Steam engine quality appraisal

steam engine is based on the core principle of thermal energy-mechanical energy conversion. By optimizing the thermal efficiency of the boiler, the pressure resistance strength of the pressure vessel and the stability of the transmission mechanism, it achieves the synergy of steam power output, energy utilization and safe operation. It is widely used in fields such as power plants, ship propulsion, industrial drives and district heating. In combined heat and power, it is used for steam turbine power generation and waste heat recovery; in the field of shipbuilding, it meets the high reliability requirements of main engine power output; in process industries such as papermaking and textiles, it ensures the continuity and stability of steam drive. Compared with internal combustion engines, steam engines have the characteristics of wide fuel adaptability, low speed, high torque, and long life. They are key power equipment for combining traditional and new energy sources.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide steam engine quality appraisal services. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for steam engine quality appraisal.

With the upgrade of energy efficiency and safety standards, related disputes have increased significantly. The judicial dispute focuses on:

1. Dispute over performance indicators: The thermal efficiency does not meet the standard (such as the agreement ≥85%, the actual measurement ≤75%), the steam leakage rate exceeds the standard (>0.1kg/h·m);

2. Material defects: The boiler steel plate has insufficient impact toughness (-20℃ AKV＜27J), high temperature bolt creep rupture (service cycle＜design life 50%);

3, process problem: pressure vessel welding is not fused (UT detection defect equivalent ≥Φ 4mm), cylinder inner wall processing roughness Ra>1.6μm;

4, contract performance dispute: key configurations (such as condenser heat exchange area, governor brand) are inconsistent with the technical agreement.

Steam engine quality appraisal mainly uses the following technical methods:

1. Appearance inspection: Check the appearance of the steam engine for defects such as deformation, cracks, and defects.

2. Dimensional measurement: Measure the dimensions of key components of the steam engine, such as cylinder thickness, hub diameter, etc., to determine whether they meet the design requirements.

3. Material testing: Conduct chemical composition analysis, mechanical performance testing, etc. on the materials of key components of the steam engine to determine whether the materials meet the design requirements.

4. Pressure test: Conduct a water pressure or steam pressure test on the steam engine to check whether there are leaks or insufficient strength.

A power plant of the applicant signed a "10MW Steam Turbine Procurement Contract" with a manufacturer of the respondent, agreeing that the thermal efficiency is ≥86%. After it was put into operation, coal consumption exceeded the standard by 20%. The manufacturer argued that it was caused by insufficient calorific value of coal.

Identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of the "steam engine", contract technical agreement, on-site investigation case materials and other data, and made the following quality analysis opinions:

The processing roughness of the inner wall of the steam engine cylinder involved in the case Ra 2.5 μm (agreement ≤ 1.6 μm), resulting in an 8% increase in steam leakage loss; the condenser vacuum is only -90kPa (agreement ≥ -95kPa), and the measured thermal efficiency is 78%; the Cr content of high-temperature bolt materials is 1.2% (agreement ≥ 1.5%), and the intergranular corrosion crack expansion rate exceeds the standard.

The appraisal conclusion determined that defects in processing technology and materials were the main reasons for insufficient energy efficiency.

The steam engine quality appraisal report should include:

1, the purpose of the appraisal (such as attribution of performance disputes, safety compliance verification) and cited standards (GB/T 16507, ASME BPVC, etc.);

2, equipment model, design parameters, operation logs involved;

3, detection methods and equipment list (such as thermal balance tester, spectrometer);

4, analysis of the correlation between test data and failure (such as the impact of roughness on gas consumption);