Modernization of Gradiren of Oil-Refining Plants

Приводится анализ вариантов модернизации вентиляторных градирен нефтехимических предприятий. Рассмотрены особенности эжекции в градирнях, предложены возможные варианты улучшения работы эжекционных градирен, связанные с конструктивным и материальным исполнением эжекционных сопел в градирнях.= This article gives an analysis of the options for upgrading the cooling towers of petrochemical enterprises. In the article are considered features of ejection in cooling towers, possible options for improving the operation of ejection cooling towers, related to the design and material execution of ejection nozzles in cooling towers are suggested

Traditional Biocidal Replacement Viability of Microcrystalline Silver Chloride

The antimicrobial effects of silver ions and silver chloride nanoparticles have been well established while the efficacy of microcrystalline silver chloride has been less studied. Certex-AM, a microcrystalline silver chloride product produced by Cerion, Rochester, NY, was tested for its antimicrobial properties as a possible replacement for traditional biocidal techniques used in water cooling towers. The minimum inhibitory concentration (MIC) of the compound was determined using a microtiter broth assay. The compound was found to have inhibitory effects on bacterial growth for all tested organisms at concentrations greater than 9 ppm. Additional testing simulating a water cooling system showed the effectiveness of reducing an established wild population at concentrations of 10 ppm of the microcrystalline silver chloride. Certex-AM was found to be a promising replacement for traditional biocides as well as for other applications. Introduction of effective antimicrobial compounds such as this could reduce the pathogenic risk to humans associated with water cooling towers

Improving Energy Efficiency of Cooling Towers the Plant “Polymir” of Jsc “Naftan”

Представлен сравнительный анализ работы вентиляторных и эжекционных градирен. Показаны их преимущества и недостатки. Рассмотрены особенности работы эжекторов в градирнях. Произведена оценка энергоэффективности при использовании эжекционных градирен. Показано, что вентиляторные градирни могут быть переоборудованы в эжекционные, причем реконструкция возможна с незначительными капитальными затратами: сохраняется корпус ранее функционирующей градирни, но меняется его обшивка; при необходимости производится ремонт несущих конструкций, устанавливается коллектор с эжекционными форсунками.= The paper provides a comparative analysis of the ejection fan and cooling towers and their advantages. The features of the work of ejectors in cooling towers, the possibility of reconstruction of the existing fan coolers are considered. Energy efficiency rating when using ejection of cooling towers is produced. It is shown that the existing cooling towers can be converted into the ejection, the body remains of the old tower, changing the body paneling, as necessary, repaired bearing structures, installed collector ejection nozzles. Those reconstruction can be carried out with little capital expenditure

Computer optimization of the MIT advanced wet/dry cooling tower concept for power plants

There is a projected water shortage problem in the electrical power industry by the end of this century. Dry and wet-dry cooling towers are going to be the solution of this problem. Our previous study on the combination of separate dry and wet cooling towers indicated that wet-dry cooling is an economical choice over all-dry cooling when some water is available but the supply is insufficient for an evaporative tower. An advanced wet-dry cooling tower concept was experimentally studied at MIT's Heat Transfer Laboratory and a computer model was developed for predicting the performance of this cooling concept. This study has determined the cost of the cross-flow type of this cooling concept in conjunction with steam electrical power plants. Aluminum is found to be economically preferable to galvanized steel as the cooling plate material. In our base case study using aluminum plates for a 1094 MWe nuclear plant at Middletown, the MIT advanced cooling concept is comparable to conventional wet-dry towers at water makeups larger than 45% and is slightly more economical at makeup larger than 50%. The incremental costs over the power production cost, 32.3 mills/Kwhr, of zero condenser system are 14, 13 and 12 percent for makeups of 45, 60 and 55 percent, respectively. For an 800 MWe fossil plant at Moline, this cooling concept is more economical than conventional wet-dry towers at water makeups larger than 27%. The incremental costs over 20.8 mills/Kwhr of zero condenser system are 12.2 and 10.6 percent for makeups of 37 and 50 percent, respectively. For these two makeups, going from conventional wet-dry to MIT advanced concept results in 13 and 21 percent, respectively, savings in the incremental cost. When the water makeup exceeds 30%, the MIT advanced wet-dry concept is pre- ferable to conventional wet-dry towers for a 1200 MWe nuclear plant at Moline, Ill. The incremental costs over zero condenser system of 21.1 mills/ Kwhr are 12.8 and 11.5 percent for makeups of 40 and 50 percent, respectively. Using the MIT advanced concept instead of conventional wet-dry towers results in 28 and 33 percent reduction of incremental power production cost for these two makeups, respectively."Prepared under the support of the Environmental Control Technology Division Office of the Assistant Secretary for the Environment

Comparing Poynting flux dominated magnetic tower jets with kinetic-energy dominated jets

Magnetic Towers represent one of two fundamental forms of MHD outflows. Driven by magnetic pressure gradients, these flows have been less well studied than magneto-centrifugally launched jets even though magnetic towers may well be as common. Here we present new results exploring the behavior and evolution of magnetic tower outflows and demonstrate their connection with pulsed power experimental studies and purely hydrodynamic jets which might represent the asymptotic propagation regimes of magneto-centrifugally launched jets. High-resolution AMR MHD simulations (using the AstroBEAR code) provide insights into the underlying physics of magnetic towers and help us constrain models of their propagation. Our simulations have been designed to explore the effects of thermal energy losses and rotation on both tower flows and their hydro counterparts. We find these parameters have significant effects on the stability of magnetic towers, but mild effects on the stability of hydro jets. Current-driven perturbations in the Poynting Flux Dominated (PDF) towers are shown to be amplified in both the cooling and rotating cases. Our studies of the long term evolution of the towers show that the formation of weakly magnetized central jets within the tower are broken up by these instabilities becoming a series of collimated clumps which magnetization properties vary over time. In addition to discussing these results in light of laboratory experiments, we address their relevance to astrophysical observations of young star jets and outflow from highly evolved solar type stars.Comment: 11 pages, 4 figures, accepted for publication in the High Energy Density Physics Journal corresponding to the proceedings of the 9th International Conference on High Energy Density Laboratory Astrophysics, May 4, 2012, Tallahassee Florid

An environmental and economic comparison of cooling system designs for steam-electric power plants

Originally presented as a thesis (M.S.), M.I.T., Dept. of Civil Engineering, 1978, by Kenneth F. Najjar.The selection of waste heat rejection systems for steam-electric power plants involves a trade-off among environmental, energy and water conservation, and economic factors. This study compares four general types of cooling systems on the basis of these factors. The cooling systems chosen for study are: once-through systems including surface canals and submerged multiport diffusers; shallow closed cycle cooling ponds; mechanical and natural draft evaporative cooling towers; and mechanical draft dry towers. The cooling system comparison involves, first, an optimization of each cooling system and then a comparison among optimal systems. Comparison is made for an 800 MWe fossil unit and a 1200 MWe nuclear unit located at a hypothetical midwestern river site. A set of models has been developed to optimize the components of each cooling system based on the local meteorological and hydrological conditions at the site in accordance with a fixed demand, scalable plant concept. This concept allows one to compare the costs of producing the same net power from each plant/cooling system. Base case economic parameters were used to evaluate the optimum system for each of the four general cooling systems followed by a sensitivity study for each parameter. Comparison of energy and water consumption follows from the results of the performance model, while comparison of environmental impacts is mostly qualitative. Some quantitative modelling was performed for the environmental effects of thermal discharges from once-through systems, fogging from wet cooling towers and water consumption from the ponds, wet towers and once-through. The results of the optimization models of each of the systems are compared on the basis of: performance - discrete distributions of environmental conditions and transient simulation; economics - using base case scenarios and sensitivity values to arrive at costs expressed in terms of production costs, annualized costs and present value costs; energy and water consumption; and environmental effects. The once-through systems were found to be the least expensive of the four systems, the most energy efficient, but potentially the most environmentally damaging. On the other extreme, dry cooling towers are the most environmentally sound while being the most expensive and least energy efficient. Finally, the results of the economic optimization are compared with results from previous comparative studies

Perancangan Desain Ergonomi Ruang Proses Produksi untuk Memperoleh Kenyamanan Termal Alami

Thermal comfort in a production process will increase the productivity of labor. Thermal comfort is affected by the dry bulb temperature, relative humidity and ventilation systems. The design space of the production process is designed to have area 1500 m2 and has six cooling towers. From the research results obtained the production process of circulation space which occurred 26.5 / h, air flow rate into the system is 0.9648 m / s with a correction factor of 0.4, has a power ventilation evaporative cooling tower total of 5472 Watts and has a cooling load 18 173, 3 kW. This condition is able to meet the thermal comfort requirements for the production of space used as a kitchen and a number of employees about 100 people. The design of cooling towers to meet the needs of the cooling load around 4%

Investigating the Effects of Flue Gas Injection, Hot Water Distribution, and Fill Distribution on Natural Draft Wet Cooling Tower Performance

Natural draft wet cooling towers (NDWCT) are a common method of heat removal in powerplants. This study employs a numerical cooling tower model developed by Eldredge, Benton & Hodgson (1997) to examine whether utilizing nonuniform water, fill profiles, and flue gas injection can improve NDWCT efficiency. The results show that each of these variables can be optimized to lower outlet water temperature. Within the range tested for each parameter, the water profile had the most significant effect on outlet water temperature, followed by the flue gas temperature and then the fill profile. The optimum parameter combination reduced the predicted outlet water temperature by 0.5 °C which corresponds to annual fuel savings of up to 55 million dollars and 1.83 million metric tons of carbon dioxide for fossil plants in the United States