DOI 10.35776/MNP.2019.10.04
УДК 614.844
Yepifanov S. P., Zorkaltsev V. I., Baranchikova N. I., Korel’stein L. B.
Hydraulic calculation of automatic firefighting systems
combined with internal fire water pipeline system
Summary
In recent decades the construction of large buildings has risen sharply: shopping and entertainment centers, multifunctional high-rise buildings for residential and public purposes with underground parking lots, storage facilities for the storage of combustible materials. During construction finishing materials are often used that emit toxic substances if ignition occurs. Fires can result in fatalities and substantial material losses. For the fire safety of buildings and structures the use of firefighting water supply – both outdoor and internal is most effective. Due to the inability to provide for outdoor firefighting of a large part of the premises of the upper floors of high-rise buildings, the effectiveness and reliability of internal firefighting systems is of particular importance. Water consumption for fire water supply can be 200 l/s or more. To supply water in such a volume to the fire points, effective internal fire water supply systems are required: automatic firefighting systems (sprinkler and deluge), internal fire water pipelines, deluge water curtains. Combined internal firefighting systems include automatic firefighting installations and internal firefighting water pipeline. The method of hydraulic calculation of each of these systems is available in the regulatory and specialized literature. However, in the process of hydraulic calculations of combined (integrated) firefighting water supply systems, their essential features should be taken into account. In this regard, a mathematical model of flow distribution in automatic firefighting systems combined with an internal fire water pipeline system is considered. The technique of hydraulic calculation of arbitrary combined firefighting water supply systems is given. The proposed model allows you to get an actual value of water abstraction through nozzles (sprayers) and hand control branch pipes.
Key words
pressure , head , hydraulic design , water curtain , automatic firefighting installations , internal fire water pipeline , flow distribution task , variable abstraction
|
bbk 000000
UDC 628.12: 628.171.001.24
Kirsanov A. A., Kolchev V. N., Shmigol V. V., Chernosvitov M. D.
Research in Relift Pumping Stations
Summary
Results of the research in operation of relift pumping stations of Samara (water consumption, pressure in the suction and pressure pipelines) are presented. The aligned graphs of distribution of specific water consumption, an average value of factual specific water consumption and coefficients of irregularity, diagrams of annual and daily changes of water consumption are given. The comparison of results obtained with the standards in force is made. Values of specific consumption of 5 and 95% provision and also a probability of ingress of factual water consumption into the interval defined by the standard specifications are determined. The efficiency of the use of frequency regulation at intra-block pumping stations is substantiated.
Key words
water meter , head , pumping station , diagram of water consumption , hourly irregularity , frequency converter
|
bbk 000000
UDC 628.22:532.542
Chupin V. R., Melekhov E. S., Chupin R. V.
Pressure Movement of Flows in Gravity Manifolds
Summary
A new approach to the design of water disposal systems based on their simulation with hydraulic chains with unrecorded withdrawals and inflows of runoffs is offered. It makes it possible, on one hand, to determine the presence of counterflows in the network, possible effusions of flows on the ground surface, volumes of runoffs running out, carrying capacity of a water disposal system and, on the other hand, to simulate various conditions of flow transportation with due regard for possible cloggings, encrustation of pipes and other violations which can occur during the operation.
Key words
wastewater , head , water disposal system , collector , hydraulic design , well , simulation
|
DOI 10.35776/MNP.2020.02.08
UDC 628.144:614.842.62:006.015.7
Primin Oleg
Optimization of the choice of diameters of the pipelines
in the water distribution network considering the fire safety
Summary
With the arrangement of combined drinking water and fire water supply systems, the importance of the distribution network increases even more, since additional functions are assigned to provide for the transportation of large amounts of water for firefighting. Meeting the firefighting requirements in conditions of a significant reduction in water consumption in most cities of Russia leads to negative consequences associated with low (0.1–0.3 m/s and less) flow rates and stagnation of water in some sections of the distribution network. Thereby, the organoleptic properties of water may deteriorate expressed in the appearance of flavors, unpleasant odors, increased turbidity and color, etc. In this regard, measures are required to optimize the choice of pipe diameters, to ensure and maintain the required quality of transported water in outdoor urban and distribution networks, and to guarantee meeting the required fire extinguishing standards. The research results and hydraulic calculations for assessing the minimum permissible water flow rates and minimum pipe diameters of submain networks are given taking into account the provision of external and internal firefighting. The tests were carried out in real conditions of the municipal water supply ring main in high- and low-pressure zones.
Key words
water consumption , flow rate , water supply network , head , water supply system , firefighting , velocity , nodal abstraction
Скачать/download (PDF) free access
|
bbk 000000
UDC 628.162
GALPERIN E. M.
Improvement of a Design Model of Operation of a Ring Water Supply Network
Summary
Issues of improvement of the design model of operation of the ring water supply network taking into account statistical data on its operation are considered. It is proposed to make corrections in the standards of water supply systems designing and supplement them with execution of reliability calculations of the ring water supply network.
Key words:
water supply network , water supply , head , reliability , failure , leak-proofness , Failure , designed model
|
bbk 000000
UDC 628.144.23.001.23
Novitskaia O. S.
Taking into account the actual conditions of water consumption
in hydraulic designing water distribution networks
Summary
Pipeline hydraulic estimation is a basis of the process and technical-and economic, optimization, in particular, design of water supply systems. Improving hydraulic design of the water distribution networks with due account for the actual water consumption is a topical task; whereas estimation of the water flow rate dependence from free head values is an important and essential basis for calculations. The method of hydraulic design of water distribution networks with account of water flow rate dependence from free head values in the zones of both deficient and excessive head was developed and presented. To account for water losses the correlation factors of total water losses and total consumption, between water loss values in residential buildings and between total water loss values were introduced. The exponents reflecting water flow rate variation at nodal points were introduced. GRS NEW software for the hydraulic estimation of the joint operation of the entire system of water supply and distribution was improved. The software takes into account water flow rate increase at every nodal point depending on the available water head and allows identifying the problem points.
Key words
losses of water , water supply network , head , water supply and water distribution system
|
bbk 000000
UDC 621.65:62-531.3
Economic efficiency of using pumping units with variable-speed drives at low water supply
Summary
In the process of operating pumps with variable-speed drive at low water flow rates the reduction of the pumping unit efficiency factor is observed. It is suggested to determine the amount of energy lost during the operation of such pumping units with actual efficiency factor differing from the rated one. In some instances operating with low water flow rate results in power consumption increase. In this context experimental studies on determining the pumping unit efficiency factor at different impeller speeds were carried out. The results of the studies provided for identifying the optimal operation zone where the pumping unit efficiency factor was reduced by less than 2% of the maximum value, and the less economic zone where the efficiency factor was reduced to 35% of the maximum value. To evaluate the economic efficiency and determine the optimal operation area of pumping units with variable-speed drives at low water flow rate the efficiency curves for different pump impeller speeds are required. It is appropriate to include this data in pump catalogues.
Key words
adjustable electric drive , water supply , flow rate , head , frequency of pump impeller rotation , pump , water disposal , lifting efficiency , electric motor power
|
|
