SU1000717A1 - Film-type heat exchanger - Google Patents

Description

(54) FILM HEAT EXCHANGER

The invention relates to refrigeration engineering, in particular to condensing technology for cooling various fluids with water.

A two-film heat exchanger is known, consisting of a package of vertical heat exchanging tubes combined in. tube bundle with three tube sheets, and a cylindrical body. Coolant liquid is supplied to a distribution chamber located directly below the top tube rack. With the help of the distribution grid and the annular gaps in it, the cooled liquid is distributed along the outer surface of the pipes and flows down in the form of a film from top to bottom. Each of the heat exchange tubes at the top has a nozzle and a gap between the nozzle and the inner surface of the heat exchange tube into which the spiral conical ring insert is mounted. The cooling water is introduced into the refrigerator, overflows through the slit and in the form of a film flows freely from top to bottom along the inner walls of the pipes, is collected in the pan, and then is removed from the refrigerator. When moving over the surface, the pipe water is evaporated in an individual way and in the form of vapor is drawn through the nozzles, increasing heat exchange 1.

The disadvantages of this heat exchanger are:

design complexity - three tube sheets, for one of which (internal) it is necessary to withstand a certain annular gap of the passage, which is the same for all heat exchange pipes

10 of the cooled fluid between the grate and the heat exchange tube in the form of a film; .

With an increase in the flow rate of the cooled flow, the film coitact from the side of the annulus disrupts and part of this flow, falling between the heat exchange tubes, does not participate in the heat exchange. Consequently, this refrigerator has a narrow performance rig. There is an inefficient evaporation of water, since the vapor of the evaporated part of the water is drawn through a nozzle without an extension.

The closest in technical essence to the proposed inJJ ets film heat exchanger, containing a vertical case with

Claims (2)

30 pipe and tray in the top and parts, respectively, and a tube bundle located in the housing, fixed in the top and bottom grids, above the first of which is installed a distribution device, and the tray is provided with a drain pipe f 2. The disadvantage of this heat exchanger is relatively low, the intensity of heat exchange between cooled and cooling media. The purpose of the invention is to intensify heat transfer. This goal is achieved by the fact that the heat exchanger further comprises by-pass pipes placed outside the housing and connecting the drain pipe to the ventilation pipe, and the sump is provided with windows and a side surface for air leaks. Figure 1 shows the heat exchanger circuit; in FIG. 2, node 1 in FIG. 1. The heat exchanger (fitl) contains kosus 1, vent pipe 2, poddo 3, tube bundle 4, bottom 5 and top tube grids, distribution device 7, drain pipe 8, bypass pipes 9, windows 10, fitting 11 and outlet 11 cooled medium, shguzer 12 coolant supply (water). The distribution device 7 (figure 2) contains a nozzle 13 and a spiral insert 14. The heat exchanger works as follows. Cooling flow (liquid petroleum product, gasoline, kerosene gas, etc.) flows through the lower fitting 11 into the annular space, where ONM leads to the outer surface of the heat exchanging pipes 4, the refrigerant (water enters through the upper fitting 12 to the upper tube sheet 6 and CTeijaeT through the slit along the spiral conical ring insert 14 on the inner surface of the heat-transfer tubes 4, where it moves in a spiral, stacks into the tray 3. The movement of water in a spiral increases the path length and time in the heat exchange tubes 4. Due to the thermal energy of the cooled The water flow partially evaporates, formations from the vapor pipe move upward along the heat exchange tubes and out through the nozzle 13. To reduce the total pressure in the heat exchange pipes and thus provide an intensive evaporation mode, the ventilation tube 2 is 4-6 meters long, increasing in order to reduce aerodynamic losses in the ventilation pipe and to further increase the thrust effect due to the ejection of a part of the steam-air mixture discharged from the nozzle by the flow of exhaust water, the lower part of the ventilation constant is connected to the pipe you aqueous water-pipe 9. The suction pipe 8 due to thrust air through the window 10 as an inert component further increases the effect of water evaporation. In addition, the air, as a result of drawing, disperses water at high speed and reduces the thickness of the water film on the pipe wall, i.e. there are effects of air humidification, additional cooling of water and molecular (heat transfer through a thin film of water. All this increases the heat transferred from the cooled flow to the water. The generated ha provides suction and high air speeds without energy for its transportation. Offered the device has a simplified design (two tube sheets instead of three, provides a combination of film contact with intensive forced, but without energy, evaporation. refrigerant, which allows for a higher Kjjg irrespective of the flow rate of the coolant liquid. Formula of the invention A film heat exchanger comprising a vertical case with a ventilation pipe and a tray in the upper and lower hours, st x, respectively, and a tube bundle mounted in the housing, fixed in the upper part and lower gratings, above the first of which is installed distributor devices, and the pallet is equipped with a drain nozzle, characterized in that, in order to intensify heat exchange, it additionally contains by-pass pipes located outside the housing and a drain connection The cartridge is equipped with a ventilation pipe, and the pallet is made with windows on the side surface for air leaks. Sources of information taken into account in the examination 1. Two: splenochnym heat exchanger. Inter-sectoral territorial center of scientific and technical information and propaganda. Information sheet. Sverdlovsk, 1977. 2. USSR author's certificate 366332, cl. F 28, 1970.