HEAT EXCHANGER Russian patent published in 1995 - IPC

FIELD: thermal power engineering. SUBSTANCE: heat exchanger housing provided with end plates 2 and 3 accommodates two groups of heat-transfer elements assembled in each group of flat similar coils in sectional area; turns of one of coils are arranged between those of other coil. Heat-transfer elements are made of tubes 4 and coaxially arranged tubes 5 of smaller diameter. Tubes 4 of heat-transfer element of one group are fixed in tube plate 6 and tubes 5 of smaller diameter, in tube plate 8 mounted in a spaced relation to tube plate 6 to form chamber 9 for outlet of heating medium "a". Chamber 10 for admitting this medium is formed by end plate 2 mounted in a spaced relation to tube plate 8. In the same manner, tubes 4 of heat-transfer element of other group are fixed, respectively, in tube plate 11, and tubes 5 of smaller diameter, in tube plate 12. Chambers 13 and 14 for outlet and admission of heated medium "b" are formed between tube plates 11 and 12 and between tube plate 12 and end plate 3. Tubes 4 in each group of heat-transfer elements are attached by means of guide spacers to adjacent heat-transfer elements to form similar coils. Intermedient heat-carrying agent "c" transferring heat from heating medium "a" to heated medium "b" circulates between coil turns and tube plates 6 and 11. EFFECT: improved efficiency of heat exchanger due to sequential flow of intermediate heat-carrying agent over heat exchanger tubes while retaining compact design; improved stiffness of tube assembly, facilitated assembly of heat exchanger. 2 cl