Operation analysis of C3-MR process cold box by grey system theory

In this paper, the problems of high refrigerant line differential pressure and uneven distribution of cold energy in cold box regulation under C3-MR process are studied. Five reasons are predicted by engineering performance. Using gas chromatography experiment and grey system pure mathematics analysis, it is determined that the main causes of the problem are unreasonable distribution ratio of each group of mixed refrigerants and disordered latent heat of vaporization of refrigerants. Furthermore, the grey system model is used to study: 1. grey relation analysis model shows that the correlation degree of T3 temperature measuring point is 0.8552, which is the only main factor. The abnormal working condition is determined by the project to be caused by incorrect proportion of N2 components. 2. According to GM(1,N) model, the driving term of T3 temperature measuring point is 3.8304, which needs to be supplemented with N2 component to eliminate the problem. 3. After adding N2 to 10% (mol component), abnormal working conditions disappeared. The GM(1,N) model is used again to verify that the difference of driving results is small, the average relative error is 24.91%, and the accuracy of the model is in compliance.

Experience in the use of absorption and biochemical installations for cleaning ventilation emissions in foundry production

The relevance of the use of gas cleaning equipment in foundry production is considered. Examples are given of equipping the casting, cooling and knocking areas of molds and rods manufactured according to ALFASET and Cold-box-amin processes with absorption-biochemical installations (ABCHI) for cleaning the ventilation air from pollutants. The technical and economic parameters of the ABCHI operation are considered. The list of the enterprises successfully operating ABHI is given. The advantages of using ABCHI in comparison with alternative methods are considered.

Towards Safety Barrier Analysis of Hydrogen Powered Maritime Vessels

This paper focuses on the use of safety barrier analysis, during the design phase of a vessel powered by cryogenic hydrogen, to identify possible weaknesses in the architecture. Barrier analysis can be used to evaluate a series of scenarios that have been identified in the industry as critical. The performance evaluation of such barriers in a specific scenario can lead to either the approval of the design, if a safety threshold is met, or the inclusion of additional barriers to mitigate risk even further. By conducting a structured analysis, it is possible to identify key barriers that need to be included in the system, intended both as physical barriers (sensors, cold box) and as administrative barriers (checklist, operator training). The method chosen for this study is the Barrier and Operational Risk Analysis (BORA) method. This method, developed for the analysis of hydrocarbon releases, is described in the paper and adapted for the analysis of cryogenic hydrogen releases. A case study is presented using the BORA method, developing the qualitative barrier analysis. The qualitative section of the method can be easily adapted to vessels of different class and size adopting the same storage solution. The barrier analysis provides a general framework to analyze the system and check that the safety requirements defined by the ship operator and maritime certification societies are met.

STRENGTHENING FEATURES AND AGING KINETICS OF HIGH-STRENGTH CAST ALUMINUM ALLOY AL4MS BASED ON Al–Si–Cu–Mg SYSTEM

Based on the conducted research, it has been found that quenching with hot isostatic pressure and step-by-step aging with consistently increasing temperatures of low-temperature aging (first stage) and high-temperature aging (second stage) provides high tensile strength for AL4MS copper silumin during cold box casting, increases the flow stress by 10%, and maintains high plasticity compared to the level of properties after single-stage aging.