Repair and maintenance of engineering systems, IHP, central heat supply stations
During the operation of water supply and heating systems, due to calcium and magnesium salts contained in water, iron oxides, as well as due to the vital activity of bacteria, scum and other deposits appear over time on the internal surfaces of equipment and pipelines, which create internal build-ups on pipes and heat exchangers, violate hydraulic and thermal modes of operation, since the internal fouling of pipes and heat exchange surfaces entails a reduction in the flow area up to its complete blockage and water outage to the consumer. Especially negatively such deposits affect the automated systems, as they cause depressurization of automation elements. With very serious violations it is necessary to change the construction of pipes and heat exchangers, and this is a very serious financial cost.
That is why the specialists of ASGARD-Service recommend cleaning the engineering systems (hereinafter referred to as ES) before each heating season, since timely removal of sediments will prolong the life of your ES and reduce the cost of energy, heat carrier and consumables. It should be noted that when cleaning the network the quality of water also improves.
Our specialists act as follows:
- On-site visit, inspection of ES.
- Sampling of internal deposits for the selection of an optimal and safe method of cleaning.
- Carrying out activities directly for cleaning.
- Pressure testing of engineering systems.
After collecting the sediment samples, the method of ES cleaning is selected. There are 3 main ways, all the rest – only a combination of these three:
- chemical flushing;
- hydropneumatic flushing;
- combined method.
Chemical flushing of engineering systems
It is applicable to remove contaminations in heating networks, including pipelines and heating units themselves. Sediments are transferred to the dissolved state and are removed. For flushing, specialized reagents are used that do not cause metal corrosion and are safe for all types of pipes. The technology of chemical flushing is as follows:
- familiarization with project documentation – it is necessary for accurate data on the commissioning date, for information on pipe materials, etc.
- it is also important to know what cleaning methods have been used before;
- visually determine the degree of ES wear for the possibility of carrying out chemical flushing;
- further it is necessary to perform sediment sampling for accurate selection of the reagent;
- flushing itself;
- treatment of the pipe network with corrosion inhibitors;
- pressure testing of the system.
The specialists of ASGARD-Service Company use the following equipment for chemical flushing:
- chemically resistant to alkalis and acids pump
- clean in place (tank for flushing liquid)
The circulation of the fluid is made with the change of direction using a pump. The change in the course of the fluid contributes to more effective removal of wall sediments.
Chemical flushing lasts from several hours to several days depending on the volume of the system.
This method has the following advantages:
- reagents used by our specialists do not cause metal corrosion;
- short cleaning time;
- improved heat transfer;
- cost-effective method, because it does not require large installation and dismantling costs.
Hydropneumatic flushing of engineering systems
Hydropneumatic flushing of the heating system is carried out with compressed air. Compressed air is supplied to the network under pressure, while the velocity of the fluid in the system increases dramatically, and the uneven movement of the compressed air provides mechanical separation of the deposits from the surface of the pipes. Deposits are carried by the flow of water out through the discharge point.
For hydropneumatic flushing, specialists of ASGARD-Service Company use a compressor that can add reagents to the air flow for cleaning and disinfection, as well as which produces a pressure of at least 0.6 MPa at the outlet.
In addition, ASGARD-Service Company offers a unique method of air-pulse cleaning with the help of specially developed equipment PnIU-200:
Using a sharp supply of compressed air, pulses under high pressure creates wave oscillations in the fluid in the pipeline, which contributes to the detachment of scale and other near-wall deposits in the pipeline, which are then removed through the discharge point.
After any flushing, hydraulic testing should be performed.
Pressure testing or hydraulic testing is a set of measures that allows to test the performance of the system as a whole by overpressure pumping. These testings are carried out to test: heat exchangers, pumps, pipelines, radiators and other heating or cooling equipment operating under pressure for tightness and reliability.
Hydrochemical flushing method allows to effectively remove various contaminants of internal surfaces and restore pipeline capacity and heat transfer without disturbing the integrity of the pipeline network and water-heating equipment using special tools.
Flushing of hot water system
The scale that occurs during operation creates a large thermal resistance to heat flow, which leads to a decrease in the heat carrier temperature and a decrease in the thermal conductivity of the heating system, and a decrease in the temperature of the hot water system. This means that heat dissipation and throughput of pipes decreases. The temperature both in the premises and in the pipes of hot water system drops, and in order to increase it, it is necessary to increase the cost of fuel in the boiler plants, and the gas consumption for heating water increases in private homes.
Flushing of the HWS circuit is performed in similar ways, but there are some special features.
- As a rule, pipes of the HWS system are galvanized pipes. In order not to disturb the galvanized layer, it is necessary to carefully study the nature and thickness of the deposits, as well as clearly understand the rate of the reaction. This will reduce the time of interaction of the reactants with the pipe metal.
- Only special reagents can be used for galvanized pipes. At the end of chemical flushing, the spent solution is discharged into a separate container and neutralized before discharge into the sewage system, or removed from the facility.
- Special attention should be paid to heating networks in which any antifreeze is poured as a heat carrier – when replacing antifreeze with water, the heating system and the boiler must be rinsed using special means.
If a high-quality flushing is not carried out, it can lead to such a phenomenon as “noise” in the boiler and the heating system – these are the remnants of antifreeze that foam and cause these phenomena. In some cases, there is an emergency shutdown of the boiler at the most inopportune moment. As our specialists’ experience shows, in schemes in which heating system has not been flushed for about ten years, the sediment layer can be 50% of a pipe cut, which reduces the functionality of the entire heating system in half.
Regular and competent professional maintenance of the heating ES will keep the equipment in working condition for many years and save money on the purchase of a new system.
Often the following questions arise:
- How and what can flush and clean the heating system?
- How to make seasonal maintenance of the heating system?
- How to choose an agent, solution, composition, reagent for flushing?
- How and what can flush and clean the hot water system (HWS), cold water system (CWS), equipment for heating systems?
These and other questions will be answered by ASGARD-Service specialists. Spesialist’s visit for evaluation is free.