Figure 2
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In the present study, an attempt is made to enhance the performance of heat pump by utilizing two types of nanofluids namely, copper and alumina nanofluids. These nanofluids were employed around the evaporator coil of the heat pump. The nanofluids were used to enhance the heat input to the system by means of providing an external jacket around the...
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... setup is shown in Fig. 1. The system operates with R-134a refrigerant. The internal helix diameter is 13 cm for both the evaporator and condenser coils. The type-K thermocouple has nickel-chrome (NiCr-Ni), 1.5 mm tip. The connecting tubes are 2 m in length and 6 mm in diameter. The schematic of the heat pump system with nanofluid is shown in Fig. ...
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To address environmental concerns and the need for more environmentally friendly cooling and heating solutions, the U.S. Department of Energy (DOE) is supporting the development of smarter, more efficient, and affordable heat pumping systems operating with low-or no-GWP refrigerants through the Energy, Emissions, and Equity (E3) Initiative. In the...
Citations
... Ahmed et al., [4] used an outer jacket over the evaporator in the HP, and observed the changes in system performance by using nanofluid inside the jacket. Cu and Al 2 O 3 nanoparticles and water as base fluid were used in nanofluids obtained in 1 %, 2 % and 2 % volume fractions. ...
... The performance of the HP was analyzed with and without jacket. As a result of the experiments, a 23 % improvement in the coefficient of performance (COP) value of Al 2 O 3 /water nanofluid at 5 % volume fraction was determined [4]. Mishra et al., [33] tested the performance of a ground source HP using water-based nanofluids. ...
... Nanofluids may be constructed using a variety of nanoparticles, including metallic nanoparticles, polymeric nanoparticles, and non-metallic nanoparticles. On the other hand, these nanoparticles contribute in the development of the heat transfer characteristics of nanofluids [20,21]. Numerous research on the thermophysical properties of nanofluids have established mathematical connections between specific heat capacity, density, dynamic viscosity, and thermal conductivity [22][23][24]. ...
Desalination powered by solar energy is a hot topic of investigation currently. Access to safe, pure water is one of human’s most basic needs. There is an urgent need for solutions that use less conventional energy or depend on renewable energy sources to purify seawater and industrial wastewater. Solar stills are one method of using solar energy to generate pure water. The fundamental concepts of nanofluids, heat transfer in nanofluids, and preparation procedures are described in this paper. Further, this paper is aimed at bringing the readers up to date on current advancements on utilization of nanomaterials in solar distillers. As means of promoting this technique, the authors emphasized the environmental and health consequences of nanoparticles. A significant result reported here is the conductivity of nanofluids being directly related to nanoparticle volume fraction. To optimize the quantity of purified water generated, each nanoparticle will have an optimal concentration at the point of greatest thermal conductivity.
... Also, when the copper oxide is used at this ratio, the cooling impact improves, and the compressor performance drops. Ahmed et al. [15] utilized two forms of nano-fluids, Cu and Al 2 O 3 , to enhance the efficiency of the heat pump system. The two nano-fluids were created in three volume fractions of (1, 2, and 5%). ...
... The effective viscosity is computed by using Eq. (2), which is valid for spherical particles with volume fractions under 5.0 vol% [15]. ...
The current work focuses on the experimental research of a vapor compression cycle using Polyol
Oil Ester (POE) with nano copper oxide (CuO) and a fluidized bed for condenser cooling to
enhance its performance. The efficiencies of the modified and normal systems using only POE oil
have been compared to present the actions of using nano CuO and a fluidized bed. Three volume
fractions of CuO 0.1%, 0.3%, and 0.5% have been used. The fluidized bed contained a uniform
particle size (0.5 mm) to sink heat from the condenser, where the bed height was 2.5 mm to get
good mixing of particles. The experiment outcomes indicated that adding nanoparticles to the
lubricant and using a fluidized bed for condenser cooling improves the refrigeration system’s
performance. The results demonstrated that employing nano-lubricant (POE oil+0.5% CuO)
rather than just POE oil boosted the coefficient of performance of the system by approximately
15.96% while reducing power consumption by 50%. Also, the refrigeration impact was raised,
and the compressor’s performance was reduced with the volume fractions of CuO rising.
... 3D NoC uses a three-dimensional packaging method to encapsulate multiple chips with a twodimensional structure into one chip [4]. Chips are connected mainly by through-silicon-via (TSV) technology [4,5]. The TSV technology proffers 3D NoC the highest stacking density in the threedimensional direction, faster transmission speed, and lower system power consumption [6]. ...
... In order to make the selection more accurate, the scoring strategy also considers the next candidate node of the candidate node in Eqs. (4), (5). ...
... score freeslot = cs freeslot + n k=1 ncs(k) freeslot /n (4) score thermal = cs thermal + n k=1 ncs(k) thermal /n (5) where k and n respectively represent the number of indexes and the number of candidate nodes for the next candidate node. cs freeslot represents the score of the number of candidate node free buffer slots, and ncs freeslot represents the score of next candidate node of free buffer slots. ...
In the present study, a new technique of utilizing nanofluid as a secondary fluid in a secondary loop of refrigeration system is examined. This secondary loop serves for providing cooling in specific applications such as walk-in coolers and freezers. The secondary loop is obtained across the evaporator section wherein the refrigerant R134a extracted heat from the nanofluid. The evaporator here is classified as shell and coil heat exchanger where nanofluid flowed in the shell side and refrigerant flowed in the coil. A compressor, expansion valve and water cooled condenser are the major integral parts of the system. Experiments were conducted for various volume concentrations of Al2O3 nanofluid (0-15%), mass flow rates (40-80 g/s) and nanofluid inlet temperatures (30-40 °C). The modified system exhibited superior performance when Al2O3 nanofluid was employed in the secondary loop as compared to base fluid (distilled water) while operating at the same mass flow rate and inlet temperature. A maximum COP of 6.5 was achieved for nanofluid inlet temperature 40 C at mass flow rate 80 g/s and volume concentration 15%. The enhancement in refrigeration effect and coefficient of performance is attributed to micro conduction effect due to the rise in thermal conductivity of nanofluid as compared to distilled water.
