Determining the causes, prevention and elimination of unstable modes of gas turbochargers of marine diesels

Annotation – With commissioning of the “Socofl Star” ship’s series, negative occurrences relative to surging of the Main Engine (ME) «Hanshin Diesel» 6LF46 turbochargers (TC) VTR 401-2. To elimination of a surging, it was necessary reduce loading of ME to the safe level. This action caused the ship’s speed to fall from 11 – 10 to 4 knots which resulted in worsening of the ship’s maneuverability characteristics and lead to the failure to provide the ship’s service speed stipulated in the contractual arrangements. Existence of this problem instigated the shipowner to charge us as experts with the mission of carrying out appropriate investigations and working out recommendations as to how to prevent and eliminate surging of TC. This task was solved on the m/v “Socofl Star”. Based on results the ME shop test and trial test of the vessel and also the saved-up data of work of ME in various conditions of swimming, the analysis of the causes of a surge of the TC was made. It is established that small values of safety factor of stability of the compressor of TC on a surging – KCT which are not allowing to ensure effective functioning of TC on the main modes of loading of ME are its reason. For increase in area of steady work of TC it is necessary to reduce the hydraulic resistance of components of the Air-Gas Path (AGP) of the ME which can be realized by changes in a design of units of air supply and gas exchange or reduction of productivity and extent of increase in pressure of air in the compressor of TC. Under operating conditions vessels an optimal solution an objective is removal of a part of blowing-off air after compressor of the TC. The air can be discharged into the flue gas header after the waste heat recovery boiler or directly into the atmosphere. This allowed the shipowner not to make constructive changes to the components of the AGP of ME and TC. The description of the operated unloading device controlled remotely on removal of air which ensures effective functioning of TC and ME that is confirmed by results of natural tests and the subsequent operating experience of vessels of the “Socofl Star” series is provided.

Evaluation and analysis of exergoeconomic performance for the calcination process of green petroleum coke in vertical shaft kiln

The main objective of this paper is to establish a mathematical framework to analyze the complex thermal economic performance of the calcination process. To find the factors affecting exergy efficiency loss, different exergy destruction is investigated in detail. Furthermore, the exergy flow cost model for exergy cost saving has also been developed. The results show that the vertical shaft furnace is a self-sufficiency equipment without additional fuel required, but the overall exergy destruction accounts for 54.11% of the total exergy input. In addition, the energy efficiency of the waste heat recovery boiler and thermal deaerator are 83.52% and 96.40%, whereas the exergy efficiency of the two equipment are 65.98% and 94.27%. Furthermore, the import exergy flow cost of vertical shaft furnace, waste heat recovery boiler and thermal deaerator are 366.5197 RMB/MJ, 0.1426 RMB/MJ and 0.0020RMB/MJ, respectively. Based on the result, several suggestions were proposed to improve the exergoeconomic performance. Assessing the performance of suggested improvements, the total exergy destruction of vertical shaft furnace is reduced to 134.34 GJ/h and the exergy efficiency of waste heat recovery boiler is raised up to 66.02%. Moreover, the import exergy flow cost of the three different equipment is reduced to 0.0329 RMB/MJ, 0.1304 RMB/MJ and 0.0002 RMB/MJ, respectively.

Analysing the efficiency of thermopressor application in the charge air cooling system of combustion engine

As the analysis of the research results has shown, the use of a thermopressor makes it possible to increase the fuel and energy efficiency of a ship power plant in a wide range of the operation parameters. It can be achieved by cooling the charge air before the engine inlet receiver and by reducing the compression work of the turbocharger. A scheme with the thermopressor application in the cooling system of a low-speed main engine and in the system for utilizing the exhaust gases heat in a heat recovery boiler of one and two pressures was proposed. The use of thermopressors led to a decrease in the compressor power consumption, and therefore in the turbine required power. Therefore, it was appropriate to pass (bypass) the excess amount of gas past the turbine. Accordingly, the thermal potential of exhaust gases was increased. As a result, the temperature of gases at the inlet to the heat recovery boiler was increased by 10-15 °C, and gases heat was increased by 10-15% respectively. The obtained additional steam is advisable to use for driving the utilization turbine generator, thereby reducing the load on the ship's power plant, with a corresponding decrease in fuel consumption of diesel generators by 2-4%.

PROTECTION AGAINST CORROSION OF THE TECHNOLOGICAL EQUIPMENT OF THE OIL REFINING ENTERPRISE

A method for slowing down the corrosion of heat exchangers in the T-104 and T102 heat recovery boiler blocks is considered. PK-1 Aminate was selected as the most suitable inhibitor for process heat exchangers of the waste heat recovery boiler unit