МЕЖДУНАРОДНЫЙ НАУЧНЫЙ ЖУРНАЛ «ИННОВАЦИОННАЯ НАУКА» №06/2017 ISSN 2410-6070
районе границ блоков и вблизи других тектонических нарушений.
В связи с переходом горных работ на глубокие горизонты, и повышением требований к безопасности их ведения необходимость учета напряженного состояния массива становится все более острой, особенно на стадии проектирования горных предприятий, поскольку заложение в проект профилактических мер обеспечивает наибольший их эффект при эксплуатации рудника или шахты.
© Худойбердиев Ф.Т., Исраилов М.А., 2017
УДК 697.34
С. А. Шальнов
студент ИЭиЭ, ТГУ
г. Тольятти, Российская Федерация
ПОКАЗАТЕЛИ ЭФФЕКТИВНОСТИ РАБОТЫ ЦЕНТРАЛЬНЫХ ТЕПЛОВЫХ ПУНКТОВ
Аннотация
В статье рассматриваются основные подходы к оценке эффективности работы центральных тепловых пунктов. Приводятся конкретные показатели, посредством анализа которых можно определять эффективность. Эта проблема в настоящее время является актуальной в связи с реализацией государством и предприятиями программ энергосбережения. В результате анализа выявляются эффективные ЦТП и неэффективные, требующие проведения корректирующих мероприятий, которые позволят не только более рационально использовать тепловую энергию, но и повысить качество услуг отопления и водоснабжения.
Ключевые слова Центральный тепловой пункт, ЦТП, теплоснабжение.
S. A. Shalnov
student IE&E, TSU Tolyatti, Russian Federation
PERRORMANCE INDEXES OF THE CENTRAL HEAT POINTS
Abstract
This article presents several approaches to determining the efficiency of the central heat points. Specific indicators for the analysis are presented. They make it possible to determine the effectiveness. This problem is currently important with relation to energy saving programs, implemented by government and enterprises. As a result of the analysis, it becomes possible to find out the efficient central heat points and inefficient ones, that require corrective arrangements, which allow to use the heat energy more rationally as much as to improve the quality of heating and water supply services.
Introduction
Central heat points, being an important element of urban infrastructure, are widespread in the countries with a temperate climate, especially in Russia and ex-USSR states. They combine a complex of functions, such as control and regulation of the heat carrier medium parameters, transformation the type of heat carrier, distribution by systems of heat supply, turning the power on and off, protection from emergency incidents and accidental situations in heat distribution system, technical and commercial heat accounting, and they are meant to water and heat supply of several
_МЕЖДУНАРОДНЫЙ НАУЧНЫЙ ЖУРНАЛ «ИННОВАЦИОННАЯ НАУКА» №06/2017 ISSN 2410-6070_
buildings at once [1]. Central heat points primarily used in residential housing development [2], herewith one point usually provides with cold and hot water, as well as heating, from 2000 to 10000 inhabitants, depending on design features and housing project. The crucial problem, during an operation of central heat points, is to estimate their efficiency. It is necessary to improve the quality of water and heat supply in order to optimize the operation and performance of equipment and for energy saving, which is an important direction of state energy policy of mature economies.
Despite the applicability of this problem, there is no consistent approach to the estimation of central heat points efficiency. This is basically due to the considerable diversity of constructive solutions and equipment characteristic.
Efficiency as a measure of compliance with project regimes
The most obvious approach to determining the efficiency of the central heat point is to analyze the compliance of the operating regime parameters with the design values, which are calculated on the assumption of water and energy consumer's needs and the technical and legal requirements. These analyzing parameters include the following:
1. Temperature of hot water supply (tdhw);
2. Delivery heating water temperature (t1);
3. Returning water temperature (t2), achieved by the control of overheating and ensuring the compliance within the approved temperature chart;
4. Pressure in the heat and water supply systems inside the connected buildings;
5. Ensuring the normal and continuous operation of pressure and temperature regulators, flow control valves in the central heat point.
According to this approach, a central heat point, in which these values are as close as possible to the design values, will be considered as the most effective.
Efficiency as a heat loss minimization
As the central heat points are a component part of the heat networks and, ultimately, have the same purpose of transporting heat energy, in this view, the indicators, that characterize the efficiency of the heat networks operation, can be applicable to the central heat points. On the assumption of its destination, the efficiency of the heat networks is stated in minimizing of heat loss. Accordingly the basic indicator is the value of relative heat losses in networks:
ql = (Qo - Qn) / Qo (1)
where
Qo - is plant output of heat energy [Gcal];
Qn - is net heat supply [Gcal].
In respect to the central heat point this formula takes the following form:
ql = (Qd - Qr) / Qd (2)
where
Qd - is heat energy, delivered to the central heat point [Gcal];
Qr - is heat energy, returned from the central heat point [Gcal].
In order to increase efficiency, it is necessary to strive to the reduction of this coefficient, while designing and exploitation of the central heat point. This is achieved through using the energy-saving solutions and skilled work of operating personnel.
Complex efficiency of each processing performance
Another approach supposed different indexes for each processing [3].
In the standard technological scheme of group heating the central heat points in most cases firstly provides the chemical treatment of the source cold tap water with its heating, deaeration and then its transfer to another quality -into the hot water supply system for the needs of only one group of consumers.
At the initial stage of water treatment at the chemical water purification, the most important and well known indicator is the quality of the chemically purified water meaning its compliance with the applicable requirements. The second one is important, but already quantitative and energy-saving indicator is to consider the completeness of the source use water relative to the obtained:
_МЕЖДУНАРОДНЫЙ НАУЧНЫЙ ЖУРНАЛ «ИННОВАЦИОННАЯ НАУКА» №06/2017 ISSN 2410-6070_
g = Gsw / Gcpw (3)
where
Gsw - is discharge of source water for any considered time slot [m3];
Gcpw is volume of chemically purified water [m3].
And the difference (g-1) estimates in relative units the water losses resulted in the course of filters regeneration and possible partial leakages at this stage. Thus, a single, relative indicator of water use (water saving) has been obtained. It allows to compare any water purifier systems and to find out the systems with high water flow among them.
A similar formula is used to determine the total water loss with all the leakage in the whole heat point:
g = Gsw / Gdhw (4)
where
Gsw - is discharge of source water for any considered time slot [m3];
Gdhw - is discharge of hot water in the DHW system [m3].
It should be noted that in most cases both amounts are approximately equal because high-cube and indiscoverable leaks in the central heat point building are unlikely.
Another additional indicator of the first technological stage of obtaining chemically purified water, which estimates the energy intensity, can be the specific energy consumption for its transportation to the deaerator:
SEC Ecpw / Gcpw (5X
where
Ecpw - is total power consumption by all source water and water purifier system pumps [kWh];
Gcpw - is volume of chemically purified water [m3].
This indicator is also universal for any central heat points because the flow frictions overcome by the water from filters to the vacuum deaerator are practically the same for all heat points and makes it possible to compare them by specific values of kWh/m3.
At the second technological stage of the central heat point, when deaerated, hot and already prepared water is pumped out by the pumps of the DHW system into the outdoor network for consumers, the analogous indicator could be used. However, the simple summation of power consumption by DHW pumps is incorrect, because of different water pressure at the head of the DHW pumps for each heat point due to the unequal in terms of the hydraulic characteristics of consumer networks: buildings of different storeys and not in the same number are connected. Therefore the indicator requires to give a more precise definition.
In order to ensure the design pressure Pp at the consumption point, the water pressure value at the head of DHW pump Ph should be a little higher, approximately from 10 to 20 percent, due to the pressure losses in the ascending pipe, check valve and isolation valves. Then, if Ph=aPp, where 1,1 < a < 1,2, the modified formula for determining the electrical energy consumption of the pump could be written as:
a = Edhw / (Gdhw*Pp) (6),
where
Edhw - is power consumption by DHW pumps [kWh];
Gdhw - is discharge of hot water in the DHW system [m3].
This formula describes the specific amount of electricity, spent on overcoming the flow friction of the DHW pipes inside the central heat point building. These losses can be used to compare any central heat points as the fourth indicator, because exactly they can be influenced by operating employees or automatics, if it is installed.
In general, in each heat point there are delivery and return pipelines of the heat supply network passing through it. They, in addition to contributing to the water heating for the DHW system, also transport the heating water for consumers' heating units. This allows to control and influence the efficiency of fullness of heat utilization by consumers. For different operating modes, the corresponding coefficient suggested in [4] can be determined, which is a function that depends on the values of the outside air temperature, as well as the temperature of delivering and
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returning water.
Also, through an analysis of the temperature of delivering and returning water, recorded at the measuring points, located inside central heat point buildings, the qualitative condition of the consumer's heat pipeline can be appraised by the coefficient of maladjustment of the heat pipeline [5].
Consequently, these coefficients, applicable both for heat networks in general and for central heat points, which are their inalienable element, can be considered as the fifth and sixth indicators. Economical efficiency
In the narrow sense effectiveness often means namely economical efficiency. At the same time, this indicator can be integral, as it involves the evaluation of efficiency in the same units of measurement - value indicators.
To determine the economical efficiency, the production cost of the central heat point, which includes all operating expenditures and depreciation, and the sales proceeds from the consumers, connected to the central heat point, are compared. In such a case, revenue is calculated by multiplying the natural volume of net supply by tariffs for transportation of heat energy. If as a result of comparison it turns out that the operation of central heat point is unprofitable, it certainly requires taking the improvements. Conclusions
The performance analysis allows to appraise the quality of operation of each specific central heat point, compare with the others and consider the possibilities and directions for optimization.
In particular, the advanced way to improve the efficiency is the automation of environment operation. Also in some instances it is more efficient to stop the central heat point while organizing individual heat points in each connected building. Considering that such improvements require significant investment expenditures, the existing situation and performance targets should be adequately assessed. Список использованной литературы:
1. СНиП 41-02-2003 «Тепловые сети». Раздел 14.
2. Соколов Е. Я. Теплофикация и тепловые сети: Учебник для вузов. - М. ИД МЭИ, 2009. С. 262-304.
3. Рябцев В. И., Плетнев П. А. Определение эффективности работы центральных тепловых пунктов теплосетей // Новости теплоснабжения. 2008. № 11. С. 50-51.
4. Рябцев Г. А., Рябцев В. И. Новый общий показатель эффективности работы теплосети // Новости теплоснабжения. 2003. № 9. С. 56-59.
5. Рябцев Г. А., Рябцев В. И. Новая методика анализа эффективности работы теплосети // Промышленная энергетика. 2003. № 6. С. 2-4.
© Шальнов С. А., 2017
УДК 658.345:677(075.8)
Шмырев Д. В., к.т.н., ст.преподаватель, Булаев В.А., к.т.н., доцент, Кочетов О.С., д.т.н., проф., Российский государственный социальный университет (РГСУ),
е-mail: [email protected]
МЕТОДИКА РАСЧЕТА ВИХРЕВЫХ ЦИКЛОННЫХ ПЫЛЕУЛОВИТЕЛЕЙ
Аннотация
В работе приводится методика расчета вихревых циклонных пылеуловителей в зависимости от насыпной плотности пыли и формы частицы пыли, характеризуемой коэффициентом формы.