Savings In Electric Energy Consumption Research Articles

SAKLAR OTOMATIS BERBASIS MIKROKONTROLER UNTUK MENGURANGI PENGGUNAAN ENERGI LISTRIK

The use of electrical energy that is often encountered in households is leaving the house with the lights on, leaving electronic goods stuck in the socket, charging cell phones overnight and turning on the air conditioner when no one is around. This unwise behavior will result in a high increase in the use of electrical energy. To reduce this unwise behavior, a device will be made that functions as a switch to cut off electrical energy automatically when we leave the room. This tool uses an Arduino Uno microcontroller with a Passive Infrared Receiver sensor to flow electrical energy when we enter the room and cut off electrical energy when leaving the room. It can be concluded that the use of an automatic switch can reduce electrical energy consumption. Automatic switches with a delay of 20 seconds compared to conventional switches have a significant ratio of electrical energy consumption as indicated by the test results of a multiple ratio of 0.00 with a test level of less than 0.05. Using an automatic switch with a 20 second delay results in savings in electrical energy consumption of 48.76% of the electrical energy consumption using conventional switches.

A methodology to estimate baseline energy use and quantify savings in electrical energy consumption in higher education institution buildings: Case study, Federal University of Itajubá (UNIFEI)

Abstract Accurately forecasting energy consumption in a building is an important strategy for achieving the goal of reducing energy demand and improving energy efficiency. University campuses represent specific groups of diverse buildings with significant energy consumption. Therefore, they provide an excellent testbed to characterize and understand the energy consumption of a group of mixed-use buildings. This paper presents a novel methodology that considers the recommendations of ISO 50001: 2011 and ISO 50006: 2014 for establishing energy baselines and energy performance indicators in higher education institution buildings to identify electrical energy consumption reduction potentials in buildings and establish energy management strategies related to electricity use. The study was implemented in three buildings at the Federal University of Itajuba (Jose Rodrigues Seabra Campus). Several methods and indicators were evaluated to monitor and measure energy performance in buildings. A wide range of factors that influence operating system energy consumption in the buildings were studied and taken into account, such as the types of activities carried out in the building, weather conditions, building materials, air conditioning system and occupancy, since these contribute directly and indirectly to the difficulty of accurately measuring the building’s energy consumption. The results showed that potential annual savings in electric energy consumption for the campus could be around 9.6%, which translates into a R$ 93,647.2 economic value and a 20.3 tCO2eq emissions reduction without economic investment. It was concluded that the methodology proposed for establishing and monitoring an energy efficiency indicator can be applied to any institute of higher education because it is flexible and adaptable since each institute can define the period of analysis for the indicator. This research is expected to provide theoretical guidance and a practical data reference for relevant evaluations of building energy efficiency.

RANCANG BANGUN MESIN MINI PENGKONDISIAN UDARA TIPE WATER COOLED CONDENSOR DENGAN PENGONTROLAN TEMPERATUR KABIN BERBASIS MIKROKONTROLER ARDUINO

Abstrak
 
 Penelitian ini berupa rancang bangun sebuah prototipe mini pengkondisian udara tipe water cooled water serta melalukan pengujian prototipe dengan menggunakan variable berupa temperatur nyaman kabin yang dicapai 22,8oC~26,7oC. Dalam pengujian prototype bertujuan mengkaji kinerja hasil rancang bangun berbasis mikrokontroler Arduino Uno untuk pengontrolan temperatur kabin yaitu sensor temperatur DS18B20 dan tanpa menggunakan Arduino Uno. Penelitian ini dilakukan selama satu jam dengan lima waktu pengujian yaitu pada menit 0 ke 10, menit 11 ke 20, menit 21 ke 30, menit 31 ke 40, menit 41 ke 50 dan menit 51 ke 60. Hasil penelitian menunjukan pengunaan mikrokontroler Arduino menghasilkan konsumsi rata-rata daya kompresor berkisar 247watt~264watt dan ketika temperatur minimum evaporator sebesar 8oC tercapai, maka konsumsi daya kompresor mengalami penurunan antara 70,22% sampai dengan 93,29%. Hal yang sama juga terjadi ketika temperatur maksimum evaporator tercapai (20oC), konsumsi daya kompresor juga mengalami penurunan diantara 59,77% hingga 72,02%. Sedangkan hasil pengujian tanpa menggunakan mikrokontroler Arduino konsumsi daya kompresor selalu cenderung konstan pada menit 10 hingga menit ke 60, dimana rata-rata konsumsi daya kompresor berurutan berkisar 267watt~ 275watt untuk tiap capaian temperatur evaporator. Dalam hasil pengujian berbasis mikrokontroler Arduino memberikan penghematan konsumsi energi listrik berupa daya kompresor sebesar 14,65 watt untuk tiap 10 menit pengujian. Hasil penelitian juga diketahui pengontrolan temperatur berbasis mikrokontroler perlu dilakukan agar koefisieb kinerja (coefficient of performance) mesin dapat dijaga konstan serta salah satu langkah agar kompresor tidak bekerja secara terus-menerus (continuously) pada saat temperatur kabin tercapai, dalam hal ini dapat menjaga umur pemakaian kompresor.

(Invited) Electrospun Nanofiber Composite Bipolar Membranes

Bipolar membranes, typically a laminate of an anion-exchange and cation-exchange membrane, have the unique capability to split water at a potential as low as 0.8 V while conventional electrolysis requires at least 1.2 V. Such membranes are employed in a number of important industrial processes, including the production of mineral acids, the recovery of organic acids from fermentation processes, pH control, and ion-exchange resin regeneration. The use of bipolar membranes in electrodialysis separations eliminates unwanted salt efflux and disposal problems and offers significant savings in electrical energy consumption. Recently, bipolar membranes have also been examined for use in self-humidifying hydrogen/air fuel cells, where the recombination of electrochemically generated hydroxide ions and protons at the bipolar junction produces water that improves membrane hydration, with higher power output at reduced feed gas humidity conditions. We report here for the first time on the design, fabrication, and testing of a new bipolar membrane that was made by polymer nanofiber electrospinning, where the anion-exchange polymer is quaternized poly(phenylene oxide) and the cation-exchange polymer is sulfonated poly(ether ether ketone). This new membrane has a 3-D nanofiber bipolar junction with a very high interfacial area, unlike the typical 2D planar junction. This extended junction morphology is important for two reasons: (1) it improves the attachment (adhesion) of the two ion-exchange layers so that ballooning/delamination is minimized or eliminated and (2) the increased bipolar junction surface area will lead to a better distribution of the water splitting reaction and lower membrane voltage drop for the same operating current density. The procedure for membrane fabrication will be described and the performance of electrospun films will be compared to bipolar membranes in the literature.

Modelling and simulation of a heat pump for simultaneous heating and cooling

The heat pump for simultaneous heating and cooling (HPS) carries out space heating, space cooling and hot water production for small office and residential buildings. It works under heating, cooling and simultaneous modes to produce hot and chilled water according to the thermal demand of the building. A subcooler connected to a water tank is placed after the condenser to recover some energy by subcooling of the refrigerant during a heating mode. The water loop at a higher temperature than ambient air is used subsequently as a source for a water evaporator. Average winter performance is improved compared to a standard reversible heat pump (HP). The air evaporator is defrosted by a two-phase thermosiphon without stopping the heat production. The operation of the HPS is modelled using TRNSYS software. The model is validated using results of an experimental study carried out on a HPS prototype working with R407C. Annual simulations of the HPS coupled to a hotel are run in order to evaluate annual performance and energy consumption of the system. The results are compared to the ones of a standard reversible HP. Depending on the scenario, savings in electric energy consumption and annual performance improvement can reach respectively 55% and 19%.

Biomechanical pulping: a mill-scale evaluation

Mechanical pulping process is electrical energy intensive and results in low paper strength. Biomechanical pulping, defined as the fungal treatment of lignocellulosic materials prior to mechanical pulping, has shown at least 30% savings in electrical energy consumption, and significant improvements in paper strength properties compared to the control at a laboratory scale. In an effort to scale-up biomechanical pulping to an industrial level, 50 tons of spruce wood chips were inoculated with the best biopulping fungus in a continuous operation and stored in the form of an outdoor chip pile for 2 weeks. The pile was ventilated with conditioned air to maintain the optimum growth temperature and moisture throughout the pile. The control and fungus-treated chips were refined through a thermomechanical pulp mill (TMP) producing lightweight coated paper. The fungal pretreatment saved 33% electrical energy and improved paper strength properties significantly compared to the control. Since biofibers were stronger than the conventional TMP fibers, we were able to reduce the amount of bleached softwood kraft pulp by at least 5% in the final product. Fungal pretreatment reduced brightness, but brightness was restored to the level of bleached control with 60% more hydrogen peroxide. The economics of biomechanical pulping look attractive.

Simultaneous Nitrification-Denitrification Processes in Activated Sludge Plants: Performance and Applicability

This paper deals with the development of technologies aimed to upgrade existing waste water treatment plants, paying attention to high process efficiencies and low costs. We established conditions for good N removal efficiencies in extended aeration activated sludge plants which are not equipped with specific denitrification steps. The experimental process is based on establishing conditions in the biological reactor which allow simultaneous nitrification and denitrification without alternating (in time or in space) anoxic and aerobic phases; the aeration system is controlled by means of dissolved oxygen and/or redox potential measurements. The research was carried out on two real plants (design size: 2,500 p.e. and 440,000 p.e. respectively). The main advantages of this process (even if some aspects are still under investigation) are: total N removal efficiencies similar to a pre-denitrification process, without the need for an anoxic basin and decrease of operating costs (savings in electric energy consumption in particular) due to the low oxygen concentration required in the biological reactor.

Technical note Intelligent thermal energy meter cum controller for solar water heating systems

A microcontroller based, thermal energy meter cum controller (TEMC) suitable for solar thermal systems has been developed. It monitors solar radiation, ambient temperature, fluid flow rate, and temperature of fluid at various locations of the system and computes the energy transfer rate. It also controls the operation of the fluid-circulating pump depending on the temperature difference across the solar collector field. The accuracy of energy measurement is ±1.5%. The instrument has been tested in a solar water heating system. Its operation became automatic with savings in electrical energy consumption of pump by 30% on cloudy days.

Simultaneous nitrification-denitrification processes in activated sludge plants: Performance and applicability

This paper deals with the development of technologies aimed to upgrade existing waste water treatment plants, paying attention to high process efficiencies and low costs. We established conditions for good N removal efficiencies in extended aeration activated sludge plants which are not equipped with specific denitrification steps. The experimental process is based on establishing conditions in the biological reactor which allow simultaneous nitrification and denitrification without alternating (in time or in space) anoxic and aerobic phases; the aeration system is controlled by means of dissolved oxygen and/or redox potential measurements. The research was carried out on two real plants (design size: 2,500 p.e. and 440,000 p.e. respectively). The main advantages of this process (even if some aspects are still under investigation) are: total N removal efficiencies similar to a pre-denitrification process, without the need for an anoxic basin and decrease of operating costs (savings in electric energy consumption in particular) due to the low oxygen concentration required in the biological reactor.

Simultaneous nitrification-denitrification process in extended aeration plants: pilot and real scale experiences

This work deals with the study of technologies aimed to upgrade the existing waste water treatment plants, paying attention to high process efficiencies and low costs. We verified the possibility to reach high N removal efficiencies in extended aeration activated sludge plants which are not equipped with specific denitrification steps. The experimented process is based on particular conditions, kept in the biological reactor, which allow simultaneous nitrification and denitrification, even without alternating (in time or in space) of anoxic and aerobic phases: aeration system is controlled by means of dissolved oxygen and redox potential measurements. Our research was carried out, for about three years, on a laboratory plant (V = 40 L) fed with synthetic waste water, a pilot scale plant (V = 1,400 L) fed with waste water coming from a real plant, and two full-scale plants (1,500-2,000 p.e.). The main advantages of the studied process are the following: high total N removal efficiencies (up to 90%) without the realization of new specific basins for the denitrification process; decreasing of operating costs (savings in Electric Energy consumption) due to the low oxygen concentration required in the biological reactor.

Simultaneous nitrification-denitrification process in extended aeration plants: Pilot and real scale experiences

This work deals with the study of technologies aimed to upgrade the existing waste water treatment plants, paying attention to high process efficiencies and low costs. We verified the possibility to reach high N removal efficiencies in extended aeration activated sludge plants which are not equipped with specific denitrification steps. The experimented process is based on particular conditions, kept in the biological reactor, which allow simultaneous nitrification and denitrification, even without alternating (in time or in space) of anoxic and aerobic phases: aeration system is controlled by means of dissolved oxygen and redox potential measurements. Our research was carried out, for about three years, on a laboratory plant (V = 40 L) fed with synthetic waste water, a pilot scale plant (V = 1,400 L) fed with waste water coming from a real plant, and two full-scale plants (1,500–2,000 p.e.). The main advantages of the studied process are the following: high total N removal efficiencies (up to 90%) without the realization of new specific basins for the denitrification process; decreasing of operating costs (savings in Electric Energy consumption) due to the low oxygen concentration required in the biological reactor.

Solar-assisted vapor compression/absorption cascaded air-conditioning systems

This article describes a hybrid air-conditioning system consisting of a conventional R-22 vapor compression refrigeration system cascaded with a solar-operated, ammonia-water, vapour absorption system. The condenser of the R-22 system is cooled by the evaporator of the the ammonia system. This facilitates operation of the R-22 system at a low condensing temperature and pressure. This is found to yield considerable savings in electrical energy consumption by the compression system.

Updating a 1950s-generation aluminum smelter

Hindalco’s aluminum electrolysis cells were initially installed in 1962, and the technology was based on 1950s-generation pots. Although Hindalco expanded its aluminums melting capacity from 20,000 tonnes per year to 175,000 tonnes per year, the basic design of the pots remained unchanged. In view of energy price increases, and to keep pace with the latest developments in aluminum smelting technology, Hindalco undertook efforts to modernize its facilities. In spite of numerous constraints, the Hindalco smelter has been able to achieve performance nearly equivalent to that of 1980s-generation pots by retrofitting new technologies. This has resulted in considerable savings in electrical energy consumption and raw materials usage.