AN ARRANGEMENT IN HEATING/COOLING SYSTEMS FOR FLOW ADJUSTMENT

Abstract: An apparatus for adjusting the flow in a heating/cooling system has a fixed throttling means mounted concealed in a coupling member, located adjacent the element, of a connection conduit to the heating/cooling element. The throttling means comprises an outer sleeve (10) of resilient material and has an outer shape corresponding to the inner shape of the coupling member, as well as an inner rigid sleeve (11) which is supported in a throughpassage in said outer sleeve and has a central hole (14) of an exactly defined flow-controlling cross-sectional area.

Description: AN ARRANGEMENT IN HEATING/COOLING SYSTEMS FOR FLOW ADJUSTMENT The present invention relates generally to the flow control in heating/cooling systems and, more particularly, to an arrangement in heating/cooling systems for adjusting the flow of a heating/cooling medium through the heating/ cooling elements in the system. The rise in energy prices has led to higher demands being made on the effective control of heating systems for house heating, especially in systems where the heat transfer medium is water. In a building with several flats, but without control facilities, considerable temperature differences may thus exist between the coldest and the warmest flat. As a result, the fuel consumption will be unnecessarily high because the coldest flat more often than not is allowed to determine the heat supply, the excess heat in the warmer flats being eliminated by airing. Furthermore, the large temperature differences between the flats make it impossible to achieve a desired total reduction of the room temperatures. By adjusting the water flows, a heat distribution can be obtained which gives a very insignificant tempera¬ ture difference between the coldest and the warmest flat, and this means that also the room temperature can be generally lowered without difficulty, and in this manner also the heating costs can be reduced. In heating systems where the heat transfer medium is water, flow adjustment is made conventionally by means of mains control valves by which the flow in every circuit of the system can be adjusted. A complication in this respect is that the pumping pressure varies with the distance between the pump and the radiators so that the pressure drop to the circuit taking up the least advan¬ tageous position will have control of all circuits. In such conventionally operating systems, the major part of the pressure losses thus lies in the conduits, whereas the pressure drops in the valves of the radiators are compara¬ tively small. An alternative to the mains control valves of conven¬ tional flow adjustment are high-throttling adjustment means mounted on each radiator. This last-mentioned technique aims at reducing the generally occurring and, in many cases, heavy over-dimensioning of heating systems. Its advantages are that the pressure drop in the piping up to the adjustment means, if these are correctly set, can be made negligible so that the desired flow can be established wholly in proportion to the size of the radiators. The technique also causes a higher temperature drop across the radiators and thus a higher radiation yield than with conventional flow control. Another advantage is that a wide control area is obtained. In its practical application, the alternative tech¬ nique requires presettable radiator valves or return valves. However, the accuracy of these valves, especially in existant older systems, is not such that the desired k values (valve coefficient values) definitely are ob¬ tained. Furthermore, there is a considerable risk, upon exchange of valves, that the requisite presetting is neg¬ lected, whereby the flow conditions in the system may be drastically changed " . The present invention has for its object to provide an apparatus of the type referred to by way of introduction, said apparatus obviating the disadvantages encountered in present-day application of the alternative flow control technique. To this end, the apparatus referred to by way of introduction is given the characteristic features stated in the appended claim 1. Presently preferred embodiments of the apparatus according to the invention will appear from the appended sub-claims. By utilizing a fixed throttling means, it is possible to obtain the exact calculated flow. Further¬ more, the fixed throttling means also precludes in correct presetting caused by, for example, a reading error. The concealed mounting makes it impossible for un¬ authorized persons to interfere with the setting, and all excess consumption of energy can be safely prevented. Moreover, the once-and-for-all throttling by the fixed throttling means is not affected upon exchange of valves, for which reason there is no risk that a correctly made setting will be changed. By providing, in accordance with the present invention, the throttling means with an outer resilient sleeve, prefer¬ ably of rubber, a desired damping is achieved of the noise that may arise in the throttling means due to the high flow rate therein and ensuing heavy pressure drops. Furthermore, because of its two-part construction, the throttling means can be adapted to all coupling components available on the market, with relatively few variants of outer and inner, sleeves. The apparatus according to the invention is applicable not only to heating systems using water as the heat transfer medium, but may be used with the same advantage in other types of heating and cooling medium systems. By the apparatus according to the present invention, complete application of the above— entioned alternative technique and modifications thereof are made possible. The invention will be described in greater detail below, reference being had to the accompanying drawings in which Fig. 1 shows part of a heating system in which the heat transfer medium is water, Fig. 2 shows part of a heating or cooling medium system, Figs. 3 and 4 are respectively an end view and a longitudinal section of a throttling means according to the invention, and Figs. 5 and 6 show alternative embodiments of the outer sleeve of the throttling means. The part of the heating system shown in Fig. 1 comprises a radiator 1 having a supply conduit 2 and a return conduit 3. A radiator valve 4 is mounted in the supply conduit, and a fixed throttling means 5 according to the present invention is mounted on the radiator side of this valve 4. More particularly, the throttling means 5 is mounted in a coupling member of the supply conduit, including the usual elbows. Fig. 2 illustrates the mounting of the fixed throttling means according to the invention in a heating or cooling medium system. A part of this system includes a heating or cooling medium battery 6 having a supply conduit 7 and a return conduit 8. A shut-off valve 9 is mounted in the supply conduit, and a fixed throttling means 5 according to the invention is mounted on the battery side of the said valve 9. In the embodiment according to Fig. 1 and also in the embodiment according to Fig. 2, the fixed throttling means is concealed in a coupling member of the supply conduits 2 and 7, respectively, in that it is insertable coaxially therein so that it is inaccessible to unauthorized persons. As will appear from Figs. 3 and 4, the throttling means comprises an outer sleeve 10 of resilient material, preferably rubber, and an inner, rigid sleeve 11, prefer¬ ably of brass. The two sleeves 10 and 11 are essentially cylindrical and are provided each with one end flange 12 and 13, respectively. Furthermore, the outer sleeve 10 has an external shape .corresponding to the internal shape of the coupling member in which the throttling means is mounted. Alternative embodiments of the outer sleeve 10 to adapt it to different cross-sectional shapes of the coupling members and elbows available on the market are shown in Figs. 5 and 6. The outer sleeve 10 has a throughpassage for receiving the inner sleeve 11 which has a central hole 14 having an exactly defined flow-controlling cross-sectional area. The hole 14 has the same diameter a-long its entire length and a sharp edge at the transition to the end surface at the flange 13. The end surface preferably is planar, at least adja- cent the hole 14, the length of which is large in relation to the diameter. A length of the order 10 mm and greater has been found to be practically useful. The special design of the hole 14 guarantees an almost completely silent throttling, also at pressure drops as high as 6-8 meters of water column. The throughpassage of the outer sleeve 10 has, independently of the external shape of the sleeve, the same cross-sectional area throughout its length. Corre- spondingly, the exterior shape of the inner sleeve 11 is the same and corresponds to the passage shape of the outer sleeve 10, independently of the size of the precision- drilled hole 14 in the inner sleeve 11. Furthermore, the central hole 14 of the inner sleeve 11 preferably has a cross-sectional area of a value selected from a group of predetermined values. This value is established depending on the desired temperature drop of the heating/cooling medium across the ra-diator, and the pressure available. For example, the inner sleeve may be designed with a selected number of different k values in the range 0.02-3.00. The number of different details required for the apparatus according to the present invention will thus be equal to the sum of the different types of cross- sectional shapes of the coupling members available on the market and the desired number of different cross- sectional areas of the hole 14. In the following, a number of steps are described to illustrate the precision setting of a heating system comprising the apparatus according to the invention and using water as the heat transfer medium. It is assumed that the radiators mounted are correctly dimensioned. The temperature drop across the radiators, calculated by the designer, is checked and then is adapted to the tempera- ture range of the heating source employed. In this connection, different types of low-temperature systems may be taken into consideration. Based upon the temperature drop established, the requisite flow to the radiators is then calculated, whereupon the pressure available in the system is checked. After that, a suitable pressure drop across the throttling means is selected, and based upon this value and the maximum flow required, the k values of the fixed throttling means are calculated. These values are selected individually in relation to the net flow of each radiator. The requisite throttling means are then mounted, whereupon any mains control valves mounted in the system are fully opened. Finally, the temperature drop across the radiators is checked, as is the room temperature. This technique offers great compen¬ sation possibilities for individual rooms in which the temperature is too low. Modifications of the apparatus described above can be made within the scope of this invention. For example, the throttling means may be mounted on the side of the control or shut-off valve facing away from the radiator, but this variant is not preferred. Like- wise, the throttling means may be mounted in the outlet or return conduit, but this usually increases the risk of blocking.

Claims: CLAIMS 1. An apparatus in heating/cooling systems for adjusting the flow of a heating/cooling medium through a heating/cooling element (1, 6) in said system, c h a r ¬ a c t e r i z e d in that a fixed throttling means (5) 5 is arranged for concealed and axial mounting in a coupling member, located adjacent said element (1, 6) , of a con¬ nection conduit (2, 7) to said heating/cooling element, said throttling means (5) comprising an outer sleeve (10) of resilient material and having an outer shape Q corresponding to the inner shape of said coupling member, and an inner rigid sleeve (11) carried in a throughpassage in said outer sleeve and having a central hole (14) of an exactly defined flow-controlling cross-sectional area. * L5 ■ 2. An apparatus as claimed in claim 1, c h a r ¬ a c t e r i z e d in that the throughpassage of the outer sleeve (10) has the same cross-sectional shape throughout its length, independently of the outer shape of said outer sleeve. 20 3. An apparatus as claimed in claim 1 or 2, c h a r a c t e r i z e d in that the central hole (14) of the inner sleeve (11) has a cross-sectional area of a value selected among a group of predetermined values, said value being established in response to the desired 25 temperature drop of the heating/cooling medium across the element, and the available pressure. 4. An apparatus as claimed in any one of claims 1-3 , c h a r a c t e r i z e d in that the throttling means (5) is mounted on the element side of a control 30 or shut-off valve (4, 9) associated with said element. 5. An apparatus as claimed in any one of claims 1-4, c h a r a c t e r i z e d in that the outer sleeve (10) is made of rubber and forms both a seal and a sound- damping suspension for the inner sleeve (11) . 6. An apparatus as claimed in any one of claims 1-5, c h a r a c t e r i z e d in that the inner sleeve (11) is made of brass and has a precision-drilled hole (14) . 7. An apparatus as claimed in claim 6, c h a r ¬ a c t e r i z e d in that the inner sleeve (11) has k values in the range 0.02-3.00. 8. An apparatus as claimed in any one of claims 1-7, c h a r a c t e r i z e d in that the inner sleeve (11) is cylindrical and has at one end a flange (13) for engaging one end surface of the outer sleeve (10) . 9. An apparatus as claimed in any one of claims 1-8, c h a r a c t e r i z e d in that the outer sleeve (10) has an end flange (12) . 10. An apparatus as claimed in claim 8, c h a r ¬ a c t e r i z e d in that the central hole (14) has a constant diameter along its entire length and a sharp edge at the transition to the end surface at the flange (13) .

Inventors: HANSSON BENGT ERIC GOERAN, JOHANSSON OTTO EGON RAGNAR, HANSSON, BENGT, ERIC, GOERAN, JOHANSSON, OTTO, EGON, RAGNAR
Applicants: EB VAERMEINREGLERING HB, HANDELSBOLAGET E.B. VAERMEINREGLERING
Application year: 1983
Main classification: F24D19
IPC codes: F24D3, F24D19