AIR POLLUTION BY EMISSIONS OF HEAT SOURCES

Transcription

1 AIR POLLUTION BY EMISSIONS OF HEAT SOURCES Pavel Aleksandrovch Khavanov and Anatoly Sergeevch Chulenyov Natonal Research Unversty Moscow State Unversty of Cvl Engneerng, Yaroslavskaya Road, Moscow, Russa E-Mal: ABSTRACT In ths publcaton, a comparatve assessment of ar polluton from sources of heat supply systems for a dfferent type of development was carred out. A qualtatve and quanttatve assessment of the santary and hygenc ndces of the ar basn state s provded for the locaton of heat generatng plants. Based on a comparson of quanttatve characterstcs, one can obtan the results of comparatve calculatons and the man qualtatve ndces of the techncal solutons under consderaton. The characterstcs of the source of heat n each partcular case were determned by the power of the heat source and the techncal characterstcs of the chmneys. It s revealed that the change n the dsperson zones takng nto account the "wnd rose" does not have a sgnfcant effect. It s receved that the overlappng of dsperson zones n the housng and cottage heat supply s due to the densty of constructon and must be taken nto account when developng archtectural and plannng concepts and techncal solutons for heat supply. Keywords: heat generatng plants, ar polluton, heat, autonomous heat supply. 1. INTRODUCTION A sgnfcant reducton n the cost of heatng s possble whle ncreasng the proporton of decentralzed heatng [1]. Ths wll help create more comfortable condtons, as well as provde real fuel economy. Decentralzed heat supply s effcent and relatvely nexpensve. Reasonable applcaton of decentralzed systems of heat supply n combnaton wth energy-savng n constructon and reconstructon of buldngs wll gve huge energy savng. For the past twenty years n European countres, almost do not buld quarterly and dstrct boler houses. Autonomous heat generatng plants, such as ndvdual gas bolers [2], roof and modular boler houses are able to provde the most effectve and comfortable solutons for the needs of a separate apartment or cottage, as well as an apartment buldng or a cottage communty. Development of heat generaton systems for heat has led to the emergence of new approaches, amed manly at decentralzed systems. Comparatve evaluaton of the energy effcency of heatng systems [3] wth varyng degrees of centralzaton was carred out n many works, and authors largely determned the feld of ratonal use of such systems. However, n publcatons, the ssues of comparatve assessment of ar polluton for the varous techncal solutons under consderaton were practcally not reflected. Wth the growth of ndustral producton, exceptonal sharpness acqured the problem of the nteracton of human socety wth the envronment, n partcular the problem of protecton of the atmosphere [4], hydrosphere and sol from polluton. The needs of human socety are ncreasng contnuously. However, the amount that we take from nature, due to the needs of development, growng exponentally, because the doublng of ndustral producton n the world occurs every 8-10 years. Every year, bllons of tons of mneral resources are extracted from the bowels of the earth, but approxmately one percent of all the raw materals produced are converted nto useful products for socety. All the rest s thrown nto the envronment n an envronmentally dangerous, posonous form. All ths leads to rreversble shfts n the Earth's bosphere, and consequently, the man problem s the protecton of the envronment,.e. ts protecton from polluton and changes that occur as a result of the operaton of enterprses for technologcal processng of resources and heat and power engneerng. The man pollutants are Sulphur and ntrogen oxdes, carbon doxde, smoke and soot partcles, as well as many other gases. 2. METHOD Carryng out ths comparson, t s necessary to start from the most common ndcators and characterstcs of the operaton of systems. Do not specfy ther quanttatve sde, but hghlght, defne and evaluate qualtatve aspects. For ths purpose, three techncal solutons for the heat supply of dfferent type of development areas wth approxmately the same populaton for the same clmatc condtons are compared. A. Manor buldngs wth one source of warmth and centralzed heat supply (Fgure-1). 2607

2 Fgure-3. Dsperson of dangerous substances for opton 3 (fragment). Fgure-1. Dsperson of mpurtes for opton 1. B. Manson buldng of the same layout (Fgure- 2) wth the nstallaton of the heat generator n each cottage. For carryng out the general qualtatve research of a queston, t s possble to allow: a) the type of fuel s not crtcal for a qualtatve assessment, although accordng to pont 3 t s possble to use only network natural gas; b) the total capacty of the heat generatng plants wll be dfferent and determned by the consumpton norms n these types of buldngs; c) all emsson sources wth lumped parameters are consdered as pont, and the dmensonless total concentraton (total toxc multplcty) s defned as the addtve quantty: K С C, (1) n n b K 1 1 MAC Fgure-2. Dsperson of mpurtes for opton 2 (fragment). C. Multstory buldng (two fve-storey buldngs on the same number of mxtures) (Fgure-3) wth pokvartrnym heat supply systems of Comb bolers [5]. K - total toxc multplcty; MAC - maxmum allowable concentraton of polluton, mg/m 3 ; С - the concentraton of component, mg/m 3 ; C b - background concentraton of component, mg/m 3. In accordance wth [6], that: a) the total toxc multplcty when overlappng the zones of dsperson of harmful emssons s determned by summng the calculated values for the most unfavorable condtons accordng to the maxmum values of surface concentratons of harmful substances; 2608

3 b) calculaton of harmful emssons s carred out at the maxmum desgn capacty of heat generatng equpment; c) specfc emsson values are calculated for the comparatve evaluaton: carbon monoxde, ntrogen oxde, benz(a) pyrene, takng nto account the background concentraton C b of harmful substances [7]; d) nfluence of wnd load for clarty s taken nto account shown n Fgure-1 eght-screw "wnd rose". Calculaton of surface concentratons harmful emssons and dstance from the chmney С of Х at whch the surface concentraton of harmful substances under unfavorable meteorologcal condtons reaches a maxmum value and other characterstcs were made accordng to the recommendatons of OND-86 The characterstcs of the heat source and the chmney dsperson condtons n each specfc case were determned by the power of the heat source and the techncal characterstcs of the chmneys. м For centralzed source optons (tem 1): the total TDP 6000 kw boler wth free-standng chmney heght of 30 m, a dameter of 0.81 m (per boler Vtoplex S (Vessman). For suburban sprawl: auxlary source ACV Heat Master output 64 kw (80 cottages-total capacty of 5120 kw) wth chmney n each cottage complete wth a heght of 8 m, a dameter of 160 mm. The calculaton s performed for a sngle cottage. For mult-storey cottages: gas boler SD 235E ISOFAST TDP 32 kw (total power sources 2560 kw), the chmney of the buldng for each partton,.e. 5 bolers, wth a heght of 18 m, a dameter of 220 mm. 8 ppes per buldng, the total number of ppes (two buldngs) -16 peces. The calculaton s performed for a sngle buldng. 3. RESULTS The man results of the calculaton to the data source for the Central European zone of Russa at a o temperature of cold fve days t x5 29 C and o calculated year t x5 29 C are shown n table 1 and ther graphc llustraton gven n Fgures

4 No VOL. 13, NO. 7, APRIL 2018 ISSN Characterstc Power, kw: unt/quantty total Annual leave heat Mj/g when h year = 4300 h/g (kw h/g) Chmney: heght, m number of tubes mouth dameter, mm Table-1. Basc results of comparatve calculatons. Centralzed source Independent source (cottage) 2000/3 64/ ( ) ( ) Apartment source 32/5 (total 80 boler) ( ) 4 Natural gas consumpton, m 3 /s On one ppe The consumpton of products of combuston at the outlet from the chmney, m 3 /s Calculated values from one source, the g/s: On one ppe carbon oxdes ntrogen oxdes Mass emsson, g/kwh: The annual mass emssons, thousands of kg/year: Maxmum surface concentratons, mg/m 3 : Total toxc emssons per source multplcty (one tube), takng nto account the background concentratons Dstance to the zone of maxmum concentratons from the emsson source, Х м, м (wthout wnd load) The number of overlappng zones of dsperson for the archtectural plannng solutons, peces Possble local maxmum total toxc multplcty gven overlay zones scatterng The results of comparatve calculatons based on the comparson of quanttatve characterstcs allow us to dentfy the man qualtatve ndcators of techncal solutons [8]. Thus, the consdered archtectural and plannng solutons for the constructon of resdental areas suggest sgnfcant dfferences n lvng condtons n a mult-storey buldng or n a cottage, however, n the ssues under consderaton, t should be noted that the total nstalled capacty of all heat generators has decreased sgnfcantly (#. 1 Table-1). Therefore, the total mass of emssons reduced for hgh-rse buldngs more than two tmes (# 8 Table-1) under dentcal envronmental performance of bolers [9]. Comparng the total multplcty of toxc emssons from a sngle source of polluton, t s easy to see that the change of the capacty and heght of the chmney leads to mnmum contamnaton from a group of 2610

5 ppe wth a heght of 18 m (5 bolers, when a fve-storey buldng, # 10 Table-1) [10]. However, the analyss of the mposton of dsperson zones from all sources of polluton (# 12 Table-1) shows that resdental heat supply s nferor to other solutons consdered by envronmental ndcators (# 13 Table-1). 4. CONCLUSIONS It should be noted that changng the dsperson zones when takng nto account the "wnd rose" does not have a sgnfcant effect on qualty, and n terms of quanttatve characterstcs when usng natural gas and moderate background concentratons, the santary ndcators of ar polluton are very far from the lmt values Moreover, the lowest ar polluton at the maxmum total toxc multplcty, despte the sgnfcantly hgher values of the nstalled capacty of the heat source, takes place for the central boler house (# 13 Table-1). Certanly, the provded calculatons have estmated character and are executed wth a number of assumptons. However, t s mportant to conclude that the eghtfold mposton of dsperson zones n the apartment heat supply and the fourfold overlap n the case of cottage heat supply s due to the correspondng densty of constructon and must be taken nto account. emssons of the enterprses. Lenngrad: Gdrometeozdat. [7] Khavanov P.A. and Chulenyov A.S Waterglycol coolants n offlne heat supply. Scentfc revew. 22, [8] Sharpov A. I Economy, ecology and energy effcency for affordable housng. Energy savng. 1, [9] London A.L. and Case V.M Compact Heat Exchangers. Moscow: Energya. [10] Bruykhanov O.N. and Shevchenko S.N Heat and Mass Transfer. Textbook. Moscow: Infra-M. REFERENCES [1] Khavanov P.A Sources of heat autonomous heatng systems: monography. Moscow: MGSU. [2] Chulenyov. A.S Development of ratonal systems of autonomous heat supply wth the use of condensaton technology. Dssertaton for the degree of canddate of techncal scences. Moscow: Natonal Research Unversty Moscow State Unversty of Cvl Engneerng. [3] Kalchevsky S Renewable energy sources, waste energy n ndustry. Sofa: Avangard Prma. [4] Akmov L.M., Vnogradov P. and Akmov E.l Analyss of the nfluence of the functonal-plannng structure of the cty on ar polluton contamnaton. Envronmental assessment and mappng urban atmospherc condton. Voronezh: Voronezh State Unversty. pp [5] Bell K.J. and Ghaly M.A., An Approxmate Generalzed Desgn Method for Multcomponent/Partal Condensers, AICh E Symp. 131: [6] ONE The method of calculatng the ambent concentratons of harmful substances n the 2611