Testing Parameters and Laboratory Instrument Solutions for Secondary Water in Heat Exchange Stations and Boiler Water
Secondary water in heat exchange stations requires testing for parameters such as hardness and pH, while boiler water focuses on dissolved oxygen, phosphate radicals, and other key indicators. In accordance with the GB/T 1576-2018 standard, portable multi-parameter water quality analyzers and other equipment are recommended for rapid and accurate on-site analysis.
In heating systems, water quality issues can lead to serious consequences. Approximately 40% of heating system failures are directly related to water quality, with scaling and corrosion being the two most common types of damage. A 1 mm thick layer of scale can reduce heating efficiency by 8%-10%, while corrosion-induced pipeline leaks are a frequent cause of heating interruptions during winter.
Before the 2023 heating season, a thermal power company in a certain city conducted a water quality survey of 12 heat exchange stations and found that the total hardness of the secondary water in three stations exceeded the standard by 2-3 times. Timely intervention prevented potential heat exchanger blockages, saving approximately ¥150,000 in repair costs. This case highlights the necessity of regular water quality testing.
According to the GB/T 1576-2018 "Water Quality for Industrial Boilers" standard, the testing focus for secondary water and boiler water varies:
Key Parameters for Secondary Water:
Total hardness: Must be controlled at ≤0.6 mmol/L to prevent scaling on heat exchange surfaces.
pH value: Should range from 7.0 to 9.0 to avoid acidic corrosion.
Suspended solids: Must be ≤5 mg/L to ensure system cleanliness.
Critical Parameters for Boiler Water:
Dissolved oxygen: Must be ≤0.1 mg/L to prevent oxygen corrosion.
Phosphate radicals: Should be maintained at 5-15 mg/L to act as a corrosion inhibitor.
Alkalinity: Should be controlled between 6-24 mmol/L to maintain water stability.
These parameters collectively form a protective network for the water quality safety of heating systems. Any parameter exceeding the standard range may lead to system failures.
To meet the daily testing needs of heat exchange stations, the following instrument configuration is recommended:
Portable Multi-Parameter Water Quality Analyzer
The ERUN-SP7-11 model from Yingrun can simultaneously detect key parameters such as pH, dissolved oxygen, and conductivity, making it ideal for rapid on-site testing. Its measurement accuracy meets GB/T 1576 requirements, with pH ±0.02 and dissolved oxygen ±0.1 mg/L.
Precision Laboratory Instruments
Atomic Absorption Spectrometer: Used to detect heavy metal content.
Ion Chromatograph: Analyzes anions such as chloride and sulfate ions.
UV Spectrophotometer: Measures phosphate radicals, silicate, and other indicators.
Specialized Testing Equipment
Hardness Titrator: Dedicated to total hardness testing.
Dissolved Oxygen Analyzer: For high-precision oxygen content analysis.
Turbidimeter: For rapid determination of suspended solids.
This configuration model of "on-site rapid screening + laboratory precise verification" ensures both testing efficiency and data accuracy.
Before the 2023 heating season, a high-tech park implemented a comprehensive water quality testing solution. Using the ERUN-SP7-11 portable analyzer, a survey of eight heat exchange stations revealed the following issues:
Low pH in the secondary water at Station No. 2 (measured value: 6.3).
Insufficient phosphate radical concentration in the boiler water at Station No. 5 (measured value: 2.1 mg/L).
By installing automatic chemical dosing devices and adjusting water treatment processes, all parameters returned to normal ranges within a week. No water quality-related failures occurred throughout the heating season, saving an estimated ¥300,000 in maintenance costs.
Based on years of industry experience, we recommend that heat exchange stations establish a three-level water quality monitoring system:
Daily Inspections: Use portable equipment to test key parameters daily.
Weekly Testing: Conduct comprehensive indicator analysis.
Quarterly Evaluations: Fully assess water quality trends and optimize treatment plans.
By combining manual testing with automated monitoring, water quality issues can be effectively prevented, equipment lifespan extended, and heating system operational efficiency improved.
Reliable water quality testing is the foundation for ensuring the safe and stable operation of heating systems. Selecting appropriate testing instruments and establishing a scientific monitoring system can help companies avoid unnecessary losses and achieve energy-saving and consumption-reduction goals. For more information on water quality testing solutions, please consult professional technical personnel.
