Working principle and maintenance method of plate heat exchanger
Compared with the traditional heat exchanger, plate heat exchanger has not only advantages in appearance, but also great advantages in function use: it can make the heat can be reused, make full use of resources, and achieve the effect of energy saving!! the former tube plate principle is the same, but the effect of heat exchange is certainly not as good as plate heat exchanger.
Principle of heat exchange of plate heat exchanger:
1. The working principle of plate heat exchanger is that many very thin layers of copper in the plate heat exchanger are superposed with different structures, in which one layer is the lithium bromide solution with high temperature, the other is the solution with low temperature, and a sealing ring is added in the middle, so as to realize the cooling effect.
2. In this way, the plate heat exchanger can transfer heat better through the thin copper strip, so as to heat the low-temperature solution and reduce the high-temperature solution, which can achieve a win-win effect for cooling quenching oil and other occasions.
3. Generally speaking, the working principle of plate heat exchanger can be understood as that two relatively independent channels composed of multiple heat exchange plates walk through the cold and hot medium respectively. Through the heat conduction of white steel plate with good heat transfer performance, the heat of the hot side medium is used to increase the heat content of the cold side medium; or the low heat content of the cold side medium is used to absorb the heat of the hot side, so as to achieve the cooling effect.
4. Compared with the traditional heat exchanger, plate heat exchanger not only has advantages in appearance, but also has great advantages in function use: it can make the heat can be reused, make full use of resources, and achieve the effect of energy saving!! the former principle of tube plate heat exchanger is the same, but the effect of heat exchange is certainly not as good as plate heat exchanger.
If a worker wants to do well, he must first sharpen his tools. How to maintain the corrosion protection of plate heat exchanger in daily application? The following are summarized:
Only knowing the causes of various corrosion of heat exchanger and choosing reasonable anti-corrosion measures can we achieve the purpose of efficient utilization of equipment. In view of the corrosion situation, the following anticorrosion methods are proposed: here, the corrosion inhibitor and electrochemical protection are mainly introduced.
1. The main component of the inhibitor is chromate, which is commonly used in cooling water system. Chromate ion is an anode (process) inhibitor. When it is combined with a suitable cathode inhibitor, it can obtain satisfactory and economic anti-corrosion effect.
Chromate zinc polyphosphate: polyphosphate is used because it has the function of cleaning the metal surface and has the ability of corrosion inhibition. Polyphosphate can be partially converted into orthophosphate, and they can also form large colloidal cation with calcium to inhibit the cathode process.
Chromate zinc phosphonate: this method uses sodium phosphonate instead of polyphosphate. Similar to the previous method, carbamate can also be used in occasions with higher pH value than that specified for polyphosphate. Carbamate can prevent scale, and even pH 9 can control the precipitation of calcium salt.
Chromate zinc hydrolyzed polyacrylamide: due to the dispersing effect of polyacrylamide hydrolyzed by cationic copolymer, it can prevent or inhibit the generation of scale.
2. Electrochemical protection adopts cathodic protection and anode protection. Cathodic protection is achieved by using the external DC power supply to change the metal surface into a cathode. This method consumes a lot of electricity and costs a lot. Anode protection is to connect the protected heat exchanger with the anode of external power supply, so that a passivation film is formed on the metal surface, so as to be protected.