FR2547903A1 - Heat exchanger for stationary medium - Google Patents

Abstract

Heat exchanger for stationary medium whose exchange surface 2 is formed by elements developed with large area on a cylinder, a polyhedron, a truncated cone or a truncated pyramid, carrying a lower manifold 3 and an upper manifoled 4. The whole is surmounted by a pipe 5 causing the draught (suction), connected to the upper manifold 4. The open surface inside the lower manifold 3 is closed by the leaktight end wall 6.

Description

 Conventional heat exchangers have the effect of transferring calories from a hot fluid to a cooler fluid, the two fluids circulating on each face of the exchange walls.

 These exchanges therefore require either circulation pumps for the two fluids or pre-established pressure differences for their circulation.

 The invention which is the subject of this patent has the purpose, when one of the fluids is constituted by a large mass at rest - swimming pool, lake, sea, etc. - to allow the exchange without apparatus for setting circulation of part of this mass, in particular pump and pipes.

 To this end, the exchange circuit immersed in the generally stationary mass comprises, according to the invention, a vertical part of a length such that circulation can be established by suction under the effect of the temperature variation resulting from the exchange.

 So that this vertical circulation portion does not have prohibitive dimensions, the exchanger itself, according to the invention, is arranged on a cylindrical, prismatic, conical trunk or pyramid trunk generation surface, the generators being vertical or close to vertical, so that the exchanger itself contributes to the thermosyphon effect and that it has an overall surface normal to the speed of passage of the fluid preferably significantly greater than the section of the vertical suction circuit.

 Other characteristics of the invention will be specified during the description which follows, given solely by way of example of embodiment.

 In the single plate, FIG. 1 is the section AA in FIG. 2 or A.A in FIG. 3 of a self-circulating exchanger produced according to the invention.

 Figure 2 is an elevational view of the same exchanger.

 Figure 3 is the plan view.

 In FIGS. 1, 2 and 3 the exchanger 1 is cylindrical and formed of straight tubes 2, regularly arranged on the generatrices of a cylinder coaxial with the assembly, and opening into the collectors 3 and 4.

 On the upper manifold 4 is fixed the cylindrical conduit 5 of diameter substantially similar to that of the exchanger 1 and the height of which is determined so that the circulation can be established by difference in density between the atmosphere and the fluid contained in the thermal exchange conditions.

 On the lower collector 3 is fixed the conical or evolutive bottom preferably 6 forcing the ambient fluid to pass through the exchanger under the effect of the draft produced by 5.

 The hot circulating fluid arrives at the collector 3 by the flange connection 7 and it leaves the collector 4 by the flange connection 8.

 The operation is obvious: as soon as the hot fluid circulates in the exchanger 1 it heats by conduction the cold fluid surrounding the tubes 2 which has the effect of raising the affected fluid, which creates a call from the outside to the inside, the bottom of the exchanger 1 being closed by 6. The flow rate is then established at the desired value by the equilibrium between the draft of 5 and the different pressure drops, under the effect of the temperature difference between the inlet and outlet of the cold fluid.

 The exchanger 1 can be of rectangular, polygonal section, cynical trunk or pyramid trunk, and constituted by flat panels, the conduit 5 being prismatic and the bottom 6 flat or pyramid. The tubes 2 can be provided with fins according to the exchange conditions, or composite by welding in the manner of automobile radiators.

 If the circulating fluid is the cold fluid that the ambient fluid must heat, the collector 3 becomes the high point and the draft duct 5 becomes the low point.

Claims (6)

Claims 1. Heat exchanger in a stationary environment characterized in that it is extended by a vertical draft pipe. 2. Heat exchanger according to claim 1 characterized in that the overall passage surface in the active part is cylindrical, polyhedral, conical or pyramidal, of generally vertical axis coincident with that of the draft duct according to claim 1. 3. Heat exchanger according to any one of claims 1 and 2 characterized in that the lower open part opposite the drawing duct according to claim 1 is closed. 4. Heat exchanger according to any one of claims 1 to 3 characterized in that the lower bottom has a conical or evolving shape so that the flow inside the exchanger is carried out with the minimum of pressure losses. 5. Heat exchanger according to any one of claims 1 to 4 characterized in that the exchange elements consist of tubes with or without fins connected directly to a lower collector and an upper collector. 6. Heat exchanger according to any one of claims 1 to 5 characterized in that the exchange surface is formed by welded sheets forming fins ducts connected to the lower and upper collectors.