Search

Lead-acid batteries utilised in electrical substations release hydrogen and oxygen when these are charged. These gases could be dangerous and cause a risk of fire if they are not properly ventilated. Therefore, this research seeks to design and implement a network control panel for heating, ventilation, and air conditioning system (HVACS). This is achieved by using a specific range of controllers, which have more than thirty loops of proportional, integral, and derivative (PID) control to achieve a cost-effective design. It performs the required function of extracting hydrogen and oxygen, maintaining the desired temperature of the battery storage room within recommended limits (i.e., 25 ± 1 °C tolerance) without compromising quality, as set out in the user requirement specification. The system control panel allows the user to access control parameters such as changing temperature set-points, fan-speed, sensor database, etc. It does this automatically and allows no human interface after all necessary settings and installation are completed. The hardware is configured to detect extreme hydrogen and oxygen gas content in the battery room and to ensure that the HVACS extracts the gas content to the outside environment. The system’s results show that the network control panel operates effectively as per the recommended system requirements. Therefore, the effective operation of the HVACS ensures sufficient gas ventilation, thus mitigating the risk of fire in a typical battery storage room. Furthermore, this also enhances battery lifespan because of regulated operating temperature, which is conducive to minimise the effect of sulfation in lead–acid batteries (LAB). The extraction of toxic gases, regulation of temperature, ensuring suitable humidity in UPS battery room is important as it provides longer operational service of equipment, thus reducing frequent maintenance in these rooms. This benefits the electricity supply industry and helps in saving for unplanned maintenance costs.

Lead-acid batteries utilised in electrical substations release hydrogen and oxygen when these are charged. These gases could be dangerous and cause a risk of fire if they are not properly ventilated. Therefore, this research seeks to design and implement a network control panel for heating, ventilation, and air-conditioning systems (HVACS). This is done using a specific range of controllers, which have more than thirty loops of proportional, integral and derivative (PID) control to achieve a cost-effective design. It performs the required function of extracting hydrogen, oxygen, and maintaining the desired temperature of the battery storage room within the recommended limits (i.e. 25°C ±1°C tolerance) without compromising quality as set out in the user requirement specification in Appendix-A. The system control panel allows the user to access control parameters such as changing temperature set-points, fan-speed, sensor database amongst others. The hardware is configured to detect extreme hydrogen and oxygen gas content in the battery room and ensure that the HVACS extract the gas content to the outside environment. The results of the system show that the network control panel effectively operates as per the recommended system requirements. Therefore, the effective operation of the HVACS ensures sufficient gas ventilation, thus mitigating the risk of fire in a typical battery storage room. Furthermore, the effective operation of HVACS enhances battery lifespan because of regulated operating temperature, which is conducive to minimise the effect of sulfation in lead acid Batteries (LABs).

This paper presents a complete design of a Heating Ventilation Air Conditioning (HVAC) system for battery rooms using modern components and techniques to achieve a cost effective design that will perform the required function without compromising the quality of the system. The HVAC installation for battery rooms is designed differently from a normal room since there will be gases inside, therefore all electrical devices are required to meet the requirements of the area classifications in which they are installed. There are four main factors affecting battery performance and life which are; cycling life, depth of discharge, temperature and recharge rate. This paper focuses on all the active systems which involve electrical design approach, installation and layout. It presents all the technical information related to an efficient design proving the benefits and necessity of the design.

Indoor air quality inside NiCad battery storage rooms is investigated in the current research. A proper ventilation system will guarantee safe environment inside the battery room by keeping vented gasses within their safe threshold allowed by standards and achieve sustainable energy efficient design by selecting the proper value of Air change per hour (ACH). This should be done by selecting the optimum configuration of inlets and outlets grilles location as well as choosing the most suitable way of battery storage whether on single rack, double rack or double rack with multi steps. Indoor air quality inside the battery storage room subjected to hydrogen gas emissions from the stored vented batteries is investigated numerically throughout the current research using Computational Fluid Dynamics (CFD). ANSYS 16.0 software was used. Parametric study is done to investigate the effect of splitting the long single row into two halves vertical rows (double rack with single step and double rack with double step) on ventilation efficiency for safety considerations. Storing the batteries in double vertical racks with double steps offered the best ventilation performance, using wall type inlet grille at the lower wall section (at the side) and outlet grilles at the roof, while the batteries’ racks are surrounded by curtains to act as local exhaust ventilation technique.

Lead-acid batteries are the most frequently used energy storage facilities for the provision of a backup supply of DC auxiliary systems in substations and power plants due to their long service life and high reliability. It is possible to define the load in these systems, therefore the IEEE 485 Standard can be used for the selection of batteries according to the conventional method of selection. Special attention is paid in the paper to the technical selection of a lead-acid battery, which depends on its operational reliability that decreases with battery aging. It is defined by the extent of maintenance during its service life. A cost analysis was also carried out, which took into consideration maintenance and procurement costs, as well as the costs of the related air conditioning that keeps the prescribed temperature and ventilates the battery room. The impact is shown of selecting a lead-acid battery on the battery room&rsquo, s operating safety when charging. The final selection of lead-acid battery is performed using an optimization algorithm of differential evolution. Using the optimization process, the new battery selection method includes the technical sizing criteria of the lead-acid battery, reliability of operation with maintenance, operational safety, and cost analysis. Two cases of selection of lead-acid batteries for the backup supply of a DC auxiliary system in a transmission substation are presented in the paper, where the input data were determined based on measurements in an existing substation. A comparison is made between the existing conventional and new lead-acid battery selection method based on optimization.

Small-scale brackish water reverse osmosis (BWRO) desalination units are not a major commercial success compared to its large-scale counterpart. Integrating renewable power systems with small-scale units would theoretically aid in their deployment and subsequent commercial success. In fact, RO units are constructed using a modular approach; this would allow them to adapt to a renewable power supply. Small-scale PV-RO would be a promising form of desalination system in remote areas, where BW is more common. The aim of this study is to quantify the effect of climatic-design-operation conditions on the performance and durability of a PV-BWRO desalination system. A small-scale unit is designed, constructed, and tested for 6 months. The design was limited to a 2 kWp PV power system, five different membranes, a feed TDS of 2000 mg/l, and a permeate TDS of less than 50 mg/l. Data pertaining to solar radiation and temperature were subsequently analyzed to determine their respective influences on current and future operations of the unit. The results showed that the optimum RO load, membrane type, and design configuration were 600 W, (4″x40″ TW30-4040), and a two-stage configuration, respectively. The PV system was able to supply the load without any significant disturbances; while the RO unit showed stable levels of permeate flow and salinity. Operating the PV-BWRO system for 10 h during the day would produce 5.1 m3 of fresh water at a specific energy of 1.1 kWh/m3. It was confirmed that there are many hours of high temperatures during the operation of the PV module (exceeding 45 °C) and battery room conditions (exceeding 35 °C), both of which could negatively affect the power output and battery autonomy. This negative effect is compounded annually; therefore, optimizing thermal regulation of PV modules and battery bank room conditions is essential in maintaining excellent operating temperatures.

An internal fire analysis Level-I probabilistic safety assessment (PSA) for TRIGA PUSPATI (RTP) nuclear research reactor was initiated. Previous study on half-scope mode Level-I PSA, focusing only on internal initiating event, were developed for both full power and shutdown operational mode. Hence, in ensuring PSA remains relevant, a subsequent study to kept PSA up to date is a compulsory. The aim of this study is to present the step-by-step work done and the insights gained in identifying and screening significant compartments that are potential to had the worst consequences as an ignition sources. This preliminary study will only focus on RTP’s basement which consist of 3 compartments: switch room, battery room and basement hall. Procedure in data collection were based on IAEA document, Specific Safety Guide No. 3: Development and Application of Level 1 Probabilistic Safety Assessment for Nuclear Power Plants (SSG-3). Microsoft Excel was used as data collection media and internal fire hazard database development. A brief qualitative analysis using failure mode and effect analysis is also presented.

After the Fukushima Dai-ichi accident occurred in Japan in 2011, many countries let nuclear power plant (NPP) licensees to increase battery back-up time to cope with extended station blackout (SBO). In South Korea, it is absolutely required to include the battery back-up time enhancement in the accident management program. Because of limited battery room space and easiness, the licensee mainly considers the load shedding without increased battery capacity. To increase battery capacity, however, lithium-ion battery is considered which requires less space than conventional lead acid battery. In this paper, we presented considerations assuming lithium-ion battery to be used in NPPs as safety class battery and also as power supply for beyond design based event (BDBE). Long term discharge characteristics of lithium iron phosphate (LiFePO4) and lithium nickel-cobalt-aluminum oxide (NCA) are elaborately evaluated through a series of experimental tests.

When charging most types of industrial lead-acid batteries, hydrogen gas is emitted. A large number of batteries, especially in relatively small areas/enclosures, and in the absence of an adequate ventilation system, may create an explosion hazard. This paper describes full scale tests, which demonstrate conditions that can occur in a battery room in the event of a ventilation system breakdown. Over the course of the tests, full scale hydrogen emission experiments were performed to study emission time and flammable cloud formation according to the assumed emission velocity. On this basis, the characteristics of dispersion of hydrogen in the battery room were obtained. The CFD model Fire Dynamic Simulator created by National Institute of Standards and Technology (NIST) was used for confirmation that the lack of ventilation in a battery room can be the cause of an explosive atmosphere developing, and leading to, a potential huge explosive hazard. It was demonstrated that different ventilation systems provide battery rooms with varying efficiencies of hydrogen removal. The most effective type appeared to be natural ventilation, which proved more effective than mechanical means.

This paper presents one of the most important and representative projects in the country concerning isolated energy systems. The Institute of Planning and Promotion of Energy Solutions (IPSE) conducted this project for noninterconnected zones under the Ministry of Mines and Energy of Colombia. This project targets two main objectives: To increase the hours of electricity supply to the population and reduce the hours of use of diesel plants. This project allows for the production of electricity from solar radiation through “preinstalled solar trackers – 100kWp installed power” and a new solar farm which supplies 220kWp, plus a battery room with 480 cells and installed capacity storage 3,148kWh. Finally, the facility has been supported by two 308kW diesel plants. This paper presents the largest PV system isolated from Colombia so far. First, we make a geographical description of the area of project implementation, also an approach to the indigenous community, their customs and their social and technological issues. Likewise, the paper presents some of the challenges and difficulties of setting up the project in an isolated area of difficult access and complex environmental conditions. In addition, the stages of assembly and some technical details of installation are presented, highlighting the design features and implementation with respect to civil works, electrical works and the main

The Swiss PTT has installed an active repeater station powered by a photovoltaic energy storage system (PVES) on the peak Pit Muttler situated in the vicinity of the border corner Switzerland-Austria-Italy at an altitude of 3294 m. The PVES system consists of 72 60 W (4.32 kW-36m/sup 2/) solar panels with associated maximum power trackers and charging controllers. The photovoltaic energy is stored in 24 V batteries using 2 V VRLA Compact Power cells with a nominal capacity of 1000 Ah (C/sub 10/) per cell. In order to evaluate the worst case conditions of extremely low temperatures within the battery room, the low temperature (-30/spl deg/C) and the low voltage (0.00 V/cell) behaviour of such cells is reported. Batteries survive freeze/thaw cycles unscathed and can be recharged with the electrolyte "frozen". >

In large PV hybrid power systems battery management is critical due to the continuous operation of the power system, the limited power available for temperature control in the battery room, and the high cost of maintenance. A new C&D CPV deep-cycle low antimony vented battery has been tested in the laboratory and at the Grasmere Idaho PV hybrid power system to evaluate battery capacity, charge requirements, temperature, and cost. Laboratory cycle tests on the battery were used to evaluate appropriate charge control for PV hybrid applications and battery field performance was verified after 2.5-years of operation at Grasmere Idaho. Test results demonstrated that with proper system and battery design using appropriate charge control, the battery will operate reliably with minimal maintenance under the continuous operational requirements of a large PV hybrid power system.

There has been a proliferation of application-sensitive, normally gas efficient recombining VRLA batteries. In many applications this product is housed in relatively small rooms with minimal control of ambient temperature or battery charge current. At less than extreme excesses of these variables the recombination of the hydrogen and oxygen evolving from the battery becomes inefficient. Under these conditions potentially explosive mixtures of hydrogen in air develop and the battery room is no longer a safe environment. A thorough understanding of the properties of hydrogen transport and its ventilation is essential to prevent a dangerous buildup of hydrogen. We have tested the parameters necessary to provide efficient hydrogen ventilation and have found the following: a H/sub 2/ diffusion coefficient that is approximately a fifth of the literature value; the vent path length association to the hydrogen concentration in the battery room is not one to one, as indicated by the classical diffusion equations; hydrogen ventilation calculations and methods are presented for simple diffusion and forced air convection (fans); and it is experimentally demonstrated that the friction and turbulence of air flow when using fans needs to be determined by direct measurement.

In recent years, there has been a proliferation of application-sensitive, normally gas efficient recombining VRLA batteries. In many applications, this product is housed in relatively small rooms with minimal control of ambient temperature or battery charge current. At less than extreme excesses of these variables, the recombination of the hydrogen and oxygen evolving from the battery becomes inefficient. Under these conditions potentially explosive mixtures of hydrogen in air develop and the battery room is no longer a safe environment. A thorough understanding of the properties of hydrogen transport and its ventilation is essential to prevent a dangerous buildup of hydrogen. The authors have tested the parameters necessary to provide efficient hydrogen ventilation and have found the following: a H/sub 2/ diffusion coefficient that is approximately a fifth of the literature value; the vent path length association to the hydrogen concentration in the battery room is not one to one, as indicated by the classical diffusion equations; hydrogen ventilation calculations and methods are presented for simple diffusion and forced air convection (fans). It is experimentally demonstrated that the friction and turbulence of air flow when using fans needs to be determined by direct measurement.

The efficacy of employing battery condition management equipment and procedures is demonstrated on the solid basis of field experience in which the host batteries were found either to be flawed or operated in ways that would compromise reliability. Examples found using such equipment and reported in this paper include a cell whose voltage vacillated daily while on float, post/strap joints whose accept/reject connection integrity was erratic with time, chargers whose voltages were improperly set (both high and low), and a battery room environment whose conditions were life-shortening to electrolytic cells.

The objective of the study is to estimate the probability of failure of the battery system of a nuclear power plant due to loss of ventilation in the battery room during ac blackout. This is part of the more general problem of the interaction between non-safety systems and safety systems. The emergency battery system and the associated ventilation system are a pair of interactive systems, the former being a safety system and the latter a non-safety system. Described are: (1) the emergency battery room; (2) the heat sources in the room following ac blackout; (3) the overall problem of insufficient power in the plant, the frequency of loss of ac power, and the time-dependent probability of nonrestoration of ac power; (4) the probabilistic approach to the problem; and (5) the thermal models used to evaluate the temperature rise in the battery room. A series of tables show the failure probabilities at several times and for different values of the standard deviations of the parameters of importance.

For the past three years cannibalism has been controlled and prevented by the use of natural colored ruby lights in battery brooders and fattening batteries at the Washington Agricultural Experiment Station. During the winter of 1929 in the experiments being conducted in the nutritional laboratory, considerable difficulties were encountered by the development of cannibalistic habits with the White Leghorn chicks closely confined in batteries. The trouble appeared when the chicks reached five or six weeks of age and were developing new feathers at a rapid rate. Close confinement and the presence of blood-filled shafts of new feathers in a well lighted battery room were apparently major contributing causes of these outbreaks of cannibalism. The cannibalism was so severe that many of the chicks were killed before any method of prevention could be devised. In attempting to control these outbreaks, various shades of colored light bulbs were tried to observe the . . .

The sealed lead-acid stationary batteries having capacities in the range of 200 Ah to 1000 Ah have been developed lately by Yuasa. The principal features of these batteries are as follows: 1) These batteries are about 15% superior in discharge capacity at one hour rate compared with a conventional flooded battery. 2) The expected service life of these batteries used in float service is more than 10 years. 3) These batteries can be placed on their side without deterioration in their capacity with respect to time. Hence, the space for installation of an assembly of the batteries can be decreased to 60% to 80% of that for an assembly of the conventional flooded batteries. 4) The batteries can be provided with a connector for the battery voltage and temperature, fixed to each battery beforehand, which can be connected with a single touch to make it easy to monitor the battery condition. 5) No gas is generated during normal float service, and hence the battery can be installed in the vicinity of its load, such as electric telecommunication equipment, without the need for preparing a special battery room.

An uninterruptible DC power supply system for telecommunications consists of batteries, which supply the load with electric power in case of a commercial power failure, and a rectifier which supplies the load with electric power as long as the commercial power is available, while charging the batteries. The conventional vented type batteries are usually installed in a large battery room because of gas generation and their complicated inspection and maintenance requirements. However, as reported separately in the INTELEC 1986, sealing of batteries having a large capacity up to 1000AH has been made possible, and thereby the need for maintenance and checking of the batteries has become less necessary and also gas generation has been eliminated, resulting in compact installation of batteries in a corner of the communication equipment room made possible. On the other hand, for the rectifier, the thyristor phase control system was employed in the past which was large in size and heavy in weight. With the use of the sealed batteries, however, the demand for small-sized light-weight rectifiers is now strong. For this reason, making the rectifier smaller and lighter by the switching regulator system (hereafter abbreviated as SWR) has drawn attention. In order to realize a large capacity rectifier by employing the SWR, however, special components are necessary as well as the circuits become complicated, which makes the rectifier very costly.

Lead-acid storage batteries are used extensively in the Telecommunications industry as a source of standby power in the event that utility supplied electrical power, is for whatever reason, interrupted. Lead-acid batteries offer many advantages over alternative power sources, the most important one being low cost, reliable power. However, despite all of their inherent advantages, they do possess several unpleasant shortcomings, especially from the user's point of view. During charging, water contained in the electrolyte of lead acid batteries is electro-chemically broken down into hydrogen and oxygen gas which escapes into the atmosphere. This characteristic creates the need to periodically replace lost water, and to provide adequate means to remove the dangerous gasses that are released. Furthermore, as the gasses are emitted from the cells, acidic mist is carried with them, which causes corrosion of battery hardware, racks and any equipment which is located nearby to the battery. These idiosyncrasies have lead users of lead acid batteries to contain them in isolated rooms, separate from the telecommunications equipment which they support. Finally, conventional lead acid cells are installed on steel racks to make up a battery, which is a costly, labor intensive process. Also, the steel rack packaging concept requires a large amount of floor space leading to increased battery room sizes. A new lead acid battery, utilizing the principal of oxygen recombination, has been developed which solves all of the problems previously associated with conventional batteries, as listed above.