Spray type shell-and-tube heat exchanger adopting nonmetal heat exchange tubes

Abstract

The invention relates to the technical field of shell-and-tube heat exchange, and discloses a spray type shell-and-tube heat exchanger adopting nonmetal heat exchange tubes. The heat exchanger comprises a shell, a sprayer, the heat exchange tubes arranged in parallel in the shell, a supporting plate for supporting the heat exchange tubes and a tube plate connected with the heat exchange tubes, wherein the heat exchange tubes are made of nonmetal material with the heat conductivity coefficient of 0.5 W / m*K-10 W / m*K, and the outer diameter of the heat exchange tubes is 5 mm-15mm. The corrosion prevention problem of heat exchange tubes in low-temperature multi-effect distillation sea water desalting equipment and a lithium bromide absorption refrigerator can be solved, and the spray type shell-and-tube heat exchanger has the advantages of being low in heat transfer temperature difference and cost and the like.

Description

technical field [0001] The invention relates to the field of shell-and-tube heat exchange, in particular to a spray-type shell-and-tube heat exchanger using a new type of non-metal material heat exchange tube. Background technique [0002] Spray shell and tube heat exchangers are widely used in distillation seawater desalination technology and lithium bromide absorption refrigerators and lithium bromide heat pump systems. The spray shell and tube heat exchanger is characterized in that a series of horizontal tube spray falling film evaporators are connected in series, and a certain amount of steam is input through multiple evaporation and condensation processes. The smaller the evaporation temperature difference of each effect, the better Well, the evaporation temperature of the latter effect is slightly lower than that of the first effect, so that the whole desalination process can obtain distilled water that is many times the amount of input steam. [0003] The spray heat...

AI Technical Summary

Problems solved by technology

At present, the commonly used method is to add trace elements such as boron and nickel to the copper alloy to improve the corrosion resistance of the alloy; what's more, in the existing multi-effect evaporation heat exchanger, in order to resist corrosion, usually in The upper portion closest to the sprinkler head uses titanium tubes, which further increases the cost of the system

Moreover, these methods can only slow down the process of pipeline corrosion, and cannot fundamentally solve the problem of corrosion resistance

At the same time, another disadvantage of using copper alloy materials as heat exchange tubes is that the material is expensive, and the high cost of the system restricts the wider application of low-temperature multi-effect distillation seawater desalination systems, lithium bromide refrigerators and lithium bromide heat pumps

Recently, some manufacturers have switched to aluminum alloy tubes for their heat exchange systems, but the process of protecting the tubes through a variety of special measures such as anodizing is complicated, and the corrosion resistance is only slightly improved, which still cannot meet the requirements of anti-corrosion.

On the other hand, although there are many materials that can meet the requirements of preventing seawater corrosion, since the thermal conductivity of these materials is only 5W / mK or lower, according to the current design and manufacturing methods of spray heat exchangers, the heat transfer temperature difference Both are too high to achieve heat transfer with low temperature difference, which is contradictory to the requirement of spray shell and tube heat exchangers that the lower the heat transfer temperature difference, the better.

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