EP2895805A1

EP2895805A1 - Method for the controlled removal of foreign gases from a sorption device with an inert gas trap

Info

Publication number: EP2895805A1
Application number: EP13762467.2A
Authority: EP
Inventors: Niels Braunschweig; Sören PAULUSSEN; Eythymios Kontogeorgopoulos
Original assignee: INVENSOR GmbH
Current assignee: INVENSOR GmbH
Priority date: 2012-09-12
Filing date: 2013-09-12
Publication date: 2015-07-22
Also published as: BR112014032529A2; AU2013314315A1; IN2014DN10906A; KR20150054814A; JP2015527561A; CN104641189A; WO2014041083A1; US20150247659A1

Abstract

The invention concerns a method which enables an inert gas to be removed from an inert gas trap during operation of a sorption machine, in particular an adsorption machine, thus ensuring improved control of the removal.

Description

Process for the controlled removal of foreign gases from a sorption device with an inert gas trap

PRIOR ART Sorption devices, in particular sorption refrigerators, are known in the art.

Materials and materials in a sorption system may outgas or, for example, release gases through chemical conversion. These interfering gases or vapors prevent a rapid sorption, since they are in the adsorption or

Absorption impede the access of the vaporous working fluid to the sorbent and the desorption of the access of the vaporous working fluid to the

Prevent or hinder condensation surfaces, both of which are extreme

Slowing down the generation of cooling or heat leads. A significant decline in performance of these sorption systems is the result. In general, substances which interfere with the access of the working medium vapor to the sorbent and thus hinder the sorption process (for example carbon dioxide, nitrogen, etc.) are referred to as disruptive gases. The gases are also referred to as inert gases or foreign gases. These substances may be presorbed in the sorbent, released by chemical reactions, degasified from existing housing materials, or leaked through the system. In summary, in such a vacuum sorption so basically the problem that either outgassing or leaks to a

Pressure increase and thus can lead to a functional impairment of the device.

The prior art describes methods and methods for removing an inert gas from a sorption machine, in particular an adsorption machine. For example, DE 103 10 748 B3 explains that removal of the gases takes place after determination of foreign gases in the system of an adsorption refrigerating machine.

DE 44 44 252 B4 describes a method in which a binder in the

Sorption machine is introduced. In order to keep the system of interfering inert gas or steam free for the sorption process, so that in the vapor phase only

Working medium vapor is present, a binder is added to the sorption. The binder has the task to bind existing or released in the sorption inert gases or vapors and thus escape the Arbeitsmitttampfampf raum. It must be able to bind as much inert gas or vapor as in the Sorption by degassing or chemical reaction of the substances and materials contained therein is free. In a hermetically sealed sorption system, therefore, only a limited amount of inert gas or vapor can occur, and this usually at the beginning of the sorption cycles. The binder need only bind this particular amount of inert gas during this period. Suitable binders are in principle all substances which are able to bind the resulting in a sorption inert gases or vapors. However, the binder should be capable of binding the bound inert gas as well

system-related temperature fluctuations can not be released again. Since most binders tend to be at high temperatures, the binder should be placed in a location where the lowest possible temperatures and only light

Temperature fluctuations prevail. In a sorption system occur in

Sorbent container in the sorption and desorption the highest temperatures. According to DE 44 44 252 B4, the binder is applied in an area where the comparatively lower system temperatures are present, e.g. in the condenser, evaporator or collecting tank.

In the prior art, however, there is no coordination of the removal of the foreign gases with the operation of the sorption.

It was accordingly the object of the invention to provide a method which comprises a removal of an inert gas from an inert gas trap during operation of a

Sorption machine, in particular an adsorption machine allows, while ensuring improved control of the distance.

description

The task is solved by the main claim. Advantageous embodiments emerge from the subclaims. In a first preferred embodiment, the invention relates to a method for removing a foreign gas from a sorption machine, wherein the sorption machine at least

An adsorber and a desorber, or an adsorber-desorber unit, or an absorber and a desorber, an evaporator and a condenser, or an evaporator-condenser unit

• a work equipment, • a throttle element and

An inert gas trap, wherein the inert gas trap comprises at least one cooling element and a discharge device, the process comprising the following steps:

a. Cooling the inert gas trap by the cooling element to a temperature lower, equal to, or nearly equal to the temperature of the condenser, b. Introducing a vaporous working fluid from the desorber or adsorber-desorber unit into the condenser, the working fluid in the condenser at least partially condensing and foreign gas collecting in the condenser, c. Opening a throttling element arranged between the condenser and the inert gas trap, wherein the foreign gas and vaporous working medium flow from the condenser into the inert gas trap, d. Heating the inert gas trap, e. Opening a discharge device through which the foreign gas can flow out of the inert gas trap, characterized in that one of the steps is initiated by a control signal selected from the group comprising inert gas quantity, power loss, number of cycles and / or operating time. By the invention, the inert gas trap is thus activated by one of said control signals and thus made to run. The Inertgasentfernung therefore does not take place at any time, but is also adapted to the sorption process. This leads to an increase in performance, since the inert gas can be removed at an ideal time. This prevents the inert gas from causing a power loss. By the invention, thus, the performance of the sorption can be increased, which ultimately leads to a cost savings.

It is particularly preferred that the control signal activates the intergas trap as soon as predefined parameter values are reached. These parameter values refer to either the inert gas quantity, the power, the number of cycles or the operating hours. The amount of inert gas is preferably reproduced by the inert gas partial pressure. In particular, according to the invention, the capacitor may be present as a separate capacitor or in a combined evaporator / condenser unit.

A desorber according to the invention is present in particular either as a separate desorber or in an adsorber-desorber unit. For the purposes of the invention, an inert gas trap preferably denotes a device for

Removal of inert gas from a sorption machine, in particular a

Adsorption and more preferably an adsorption chiller.

Inert gas can also be referred to as foreign gas. A sorption machine may also be referred to as a sorption device. Preferably, the throttle element is selected from the group comprising valves, through valve, angle valve, oblique seat valve, solenoid valve, non-return valve and / or float. The throttle element is preferably integrated in a connecting means and causes a local constriction of the flow cross-section. Advantageously, different valves, which can be classified according to their geometric shape, be integrated into a throttle element. By using the valves, the flow rates in the connection means can be precisely and precisely dosed by changing the nominal size, as well as being able to close securely against the environment. The throttle elements can advantageously be operated by hand, by medium, mechanically or electromagnetically. It is particularly preferred that the throttle element which is arranged between the inert gas trap and the condenser is a valve, solenoid valve, slide, check valves, capillary tube and / or a membrane. These preferred throttle elements have proven to be particularly suitable because easy opening and tight closing is possible even under different pressure and temperature conditions. It is preferable that the throttle element between the condenser and the inert gas trap is provided with a controller which opens the throttle element as soon as a higher pressure is generated in the condenser than in the inert gas trap. If the throttle element is designed as a floating body, the weight of the float must be large enough to safely close an opening on or on which it rests. During the desorption phase, the floating body is lifted by the working medium vapor flowing into the collecting tank. The float can for example plastic, z. B. polypropylene be made. It is also preferred that a temperature sensor is arranged on the condenser and / or a pressure sensor is arranged on the condenser and / or desorber or the adsorber-desorber unit, the control signal being dependent on the measured values of the pressure and / or the temperature sensor. It is particularly preferred that the amount of inert gas is determined by the inert gas partial pressure. The determination of inert gas preferably takes place in the condenser and / or in the

Desorber. An advantageous determination of the amount of inert gas is carried out via a

Temperature sensor, which is arranged in the capacitor. In addition, a pressure sensor is preferably used, which is arranged either in the condenser and / or in the desorber. Since both containers have the same pressure at the time of measurement, it does not matter where the pressure sensor is located.

That is, preferably, the temperature sensor receives temperature readings while the pressure sensor detects pressure readings. It is therefore particularly preferred that the

Intergas determination takes place via a temperature and / or pressure measurement. The measurements are carried out with the mentioned sensors. It has been found that this is a particularly accurate and convenient method to determine the amount of inert gas.

It is particularly preferred that the temperature sensor is not arranged in the vacuum region of the condenser, but so that the return temperature of the condenser is measured. Thus, the outlet temperature of the working fluid is determined. Of the

In particular, a condenser is a heat exchanger which is supplied externally, ie not on the vacuum side, with recooling agent (preferably water). Internally, ie on the vacuum side, the working fluid (preferably water) condenses on its surface. In particular, three temperatures are important: the flow and return temperature of the recooler (external) and the temperature of the condensed working fluid (condensate, vacuum side).

For the determination of the inert gas, it is preferable to determine the temperature of the condensate in a vacuum. However, since the measurement of this temperature is complicated, this is preferably determined indirectly by the return temperature of the capacitor.

About the measurement of the outlet temperature can thus indirectly the temperature in the

Vacuum range can be determined. It is particularly preferred that the

Temperature measurement is then made when the capacitor does not bring its full power. For example, this may be the case in the second half of a cycle. This embodiment is particularly advantageous because it allows very accurate measured values to be generated and therefore the amount of inert gas can be determined very accurately. It is preferred that the vapor pressure of the working fluid for the temperature of the

Capacitor determined. This value is subtracted from the measured in the desorber and / or condenser. If there were no inert gas, the difference would be zero. The pressure difference thus corresponds to the inert gas partial pressure. This determination of the amount of inert gas via the pressure and temperature measurement has proved to be particularly advantageous, since so very accurate values can be determined.

It is also a simple measurement that does not require expensive equipment.

It is therefore preferred that the activation of the inert gas trap is effected by a control signal, wherein the control signal depends on the inert gas partial pressure. It is preferred

Parameter values for the inert gas partial pressure, which act as threshold values and whose exceeding leads to the activation of the inert gas trap via the control signal. The values for these thresholds depend mainly on the size of the

Sorption machine but also from the details of the device. Thus, the type of adsorption or absorption means determine the height of the threshold value.

It is advantageous if an inert gas detection and removal in a running

Sorption, particularly preferably a Adsorptionskältemaschine takes place. It is particularly preferred that the inert gas trap is activated or turned on when a certain amount of inert gas, ie a certain inert gas partial pressure has been reached. The coordination of the removal of the foreign gases with the operation of the

Sorption device brings an advantage over the inert gas trap without them

Control element, since now a better sorption can be achieved. Preferably, the inert gas trap is already activated at an inert gas partial pressure, which had no or only a small power loss result. As a result, the power, preferably the cooling capacity, is always kept within an effective framework. In the prior art, this has not been possible in such a simple and accurate manner.

Another preferred method of activating the inert gas trap is a power-dependent control signal. This signal is influenced by the power loss. The power loss is preferably determined by a measurement on the evaporator. This measurement is preferably carried out via a temperature sensor. This temperature sensor measures the

Temperature of entering and exiting work equipment. If the temperature difference drops, this is a sign of a drop in performance.

For a preferred embodiment of the invention, a threshold is now set, from which the inert gas trap is activated. This can prevent the performance, preferably the cooling capacity is low over a longer period. Particularly preferably, the threshold value is selected so that the inert gas trap is activated as soon as there is a measurable power loss.

Also preferred is the use of the number of cycles as the activation signal. Here, the number of cycles of the sorption is meant. This embodiment may also be advantageous. This is a statistical activation signal. So there is no measurement of certain parameters via sensors, but it is set a number of cycles as a threshold. Upon reaching this number of cycles, the

Inert gas trap activated via the above steps. The advantage of this method lies above all in the simplicity of the application. So no special sensors need to be retrofitted. This method is particularly suitable for sorption machines that are already in operation and therefore there are already empirical values. However, it may also be preferred that the optimum number of cycles is effected by pressure and temperature measurements. Thus, it is checked with reference to the previously described inert gas determination, at which number of cycles the inert gas thresholds were reached. Subsequently, the control signal then depends only on the number of cycles. Another measurement of temperature and pressure no longer needs to take place.

The same applies when using the operating time as the activation signal. Again, it is an embodiment that is particularly easy in existing

Procedure can be implemented. As with the use of the number of cycles, a measurement of pressure and temperature can take place beforehand when using the operating time. So, so to speak, the most suitable operating time can be determined by means of inert gas determination. But this is only a preferred variant. It is also possible to determine the most suitable operating time by other means, so that no additional sensors are necessary.

The determination of the threshold values by number of cycles or operating time depends on many factors. Among other things, the type of adsorbent or absorbent are important. The size of the sorption device also plays an important role. One

A person skilled in the art knows how to set the optimum number of cycles or operating hours without being inventive himself.

It is particularly preferred that step d., That is, the heating of the inert gas trap, is initiated by the control signal and the sequence of steps in step d. starts. The preferred sequence is therefore step d, step e, step a, step b, step c, step d, step e.

Although at the time before step d, no inert gas from the condenser into the

Inertgasfalle was conducted, this starting point is preferred. The insertion at step d. Has the advantage that inert gas, which may have passed through the environment in the Intergasfalle, is first evacuated. Inert gas may have entered the inert gas trap, especially if the inert gas trap has not been put into operation for a long time. As a result, it may happen that ambient air has penetrated into the Intergasfalle. By starting at step d. thus preventing additional inert gas from entering the system. The intergas trap is therefore evacuated only as a precaution before step a. starts. These

Embodiment has proven to be particularly preferred, as it prevents that additional inert gas enters the device, which would then have to be removed again. Preferably, the method always ends with step e.

The present application comprises the disclosure of WO2012069048. This application relates to a "vacuum vessel for removing foreign gases from an adsorption chiller." The vacuum vessel described therein is a preferred embodiment of the inert gas trap according to the invention

Process according to the invention is not limited to adsorption devices. For the problem of removing foreign gases is just as relevant for absorption, for example. The inventive method can therefore be applied to all sorption with inert gas trap.

It is particularly preferred that the working fluid is a refrigerant, preferably water. The inert gas trap may also preferably drive a certain number of cycles / procedures. It is preferred that the sequence of steps a. to e. repeated several times.

The number of repetitions depends on the size of the inert gas trap. For example, 10 to 150 repeats are preferred, more preferably 50 to 100

Repetitions. Very particular preference is given to 75 repetitions. However, if the inert gas trap is large enough, one pass of the steps is sufficient to completely remove the inert gas. A person skilled in the art knows which number of repetitions is particularly preferred for the particular design of the inert gas trap or the sorption device.

It is both preferred that any small amount of inert gas be removed immediately or wait for removal until a higher threshold is reached and the inert gas trap is then activated. This applies to all mentioned parameters. Which is the appropriate threshold, in turn, depends on many individual factors and can not be generalized. It has been found that it is particularly advantageous to make the control of the inert gas trap dependent on the amount of inert gas in the sorption device. For the determination of inert gas in a cycled sorption device, especially an adsorption chiller, the time of the determination is important, whereby the determination is based on at least one of the following criteria:

Inert gas detection at the end of the cycle and / or

• Inert gas detection in the middle of the cycle and / or

• Inert gas determination at the conclusion of the condensation process and / or

• Determine the average amount of inert gas for several seconds at the end of the cycle and / or

• Determine the average amount of inert gas over the entire cycle.

Particularly preferred is the determination of the amount of inert gas, in the middle or towards the end of the cycle. When is the optimal time to determine the amount of inert gas, also depends on the sorption used. A person skilled in the art is able to carry out the invention so that it has the appropriate time for the determination of inert gas, depending on

Sorption device can determine. For example, there are sorption devices in which towards the end of the cycle part of the inert gas has already flowed to the evaporator. In such devices, therefore, the end of a sorption cycle is not the optimal time to detect inert gas, since there is no longer all the inert gas in the condenser.

At the beginning of the cycle, the condensation is still strong, causing the condenser to work and generate more vapor. At such a time, the inert gas in some devices can not be determined very well, so that such sorption devices are more likely to use the middle to the end of an inert gas detection cycle.

It is particularly preferred that the amount of inert gas, ie the inert gas partial pressure, is determined over a plurality of successive measurements over a certain period of time. Above all, the determination of 5 to 100 values in a period of 5 to 150 seconds is preferred. Very particular preference is given to measuring from 30 to 75 values in 10 to 25 seconds. From these values, an average value is preferably formed, which then determines the amount of inert gas. By the formation of the mean value several successive measurements are compensated for small fluctuations and the inert gas can be determined very accurately.

The method of the invention thus includes a control concept which activates the inert gas trap by a control signal and thus determines when the inert gas is discharged. This will improve the overall sorption process and increase performance.

It is particularly preferred that the new control concept together with a

Inertgasfalle according to WO2012069048 is used. Such an inert gas trap can also be described as a vacuum container for a sorption apparatus, characterized in that the vacuum container is connected via vapor-open connection means to a condenser unit of a sorption refrigeration machine and the container has a discharge device and at least one cooling element, wherein in the

Connecting means at least one component for blocking or regulating the flow of fluids is present. Particularly preferred is the method for removing a foreign gas from a

An adsorption chiller comprising at least one adsorber / desorber unit, an evaporator / condenser unit and a vacuum vessel (preferably inert gas trap) having at least one cooling element, the process comprising the following steps: a. Cooling the vacuum container by the cooling element to a temperature lower, equal or similar to that of the condenser unit, b introducing a vaporous refrigerant from the desorber unit into the condenser unit, the refrigerant in the condenser unit at least partially condensing and the inert gas collects in the condenser, c. Opening a, between the condenser unit and the vacuum container arranged member for shutting off or regulating the flow of fluids, wherein the inert gas and vapor refrigerant from the condenser unit flows into the vacuum vessel, d heating the vacuum vessel, e opening a discharge device through which Inert gas can flow out of the vacuum container, wherein the activation of the vacuum container is effected by a control signal selected from the group comprising inert gas quantity, power loss, number of cycles and / or operating time.

In WO2012069048 the inert gas trap is referred to as a vacuum container. This

Vacuum container is preferably an inert gas according to the invention. By means of the invention, this method is now supplemented with a control concept which, on the one hand, determines specific activation signals and, on the other hand, controls the activation of the inert gas trap.

example

In the following the invention will be explained with reference to figures without being limited to these.

FIG. 1 shows a preferred embodiment of the inert gas trap 1, which is connected to a condenser unit 8. The condenser unit 8 and the inert gas trap 1 are under vacuum. In the condenser unit 8 is in addition to the vaporous working medium and inert gas. The inert gas trap 1 contains in one embodiment only liquid working fluid 7 and water vapor (minimum amount or no inert gas). The connecting means with a valve 2 opens and the inert gas with vaporous working fluid flows into the inert gas trap 1. For this purpose, a pressure difference between the inert gas trap 1 and the condenser unit 8 is advantageous. The pressure difference is preferably achieved by cooling the inert gas trap 1 with a cooling element 4. If the foreign gas is to be removed from the inert gas trap 1, preferably the connecting means with a valve 2 and the inert gas trap 1 is heated in particular with a heating element. When the pressure in the inert gas trap 1 is above the ambient pressure, the vent 3 opens and water vapor and inert gas flow into the environment. Another way of cooling the inert gas trap 1 is that the connecting means are opened with a valve 2 and 6. Liquid working fluid flows via the connecting means with a valve 6 in the inert gas trap 1, evaporate and flow through the connecting means with a valve 2 back into the condenser unit 8. As a result, the inert gas trap 1 is cooled. It is further preferred that a further cooling of the inert gas trap 1 can be carried out by introducing cold refrigerant from the condenser unit 8. For this purpose, for example, a connection between the condenser unit 8 and inert gas trap 1 exist.

FIG. 2 shows a preferably adsorption chiller 12 with inert gas trap 1. The

Adsorption chiller 12 preferably has a condenser unit 8, a Adsorber unit 9, a desorber unit 10 and an evaporator unit 11 on. The inert gas trap 1 withdraws from the condenser unit 8 of the adsorption chiller 12

Foreign gas. The foreign gas can be removed by a heating element from the inert gas trap 1 by an overpressure is achieved in the inert gas trap 1 and the inert gas is released by a discharge device 3. The inert gas trap 1 is preferably through

Connecting means 2 with controlled valve or non-return valve connected to the condenser unit 8. During operation of the adsorption chiller 12, the inert gas accumulates mainly in the condenser unit 8.

It is preferred that the inert gas trap 1 is then heated when a certain threshold value for the inert gas partial pressure has been reached. The following is an example of control after inert gas detection: typical temperature in the condenser 30 ° C

Vapor pressure of the working fluid (preferably water) at 30 ° C -> 42.4mbar

Measured pressure via the pressure sensor in the desorber / condenser is 55 mbar. Inert gas partial pressure: "measured pressure" minus "steam pressure working medium" -> 55 mbar - 42.4 mbar = 12.6 mbar

Without inert gas, the measured pressure would be equal to the vapor pressure calculated by the temperature. The difference corresponds to the inert gas partial pressure.

The value of 12.6 mbar thus indicates that inert gas is present in the sorption device. If the threshold is 12.6 mbar or less, then the inert gas trap is activated.

LIST OF REFERENCE NUMBERS

1 inert gas case

2 connecting means to the condenser unit

3 discharge device

4 cooling element

6 Additional connection means to the condenser unit

7 Liquid work equipment

8 capacitor unit

9 adsorber unit

10 desorber unit

1 1 evaporator unit

12 adsorption chiller

13 Connecting means to the evaporator unit

Claims

claims

Method for removing a foreign gas from a sorption machine, wherein the sorption machine at least

An adsorber and a desorber, or an adsorber-desorber unit, or an absorber and a desorber,

• an evaporator and a condenser, or an evaporator-condenser unit

• a work equipment,

• a throttle element and

• an inert gas trap

includes,

wherein the inert gas trap comprises at least one cooling element and a discharge device, wherein

the method comprises the following steps:

a. Cooling the inert gas trap by the cooling element to a temperature lower, equal to, or nearly equal to the temperature of the condenser, b. Introducing a vaporous working fluid from the desorber or the adsorber-desorber unit into the condenser, the working fluid in the condenser at least partially condensing and foreign gas collecting in the condenser,

c. Opening a throttle element arranged between the condenser and the inert gas trap, the foreign gas and vaporous working medium flowing from the condenser into the inert gas trap,

d. Heating the inert gas trap,

e. Opening a discharge device through which the foreign gas can flow out of the inert gas trap,

characterized in that

one of the steps is initiated by a control signal selected from the group comprising inert gas quantity, power loss, number of cycles and / or operating time.

Method according to claim 1,

characterized in that

Step d. is initiated by the control signal and the sequence of steps in step d. starts.

3. The method according to claim 1 or 2,

characterized in that

the control signal activates the intergas trap as soon as predefined parameter values are reached.

4. The method according to at least one of the preceding claims,

characterized in that

the Intergasmenge is determined by a temperature and / or pressure measurement.

5. The method according to at least one of the preceding claims,

characterized in that

a temperature sensor is arranged on the condenser and / or a pressure sensor is arranged on the condenser and / or desorber or the adsorber-desorber unit, the control signal of the inert gas quantity being dependent on the measured values of the pressure and / or the temperature sensor.

6. The method according to at least one of the preceding claims,

characterized in that

the sequence of steps a. to e. repeated several times.

7. The method according to at least one of the preceding claims,

characterized in that

the amount of inert gas is determined at the end or in the middle of a cycle.

8. The method according to at least one of claims 1 to 6,

characterized in that

the amount of inert gas is determined at the conclusion of the condensation process.

9. The method according to at least one of claims 1 to 6,

characterized in that

the inert gas quantity is determined over several seconds at the end of a cycle or the average amount of inert gas over the entire cycle.

10. The method according to at least one of the preceding claims,

characterized in that

the sorption process is an adsorption process.

1. The method according to at least one of the preceding claims, characterized in that

the working fluid is a refrigerant, preferably water.