DE3139451A1 - HEAT EXCHANGER WITH SINK OR RISING SHAFT - Google Patents

Abstract

1. Heat exchangers consisting of winded tube, surrounded by an ascending or sinking shaft (2, 3) which in its not directly the heat exchanger enclosing zone (3) is consisting of one or several shafts, that exhibit a smaller inner diameter than outer diameter of the heat exchanger (1) thereby characterized, that the heat exchanger (1) is winded spirally for intensification of the free convection, the ascending or sinking shaft (2, 3) holds in its zone (3) that does not enclose directly the heat exchanger, altogether almost the same inner crossectional area as the passage area of the heat exchanger (1) for the storage medium, and the heat exchanger (1) is arranged at the shaft end (2).

Description

CHEMOWERK BAYEEN, 8801 Schnelldorf Heat exchanger with sink or riser shaft

The invention relates to a heat exchanger for direct heating or cooling of a storage medium, preferably in domestic water or heating buffer storage tanks.

In such heat exchangers, the highest possible transfer power with the smallest possible temperature difference between Storage medium and cooling or heating water outlet required. Due to the limited size of the container openings in practice and for reasons of cost, this optimum performance must be achieved with a limited size of the heat exchanger can be achieved.

Usually, because of the low flow rate of the storage medium on the outside of the heat exchanger tube Finned tubes are used, due to their large outer surface the low alpha value of the outside at least partially is compensated. However, the achievable increase in performance does not increase linearly with the enlargement of the surface, because in particular with the desired low temperature differences, there is only very little convection and on the other hand a so-called fin efficiency dependent on the fin height becomes effective. ·

The performance can thus be further improved by forcibly flowing around the fiippenrohres via a pump arrangement (see publication 50.04-0.977 from SuIo). These However, the design requires a comparatively high expenditure of energy for the circulation pumps used for this purpose.

It is also known to surround heat exchangers with tubes to avoid uniform heating of the contents of the container and a very advantageous, especially for the domestic water sector, To generate heat stratification (French Patent No. 75094-32, utility model GM 78 00 4-93).

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However, the arrangement and design of these pipes are not suitable, To increase the efficiency of the heat exchanger, this is also not intended.

The invention is therefore based on the object of improving the efficiency of heat exchangers in containers. This task will according to the invention solved in that the natural thermal Convection around the heat exchanger through ascending or sinking shafts reaching from the upper to the lower container area, one of them have approximately the same flow cross-section as the heat exchanger bundle, is increased decisively. The inflow area to the heat exchanger should consist of the largest possible, preferably horizontal surface. The convection effect can through partial or complete filling of the not directly from the heat exchanger controllable passage cross-sectional areas are further increased within the sink shaft funnel. Advantageous furthermore, the height of the heat exchanger bundle is as low as possible, because this reduces the internal friction of the container medium as well as disruptive turbulence that hinder the convection flow can be reduced.

The advantages of this sink shaft principle are based on a significantly improved by the higher convection speed Alpha value of the outer surface. This increases the performance of the heat exchanger without the need for energy or a larger construction volume greatly increased, there is also the possibility of using cheaper, low-finned ear tubes. The invention therefore enables small, lightweight and inexpensive heat exchangers without energetic and high equipment expenditure md / fc higher To equip efficiency.

An embodiment 'of the invention is shown in the drawing and is described in more detail below.

ffig. 1: The heat exchanger (1) is located in the funnel-shaped Head part (2) of the riser shaft (3). The free one Cross section of the preferably spirally wound The heat exchanger is closed by a cover (4),

so that all the water circulated through the Eonvektioa brushes the finned tubes. Advantageous here is the arrangement of the closure cover at the end of the heat exchanger facing the riser and the somewhat conical design of the side wall of the head part (2)
can be so that in a larger area of the
Heat exchanger the maximum possible temperature difference
used between heat exchanger and storage medium
can be. The arrangement shown is used to heat the storage medium, to cool it is reversed
Arrangement around.

Claims (1)

Patent claims Η .j) Heat exchanger system, preferably made of a spiral wound pipe, surrounded by a rising or sinking shaft to strengthen free convection, characterized in that the rising or sinking shaft in its area not directly surrounding the heat exchanger consists of one or more shafts, the one have smaller inner diameter than the outer diameter of the heat exchanger bundle and preferably have an overall approximately the same inner cross section as the passage cross section of the heat exchanger collar for the storage medium and the heat exchanger is arranged at the shaft end. "■ # - 2 ») Heat exchanger system according to claim 1, characterized in that that the rising or sinking shafts extend from approximately the top to the approximately bottom container area. Jo) heat deception system according to claim 1, characterized in that that the heat exchanger bundle has a smaller height in relation to its diameter. 4 _O ) heat exchanger system according to claim 1, characterized in that all superfluous free passage cross-sections of the heat exchanger are closed by suitable barriers. 5.) Heat exchanger system according to claim 1, characterized in that that the side wall of the head part is conical.