Строительная теплофизика / 10
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E L_ieh b \eZ]h i_j_^ZqZ \ HD <k_]h qZkh\ ba gbo e_dpbb±qZkZ ijZdlbdZ±qZkZ
JZkq_l \eZ]hi_j_^Zqb q_j_a HD gZ hkgh\_ ihl_gpbZeZ \eZ`ghklb
< gZklhys__ \j_fy bf__lky jy^ f_lh^h\ jZkq_lZ \eZ]hi_j_^Zqb q_j_a HD hkgh\Zgguo gZ l_hjbb ^bnnmabb iZjZ b \eZ]hijh\h^ghklb H^gZdh hgb bf_xl jy^ g_^hklZldh\hlf_q_gguo gZfb jZg__ dhlhju_ aZljm^gyxl bo bkihevah\Zgb_ ^ey jZkq_lZ fgh]hkehcguo HD ijb k\_jo khj[pbhgghc ih\ur_gghc \eZ`ghklb \ h[eZklb iheh`bl_evguo b hljbpZl_evguo l_fi_jZlmj ijb keh`guo ]jZgbqguo mkeh\byo khj[pby± kihkh[ghklv fZl_jbZeZ ih]ehsZlv \eZ]m khj[_glu
Bkihevah\Zgb_ ihl_gpbZeZ \eZ`ghklb iha\hey_l ijhba\h^blv jZkq_lu \eZ`gh]h j_`bfZ HD \h \k_o wlbo kemqZyo dZd \ klZpbhgZjguo lZd b g_klZpbhgZjguo mkeh\byo \eZ]hi_j_^Zqb
KlZpbhgZjgZy \eZ]hi_j_^ZqZ
Keh`ghklv jZkq_lZ \eZ]hi_j_^Zqb khklhbl \ g_ebg_cghklb hkgh\guo mjZ\g_gbc l d \ mkeh\byo klZpbhgZjghc \eZ]hi_j_^Zqb jZkq_l aZljm^g_g kms_kl\mxs_c aZ\bkbfhklvx \eZ]hijh\h^ghklb fZl_jbZeZ [ hl ihl_gpbZeZ \eZ`ghklb 4 < kbem wlh]h ijb ijh\_^_gbb jZkq_lZ m^h[gh \hkihevah\Zlvky kihkh[hf ihke_^h\Zl_evgh]h ijb[eb`_gby
K_q_gb_ HD ^_eblky gZ we_f_glZjgu_ kehb δ L < fgh]hkehcguo HD ]jZgbpu we_f_glZjguo keh_\ ^he`gu kh\iZ^Zlv k ]jZgbpZfb fZl_jbZevguo keh_\ \ HD
AZ^Z_lky ijb[eb`_gguf gZijbf_j ebg_cguf jZkij_^_e_gb_ ihl_gpbZeZ \eZ`gh]h ih k_q_gbx HD < ij_^_eZo dZ`^h]h kehy agZq_gb_ \eZ]hijh\h^ghklb [L ijbgbfZ_lky FRQVW khhl\_lkl\_ggh ihl_gpbZem \eZ`ghklb kehy 4L Bkoh^y ba ijbgyluo agZq_gbc [L hij_^_ey_lky h[s__ khijhlb\e_gb_ \eZ]hi_j_^Zq_ HD
54 = ∑ |
δ L |
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Khijhlb\e_gb_ \eZ]hh[f_gZ gZ ih\_joghklyo HD h[uqgh fZeu b khhl\_lkl\_ggh \_ebqbgZ ihlhdZ \eZ]b
L = (4% − 4+ )
54
Ihke_ wlh]h jZkq_l \_^ml³af_cdhc´hl kehy d kehx gZqbgZy k i_j\h]h kehy ]jZgbqZs_]h k \gmlj_gg_c ih\_joghklvx Ijbgy\ [L wlh]h kehy ih ihl_gpbZem \eZ`ghklb \gmlj_gg_c ih\_joghklb HD \ h[s_f kemqZ_ ih 4 b W ih\_joghklb dh]^Z [ y\ey_lky nmgdpb_c 4 b W \uqbkeyxl agZq_gb_ 4] gZ ijhlb\hiheh`ghc ]jZgbp_ kehy gZ ]jZgbp_ kh \lhjuf keh_f
4] = 4e − L δ L
[L
Ihemq_ggh_ agZq_gb_ 4] gZ ]jZgbp_ f_`^m i_j\uf b \lhjuf [ehdZfb y\ey_lky bkoh^guf ^ey hij_^_e_gby [ \ ij_^_eZo \lhjh]h kehy JZkq_l ijh^he`Z_lky ^h ihke_^g_]h we_f_glZjgh]h kehy.gZ ]jZgbp_ k gZjm`ghc ih\_joghklvx HD
Ihemq_ggu_ ^ey gZjm`ghc ih\_joghklb agZq_gby 4. g_ [m^ml ^hklZlhqgh [ebadbfb d 4+ G_h[oh^bfhc lhqghklb jZkq_lZ wlbf kihkh[hf m^Z_lky ^hklbqv k ÷ o ihiulhd
Ijbf_j Ihkljhblv klZpbhgZjgh_ ihe_ \eZ]hkh^_j`Zgby fZl_jbZeh\ \ HD ba djZkgh]h dbjibqZ lhesbghc f ml_ie_gghc bagmljb keh_f i_gh[_lhgZ lhesbghc f JZchg kljhbl_evkl\Z±Fhkd\Z W+ = − °& Ihl_gpbZe
\eZ`ghklb gZjm`gh]h debfZlZ \ abfgbc i_jbh^ 4+ = °% Mkeh\by \ ihf_s_gbb
W% |
= °& ϕ % |
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4% |
= °% OZjZdl_jbklbdb fZl_jbZeh\ |
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ρ D |
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f°K |
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J_r_gb_
JZkkqblu\Z_f klZpbhgZjgh_ l_fi_jZlmjgh_ ihe_ \ HD jZa[b\ _]h gZ we_f_glZjgu_ kehb ^_e_gb_f kehy dbjibqZ b i_gh[_lhgZ ihiheZf
H[s__ l_jfbq_kdh_ khijhlb\e_gb_ h]jZ`^_gby
5 = 5 |
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JZkij_^_e_gb_ l_fi_jZlmju ih k_q_gbx HD °K |
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− W+ |
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W[= = W% |
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I; )(W% |
− W+ ) |
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W[= |
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W[= |
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GZghkbf l_fi_jZlmjgh_ ihe_ gZ jZaj_a HD jbk Z
Jbk D ijbf_jm jZkq_lZ klZpbhgZjghc \eZ]hi_j_^Zqb q_j_a HDZ±ihkljh_gb_ jZkij_^_e_ggh]h l_fi_jZlmjgh]h ihl_gpbZeZ \eZ`ghklb 4 b hlghkbl_evgh]h ihl_gpbZeZ \eZ`ghklb ϕ 4
[±ihkljh_gb_ jZkij_^_e_gby \eZ]hkh^_j`Zgby fZl_jbZeh\\±djb\u_ aZ\bkbfhklb jZ\gh\_kghc \eZ`ghklb i_gh[_lhgZ I; b djZkgh]h dbjibqZ DD hl \eZ`ghklb nbevljh\Zgghc [mfZ]b b hlghkbl_evgh]h ihl_gpbZeZ \eZ`ghklb]±ijbgylZy aZ\bkbfhklv \eZ]hijh\h^ghklb χ hl ihl_gpbZeZ \eZ`ghklb ^ey i_gh[_lhgZ
b dbjibqZ
JZkq_l ihey ihl_gpbZeZ \eZ`ghklb
HklZ\eyy ijbgylmx jZa[b\dm i_gh[_lhgZ b dbjibqZ gZ kehb hij_^_ebf dhwnnbpb_glu \eZ]hijh\h^bfhklb b l_fi_jZlmjm gZ ]jZgbpZo [ehdh\ AZ^Z_fky ih ^Zgguf jZkq_lZ hjb_glbjh\hqghc \_ebqbghc ihlhdZ \eZ]b L = d] f q
Kehc Kh klhjhgu ihf_s_gby gZ ih\_joghklb kehy 4% = °% W = °& ih jbk ]
χ = − |
d] |
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f q °< |
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4[= = 4[= − L δ = − − = °% |
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[ |
Kehc ih 4 |
= °% bW = °& hij_^_ey_f χ = − d] f q °< |
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4[= = − − = °% |
Kehc ih 4 |
= °% bW = − °& hij_^_ey_f χ = − d] f q °< |
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4[= = − − = °% |
Kehc ih 4 |
= °% bW = − °& hij_^_ey_f χ = − d] f q °< |
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4[= = − − = °% |
JZkij_^_e_gb_ 4 ih k_q_gbx HD ihdZaZgh gZ jbk Z Ih mkeh\byf aZ^Zqb ihl_gpbZe \eZ`ghklb kgZjm`b 4+ = °% qlh [ebadh d ihemq_gghfm Ijb g_h[oh^bfhklb agZq_gby
4[= ke_^m_l ih\lhjblv m\_ebqb\ \ ^Zgghf kemqZ_ ijbgbfZ_fh_ agZq_gb_ ihlhdZ \eZ]b L
Ih ba\_klghfm l_fi_jZlmjghfm ihex b ihex ihl_gpbZeZ \eZ`ghklb jbk Z
gZoh^bf agZq_gby ϕ 4 \ hl^_evguo k_q_gbyo HD jbk Z Ih ihemq_gguf \_ebqbgZf ϕ 4L k
ihfhsvx aZ\bkbfhklb ]jZnbdZ gZ jbk \ hij_^_ey_f \eZ]hkh^_j`Zgb_ fZl_jbZeh\ \ dZ`^hf k_q_gbb HD jbk [
G_klZpbhgZjgZy \eZ]hi_j_^ZqZ
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wlZi_ \k_ k_q_gb_ HD ijb\h^bf d h^ghjh^ghfm ih agZq_gbx χ |
GZihfgbf qlh χ |
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\eZ]hijh\h^ghklv fZl_jbZeZ ρ iehlghklv h[t_fgZy fZkkZ i_j\h]h d gZjm`ghc |
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>ey wlh]h \uqbkebf lhesbgm ∆ |
[L \k_o hklZevguo ijb\_^_gguo we_f_glZjguo [ehdh\ ba |
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mkeh\bc jZ\_gkl\Z djbl_jb_\ Nmjv_ ijb h^bgZdh\hf jZkq_lghf bgl_j\Ze_ \j_f_gb |
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τ \j_fy k_d O oZjZdl_jguc jZaf_j l_eZ f djbl_jbc Nmjv_ oZjZdl_jbam_l k\yav |
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f_`^m kdhjhklvx baf_g_gby l_fi_jZlmjgh]h ihey nbabq_kdbfbFRQVWb jZaf_jZfb l_eZ
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O = ∆ [ + ∑ ∆ [L
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>Ze__ hij_^_ebf jZkij_^_e_gb_ hlghkbl_evgh]h ba[ulhqgh]h ihl_gpbZeZ \eZ`ghklb
4 = 4 − 4
4+ − 4%
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