S32205 Duplex 2205 stainless steel chemical composition Influence of capillary length on the characteristics of environmentally friendly refrigerant R152a in household refrigerators

Thank you for visiting Nature.com. You are using a browser version with limited CSS support. For the best experience, we recommend that you use an updated browser (or disable Compatibility Mode in Internet Explorer). In addition, to ensure ongoing support, we show the site without styles and JavaScript.
Sliders showing three articles per slide. Use the back and next buttons to move through the slides, or the slide controller buttons at the end to move through each slide.

Specifications – Duplex 2205

• ASTM: A790, A815, A182
• ASME: SA790, SA815, SA182

Chemical Composition – Duplex 2205

Typical Applications – Duplex 2205

Some of the typical applications of duplex steel grade 2205 are listed below:

• Heat exchangers, tubes and pipe for production and handling of gas and oil
• Heat exchangers and pipes in desalination plants
• Pressure vessels, pipes, tanks and heat exchangers for processing and transport of various chemicals
• Pressure vessels, tanks and pipes in process industries handling chlorides
• Rotors, fans, shafts and press rolls where the high corrosion fatigue strength can be utilized
• Cargo tanks, piping and welding consumables for chemical tankers

Physical Properties

The physical properties of grade 2205 stainless steels are tabulated below.

Home heating and cooling systems often use capillary devices. The use of spiral capillaries eliminates the need for lightweight refrigeration equipment in the system. Capillary pressure largely depends on the parameters of the capillary geometry, such as length, average diameter and distance between them. This article focuses on the effect of capillary length on system performance. Three capillaries of different lengths were used in the experiments. The data for R152a were examined under different conditions to evaluate the effect of different lengths. The maximum efficiency is achieved at an evaporator temperature of -12°C and a capillary length of 3.65 m. The results show that the performance of the system increases with increasing capillary length to 3.65 m compared to 3.35 m and 3.96 m. Therefore, when the length of the capillary increases by a certain amount, the performance of the system increases. The experimental results were compared with the results of computational fluid dynamics (CFD) analysis.
A refrigerator is a refrigeration appliance that includes an insulated compartment, and a refrigeration system is a system that creates a cooling effect in an insulated compartment. Cooling is defined as the process of removing heat from one space or substance and transferring that heat to another space or substance. Refrigerators are now widely used to store food that spoils at ambient temperatures, spoilage from bacterial growth and other processes is much slower in low temperature refrigerators. Refrigerants are working fluids used as heat sinks or refrigerants in refrigeration processes. Refrigerants collect heat by evaporating at low temperature and pressure and then condense at higher temperature and pressure, releasing heat. The room seems to be getting cooler as the heat escapes from the freezer. The cooling process takes place in a system consisting of a compressor, condenser, capillary tubes and an evaporator. Refrigerators are the refrigeration equipment used in this study. Refrigerators are widely used all over the world, and this appliance has become a household necessity. Modern refrigerators are very efficient in operation, but research to improve the system is still ongoing. The main disadvantage of R134a is that it is not known to be toxic but has a very high Global Warming Potential (GWP). R134a for household refrigerators has been included in the Kyoto Protocol of the United Nations Framework Convention on Climate Change1,2. However, therefore, the use of R134a should be significantly reduced3. From an environmental, financial and health point of view, it is important to find low global warming4 refrigerants. Several studies have proven that R152a is an environmentally friendly refrigerant. Mohanraj et al.5 investigated the theoretical possibility of using R152a and hydrocarbon refrigerants in domestic refrigerators. Hydrocarbons have been found to be ineffective as stand-alone refrigerants. R152a is more energy efficient and environmentally friendly than phase-out refrigerants. Bolaji and others6. The performance of three environmentally friendly HFC refrigerants was compared in a vapor compression refrigerator. They concluded that R152a could be used in vapor compression systems and could replace R134a. R32 has disadvantages such as high voltage and low coefficient of performance (COP). Bolaji et al. 7 tested R152a and R32 as substitutes for R134a in household refrigerators. According to studies, the average efficiency of R152a is 4.7% higher than that of R134a. Cabello et al. tested R152a and R134a in refrigeration equipment with hermetic compressors. 8. Bolaji et al9 tested R152a refrigerant in refrigeration systems. They concluded that R152a was the most energy efficient, with 10.6% less cooling capacity per ton than the previous R134a. R152a shows higher volumetric cooling capacity and efficiency. Chavkhan et al.10 analyzed the characteristics of R134a and R152a. In a study of two refrigerants, R152a was found to be the most energy efficient. R152a is 3.769% more efficient than R134a and can be used as a direct replacement. Bolaji et al.11 have investigated various low-GWP refrigerants as replacements for R134a in refrigeration systems due to their lower global warming potential. Among the evaluated refrigerants, R152a has the highest energy performance, reducing electricity consumption per ton of refrigeration by 30.5% compared to R134a. According to the authors, the R161 needs to be completely redesigned before it can be used as a replacement. Various experimental work has been carried out by many domestic refrigeration researchers to improve the performance of low-GWP and R134a-blended refrigerant systems as a forthcoming replacement in refrigeration systems12,13,14,15,16,17,18, 19, 20, 21, 22, 23 Baskaran et al.24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 studied the performance of several environmentally friendly refrigerants and their combination with R134a as a potential alternative for various vapor compression tests. System. Tiwari et al. 36 used experiments and CFD analysis to compare the performance of capillary tubes with different refrigerants and tube diameters. Use ANSYS CFX software for analysis. The best spiral coil design is recommended. Punia et al.16 investigated the effect of capillary length, diameter and coil diameter on the mass flow of LPG refrigerant through a spiral coil. According to the results of the study, adjusting the length of the capillary in the range from 4.5 to 2.5 m allows increasing the mass flow by an average of 25%. Söylemez et al.16 performed a CFD analysis of a household refrigerator freshness compartment (DR) using three different turbulent (viscous) models to gain insight into the cooling speed of the freshness compartment and the temperature distribution in the air and compartment during loading. The forecasts of the developed CFD model clearly illustrate the air flow and temperature fields inside the FFC.
This article discusses the results of a pilot study to determine the performance of household refrigerators using R152a refrigerant, which is environmentally friendly and has no risk of ozone depletion potential (ODP).
In this study, 3.35 m, 3.65 m and 3.96 m capillaries were selected as test sites. Experiments were then carried out with low global warming R152a refrigerant and operating parameters were calculated. The behavior of the refrigerant in the capillary was also analyzed using the CFD software. The CFD results were compared with the experimental results.
As shown in Figure 1, you can see a photograph of a 185 liter domestic refrigerator used for the study. It consists of an evaporator, a hermetic reciprocating compressor and an air-cooled condenser. Four pressure gauges are installed at the compressor inlet, condenser inlet and evaporator outlet. To prevent vibration during testing, these meters are panel mounted. To read the thermocouple temperature, all thermocouple wires are connected to a thermocouple scanner. Ten temperature measurement devices are installed at the evaporator inlet, compressor suction, compressor discharge, refrigerator compartment and inlet, condenser inlet, freezer compartment and condenser outlet. The voltage and current consumption is also reported. A flowmeter connected to a pipe section is fixed on a wooden board. Recordings are saved every 10 seconds using the Human Machine Interface (HMI) unit. The sight glass is used to check the uniformity of the condensate flow.
A Selec MFM384 ammeter with an input voltage of 100–500 V was used to quantify power and energy. A system service port is installed on top of the compressor for charging and recharging refrigerant. The first step is to drain the moisture from the system through the service port. To remove any contamination from the system, flush it with nitrogen. The system is charged using a vacuum pump, which evacuates the unit to a pressure of -30 mmHg. Table 1 lists the characteristics of the domestic refrigerator test rig, and Table 2 lists the measured values, as well as their range and accuracy.
Characteristics of refrigerants used in domestic refrigerators and freezers are shown in Table 3.
Testing was conducted according to the recommendations of the ASHRAE Handbook 2010 under the following conditions:
In addition, just in case, checks were made to ensure the reproducibility of the results. As long as operating conditions remain stable, temperature, pressure, refrigerant flow and energy consumption are recorded. Temperature, pressure, energy, power and flow are measured to determine system performance. Find the cooling effect and efficiency for specific mass flow and power at a given temperature.
Using CFD to analyze two-phase flow in a domestic refrigerator spiral coil, the effect of capillary length can be easily calculated. CFD analysis makes it easy to track the movement of fluid particles. The refrigerant passing through the interior of the spiral coil was analyzed using the CFD FLUENT program. Table 4 shows the dimensions of the capillary coils.
The FLUENT software mesh simulator will generate a structural design model and mesh (Figures 2, 3 and 4 show the ANSYS Fluent version). The fluid volume of the pipe is used to create the boundary mesh. This is the grid used for this study.
The CFD model was developed using the ANSYS FLUENT platform. Only the moving fluid universe is represented, so the flow of each capillary serpentine is modeled in terms of the diameter of the capillary.
The GEOMETRY model was imported into the ANSYS MESH program. ANSYS writes code where ANSYS is a combination of models and added boundary conditions. On fig. 4 shows the pipe-3 (3962.4 mm) model in ANSYS FLUENT. Tetrahedral elements provide higher uniformity, as shown in Figure 5. After creating the main mesh, the file is saved as a mesh. The side of the coil is called the inlet, while the opposite side faces the outlet. These round faces are saved as the walls of the pipe. Liquid media are used to build models.
Regardless of how the user feels about pressure, the solution was chosen and the 3D option was chosen. The power generation formula has been activated.
When the flow is considered chaotic, it is highly non-linear. Therefore, the K-epsilon flow was chosen.
If a user-specified alternative is selected, the environment will be: Describes the thermodynamic properties of R152a refrigerant. Form attributes are stored as database objects.
Weather conditions remain unchanged. An inlet velocity was determined, a pressure of 12.5 bar and a temperature of 45 °C were described.
Finally, at the fifteenth iteration, the solution is tested and converges at the fifteenth iteration, as shown in Figure 7.
It is a method of mapping and analyzing results. Plot pressure and temperature data loops using Monitor. After that, the total pressure and temperature and the general temperature parameters are determined. This data shows the total pressure drop across the coils (1, 2 and 3) in figures 1 and 2. 7, 8 and 9 respectively. These results were extracted from a runaway program.
On fig. 10 shows the change in efficiency for different lengths of evaporation and capillary. As can be seen, the efficiency increases with increasing evaporation temperature. The highest and lowest efficiencies were obtained when reaching capillary spans of 3.65 m and 3.96 m. If the length of the capillary is increased by a certain amount, the efficiency will decrease.
The change in cooling capacity due to different levels of evaporation temperature and capillary length is shown in fig. 11. The capillary effect leads to a decrease in cooling capacity. The minimum cooling capacity is achieved at a boiling point of -16°C. The greatest cooling capacity is observed in capillaries with a length of about 3.65 m and a temperature of -12°C.
On fig. 12 shows the dependence of compressor power on capillary length and evaporation temperature. In addition, the graph shows that the power decreases with increasing capillary length and decreasing evaporation temperature. At an evaporating temperature of -16 °C, a lower compressor power is obtained with a capillary length of 3.96 m.
Existing experimental data were used to verify the CFD results. In this test, the input parameters used for the experimental simulation are applied to the CFD simulation. The results obtained are compared with the value of static pressure. The results obtained show that the static pressure at the exit from the capillary is less than at the entrance to the tube. The test results show that increasing the length of the capillary to a certain limit reduces the pressure drop. In addition, the reduced static pressure drop between the inlet and outlet of the capillary increases the efficiency of the refrigeration system. The obtained CFD results are in good agreement with the existing experimental results. The test results are shown in Figures 1 and 2. 13, 14, 15 and 16. Three capillaries of different lengths were used in this study. The tube lengths are 3.35m, 3.65m and 3.96m. It was observed that the static pressure drop between the capillary inlet and outlet increased when the tube length was changed to 3.35m. Also note that the outlet pressure in the capillary increases with a pipe size of 3.35 m.
In addition, the pressure drop between the inlet and outlet of the capillary decreases as the pipe size increases from 3.35 to 3.65 m. It was observed that the pressure at the outlet of the capillary dropped sharply at the outlet. For this reason, the efficiency increases with this capillary length. In addition, increasing the pipe length from 3.65 to 3.96 m again reduces the pressure drop. It has been observed that over this length the pressure drop drops below the optimum level. This reduces the COP of the refrigerator. Therefore, the static pressure loops show that the 3.65 m capillary provides the best performance in the refrigerator. In addition, an increase in pressure drop increases energy consumption.
From the results of the experiment, it can be seen that the cooling capacity of the R152a refrigerant decreases with increasing pipe length. The first coil has the highest cooling capacity (-12°C) and the third coil has the lowest cooling capacity (-16°C). The maximum efficiency is achieved at an evaporator temperature of -12 °C and a capillary length of 3.65 m. The compressor power decreases with increasing capillary length. The compressor power input is maximum at an evaporator temperature of -12 °C and minimum at -16 °C. Compare CFD and downstream pressure readings for capillary length. It can be seen that the situation is the same in both cases. The results show that the performance of the system increases as the length of the capillary increases to 3.65 m compared to 3.35 m and 3.96 m. Therefore, when the length of the capillary increases by a certain amount, the performance of the system increases.
Although the application of CFD to the thermal industry and power plants will improve our understanding of the dynamics and physics of thermal analysis operations, limitations require the development of faster, simpler, and less expensive CFD methods. This will help us optimize and design existing equipment. Advances in CFD software will allow for automated design and optimization, and the creation of CFDs over the Internet will increase the availability of the technology. All these advances will help CFD become a mature field and a powerful engineering tool. Thus, the application of CFD in heat engineering will become wider and faster in the future.
Tasi, WT Environmental Hazards and Hydrofluorocarbon (HFC) Exposure and Explosion Risk Review. J. Chemosphere 61, 1539–1547. https://doi.org/10.1016/j.chemosphere.2005.03.084 (2005).
Johnson, E. Global warming due to HFCs. Wednesday. Impact assessment. open 18, 485-492. https://doi.org/10.1016/S0195-9255(98)00020-1 (1998).
Mohanraj M, Jayaraj S and Muralidharan S. Comparative evaluation of environmentally friendly alternatives to R134a refrigerant in household refrigerators. energy efficiency. 1(3), 189–198. https://doi.org/10.1007/s12053-008-9012-z (2008).
Bolaji B.O., Akintunde M.A. and Falade, Comparative performance analysis of three ozone-friendly HFC refrigerants in vapor compression refrigerators. http://repository.fuoye.edu.ng/handle/123456789/1231 (2011).
Bolaji B.O. Experimental study of R152a and R32 as substitutes for R134a in household refrigerators. Energy 35(9), 3793–3798. https://doi.org/10.1016/j.energy.2010.05.031 (2010).
Cabello R., Sanchez D., Llopis R., Arauzo I. and Torrella E. Experimental comparison of R152a and R134a refrigerants in refrigeration units equipped with hermetic compressors. internal J. Refrigerator. 60, 92-105. https://doi.org/10.1016/j.ijrefrig.2015.06.021 (2015).
Bolaji B.O., Juan Z. and Borokhinni F.O. Energy efficiency of environmentally friendly refrigerants R152a and R600a as a replacement for R134a in vapor compression refrigeration systems. http://repository.fuoye.edu.ng/handle/123456789/1271 (2014).
Chavkhan, S.P. and Mahajan, P.S. Experimental evaluation of the effectiveness of R152a as a replacement for R134a in vapor compression refrigeration systems. internal J. Department of Defense. project. storage tank. 5, 37–47 (2015).
Bolaji, B.O. and Huang, Z. A study on the effectiveness of some low-global warming hydrofluorocarbon refrigerants as a replacement for R134a in refrigeration systems. J. Ing. Thermal physicist. 23(2), 148-157. https://doi.org/10.1134/S1810232814020076 (2014).
Hashir S.M., Srinivas K. and Bala P.K. Energy analysis of HFC-152a, HFO-1234yf and HFC/HFO blends as direct substitutes for HFC-134a in domestic refrigerators. Strojnicky Casopis J. Mech. project. 71(1), 107-120. https://doi.org/10.2478/scjme-2021-0009 (2021).
Logeshwaran, S. and Chandrasekaran, P. CFD analysis of natural convective heat transfer in stationary household refrigerators. IOP session. TV series Alma mater. the science. project. 1130(1), 012014. https://doi.org/10.1088/1757-899X/1130/1/012014 (2021).
Aprea, C., Greco, A., and Maiorino, A. HFO and its binary blend with HFC134a as a refrigerant in domestic refrigerators: energy analysis and environmental impact assessment. Apply temperature. project. 141, 226-233. https://doi.org/10.1016/j.appltheraleng.2018.02.072 (2018).
Wang, H., Zhao, L., Cao, R., and Zeng, W. Refrigerant replacement and optimization under greenhouse gas emission reduction constraints. J. Pure. product. 296, 126580. https://doi.org/10.1016/j.jclepro.2021.126580 (2021).
Soilemez E., Alpman E., Onat A., and Hartomagioglu S. Predicting the cooling time of household refrigerators with a thermoelectric cooling system using CFD analysis. internal J. Refrigerator. 123, 138-149. https://doi.org/10.1016/j.ijrefrig.2020.11.012 (2021).
Missowi, S., Driss, Z., Slama, R.B. and Chahuachi, B. Experimental and numerical analysis of helical coil heat exchangers for domestic refrigerators and water heating. internal J. Refrigerator. 133, 276-288. https://doi.org/10.1016/j.ijrefrig.2021.10.015 (2022).
Sánchez D., Andreu-Naher A., ​​Calleja-Anta D., Llopis R. and Cabello R. Evaluation of the energy impact of different alternatives to low-GWP R134a refrigerant in beverage coolers. Experimental analysis and optimization of pure refrigerants R152a, R1234yf, R290, R1270, R600a and R744. energy conversion. manage. 256, 115388. https://doi.org/10.1016/j.enconman.2022.115388 (2022).
Boricar, S.A. et al. A case study of experimental and statistical analysis of the energy consumption of domestic refrigerators. topical research. temperature. project. 28, 101636. https://doi.org/10.1016/j.csite.2021.101636 (2021).
Soilemez E., Alpman E., Onat A., Yukselentürk Y. and Hartomagioglu S. Numerical (CFD) and experimental analysis of a hybrid household refrigerator incorporating thermoelectric and vapor compression cooling systems. internal J. Refrigerator. 99, 300–315. https://doi.org/10.1016/j.ijrefrig.2019.01.007 (2019).
Majorino, A. et al. R-152a as an alternative refrigerant to R-134a in domestic refrigerators: An experimental analysis. internal J. Refrigerator. 96, 106-116. https://doi.org/10.1016/j.ijrefrig.2018.09.020 (2018).
Aprea C., Greco A., Maiorino A. and Masselli C. Mixture of HFC134a and HFO1234ze in domestic refrigerators. internal J. Hot. the science. 127, 117-125. https://doi.org/10.1016/j.ijthermalsci.2018.01.026 (2018).
Bascaran, A. and Koshy Matthews, P. Comparison of the performance of vapor compression refrigeration systems using environmentally friendly refrigerants with low global warming potential. internal J. Science. storage tank. release. 2(9), 1-8 (2012).
Bascaran, A. and Cauchy-Matthews, P. Thermal analysis of vapor compression refrigeration systems using R152a and its mixtures R429A, R430A, R431A and R435A. internal J. Science. project. storage tank. 3(10), 1-8 (2012).