel tube sheet and the copper Heat Exchanger tube, and the application effect of the new technology of the glue expansion and expansion joint Leakage problem. When manufacturing a heat exchanger of this type, a heat exchanger manufacturing company started from the type of joints and adopted a new process of glue expansion. Through many simulation process tests and pressure tests, this new process has been continuously improved, and finally successfully applied to the production process of manufacturing the Shell And Tube Heat Exchanger's steel tube sheet and copper heat exchanger tube. And by tracking the quality of this type of heat exchanger equipment, during the heat exchanger's working cycle, no quality problems of leakage and leakage have occurred, making the new process of glue expansion and expansion recognized by users.
Glue-joint expansion process 1) Annealed about 200,200mm of copper pipe on both sides at about 600, holding time for 1015min, wrapped with asbestos after taking out, and gradually cooled. 2) Do a good job of surface treatment of the bonded parts. Degrease first to remove grease, dirt, etc .; then sand the joint surface with sandpaper (or gauze) to remove oxides and increase surface roughness. 3) Correctly select the cement according to the working conditions of the bonded parts. When the copper heat exchange tube is glued to the steel tube sheet, the epoxy-based self-adhesive is selected according to the working temperature of the heat exchanger. The ingredients of the compounding compound should be weighed accurately, the manufacturing sequence should be reasonable, and they must be used up within the required time after compounding.
Problems of baffle Plate heat exchanger under vibration
(1) When the velocity of the shell-side medium is large, the vibration amplitude of the heat exchange tube is large, which may cause the tube to collide, causing the tube wall to be worn thinner and thinner, resulting in damage to the heat exchange tube.
(2) When the heat exchange tube passes through the baffle plate, the heat exchange tube and the baffle plate hole wall continuously collide due to vibration, resulting in the thinned part of the tube wall until the tube splits.
(3) The connection between the heat exchange tube and the tube sheet is expansion joint and welding. Vibration causes the joint between the heat exchange tube and the tube sheet to be subject to greater stress, which causes the expansion joint and the weld to split, the tube sheet end leaks, and the tube Shell-side media are mixed.
(4) The tube itself is prone to fatigue due to long-term vibration, which will eventually cause the tube to split.
2 · Baffle rod heat exchanger features
The shell side is no longer a traditional plate-type baffle method, but a baffle formed by a plurality of baffle rods instead of a baffle. This kind of planning fully improves the induced vibration of the shell-side medium, which not only has the effect of disturbing the shell-side medium, but also has the effect of supporting the heat exchange tube, so that the resistance of the medium flowing in the shell-side is reduced, and the heat transfer power is more high.
Rules of Plate Heat Exchanger
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1. The layout of equipment and pipelines should be reasonable in structure, standard in wiring, convenient for maintenance, easy to operate and observe, pipeline interface flowing and resistance loss should be small.
2. The base and support structure should have satisfactory strength and stability, and repair space should be left on both sides of the plate heat exchanger.
3. A bypass pipe with a valve should be installed at the inlet and outlet of the plate heat exchanger, and its pipe diameter should be the same as the pump outlet pipe diameter.
4. For the system of circulating water pump motor power greater than 15 kW, a bypass pipe with check valve should be set at the inlet and outlet of the circulating water pump, and its diameter should be the same as the outlet pipe diameter of the circulating water pump.
5. The inlet and outlet of the circulating water pump should be provided with a soft joint, and the circulating water pump should have a vibration reduction method.
6. When the primary medium is steam, the velocity of the medium in the pipeline should be less than 50 m / s;
When the primary medium is hot water, the velocity of the medium in the pipeline should be less than 2.5 m / s;
The velocity of the secondary medium in the pipeline should be less than 3 m / s.
7. In the water-water unit, the electric regulating valve on the primary side should be installed on the water supply pipe, and the heat meter should be installed on the return water pipe.
8. In the steam-water unit, the steam pipe on the primary side should be equipped with electric (pneumatic) regulating valve and flow meter. Valves should be set before and after the electric regulating valve, and bypass pipes with valves should be set.
9. The secondary side flowmeter should be installed on the secondary side water supply pipe.
10. In steam-water units, traps that can drain water continuously should be set. The selection of traps should meet the requirements of GB / T 12712.
11. The water supply point should be set at the inlet of the circulating water pump.
12. The control system should satisfy the following environmental requirements:
a) Working temperature: 0 ℃ ~ 40 ℃.
b) Storage temperature: -20 ℃ ～ 70 ℃
