The Effect of Water Impact on the Refrigerant Pipeline between Compressor and Condensor on COP and Efficiency of Cooling Machine

The purpose of this research is (a) to design and assemble a steam compression cycle cooling machine using the main components on the market (b) to obtain the characteristics of the cooling engine, which includes the Coefficient of Performance (COP) and the efficiency of the cooling engine. The research was conducted experimentally in the laboratory. The refrigeration machine works by using a steam compression cycle, with the main components: a compressor, an evaporator, a capillary tube and a condenser. The compressor power is 1/6 PK, while the other main components are adjusted to the size of the compressor power. The refrigerant used is R134a. Variations of the research were carried out on the condition of the refrigerant pipe located between the compressor and condenser: (a) without being submerged in water (b) submerged in 0.50 liters of water and (c) submerged in 0.75 liters of water. The results of the study provide information that the water immersion in the refrigerant pipe which is located between the compressor and condenser affects the COP value and the efficiency of the refrigeration machine. Consecutively (1) without being submerged in water, the COP value is 2.45 and the efficiency is 0.64 (2) submerged in liter of water, the COP value is 2.41 and the efficiency is 0.62 (3) submerged in liter of water, the value COP is 2.34 and efficiency is 0.60.

Experimental Performance Analysis of R1234yf in an Air-Conditioning System as Substitute of R134a

In this work, R1234yf is tested in an air-conditioning system as a proposed alternative to R134a. The system is tested at 30, 35, 40, 45 and 50[Formula: see text]Hz evaporator fan frequency to cool the air entering into the evaporator section at a fixed temperature of 35∘C. The system is charged with 600, 700, 800, 1000 and 1200[Formula: see text]g of each refrigerant. The charge mass of 800 grams gives the best performance for both refrigerants. Also, R1234yf has higher COP, exergetic efficiency, second law efficiency, and lower compressor power consumption. Both refrigerants operate at a moderate range of compressor discharge temperature of 85∘C.

Design and fabrication of multi-functional equipment to produce gaseous nitrogen/oxygen and water from ambient air

Mother earth provides all the necessary resources for the existence of life. Despite the rich resources of water on our planet, majority of world’s total population experiences water shortage annually. Studies have shown that with the increase of global warming, the average humidity of ambient air is rising annually. Due to the decrease of water table on land, alternative sources of acquiring potable water can be of great utility. Out of the several methods available to tap potable water, this paper aims to achieve an alternate source of receiving fresh water directly from ambient air. This process is completely different from distillation. The ambient air also comprises a majority of Nitrogen, and this N2 is used for the purpose of creating an inert environment in packaging industries and for the purpose of extinguishing fire, a multi-functional equipment has been fabricated in order to extract water, along with pure Nitrogen gas from the residual dry air. A Pressure Swing Adsorption (PSA) system is used to separate the Nitrogen from remaining air molecules based on their relative molecular size. In the current industrial sectors, the valves required to actuate the flow of air in PSA system are controlled by PLC circuits and Cam followers. These electro-mechanical components are overpriced. In this work electronic timers are used to actuate the valve timing, which resulted in economical. The system fabricated is simple in construction and it is easy to replace the Carbon Molecular Sieves (CMS) with Zeolite Molecular Sieves in order to obtain Oxygen gas as the pure product that can be used to help Covid-19 patients using medical grade filters. The system can be scaled up with larger mass of CMS, bigger PSA towers and greater compressor power in order to increase productivity.

Tailored Centrifugal Turbomachinery for Electric Fuel Cell Turbocharger

Hydrogen fuel cell technology is identified as one option for allowing efficient vehicular propulsion with the least environmental impact on the path to a carbon-free society. Since more than 20 years, IHI is providing charging systems for stationary fuel cell applications and since 2004 for mobile fuel cell applications. The power density of fuel cells substantially increases if the system is pressurized. However, contaminants from fuel cell system components like structural materials, lubricants, adhesives, sealants, and hoses have been shown to affect the performance and durability of fuel cells. Therefore, the charging system that increases the pressure and the power density of the stacks inevitably needs to be oil-free. For this reason, gas bearings are applied to support the rotor of a fuel cell turbocharger. It furthermore comprises a turbine, a compressor, and, on the same shaft, an electric motor. The turbine utilizes the exhaust energy of the stack to support the compressor and hence lower the required electric power of the air supply system. The presented paper provides an overview of the fuel cell turbocharger technology. Detailed performance investigations show that a single-stage compressor with turbine is more efficient compared to a two-stage compressor system with intercooler. The turbine can provide more than 30% of the required compressor power. Hence, it substantially increases the system efficiency. It is also shown that a fixed geometry turbine design is appropriate for most applications. The compressor is of a low specific speed type with a vaneless diffuser. It is optimized for operating conditions of fuel cell systems, which typically require pressure ratios in the range of 3.0.

Comparative Analysis of Heat Pump System with IHX Using R1234yf and R134a

This research presents an energy performance analysis of the heat pump system with internal heat exchanger (IHX). The mathematical model of the heat pump outlined in this paper has been created by the author, it is steady-state with lumped parameters. The experimental validation of the model has been carried out using R1234yf and R134a as refrigerant. The aim of this work is to compare the energy performance in a wide range of operating conditions of a monitored heat pump system using both refrigerants. Finally, the heating capacity for R1234yf was lower from 0.63 % to 7.54 % compared with R134a, while the compressor power was similar from 0.12 % to 3.51 %. The COP values of R1234yf were lower than those obtained of R134a, ranging from 1.39 % to 4.22 %.

Experimental Investigation of a Split Air Conditioning Using Condensate as Direct Evaporative Cooling

Split air conditioning systems produce reasonable amount of condensate which is usually not utilized and thrown away to the environment. On the other hand, it consumes a lot of energy during operation. The aim of this study is to investigate the improvement of air conditioning systems performance utilizing condensate. A direct evaporative cooling using condensate is incorporated on a 0.74 ton-cooling capacity of split air conditioning to decrease the air temperature before entering the condenser. Performances of the split air conditioning with and without direct evaporative cooling are compared and presented in this paper. The results show that the use of direct evaporative cooling using condensate into the air before passing through the condenser reduces the compressor discharge pressure. The decrease of the condenser pressure led to 4.7% and 7% reduction of power consumption for air conditioner without cooling load and air conditioner with 2000 W cooling load, respectively. The cooling effect and coefficient of performance (COP) increase with the decrease of compressor power. The use of direct evaporative cooling with condensate into the air before entering the condensing system can enhance the system performance and protect the environment.

Analisis Laju Penurunan Temperatur di Dalam Ruangan Menggunakan AC Low Watt 0,5 HP

Heat absorb ability split AC is the most important factor in the cooling speed on room temperature. The rate of temperature drop is determined by many factors, including compressor power. Nowadays, there are many Split AC are produced that have low power (low Watt), so that research is needed to determine the cooling speed in a room. This study uses a low watt split AC with a power of 0.5 HP. The distance from the evaporator and the outside temperature are used as independent variables, while the rate of temperature reduction or cooling speed in the room is used as the dependent variable. The results showed that the distribution of room temperature and the rate of temperature reduction in the room varied based on the position of the distance to the location of the AC Split Low Watt. The lowest temperature and reduction rate in the room occurs at a distance of 2 m and 3 m in front of the AC location. The outside temperature or the temperature around the location of the AC condenser affects the temperature distribution at each distance in front of the AC. When the outside temperature is low, the temperature conditions at a distance of 1 m, 4 m, and 5 m have a significant difference. While the high outside temperature conditions, the temperature at a distance of 1 m, 4 m, and 5 m, namely the positions close to the wall, is almost the same. Kata kunci: AC, split, low watt, evaporator

ANALISIS EFISIENSI SISTEM PENDINGIN PADA KERETA API KELAS EKONOMI

The purpose of this study was to determine the efficiency of the cooling system (Split AC) on economy class trains. The method used in this study is a qualitative analysis research method. Where the results of this study are in the form of efficient or not the performance of AC Split on the economy train (K3). Based on the data obtained from the research results obtained that the largest compressor power input is 7332.79 W and the smallest compressor power of 6906.22 W produces the largest AC cooling load output at 11200.56 W and the smallest cooling load at 9641.55 W. From The resulting COP value can be concluded that the use of Split AC in the economy train is less efficient because the COP value is still below the SNI03-6390-2000 standard which is a minimum of 2.6. Abstrak Tujuan dari penelitian ini adalah untuk mengetahui efisiensi sistem pendingin (AC Split) pada kereta api kelas ekonomi. Metode yang digunakan dalam penelitian ini adalah metode penelitian analisis kualitatif. Dimana hasil dari penelitian ini adalah berupa efisien atau tidaknya performansi AC Split pada kereta api ekonomi (K3). Berdasarkan data hasil penelitian yang diperoleh didapat bahwa input daya kompresor terbesar sebesar 7332,79 W dan daya kompresor terkecil sebesar 6906,22 W menghasilkan output beban pendinginan AC terbesar pada sebesar 11200,56 W dan beban pendinginan terkecil pada sebesar 9641,55 W. Dari nilai COP yang dihasilkan dapat disimpulkan bahwa penggunaan AC Split pada kereta api ekonomi kurang efisien karena nilai COPnya masih dibawah standar SNI03-6390-2000 yaitu minimal 2,6.

Nonlinear Steady-State Optimization of Large-Scale Gas Transmission Networks

The major optimization problem of the gas transmission system is to determine how to operate the compressors in a network to deliver a given flow within the pressure bounds while using minimum compressor power (minimum fuel consumption or maximum network efficiency). Minimization of fuel usage is a major objective to control gas transmission costs. This is one of the problems that has received most of the attention from both practitioners and researchers because of its economic impact. The article describes the algorithm of steady-state optimization of a high-pressure gas network of any structure that minimizes the operating cost of compressors. The developed algorithm uses the “sequential quadratic programming (SQP)” method. The tests carried out on the real network segment confirmed the correctness of the developed algorithm and, at the same time, proved its computational efficiency. Computational results obtained with the SQP method demonstrate the viability of this approach.