In-position cleaning method for town regenerated water plate type heat exchanger

Abstract

The invention relates to an onsite cleaning method used for a town recycled-water plate heat exchanger. The cleaning method has two steps: the cleaning of a first step adopts an oxidizing bactericide, a carboxyl group chelate agent and a dispersant, aiming at removing surface substances of dirt on the heat exchanging wall face with an effect of killing microorganisms in dirt and removing dirt and also with the effect of leading Ca<2+>, Mg<2+>, Fe<2+> and Fe<3+> in dirt to be converted into dissolving chelate matter and distributing a large quantity of dirt components into particulates to be stably suspended in water; the cleaning of the second step adopts an organic acid dirt-rust removing agent, the oxidizing bactericide and the carboxyl group chelate agent and the dispersant, aiming at removing the bottom substances of the dirt on the heat exchanging wall face with the effect of removing organic dirt and rest microorganism films. The cleaning method proposed by the invention can be applied in the town recycled-water plate heat exchanger made of 304, 316 or further anti-corrosion stainless steel materials, with low corrosion rate, quick dirt removing speed and better effect. The plate heat exchanger can be safely and economically operated for a long period.

Description

technical field [0001] The invention relates to an in-situ cleaning method for a heat exchanger, in particular to an in-situ cleaning method for a plate heat exchanger using urban reclaimed water as a heat exchange medium. Background technique [0002] The thermal energy reuse of urban recycled water is a renewable energy application technology with obvious benefits of energy saving and emission reduction. Although urban reclaimed water has been treated in multiple stages by sewage treatment plants and has reached the discharge standard stipulated in the national standard GB18918-2002, its water quality is still relatively complicated, with various ions and suspended solids dissolved, especially high amounts of slime-producing oxygen bacteria. Due to the existence of these substances, scaling and corrosion hazards will inevitably occur when urban recycled water is used as a heat exchange medium. [0003] For example, regenerative water source heat pump is a typical way of ...

AI Technical Summary

Problems solved by technology

Experiments have proved that if the cleaning agent of the existing circulating cooling water system is directly applied to the in-situ cleaning of the urban reclaimed water plate heat exchanger, the cleaning rate will be slow and the dirt stripping effect will be poor, and the flow and heat transfer performance of the plate heat exchanger will not be restored. cleaning target

[0007] All in all, in view of the particularity of dirt composition and dirt adhesion, there is currently no reliable in-place cleaning method for urban recycled water plate heat exchangers, which seriously restricts the popularization and application of urban recycled water heat energy efficient recycling technology

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