DK1855060T3

DK1855060T3 - Process for degassing and / or pressure maintenance in a closed water circuit

Info

Publication number: DK1855060T3
Application number: DK07006001.7T
Authority: DK
Inventors: Matthias Feld
Original assignee: Reflex Winkelmann Gmbh
Priority date: 2006-05-11
Filing date: 2007-03-23
Publication date: 2018-11-26
Also published as: DE102006021916A1; PT1855060T; LT1855060T; EP1855060A2; EP1855060A3; TR201816345T4; EP1855060B1; ES2694500T3; PL1855060T3; HUE039867T2; SI1855060T1; DE202006020835U1

Description

The invention relates to a method for degassing and/or pressure control in a closed water cycle with at least one container for degassing and/or pressure control, to which water from the closed water cycle is supplied via at least one inlet and from which water is drained via at least from one outlet into the closed water cycle, wherein the delivery of water from the container into the water circuit is performed by means of at least one pump disposed in the outlet and connected to a controller, wherein the controller in addition to the at least one pump activates a valve provided in the inlet.

During the operation of systems with closed water cycles, such as heating or cooling circuits, the loss of pressure and liquid and the penetration of gases into the liquid circuit are largely unavoidable.

In order to address said problems generic methods are known which ensure degassing and/or pressure control in a closed water cycle, wherein optionally also an automatic water make-up line can be provided. A device of the applicant for performing such a method for pressure control comprises a system pressure control and at least one water collecting container. If the system pressure falls below a set target pressure, at least one pump is activated and conveys water from a collecting container into the closed water cycle, until a pre-set switch-off pressure is reached. If however the system pressure increases, at least one overflow valve in the inlet to the container opens and water from the system is directed into the collecting container. Said overflow valve is usually formed by a solenoid valve. If in addition a make-up line is also provided, when a predefined filling level is not reached in the collecting container water is supplied via a make-up solenoid valve into the collecting container up to an upper prespecified level. A device described above is also suitable in principle for degassing, said degassing being performed via pressure relief in the non-pressurised collecting container. The operating principle of this kind of degassing is described in a special embodiment in document EP 0 933 109 BI of the applicant. During the degassing the pump is started for conveying water from the container into the water cycle and the shut-off element designed as a solenoid valve is opened by the controller. By means of the suction process negative pressure is created in the container into which the water to be degassed is preferably sprayed, whereby degassing is performed. As each system, i.e. each closed water cycle to which such a degassing device is connected, has a different pressure, the conveying amount of the pump also differs accordingly and according to the characteristic curve the conveyed amount is smaller the higher the system pressure. The solenoid valve connected upstream of the degassing container behaves in exactly the opposite way, i.e. the greater the system pressure, the greater the overflow amount. In order to keep the system pressure constant during the degassing and avoid a clock cycle, therefore a restrictor or the like is arranged in front of the solenoid valve. Said restrictor is set at the start-up so that the pump output corresponds with the overflow amount of the solenoid valve (hydraulic balancing). Related methods are also disclosed in EP 0 292 814 Al, EP 0 924 472 A2 and DE 197 39 142 Al. Document EP 0 292 814 Al discloses the preamble of claim 1. A disadvantage of this known method is that with each change in pressure the hydraulic balancing has to be repeated. Furthermore, any dirt or the like in the inlet to the container has a negative effect on the hydraulic balancing. Additionally, solenoid valves are prone to dirt because of their structure. Furthermore, solenoid valves can also generate pressure shocks by opening and closing rapidly, which is also undesirable.

The objective of the invention is to improve a generic method so that the structural assembly required for performing the method and the control is simplified.

Said objective is achieved by a method of the aforementioned kind according to the invention having the features of claim 1.

In the method according to the invention thus an electric motor operated control valve is used which is constantly controlled by the controller, i.e. by means of the controller the electric motor operated control valve dependent on the system pressure is always driven automatically into the optimal position. At the start up of a device for performing the method thus no restrictors or the like need to be adjusted as it is completely unnecessary to use a restrictor. Only the controller of the target pressure of the system is defined. Pressure shocks in the system are avoided as the electric motor operated control valve closes and opens slowly.

Electric motor operated control valves, for example electric motor operated ball valves, are known in principle for use in pipelines e.g. from DE 44 25 698 B4.

Particularly preferably, an electric motor operated ball valve is used as a control valve. Such an electric motor operated ball valve operates independently of dirt, as is usually the case in heating circuits, i.e. such a ball valve is also suitable for dirty media.

Depending on the size of the closed water cycle, according to one embodiment it is possible that in the inlet of the device two parallel electric motor operated control valves are used and in the outlet two parallel pumps are used.

It is possible that the container is used both for degassing and also for pressure control, alternatively it is also possible to use one container for degassing and a further container for pressure control, wherein preferably both containers are connected via a common electric motor operated control valve.

In one embodiment it is possible to use an electric motor operated control valve in each container inlet respectively.

The invention is explained by way of example in more detail in the following with reference to the drawings. In the latter:

Fig. 1 shows a schematic diagram of a device for performing the method according to a first embodiment and

Fig. 2 shows a device according to a second embodiment. A device for pressure control and/or degassing in a closed water cycle comprises an inlet 1 and an outlet 2 for connecting to the not shown water cycle, which for example can be a heating circuit. The inlet 1 leads into at least one container 3 for degassing and/or pressure control. The outlet 2 is also connected to the container 3.

The device comprises an electronic controller denoted generally by the number 4, which in the shown embodiment is connected via different control lines to different system components. Thus a pressure sensor 5 is arranged firstly in the inlet 1, which is connected via a control line 5a to the controller 4. Furthermore, in the inlet 1 downstream of the pressure sensor 5 an electric motor driven control valve, preferably a ball valve 6, is arranged, the electric motor 7 of which is connected via a control line 7a to the controller 4.

Furthermore, the controller 4 is connected via a control line 8a to a pump 8 in the outlet 2. Lastly, the container 3 can be provided with a filling level control sensor 9, which is connected via a control line 9a to the controller 4.

Furthermore, a dirt trap 10 is provided in the inlet 1, preferably in front of the electric motor operated control valve 6, and a check valve 11 is provided in the outlet 2 downstream of the pump 8. Furthermore, compensators 12 are arranged in both the inlet 1 and the outlet 2.

Furthermore, the container 3 on the inside comprises a membrane 15 forming the water space, which is provided at the upper side with a ventilation opening 13. The inner container space surrounding the membrane 15 is connected via a vent 14 to the environment and is thus unpressurised. A not shown make-up line can lead into the inlet 1 which enables the make-up of water via a suitable valve, if the filling level control sensor 9 establishes that the filling level within the membrane 15 of the container 3 has fallen below a predefined level.

The electric motor operated control valve 6 used as an excess pressure limiter is controlled continually by the controller 4 by a signal, for example a 0-10 volt signal, wherein then the signal strength 0 volt corresponds to a closed position of the control valve 6 and the maximal signal of 10 volt corresponds to a fully opened position of the control valve 6. Depending on the pressure in the connected system the electric motor operated control valve 6 is always moved by the controller 4 into the optimal opening position. Here the control valve 6 operates independently of dirt, at the start-up only the target pressure for the controller 4 has to be prespecified.

The device can also be used for degassing, in that by means of a suitable adjustment of pump 8 and electric motor operated control valve 6 in the container 3 or the membrane 15 forming the water space there is reduction of pressure, by means of which the gases contained in the water are released from the water and are discharged as gas from the container 3 via the ventilation opening 13, as is known in principle.

Figure 2 shows a second embodiment of a device, in which the same reference numerals are used as in Figure 1. Unlike the embodiment according to Figure 1, in the inlet 1 two electric motor operated control valves 6 are arranged in parallel which are connected respectively via control lines 6a to the controller 4.

In the outlet 2 two pumps 8 are arranged in parallel, which are connected respectively by control lines 8a to the controller. Thus, a separate dirt trap 10 is assigned to the control valves 6 and a separate check valve 11 is assigned to the pumps 8 respectively.

Of course, the invention is not limited to the shown embodiments. Further configurations are possible without departing from the core concept. Thus, the device can also have two containers 3, wherein one is preferably used for pressure control and the other is only used for degassing.

Claims

A method of degassing and / or pressure maintaining in a closed water circuit with at least one vessel for degassing and / or pressure maintaining, to which water is supplied via at least one water inlet from the closed water circuit and from which water is drained at least from one drain to the closed water circuit, wherein the supply of water from the vessel to the water circuit takes place by means of at least one pump arranged in the drain and connected to a controller, in which the controller controls, in addition to the at least one pump, a valve provided in the inlet, characterized in that a pressure sensor (5) is arranged. in the inlet, which is connected via a control line (5a) to the controller (4), where an electric motor-driven control valve (6) is used as a valve, which is arranged as a pressure limiter and is continuously controlled by the controller (4) depending on the system pressure, where an electric motor (7) of the control valve (6) is connected via a control line (7a) to the controller (4).

Method according to claim 1, characterized in that an electric motor-driven ball valve is used as a control valve (6).

Method according to claim 1 or 2, characterized in that two parallel electric motor-driven control valves (6) are inserted into the inlet (1) and two parallel pumps (8) are inserted into the outlet (2).

Method according to claim 1 or 2, characterized in that a container (3) for degassing and an additional container for pressure maintenance is inserted.

Method according to claim 4, characterized in that in each case inlet, in each case an electric motor-driven control valve (6) is inserted.