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21SYSTEMATIC ANALYSIS OF PROCESS INTENSIFICATION IN HEAT
EXCHANGE PRODUCTS
Polytechnic Institute Polytechnic Institute Polytechnic Institute Polytechnic Institute
The article examines the issues of process intensification in shell tube heat exchangers used in industrial enterprises. Based on the analysis of the existing problems, a multi-stage systematic analysis of the application of rib structures in shelltube apparatus and its effect on work efficiency and heat exchange processes was carried out. The hierarchical levels of the systematic analysis are determined and the optimal options are based.
Keywords: shell tube, rib, heat exchange, hierarchical level, quasi-apparatus, reverse flow.
INTRODUCTION
Most processes in the oil and gas refining industry are under the influence of heat, and various heat exchange devices are used to carry out such processes. In order to increase production capacity, heat exchangers must be efficient, simple in design and not affect product quality. In addition, it is important to increase the heat exchange surfaces in the device, maximize the use of heat transfer agents, accelerate the process and reduce energy consumption [1]. These factors serve to increase the performance of the device and reduce its design size. This in turn reduces the cost of operating and repairing heat exchangers.
Most of the research currently being done in this area is focused on constructions that accelerate the process and have achieved certain results. But achieving high productivity at low energy consumption remains important.
The most effective and sensible way to solve the problem is to intensify the process of heat exchange by increasing the speed of flow in the pipes of heat exchangers and to clean the inner surfaces of the pipes. In addition, the installation of ribs in the inner pipes in order to increase the heat transfer coefficient on the heat exchange surface. In this case, the selection of the rib surface 5-10 times larger than the surface of the inner tube. Make the ribs as thin as possible relative to the pipe wall.
The above method dramatically increases the process intensity, but has a negative effect on the overall performance of the apparatus. To solve the problem, it is necessary
Abdurasul Islomjon Qoxorov Davronbekov
Assistent, Fergana Master, Fergana
Xushnudbek Abrorjon
Xomidov Maxmudov
Master, Fergana Master, Fergana
ABSTRACT
to connect the heat exchange processes in each zone of the apparatus to the structure and make a systematic analysis.
RESEARCH RESULTS
This article discusses the effect of the inner tubes of the shell tube heat exchanger and the heat exchange zones on the heat exchange process and the events occurring inside the apparatus. A four-step systematic analysis method was used in the experiments [2].
First stage: At the first initial hierarchical level, a heat exchange apparatus in the form of a system with a heat exchange process was seen. The apparatus was divided into zones (quasi-apparatus) for heat dissipation and excitation. The system input and output parameters are defined. Figure 1 shows a schematic of the shell tube apparatus being analyzed.
Figure 1. The scheme of division and operation of the shell-tube heat exchanger into quasi-devices along the length of the working zone.
Second stage: In the second hierarchical stage, the temperature change in each zone (quasi-apparatus) was analyzed over time, assuming that the apparatus consisted of the heating agent and the heat transfer product delivery elements, the working zone and the output zone. The input and output parameters of each system are determined separately. Figure 2 shows a graph of the change in temperature over time in the zones (quasi-apparatus).
Figure 2. Temperature change of heating and heating agents in zones (quasidevices) over time
Third stage: At the third hierarchical level, the dynamics of the start-up of the working zone of the heat exchanger (multi-quasi-apparatus) was analyzed and a schematic of the start-up dynamics was constructed using the computer modeling method. Figure 3 shows the start-up dynamics of each zone (quasi-apparatus).
Figure 3. Computer model of starting each zone (quasi-apparatus) Four stage: At the fourth hierarchical level, each quasi-apparatus in the apparatus (elements such as the heating chamber, the inner tube ribs, the tube walls, and the fluid inside the tube) were viewed separately for their effects on the process. The indicators to be determined were taken as the input and output parameters of each system. The temperature at which the heating product passes through each cavities was analyzed for apparatus length and time. The maximum rise temperature was assumed to be 100oS and the minimum rise temperature was assumed to be 70oS. During the experiments, apparatus with a length of 800 and 1000 mm was selected. Figures 4 and 5 show the temperature change of the heating product over the length of the apparatus and over time.
Figure 3. An increase in the temperature of the heating product in an apparatus
with a length of 800 mm
Figure 4. An increase in the temperature of the heating product in a apparatus
with a length of 1000 mm
From the data given in Figures 3 and 4, it can be seen that the increase in the zones (quasi-apparatus) improves the intensity of heat exchange, but leads to an increase in the hydraulic resistance in the apparatus. It is necessary to take into account the time spent on each process. The following empirical formulas were obtained using the least squares method for the graphical dependencies in Figures 3 and 4 [3].
On hardware with a length of 800mm:
y = 0,062x + 51 y = 0,063x + 20,2 On hardware with a length of 1000mm:
y = 0,0557x + 42,476 y = 0,0397x + 29,143
R2 = 0,9966 R2 = 0,9990
R2 = 0,9916 R2 = 0,9929
(1) (2)
(3)
(4)
CONCLUSION
In quasi-devices of a heat exchanger with opposite flow, the temperature change of the temperature of the heating and heating products over time was found. As the temperature of the cold liquid increases from quasi-apparatus to quasi-apparatus, the temperature of the hot liquid decreases [4]. Using the results of the analysis, it is possible to select the optimal length of the quasi-apparatus pipe, or the optimal size of the heat exchange surface and at the same time the heat exchange apparatus [5]. As the number of quasi-apparatus increases, the model accuracy increases, but the hydraulic resistance increases. This systematic analysis method allows accurate calculation of the heat exchange system and process.
SCIENTIFIC PROGRESS VOLUME 2 I ISSUE 1 I 2021
ISSN: 2181-1601
REFERENCES
[1] Kalinin, EK Effective surfaces of heat transfer M .: Energoatomizdat, 1998. - 407 p.
[2] A.A. Artikov. Computer methods of analysis and synthesis of chemical technology systems // Textbook for masters of theological specialties. Tashkent: Voris nashriyot. 2012.-457 p.
[3] Kobzar A.I. Applied Mathematical Statistics. For engineers and scientific workers. -Moscow: Fizmatlit, 2006. -816 p.
[4] Askarov, X. A., Askarova, M. B. Q., & Axmadaliyev, U. S. O. (2021). BINO VA INSHOATLARNI QURISHDA ISHLATILADIGAN G'ISHTLARNING TAHLILI. Scientific progress, 7(6), 1112-1116.
[5] Abdumannonovich, A. B., Mansurovich, S. H., & Mahmudovich, M. I. (2021). Development Of High-Efficiency Extraction Equipment And Prospects For Industrial Application Of Extractors With Pneumatic Fluid Mixing. The American Journal of Engineering and Technology, 3(04), 95-101.
