1. Routine maintenance: Remove "obstacles" from the heat exchange surface, reduce thermal resistance, and clean scaling regularly to avoid a surge in thermal resistance. Physical cleaning: Use low-pressure compressed air to blow off, high-pressure water guns to flush, or sponge balls and rubber balls to scrub the inner walls of the pipeline to remove surface suspended matter and soft scale;

Chemical cleaning: For hard scales such as calcium and magnesium salts, oil stains, etc., choose citric acid, dilute hydrochloric acid (concentration needs to be controlled to avoid corrosion) or specialized scale inhibitors. After circulating cleaning, thoroughly rinse with clean water to remove residual chemicals;

Preventive measures: Install a precision filter at the water inlet and add scale inhibitors and dispersants to reduce the adhesion of scaling substances at the source.

Scaling is the number one killer of heat exchange efficiency, and regular cleaning of heat exchange tubes/plates is required based on the type of wastewater:

Keep the heat exchange surface clean, remove impurities and oil stains, and regularly wipe off dust and oil stains on the surface of the heat exchanger, especially on the cooling fins of the condenser, to avoid dust accumulation affecting heat dissipation;

Inspect and clean the inlet and outlet filter screens of the heat exchanger to prevent impurities from blocking the pipeline and ensure smooth flow of the medium.

II. Operating condition optimization: Match the optimal operating parameters, enhance heat transfer by optimizing the medium flow rate, and avoid laminar flow. When the flow rate of cold and hot mediums in laminar heat exchange is too low, it is prone to form a laminar state, resulting in low heat transfer efficiency. Appropriately increasing the medium flow rate (within the design range of the equipment) can form turbulence, enhance the contact between the fluid and the heat exchange surface, and improve heat exchange efficiency;

Avoid excessive fluctuations in feed flow rate, maintain a stable flow velocity, and prevent local overheating or insufficient cooling of the heat exchange surface.

Precisely control temperature and vacuum degree, and match boiling point parameters. The higher the vacuum degree, the lower the boiling point of wastewater, and the greater the temperature difference between the heating source and the wastewater, the faster the heat transfer rate. Regularly check the tightness of the vacuum system, promptly repair leakage points, and maintain a stable high vacuum degree;

Control the temperature of the heat source (such as the outlet temperature of the heat pump) to be slightly higher than the boiling point of the wastewater by 5~10℃, to avoid excessive temperature difference that may cause local scaling, or a temperature difference that is too small and reduces the heat transfer motivation.

Ensure uniform distribution of the medium and avoid "dead zones". Check the integrity of the water distributor and splitter plate of the heat exchanger to ensure that wastewater flows evenly through each heat exchange tube/plate, avoiding areas without medium flow and resulting in waste of heat exchange area;

Timely remove the air from the heat exchange system (air blockage can hinder heat transfer), regularly open the exhaust valve to vent, and ensure that the medium fills the heat exchange chamber.

III. Equipment transformation: Upgrade hardware configuration, enhance heat transfer performance, and replace with high-efficiency heat transfer materials to improve thermal conductivity. Traditional carbon steel heat exchanger tubes have poor thermal conductivity and are prone to corrosion, and can be replaced with 316L stainless steel, titanium alloy, or graphite heat exchanger tubes/plates. These materials have high thermal conductivity and strong corrosion resistance, enabling long-term efficient heat transfer;

Special treatments are applied to the heat exchange surface, such as spraying thermal conductive coatings, adding fins or corrugations, to expand the effective heat exchange area.

Install auxiliary heat exchange devices to enhance heat recovery. Add a preheater to the system, utilizing the waste heat from high-temperature condensate water and concentrated solution discharged from the evaporator to preheat the incoming wastewater, reducing the heating load on the heat source and indirectly improving the overall heat exchange efficiency;

Upgrade the heat pump system, select compressors with higher energy efficiency ratios, improve the utilization rate of heat recovery, and reduce heat loss.

Key precautions: All operations must be carried out after the equipment has been shut down, powered off, and the medium has been drained to avoid electric shock or chemical burns;

During chemical cleaning, it is necessary to strictly control the concentration of chemicals and the cleaning duration to prevent corrosion of the heat exchange surface;

Establish a monitoring ledger for heat exchange efficiency, regularly record data such as inlet and outlet temperatures, temperature differences, and flow rates, promptly identify trends of efficiency decline, and investigate the issues.