RU2184917C2 - Method of heat exchange between heat carriers separated by wall - Google Patents

Abstract

FIELD: methods used in manufacture of heat exchangers in various industries. SUBSTANCE: method consists in that heat from hot heat carrier to cold one is transmitted directly through heat-conducting rods passing through wall, and through wall. In this case, rods are located perpendicular to flows of heat carriers, and a part of heat transmitted through wall is incommensurably less than heat transmitted through rods. EFFECT: higher intensity of heat exchange between heat carriers. 2 dwg

Description

 The invention relates to intensive methods of transferring heat from a hot coolant to a cold one and can be used in heat exchangers of the energy, metallurgical and other industries, including in waste heat recovery systems of technological plants.

 It is known that if heat is transferred in heat exchangers through a smooth dividing wall, then the heat exchange between the heat carriers cannot be intense. In this case, the flow of hot coolant washes the dividing wall and transfers to it the more heat, the greater the temperature difference between this coolant and the wall. On the opposite side, the wall is washed by a coolant that receives heat from the wall. The amount of heat transferred by the wall also increases in proportion to the temperature difference between the wall and the coolant. In this case, the interaction of the flow with the wall occurs only in a thin layer near the surface of the wall. In other words, only a small part of the heat carrier, which is located near the wall, is involved in heat transfer.

 The technical solution is known from the prior art — a method of heat exchange between heat carriers separated by a wall, in which heat is transferred directly from a hot heat carrier to a cold one directly through a heat-conducting core passing through the wall (SU 1027502 A, 07.07.1983).

 The direct participation of the wall in the process of heat transfer leads to a certain decrease in heat transfer, since the temperature in the wall naturally aligns along its length and, consequently, to a decrease in the local temperature difference between the coolant and the wall.

 From the analysis of patent and scientific and technical literature, we can conclude that for the intensification of heat transfer between the heat carriers separated by the wall, means (turbulators) are used, which in all cases significantly increase the resistance of the heat exchanger and are not technologically advanced to manufacture.

 The objective of the present invention is to propose a new intensive method of heat transfer between heat carriers separated by a wall, the implementation of which does not entail an increase in resistance, since it does not require additional turbulization of the heat carrier flow.

 In the proposed method, heat is exchanged between the heat carriers separated by the wall, and according to the invention, heat is transferred directly from the hot heat carrier to the cold directly through the heat-conducting rods passing through the wall and the wall itself, while the rods are perpendicular to the heat carrier flows, and the part of the heat transmitted through the wall is incommensurably less than the heat transferred through the rods.

 The essence of the new method lies in the fact that the hot heat carrier, washing the part of the heat-conducting rod located inside the channel with the hot heat carrier, transfers heat to it, which is immediately transferred to the cold heat carrier through the other part of the rod washed by the cold heat carrier. The dividing wall in this method of heat transfer does not play a decisive role and may not even participate in heat transfer at all.

 A new technical result consists in the fact that the method of heat transfer due to the elimination of the need for heat transfer to the wall in heat transfer is very intensive and at the same time economically advantageous, since it does not have a lot of resistance to the flow of the heat carrier, it does not require large powers for pumping it through the heat exchanger. Making holes in the wall and installing heat-conducting rods in them is technologically much simpler than making ribbed walls, especially inside finned tubes.

 In FIG. 1 schematically illustrates heat transfer by the proposed method. The arrows show the movement of heat from the hot coolant 1, washing the part of the rod 2, protruding above the wall 3 from the channel side with the hot coolant, then along the rod 2 bypassing the wall 3 to the coolant 4. The part of the heat transferred directly through the wall is incommensurably less than the heat transmitted through the rods, and not shown in figure 1.

 In FIG. 2 shows a device for implementing the claimed method of heat transfer. The device comprises a housing 1, inside which a channel for a hot coolant and channels 3 for a cold coolant are placed. Channels 3 and 3 are separated by a wall 4, in which holes 5 are made. In them heat-conducting rods 6 are hermetically sealed (to exclude coolant flows) in a direction perpendicular to the wall surface. Based on specific thermotechnical problems, the length, diameter, material, number of rods, as well as their location on the wall surface are selected so that part of the heat transferred through the wall is at least an order of magnitude less than the heat transferred through the rods.

 The heat exchange device can be manufactured in a modular manner, i.e. design heat exchangers with the required number of modules.

Claims (1)

 A method of heat exchange between heat carriers separated by a wall, in which heat is transferred from the hot coolant to the cold directly through heat-conducting rods passing through the wall, and the wall, characterized in that the rods are perpendicular to the heat carrier flows, and the part of the heat transmitted through the wall is incommensurably smaller, than the heat transferred through the rods.

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