WO1984001017A1

WO1984001017A1 - Flow regulator for heating system

Info

Publication number: WO1984001017A1
Application number: PCT/SE1982/000278
Authority: WO
Inventors: Alf Elm
Original assignee: Bremia Fastighets Ab
Priority date: 1982-09-10
Filing date: 1982-09-10
Publication date: 1984-03-15
Also published as: EP0119189A1

Abstract

A flow regulator (1) for coupling between a heat source and a heat emitter in a heating system has a primary part (2) and a secondary part (3) in mutual flow communication and orientable in different mutual relative positions. The primary part (2) is connectable to the heat source and to the heat emitter, whereas the secondary part (3) is solely connectable to the heat emitter. Different flow regulating valves (10-14) and constricting means (15, 16) are built into the regulator. Hot water from the heat source passes the primary part (2) on its way to the heat emitter and returns entirely or partially to the heat source via the secondary part (3). Both primary and secondary parts are intended for putting in the supply line to a control valve connected to the heat emitter.

Description

Flow regulator for heating system

The invention relates to a flow regulator for connection between at least one heat source and at least one heat emitter in a heating system.

5 In heating systems such as those for heating buildings water is often used as the heat conveyor. The distribu¬ tion of heat in the building is achieved by controlling the flows to the different heat emitters e.g. air flow heaters, radiators, floor coils, heat exchangers, post-

-jo heating units. For each type of heating system there is however required rather extensive and time-consuming labour for connecting piping and fittings. Varying arrays of fittings are also required, dependin on how the heating system is implemented. Thus, there may be

15 difficulties in selecting fittings having mutually well-suited characteristics, while tuning the system may be seriously hindered or made impossible if the different fittings are not well adapted to each other.

0 The object of the invention is to eliminate the above- mentioned disadvantages a.d to provide a flow regulator which both simplifies the labour of installation and enables good function in the heating system to which it is fitted. 5

In accordance with the invention, this is achieved by the flow regulator comprising a primary part and a secondary part in mutual flow communication, in that the primary part has a) an input and a first output 0 connectable to the heat source, and b) a second output connectable to the heat emitter, and in that the second¬ ary part has an output and an input connectable to the heat emitter, and which are in mutual flow communica¬ tion, at least the secondary part's input being in 5 flow communication with the primary part's first output, An advantageous embodiment is obtained when primary part and secondary part may be oriented in different positions relative each other and when there is a heat barrier between the primary part and secondary part.

A flow regulator in accordance with the invention is easily adaptable to different types of heating systems in the art, while at the same time enabling, due to its construction, a large variety of assembly alternatives and substantially reduced fitting labour.

The invention will now be described in detail in the following with the aid of an embodiment example illu¬ strated on the appended drawing, where: Figure 1 illustrates a flow regulator in accordance with the invention.

Figure 2 is a section along the line II-II in Figure 1 , Figure 3 is a section along the line III-III in Figure 2, Figure 4 is a hydraulic diagram for the flow regulator in accordance with the invention, and

Figure 5 is a sketch illustrating the inventive regulator connected between a heat source and a heat emitter in a heating system.

As will be seen from Figures 1-3 a^*heat regulator 1 in accordance with the invention is made up from a primary part 2 and a secondary part 3 , joined by a connector 4. This connector 4 prevents direct contact between the primary part 2 and secondary part 3, and in combination with the connector being made from a material with low heat conductivity this results in that a heat barrier is formed between the primary and secondary parts. The hot water in the primary part can thus not heat up the cold water in the secondary part when no heating effect is desired. Due to its elasticity, the connector 4 also reduces stresses cause during installing the regulator

O P and enables the two parts to be turned relative each other for being oriented in different relative posi¬ tions, thus increasing flexability in fitting the regulator.

The primary part 2 is intended for connection to a- heat source via an input 5 and a first output 6. A sec ^*>nd output 7 on this part is intended for connection to a heat emitter. The secondary par 3 is in turn intended for connection to a hear emitter via m output 8 and an input 9.

A shunt valve 10 is disposed between the input 5 and the first output 6 on the primary part 2, and with the help of this valve comm-inicat: on between the input 5 and the first output 6 can be opened or closed. When the shunt valve 10 is in its illustrated closed posi¬ tion, all the water flowing in via the input 5 will con¬ tinue out through the second output 7. On the other hand, when the valve 10 is in its open position, a portion of the water flowing in via the input 5 will continue to the first output 6. Communication between input 5 and the second output 7 is always open, irrespective of the position of the valve 10. The shunt valve 10 is set outside the primary part 2 in conjunction with fitting the regulator 1. The advantages of the shunt valve 10 will be illustrated hereinafter.

There is a first non-return valve 11 between the input 5 and the first output 6 on the primary part 2, this valve opening for a flow in a direction towards the first out¬ put 6. In the communication between primary part 2 and secondary part 3 there is a second non-return valve 12 opening for a flow in a direction towards the primary part 2, this valve being fitted into the primary part 2 just at the junction to the secondary part 3. The second non-return valve 12 is provided with an overflow valve 13

OMPI

Yλ, WIFO allowing, for a predetermined pressure difference be¬ tween primary part 2 and secondary part 3, a flow in a direction counter to the flow permitted by the second non-return valve 12. The implementation of the overflow valve 13 may be such that there is a passage going through it to the second non-return valve 12, said passage being kept closed with the aid of a spring-biased ball in the end opening out into the secondary part 3. Between the output 8 and input 9 in the secondary part 3 there is a third non-return valve 14, opening for a flow in a direction towards the output 8.

The ^"magnitude of the flow through the first output 6 on the primary part 2 and the input 9 on the secondary part 3 is controlled with the aid of a variable constriction 15, 16, respectively. Each of these constrictions is settable from the outside and is of the type where a throttle butterfly is turnable to block a through-flow opening to a varying degree. Constrictions of this type are well known to one skilled in the art and therefore do not need to be described in more detail here.

The regulator 1 is provided with a plurality of tempera¬ ture measurement outlets 17. In the illustrated embodi- ment, temperature measurement is intended to.be executed with the aid of thermometers, and at each temperature measurement outlet there is thus a closed-off insert tube 18 inserted into the regulator. There is also a plurality of pressure measurement outlets 19.

The inventive regulator 1 is illustrated in simplified form with the aid of a hydraulic diagram in Figure 4, the same denotations as for Figures 1-3 being used.

In Figure 5 there is illustrated how the regulator 1 may be coupled into a heating system 20 where a heat source 21 e.g. an oil-fired boiler or a heat exchanger of some

OMP V.IP kind, supplies heat to a heat emitter 22, e.g. one or more radiators. Outgoing water from the heat source 21 is supplied via a pipe 23 in which there is mounted a main pump 24, to the output 5 in the primary part 2 of the regulator. From the first output 6 in the primary part 2 there is a pipe 25 for return water to the heat source 21. From the output 8 on the secondary part 3 a pipe 26 leads to a control valve 27, from which a pipe 28 into which there is coupled a circulation pump 29, • leads to the heat emitter 22. Return water from the heat emitter 22 is taken to the input on the secondary part 3 via a pipe 30. The secondary input 7 on the primary part 2 is connected via a pipe 31 to the control valve 27, with the aid of..which the mixing ratio between water from the pipes 26 and 31 is regulated conventionally for regulating the heat supply to the heat emitter 22.

In the heating system 20 illustrated in Figure 5, the setting of the shunt valve 10 is dependent on what type of heat source 21 that is used. The valve 10 is open when the hot water boiler is used and completely closed when a heat exchanger is used. In a closed position, the shunt valve 10 may be sealed or closed off permanently, if so desired,.so that it can not be opened by mistake. The result of this will be that, when going over to a heat source in the form of a heat exchanger other parts of the system do not need to be exchanged or modified, which has previously been necessary.

When the heat source 21 is a hot water boiler and the shunt valve 10 is thus completely open, the flow water through the main pump 24, primary part 2 and heat source 21 will be constant.irrespective of the instantaneous energy take-off at the heat emitter 22. The heating system 20 is then said to be implemented according to the constant flow principle. The energy emitted by the heat emitter 22 is then varied by reducing or increasing the proportion of mixed-in water from the- pipe 31 with the aid of the control valve 27.

If a heat exchanger of some kind constitutes the heat source 21 instead, and when the shunt valve 10 is thus completely closed, the heating system 20 is said to be implemented according to the variable flow principle. In this case the return water temperature in the pipe 25 should be kept as low as possible, which may be achieved by selecting a heat exchanger 22 such as pro¬ vides twice as large a temperature drop as usual, simul¬ taneously as the water flow through the main pump 24, primary part 2 and heat exchanger 21 varies proportional¬ ly to the energy take-off at the heat emitter 22. All the outgoing water from the heat source- 21 is in this case compelled to pass the heat emitter 22 before it is returned to the heat source 21. The emitted heating power at the heat emitter 22 is varied in the same way as pre¬ viously with the aid of the control valve 27.

For maximum energy take-off at the heat emitter 22 the control valve 27 entirely blocks-off the water supply from the pipe 26. This means that the inlet temperature at the heat emitter 22 will, be equal to the outgoing water temperature from the heat source 21. This signifies a large advantage in comparison with equipment previously available on the market. This is achieved in spite of the control valve 27 being connected in accordance with conventional rules, i.e. as a mixing valve in the return line.

The flow of water through the heat emitter 22 for reduced power is dependent on the characteristics of the control valve 27. The aim is that the mixed-in portion and the water flow through the heat emitter 22 in each inter¬ mediate position will assume such values that the power supply will be a linear function of the degree of opening

-gfR vA provided by the control valve. To obtain good control results, the so-called amplification factor must be constant over the whole range controlled. In the inven¬ tive regulator the adaption between control valve, heat emitter, pumper and piping network can always be optimal¬ ized, which is not customary with equipment already nown in the art.

The pressure drop in the flow regulator 1 is so balanced that the water flow will be equal in both end positions of the control valve 27. The task of adjustment will be facilitated considerably since measurement or control only needs to be carried out in the end position when the valve 27 lets through the entire flow from the pipe 31. This is achieved by the spring bias on the second non-return valve 12 being so adapted that the pressure drop in the bottom pipe together with that over the valve 12 are equal to the pressure drop over the third non-return valve 14.

The task of the first non-return valve 11 is to prevent return water intended for the first output 6 in the pri¬ mary part 2 from flowing out via the second output 7 in this part. The pressure drop over this non-return valve is completely neglible for a nominal flow of water.

In most cases, the flow water in the pipes 23 and 28 is equally as great. The inventive regulator may also be used for other flow relationships, however. It will be thus more common to use a flow in the pipe 28 which is less than the flow in pipe 23, often only half as much. This situation can be used advantageously if a change-over to a remote heating supply is planned within the near future. The heat emitter 22 is then dimensioned for this, and any later supplementation of the heating surfaces of the heat emitter or adjustment of the quantity of circulation water is then unnecessary at the change-over in question. The only change which needs to be carried out is closing the shunt valve 10 when changing over to a remote heating supply. It is also possible to utilize the flow relationships where the flow in the pipe 28 is greater than the flow in pipe 23, which is the case for more complex low-temperature heating systems when one or more systems at different temperature levels are to be phased in on the same network or when the outgoing temperature to certain apparatus must be considerably lower than the one available. The solution of such pro¬ blems are facilitated with the aid of the inventive flow regulator while the required functions will be correct.

When the control valve 27 closes the supply from the pipe 31, the secondary side will be completely cut off from any possibility of volume variation in the closed-off water. For a sufficiently large pressure difference resulting from such a situation, the overflow - valve 13 opens, allowing water to flow over to the se¬ condary side. -There is thus avoided damage to fittings, piping and the like e.g. when the water in the-secondary side cools off and causes a subpressure to occur.

The third non-return valve 14 prevents water-from return¬ ing to the heat source 21 -without, first passing the heat emitter 22. This is. utilized.in conjunction with a remote heat source, and when the circulation pump 29 stops un¬ intentionally. If the shunt valve 10 is then closed, the plant may be makeshift-operated with the aid of the main pump 24 until repair or exchange of the circulation pump 29 has been effected. Power can be increased further by simultaneously opening the constrictions 15 and 16.

In the dimensioning and selection of a suitable control valve 27 and heat emitter 22, no consideration needs be paid to the distance to the location of the heat source 21

- f OMP According to considerations current in- the art, the driving pressure from the main pump 24 must, inter alia, be used for covering the pressure drop in both control valve and shunt group, since the desired flow of water would not otherwise be obtained. The shunt situated farthest from the heat source will then be decisive for how great a driving pressure the main pump must perform at least. The access driving pressure must be throttled off in the remaining shunts. This leads to imbalance in the flow of water as a result of phase displacements between different units. No imbalance in the flow water can occur with the regulator in accordance with the in¬ vention, since there can be no effect on side systems even for severe .phase displacements in the power require- ent. The driving pressure from the main pump 24 only needs to cover the pressure drop in the regulator at the dimensioning flow. The control valve 27 can thus be selected for its proper task, namely guiding the flow to the heat emitter 22 so that the transfer factor will be constant through the whole of the control range.

In existing plants, the driving pressure from the main pump 24 is generally too low for enabling an extension with "old shunts" without having to replace the main pump with a larger one having a greater driving pressure. With a regulator in accordance with the invention, pump replacement can be relegated to the future, . since the requirement of high driving pressure is eliminated.

Both constricting means 15 and 16 normally only need be used for the final fine adjustments. Accordingly, the constricting means 16 is first used after all other flow adaption measures in.the circulation system have been utilized. The use of the constricting means 15 similarly has the character of fine adjustment. When the piping network for the main circuit is optimally dimensioned, the constricting means ought to be practically completely open. The illustrated single circulation pump 29 can be replaced by a double pump as needed. It is thus possible to facilitate adaption to a lower power level during the warner season, thus enabling lower operating cost. Another reason for selecting a double pump may be that of increasing operational reliability for especially sensitive heat emitters.

Older types of shunt are made for left- or right-hand fitting, which increases the difficulty of fitting and stocking. This is no problem with the regulator in accordance with the invention, since it may be quite simply turned 180°, after which the closed-off pipe in¬ serts 18 are fitted into the appropriate outlets and the thermometers put in place on the inspection side.

The pressure measurement outlets 19 are formed for mea¬ surement with hollow needles,, which are thrust straight through self-sealing rubber diaphragms.

In known shunts, inspection and maintenance of the control valve etc. are very difficult to execute, since it is often fitted so that it is practically inaccessable. One of the basic ideas behind the invention is that main¬ tenance of the regulator and particularly the control valv.i shall be substantially more simple than previosly, and so that inspection, may be made an annual routine job. A great and unnecessary waste of energy may be hereby eliminated while improving comfort at the same time. This is enabled since the control valve may be fitted as a unit by itself, while fitting and removal of the valve is facilitated.

The implementation of the heating system 20 illustrated in Figure 5 may naturally be varied in many different ways, depending on what types of heat source and heat emitter are used.

Claims

1. A flow regulator for coupling between at least one heat source (21) and at least one heat emitter (22) in a heating system (20), c h a r a c t e r i z e d in that it comprises a primary part (2) and a secondary part (3) , in mutual flow communication, that the pri¬ mary part (2) has a) an input (5) and a first output (6) , connectable to the heat source (21) and b) a second input (7) connectable to the heat emitter (22) , and in that the secondary part (3) has an output (8) and an input (9) which are connectable to the heat emitter (22) and which are in mutual flow communication, at least the input (9) of the secondary part being in.flow communica¬ tion with the first output. (6) of the primary part.

2. Regulator as claimed in claim 1, c h a r a c t e r ¬ i z e d in that the primary part (2) and secondary part (3) are orientable in different mutually relative posi¬ tions, and that there is a connector (4) formed as a heat barrier between the primary and secondary parts.

3. A regulator as claimed in claim 1 or 2, c h a r a c t¬ e r i z e d in that between the input (5) and first output (6) of the primary part there is a shunt valve (10) for optional blocking of communication between the input (5) and the first output (6), and that permanently open communication exists between the input (5) and second output (7) of the primary part.

4. A regulator as claimed in any of claims 1 - 3, c h a r a c t e r i z e d in that there is a first non-return valve (11) between the input (5) and first output (6) of the primary part, said valve allowing passage towards the first output (6) .

5. Regulator as claimed in claims 3 and 4.,. c h a e r i z e d in that the first non-return valve (11) is placed between the shunt valve (10) and the first output (6) .

6. Regulator as claimed in any of claims 1 - 5, c h a r a c t e r i z e d in that there is a second non-return valve (12) in the communication between the primary part (2) and secondary part (3) said valve allowing passage in a direction towards the primary part (2) , said valve also being arranged to advantage in the primary, part (2) .

7. Regulator as claimed in claim 6, c h a r a c t e r¬ i z e d in that there is an overflow valve (13) in the second non-return valve (12) permitting flow nor¬ mally prevented.by the second non-return valve for a pre¬ determined pressure difference between the primary part (2) and secondary part (3) .

8. Regulator as claimed in any of claims 1 - 7, c h a r a c t e r i z e d in that there is a third non¬ return valve (14) between the input (9) and output (8) of the secondary parts said valve allowing passage in a direction towards the output (8) .

9. Regulator as claimed in any of claims 1 - 8, c h a r a c t e r i z e d in that there is a variable constriction means (15, 16) for flow regulation, connected to at least either the first output (6) of the primary part and the input (9) of the secondary part.

10. Regulator as claimed in any of claims 1 - 9, c h a r a c t e r i z e d in that at least one closed-off insertion pipe (18) intended for mounting a thermometer in it projects into the regulator, which is also prefer¬ ably provided with a plurality of pressure measurement outlets (19).