The pulsating flow is one of the techniques that can enhance heat transfer, therefore leading to energy saving in tubular heat exchangers. This paper investigated the heat transfer and flow characteristics in a two-dimensional in-line tube bundle with the pulsating flow by a numerical method using the Ansys Fluent. Numerical simulation was performed for the Reynolds number Re = 500 with different frequencies and amplitude of pulsation. Heat transfer enhancement was estimated from the central tube of the tube bundle. Pulsation velocity had an asymmetrical character with a reciprocating flow. The technique developed by the authors to obtain asymmetric pulsations was used. This technique allows simulating an asymmetric flow in heat exchangers equipped with a pulsation generation system. Increase in both the amplitude and the frequency of the pulsations had a significant effect on the heat transfer enhancement. Heat transfer enhancement is mainly observed in the front and back of the cylinder. At a steady flow in these areas, heat transfer is minimal due to the weak circulation of the flow. The increase in heat transfer in the front and back of the cylinder is associated with increased velocity and additional flow mixing in these areas. The maximum increase in the Nusselt number averaged over space and time in the entire studied range was 106%, at a pulsation frequency of 0.5 Hz and pulsation amplitude of 4.5. A minimum enhancement of 25% was observed at a frequency of 0.166 Hz and amplitude of 1.25.
One of the most common energy carriers in the petrochemical industry is water vapor, which is mainly used as a heating medium in process plants. The effective functioning of steam supply, condensate collection and return systems is one of the criteria that affect the cost of production. Improper organization of the steam supply system leads to overuse of heating steam, uneven operation of the steam system and emergency situations. This paper analyzes possible problems in steam supply systems in the absence or incorrect operation of steam traps. The specific indicators of the object of study, circuit solutions and the economic efficiency of the use of steam traps are calculated.
Reducing the energy consumption for the own needs of energy sources is an urgent task that can be solved by organizing our own energy sources by using the potential energy of water vapor in steam screw machines. The article discusses some options for installing steam screw machines at the facilities of generating companies and identifies factors affecting the return on steam screw machines in the current operating conditions.
The solution to the issues of increasing energy efficiency and optimizing the work of enterprises in the petrochemical industry is due to the constant increase in prices for primary energy resources. In this article, the technological site for the production of ethylene oxide, which is characterized by high energy intensity, is considered as an object of study. The largest consumer of energy in this area are technologically furnaces. In the framework of the study, an analysis of the operation of the furnaces was carried out, a balance of the heat-technological flows of the site was compiled, the potential for energy conservation in the utilization of the exhaust gases of the process furnaces was calculated, and the possibility of the beneficial use of the obtained heat was calculated. The economic efficiency and payback period of the proposed method of utilization of flue gases is determined.
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