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Russian patent in the field of pump and compressor engineering to improve energy efficiency

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The paper examines the calculation of a liquid ring vacuum pump, using the example of the drying process of various materials. It was found that for two-stage convective vacuum-impulse drying it is economically efficient to use a two-stage liquid ring vacuum pump with the ability to turn off the second stage. A method for calculating the specific power of one-stage and two-stage liquid ring vacuum pumps, taking into account heat and mass transfer and thermal processes that occur during operation is proposed.

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Liquid-ring vacuum pumps are used in oil recovery, in processing of plastics, in distillation processes, and other elsewhere. A major drawback of liquid-ring vacuum pumps is the presence of a constant degree of internal compression in the impeller cells, a factor that produces excessive consumption of the compressive power of the gas phase, an increase in the overall power consumption in the evacuation process and, as a consequence, reduces the overall efficiency of the pump. A design of a liquid-ring vacuum pump with adjustable discharge window that is free of these drawbacks and produces an increase in the overall efficiency of the pump is proposed. In this design dynamic adjustment of the dimensions of the discharge window is achieved with the use of an automatically adjustable flap. The advantages of the newly designed design of a liquid-ring vacuum pump with adjustable discharge window as compared to designs of liquid-ring vacuum pumps with constant degree of compression are confirmed by the results of theoretical and experimental studies; these include a 25% decrease in the expenditure of the power in the evacuation process and a 10% increase in the speed of action. The use of the principle of a variable internal degree of compression in different operating regimes makes it possible to create new types of liquid-ring vacuum pumps with adjustable discharge window that exhibit improved operational indicators.

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Liquid ring vacuum pumps and compressors are mechanical positive displacement turbomachines that can operate in the mode of both vacuum compressor and vacuum pump. They are widely used in the fields of filtration, cryogenic, reaction, gas injection, condensation, evaporation, and drying. Despite their low performance, they have many advantages such as low costs, simplicity, reliability, improve suction characteristics, and in many cases, can provide a more efficient option. Improving efficiency is the key to decrease energy consumption and costs. The article analyzed and evaluated the previous investigations regarding these machines with a focus on challenges of improving efficiency, advances in numerical simulation, and experiments to afford beneficial insight on future research and next steps. The study revealed that the thermal interaction and the cavitation phenomenon are among the most important problems that require further research.

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Russian patent in the field of pump and compressor engineering to improve energy efficiency

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Researchers worldwide are studying thermal energy storage with phase change materials because of their substantial benefits in the enhancement of energy efficiency of thermal drying systems. A two-stage convective-vacuum impulsive drying plant is a technology for the manufacturing of chemical and food products with high quality and low energy costs. Energy consumption during the drying process is the main indicator in terms of economy. In this paper, a brief and focused review of the peculiarities of TEAs with PPCMs and opportunities of their application in such drying systems is done and discussed. The paper described the mentioned manufacturing system. The advantages of paraffin wax and thermal conductivity improvement techniques were demonstrated for their use as heat storage materials in CVID drying units. The results of similar previous studies were presented. The results of the experimental studies conducted by the researchers proved that the use of heat accumulators with PCMs increased the overall energy efficiency of drying systems. Finally, integration of TEAs based on modified PPCMs in the CVID system was recommended to intensify thermal energy, reduce thermal influence on the main indicators of the vacuum pump during the evacuation process, and decrease production costs.

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Solar organic Rankine cycle (SORC) is a successful approach for sustainable development and exploiting clean energy sources. The research aims to improve and evaluate the energy efficiency of the s SORC for combined heat and power generation for a residential home under the climatic conditions of Baghdad, Iraq. Thermoeconomic analysis was carried out for the proposed energy supply system. Refrigerant HFC-245fa has been used as a working fluid in a solar organic Rankine cycle, and oil poly alkyl benzene (TLV-330) was suggested as a heat transfer fluid in the solar collector field. Parametric studies for some key parameters were conducted to examine the influence of various operating conditions on energy efficiency. The results showed a significant improvement in energy efficiency. The maximum efficiency of SORC CHPG reached 79.14% when solar heat source temperatures were in the range of 100 to 150°C and the solar radiation was at a maximum value of 870 W/m2 at noon on the 15th day of July in Baghdad. The maximum energy produced by SORC CHPG was 472.5 kW when the optimal average value of global solar radiation was 7.5 kWh/m2/day in June. The economic investigations revealed that the payback period of the new energy supply system is 10 years and the positive net present cost when the solar power plant works 18 h/day.