Page 370 - Design and Operation of Heat Exchangers and their Networks
P. 370

(7.164)
                                                                      (7.165)
                                                      MÞ
                                     t j
                                                      …,
                                       5
                                     7
                                      7
                                       X U mk A ΔU nk 7
                                                      2,
                                     e
                                                      i ¼ 1,
                                      C
                                     C
                                                      ð
                                                      ^ j
                                                      t
                                           m¼1
                                      M
                                                    C7
                                                   C7
                                                     C7
                                                       C7
                                                        X U mk A5
                                               13
                ! 7
             3
                                     δ nj
                                                    ^ jk
                                                         ^
                                      CB
                                     CB
                                        + X U mk A@
                                                    U
                                                            m¼1
                                                       M
                                                      δ nj
                                           m¼1
                                                     B
                                                    B
                                                       B
                                                         + X U mk @
                                                   B
                                               0
                                      M
                                                                      T
                                                                      Θ + BT + C ^
                                        sC w,k
                                                            m¼1
                                                    U ik U nk
                                                       M
                                                                as

                                                                form
                                                         sC w,k
                   U ik U jk M w  7 θ j 7e + X U ik  sC i   δ ij  7  M  5  k¼1  + X U mk  m¼1  3  1 10  0  7 C CB  C CB  B  U jk  U ik  Dynamic analysis of heat exchangers and their networks  by  given  are  (7.165)  Eq.  in  C  B,and  A,  matrices  355
                                     δ ni
                                                                    Θ ¼ A e
                                     B
                                       n¼1 B
                                       @
                        sC w,k     M               M    n¼1     matrix  d e  dx  M M
                  M w  X  k¼1  1  C  C  C   X U mk A   X B  C  1  C  C  C   X U mk A   X  C  the  of
                    ¼ X 6             M    m¼1         M    m¼1  (7.164)  elements
             2    6  6  6  4        U jk            ^ jk  ^     in
                  M   j¼1                           U
                   d e i  θ  dx      δ ij             δ ij
                                    Δ e i U ik B                        i T .
                    C i       0    B  B  B  @  0    B  B  B  @  Eq.       The
                    _                             ! B
                                   _  C  _  C i     ^           express
                              2    6  6  4          _ U ik  C i U ik  ^ i  _  C  …, e M  θ
                                   M w  + XX 6  k¼1 6           to
                                   M   j¼1     2    6  6  4               e 1 , e 2 ,  θ
                                                   M w  k¼1 6   convenient  h  θ
                                                   M    1 XX 6  s  j¼1  is  It  e  Θ ¼ where
   365   366   367   368   369   370   371   372   373   374   375