Building a mathematical model for the heat build-up in the oil tank shell under the thermal effect of a combustible liquid pool fire within the tank dike. methodology. A thermal balance equation for an oil tank exposed to heat from the pool fire has been worked out. Both radiant and convective heat transfer processes between the pool fire and the environment have been taken into account. Estimates for the distribution of temperatures and airflow velocities in the plume above the fire have been used to account for the convection component of the heat flux from the pool fire. findings. Dynamics of the tank shell temperature change in time under the thermal effect of the pool fire within the dike has been obtained. The obtained expression is the solution of the differential equation worked out on the basis of the thermal balance analysis for the oil tank shell exposed to heat. originality. The convective component of the heat flux from the pool fire to the oil tank is taken into account and estimates of the distribution of temperatures and velocities in the plume are built. Practical value. The proposed model of the tank shell heat exposure to the pool fire within the dike could provide the basis for building a decision-making system for the fire response manager, outlining safe zones for positioning the equipment and personnel involved in fire-fighting, while developing fire pre-plans at the oil refining facilities and designing security systems for oil tanks.
Одержано математичний опис процесів гене-рації водню у вигляді системи диференційних рів-нянь та вираз для передаточної функції генера-тора. За допомогою логарифмічних частотних характеристик генератора водню ідентифікова-на наближена математична модель генератора у вигляді амплітудно-частотної характеристики. Запропонований алгоритм контролю технічного стану генератора водню із використанням його наближеного математичного опису Ключові слова: генератор водню, газогенера-тор, технічний стан, частотні характеристики, алгоритм контролю Получено математическое описание процессов генерации водорода в виде системы дифференци-альных уравнений и выражение для передаточной функции генератора. С помощью логарифмических частотных характеристик генератора водоро-да идентифицирована приближенная математи-ческая модель генератора в виде амплитудно-ча-стотной характеристики. Предложен алгоритм контроля технического состояния генерато-ра водорода с использованием его приближенного математического описания Ключевые слова: генератор водорода, газогене-ратор, техническое состояние, частотные харак-теристики, алгоритм контроля UDC 661.961; 861.968
The proposed methods for determining the dynamic characteristics of heat fire detectors in the time and frequency domains, focused on the use of existing thermal chambers. The proposed method for determining the transition function of the detector is implemented as follows. Heat fire detector creates a thermal effect in the form of a linearly increasing function. The response of the output signal to the influence of this type is measured and approximated using the Heaviside function at regular intervals.It is shown that information on the transition function of a heat fire detector can be used to determine its frequency characteristics by approximating it with Heaviside functions at the same time intervals. This method of determining the frequency characteristics will significantly reduce the time to determine them compared to the classical method, and also eliminate the need for additional equipment.As a result of the studies, the choice of the sampling interval was justified on the example of a class A1 heatfire detector and certain sampling intervals for determining their transition function (τ 0 ≤1.05 s), amplitude-frequency characteristic (τ 0 ≤0.27 s) and phase-frequency characteristic (τ 0 ≤2.0 s).The proposed methods for determining the dynamic characteristics of heat fire detectors open up new opportunities for developing methods for monitoring their technical condition. This is because the information about the transition function of the detector can be used in two ways. The first method involves comparing a certain transition function of the detector with an exemplary one. The second method consists in determining other characteristics of the detector based on information about its transient function and comparing them with standard values.
Algorithms for the control of the technical mill of gas generators in the systems of protection and supply of water, as an element of the systems of fire prevention. Algorithms for monitoring the dynamic parameters of gas generators of gas generators to control the flow and transmitting test signals to two types - from the viewer of the linearly growing function, or from the viewer of the straightforward view. One hundred percent before such test signals are broken down direct and indirect methods of control of the technical mill of gas generators in the systems of recovery and supply of water. It is shown that in the implementation of direct methods of control, no middle value of the parameters in the gas generators begins. To such parameters, the transmission efficiency is applied and continuously for an hour, as they characterize the dynamic power of gas generators in the systems of securing and supplying water. When implementing indirect methods of control, the integral characteristics of gas generators begin. In the quality of the information parameters, which are used to formulate the control algorithms, vibrating the vice in the empty gas generator of any average value. The values of these parameters are changed at two april given time of the hour, or at april given interval hour. In the quality of the criteria for the result of the control of the technical mill of the gas generators, the tolerance criteria are determined. It is shown that the priority in the vibration of the algorithm for the control of the technical mill of gas generators in the systems of gas generators and the supply of gas generators to the algorithm, which is based on the test signal in the form of a straight-flow gas generator. It should be considered that, when implementing such an algorithm, the control of the technical mill of gas generators in the systems of ensuring that the supply of vitality is kept to a minimum is minimal.
A method for determining the dynamic parameters of the operator of a mobile fire engine based on a segway, which fully characterize its dynamic properties – delay time and inertia was developed. The development of the method includes four stages. At the first stage, the problem of obtaining analytical relationships for determining the dynamic parameters of the operator is solved. These relationships include the frequency characteristics of the operator at a fixed frequency and its static parameter. At the second stage, the choice of a fixed frequency is substantiated using a criterion that minimizes errors in determining the dynamic parameters. It is shown that the fixed frequency for the characteristic parameters of the operator does not exceed 0.5 Hz. The third stage includes substantiation of the procedure for determining the frequency characteristics of the operator and its static parameter. The frequency characteristics of the operator at a fixed frequency and its static parameter are determined numerically. This procedure is based on using the data obtained by measuring the values of the operator’s transfer function at fixed time intervals. To obtain data, an interactive analog engine is used, which can also perform the functions of a simulator. The time intervals are chosen according to the Kotelnikov-Nyquist-Shannon theorem. At the last stage, the procedure for determining the dynamic parameters of the operator of a segway-based mobile fire engine is described. It is shown that the error in determining the dynamic parameters of the operator of a mobile fire engine does not exceed 9.0 %, if the error in determining its frequency characteristics at a frequency of 2.5 s–1 does not exceed 2.0 %
При формуваннi алгоритму контролю технiчного стану генераторiв водню в якостi вихiдних даних використовуються їх амплiтудно-частотнi та фазово-частотнi характеристики. При використаннi класичного методу визначення таких характеристик мають мiсце декiлька недолiкiв. Одним iз суттєвих недолiкiв є великий час, який необхiдний для формування масиву вихiдних даних. Для скорочення цього часу визначення частотних характеристик генератора водню здiйснюється за результатами вимiрювань його перехiдної функцiї в дискретнi моменти часу. В цi моменти часу перехiдна функцiя апроксимується функцiями Хевiсайда. Такий пiдхiд дозволяє скоротити час визначення частотних характеристик генератора водню на 1-2 порядки. Використання теореми Котельнiкова-Найквиста-Шеннона для визначення цих дискретних моментiв часу пов'язано iз невизначенiстю стосовно максимальної частоти спектру тест-сигналу. Для зняття цiєї невизначеностi вибiр дискретних моментiв часу для вимiру перехiдної функцiї генератора водню здiйснюється за умови допустимої похибки її апроксимацiї. Похибка апроксимацiї визначається за результатом розв'язання тест-задачi, в якiй в якостi еталону частотних характеристик використовуються модельнi характеристики. Показано, що при iнтервалi дискретностi (0,252,5) мс величина такої похибки не перевищує 1,7 %. Враховано iнерцiйнi властивостi пристрою для формування тест-впливу. Показано, що доцiльнiсть використання такої процедури має мiсце, якщо еквiвалентна постiйна часу такого пристрою перевищує величини постiйних часу генератора водню. Iнерцiйнi властивостi врахованi шляхом введення додаткового множника, який мiстить еквiвалентну постiйну часу пристрою, в аналiтичних виразах для частотних характеристик генератора водню Ключевi слова: генератор водню, вихiднi данi, частотнi характеристики, тест-задача, похибка апроксимацiї
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.