Dr. V. F.
Ochkov (MPEI - TU) http://twt.mpei.ac.ru/ochkov
(News of
Russian Power Industry, № 5, 2005. – http://www.rao-ees.ru/ru/news/news/magazin)
At the beginning of 2004
MPEI (www.mpei.ru) launched a server [1, 2]
to make calculations online, scientific, engineering as well as in heat-power engineering
field [3–5]. Address of the server home page is www.vpu.ru/mas. The typical examples of heat engineering calculations
shown below present some features of this new information technology in power
engineering. Captions contain addresses for direct access to the noted
calculations.
Figure
1 shows calculation of water and steam thermophysical properties. Initial
point (pressure and temperature) is represented on the thermodynamic surface.
The calculations have been made using WaterSteamPro program package (www.wsp.ru). To integrate such calculation to other
program environments (Mathcad, Excel, high level programming languages) one can
download it from the Web. But to make a single calculation (reference) of water
and steam parameters just visit the site which address is written at the top of
Figure 1. All functions of WaterSteamPro package in the
mode of online calculations are available at http://www.wsp.ru/en/test. To call required function one
should only type its name to the address noted above, for example: http://twt.mpei.ac.ru/MAS/Worksheets/wsp/wspKINVISPT.mcd for cinematic viscosity (KINVIS)
depending on pressure (P) and temperature (T).
Figure 2 shows Web-calculation of adiabatic (isoentropic)
expansion of steam with visualization on h, s diagram. This enables us to
see both numerical value (for example, steam humidity at the end of the adiabatic
expansion process) and the expansion line itself surrounded with reference
points, saturation lines, isotherms, isobars etc. That gives us possibility to see
not only “statics” (the value – humidity of steam) but also “dynamics” –
to forecast the results for changed inputs. Beside the simple calculations of
expansion processes (Fig. 2) the site at www.vpu.ru/mas contains some complicated calculations: steam and
other medium expansion in real steam-turbine, gas-turbine, gas and steam power
cycles.
Figure
3 shows the site for calculation of heat conductivity of some metals
depending on temperature. As in previous case, this site shows not only “statics”-
the value of heat conductivity of the metal or the alloy for given temperature –
but also “dynamics” – the plot of changing the parameter depending on
temperature with fixed working point chosen by a user. Two plots are
represented: spline interpolation and polynomial smoothing of the points taken
from a “paper” reference book [5]. Suggested by the worksheet degree of the
polynomial is limited by number of the points and requirements to accuracy of
the calculation (in some cases we can apply linear interpolation). Spline
coefficients are also represented that allow us to program required dependence
in any environments where we may need such calculations: in mathematical
packages, table processors, high level languages.
Visiting site at www.vpu.ru/mas a user will find reference data similar to
those shown in Fig. 3 for some other parameters (heat capacity, viscosity,
thermal expansion, strength properties, electrical resistance etc) of the heat
carriers and materials used in power engineering (constructive, heat-insulated,
and building materials; turbine and transformer oils, fuel oils etc).
Different formulas used in power engineering
calculations are considered among reference too. Figure
4 shows such site containing formulas for one case of static heat exchange.
The formulas are online: anyone can adjust inputs in the formulas and see the
results, and also, as in previous cases, can view “dynamics” of the process on the
plot.
All calculations at www.vpu.ru/mas are checked for dimensional consistency.
Visitors of the site can choose the units of source data (Fig. 1) and see the
result with any supported units they wish (Fig. 4). This is a general tendency
in scientific and technical calculations connecting with more flexible approach
to physical values and rejection of one unit system which has not become and
cannot become sole or dominating.
Beside plots this site
contains nomograms which completely correspond with their “paper” analogues. As
an example, Figure 5 shows normative method of thermal
design of a steam boiler [6]. As a matter of fact, this nomogram is a function
of three variables and it treats some empiric data. A nomogram seems to be superfluous
in online calculations but it visualizes the calculation, enables additional
check of the source data. Beside, engineers get accustomed to use nomograms and
old habits die hard.
In addition to reference
and normative data the site contains practical calculations connecting both
with operation of power engineering units and with possible modernization.
Figure
6 shows one page of site collection with typical power characteristics that
estimate operating of a turbine [7]. This site contains not only the function
of three arguments returning temperature difference of a condenser but also
calculation of dryness factor of the steam incoming to the condenser from a
turbine. This calculation was made on the base of WaterSteamPro package mentioned
above.
Figure
7 shows initial and final stage of technical and economic indices calculation
for possible reconstruction of water treatment plant in a heat power station.
The scheme includes two modern technologies: high-speed counterflow ion
exchange filters and membrane units. Planning reconstruction engineers and managing
staff of the power station can estimate here investments, operating costs, and
other technical and economic indices. The results obtained can be considered as
initial point for further detailed calculations.
Beside, this site contains
references to online calculations of the training aids and courses for
students, for example “Water treatment in power engineering”, www.vpu.ru, “Theory of automatic control”, http://twt.mpei.ac.ru/MAS/Worksheets/Rotach/index.html
and others.
Technology of Web
calculations allow us to solve following problems.
Engineers of power plants
and energy associations have no need to install special program for routine (and
not merely) calculations. It is sufficient to have Internet access. Anyone who
needs new calculation methods gains access to them instantly.
First, transference of
the reference information from books into Internet increase sharply efficiency of
search and convenience of work. Search can be made via different search systems
(for example, www.yandex.com, www.yachoo.com etc). Required site is fixed
in Favorites and after that calculation will always be at hand of an engineer
or a researcher. Second, transference of the table information from paper into
Internet and its treatment can easily uncover mistakes or rather misprints
often occurred in the tables.
Unfortunately, there are
mistakes and misprints in the “paper” tables and formulas. Editors and
correctors practically cannot reveal them and they are transferred from one reference
book to another. If a misprint from a “paper” table have been transferred into
electronic analogue (for example, 3737 instead of 3537), spline interpolation
shown in Fig.3 returns simultaneously disturbing wave and force us to find and
correct it.
The site may contain
misprints and mistakes too but being discovered they could be corrected quickly
and insensibly for users.
Calculation site at www.vpu.ru/mas is a result of collaboration engineering.
Calculation documents are created on the base of mathematical program Mathcad
well known by scientists, engineers, and students of technical institutions.
Worksheets created in Mathcad are converted into Internet with minimum redesign.
The group of developers
is ready to create online calculations for individual orders of power stations
and power associations. It is also possible to deliver calculation files to launch
them on computers that have not Internet access.
1.
Solodov A.,
Ochkov V. Differential Models. An Introduction with Mathcad“, Springer-Verlag
2. Очков В.Ф. Mathcad 12 для студентов и инженеров. С-Пб.: БХВ-Петербург, 2005 (сайт книги http://twt.mpei.ac.ru/ochkov/Mathcad_12).
3. Очков В.Ф. Математические пакеты: От натурального хозяйства к товарному производству через Интернет. «КомпьютерПресс», 2004, № 5.
4.
Очков В.Ф. Решение инженерно-технических задач в
среде Mathcad. Справочник «Теплоэнергетика и теплотехника». Кн.
5. Очков В.Ф., Утенков В.Ф., Орлов К.А. Теплотехнические расчеты в среде Mathcad. «Теплоэнергетика», 2000, № 2.
6. Анализ изотерм ионного обмена с использованием пакета Mathcad / В.Ф. Очков, А.П. Пильщиков, А.П. Солодов и др. «Теплоэнергетика», 2003, № 7.
7. Тепловой расчет котлов (нормативный метод). СПб.: НПО ЦКТИ, 1998.
8. Грибин В.Г., Очков В.Ф., Буринов М.А. Типовые энергетические характеристики и расчеты в Интернет. «Энергетик», 2004, № 11
Fig.
1. Online thermodynamic
parameters and thermodynamic surface of water and steam (http://twt.mpei.ac.ru/mas/worksheets/VTP_wsp.mcd)
Fig.
2. Example of calculation
of steam expansion process on the Internet http://twt.mpei.ac.ru/mas/worksheets/h_s_Exp.mcd)
Fig.3. Online
calculation and plotting a parameter of some metals (http://twt.mpei.ac.ru/MAS/Worksheets/Therm/Heat_Cond_metal_e.mcd)
Fig.3a. Parameter of
some metals (the origin table http://twt.mpei.ac.ru/MAS/Worksheets/Therm/T_T_2_Tab_3_4.gif)
Fig.
4. Example of online
formulas (http://twt.mpei.ac.ru/MAS/Worksheets/Therm/Heat_Flow_6.mcd)
Fig.
5. Example of online
nomogram (http://twt.mpei.ac.ru/MAS/Worksheets/Boiler/Th_C_B_Nom_2.mcd)
Fig.
6. Example of calculation
of typical power characteristic for a turbine (http://twt.mpei.ac.ru/MAS/Worksheets/Turbine/80_KCS/80_KCS_LMZ_1_3_5.mcd)
Fig.
7. Estimation of
technical and economic indices for reconstruction of chemistry plant of a power
station (http://twt.mpei.ac.ru/MAS/Worksheets/New_VPU/Anketa.mcd)
