DE102015006189A1 - Method for permissible level and Füllmengenerhöhung a vehicle refrigeration system and vehicle refrigeration system for performing the method - Google Patents

Abstract

The invention relates to a method for level and Füllmengenerhöhung a vehicle refrigeration system with a refrigerant circuit (1) comprising the following steps: providing components of a refrigerant circuit and connecting them by means of refrigerant pipes, the refrigerant circuit consisting of the components and the refrigerant pipes total investment volume (VA) determining, determining an optimal fill quantity (mopt) of refrigerant for the given total investment volume (VA) as a function of at least one of the parameters ambient temperature, ambient humidity, driving speed, sun load, air quantity to be conditioned, air damper position, providing an additional volume (Vzu) as buffer volume (8.1 , 8.2, 8.3, 9, 9.1, 9.11, 9.2, 9.3, 9.4, 9.5, 9.6) in the refrigerant circuit (1) in the flow direction (R) of the refrigerant between the evaporator (2) and the compressor (3), determining an optimum Additional charge (mopt, too) to Kä for the additional volume (8.1, 8.2, 8.3, 9, 9.1, 9.11, 9.2, 9.3, 9.4, 9.5, 9.6), which under the pressure and temperature conditions of the low pressure side of the refrigerant circuit (1) the additional volume (8.1, 8.2, 8.3 , 9, 9.1, 9.1.1, 9.2, 9.3, 9.4, 9.5, 9.6), and filling the refrigerant circuit (1) with one of the sum of the optimum filling quantity (mopt) and the optimal additional filling quantity (mopt, zu) corresponding new optimal filling quantity (mopt, new) of refrigerant. The invention further relates to a vehicle refrigeration system for carrying out the method according to the invention.

Description

The invention relates to a method for filling level and Füllmengenerhöhung a vehicle refrigeration system with a refrigerant circuit and a vehicle refrigeration system for carrying out this method according to the invention.

The use of refrigerant circuits in vehicle air conditioners is known, with some variants providing a 2-evaporator system, namely a front evaporator and a rear-end evaporator. Depending on the interconnection and active operation of the respective heat transfer, the demand for required active refrigerant in the refrigerant circuit varies.

Electrified vehicles require in addition to the front evaporator as at least one interior evaporator a separate cooling device for conditioning and temperature control of the energy storage device usually realized as a high-voltage battery. Such a cooling device can be realized by means of the refrigerant circuit and is referred to as active battery cooling. Such a cooling device is realized as a heat exchanger, which works as an evaporator (by cooling an air stream) or as a chiller (by cooling water).

The use of the refrigerant circuit of the vehicle air conditioning system in a heat pump operation for heating the passenger compartment is known. In its function as a heat pump, the refrigerant circuit is able to heat an air or water stream or coolant flow and to deliver this heat directly or indirectly to the air of the passenger compartment. Depending on the mode of operation of the vehicle air conditioning system, that is, whether it is heated or cooled or which number of heat exchangers are actively operated, the amount of active or actually required refrigerant in the refrigerant circuit also varies in this case.

The different modes of operation of such a refrigeration system can thus require different refrigerant charge levels as optimum depending on the interconnection of the components.

In the case of carbon dioxide (R744) as a refrigerant, the optimum filling quantity for the respective process connection is determined for a refrigerant circuit of an air conditioning system of a vehicle as part of a filling quantity determination. A special feature of this refrigerant R744 is that in addition to the optimum filling quantity, there is also a requirement for the maximum permissible filling quantity, which is directly linked to the system volume. According to DIN Spec. or SystemLeftheft, the maximum permissible value is currently 250 g / l, d. H. per liter of system volume, a maximum of 250 g of refrigerant may be added. This value is currently defined for the system at rest from pressure and temperature of 93 bar at 60 ° C. The background is the protection of the low-pressure side at high environmental loads in inactive refrigeration systems against too high a mechanical load due to a too high adjusting static pressure.

For standard R744 refrigeration systems, however, the difference between the value of the optimum filling quantity and the maximum permissible filling quantity is not large. Usually, the difference between the two values is 20 to 50 g.

If, on the one hand, the buffer quantities are considered in conventional systems with amounts of 50 to 150 g (lifetime filling) and on the other hand possible tolerances on the filling equipment of conveyor systems within the production and service equipment in customer service and workshops, the above-mentioned zufüllbare difference of 20-50 g to low. Therefore, early workshop visits for the customer may occur due to refrigerant losses or lack of refrigerant as well as overfilling and exceeding of the 250 g / l specification.

Therefore, in a vehicle refrigeration system, overfilling or underfilling as well as exceeding the 250 g / l requirement must be avoided. If there is too little refrigerant / oil mixture in the refrigerant circuit, it may damage the compressor due to lack of oil. From the prior art concepts for monitoring the Kältemittelfüllgrades are known, however, require a complex sensors and therefore leads to high costs. As an example, let us look at the DE 10 2007 021 874 A1 directed.

The object of the invention is to provide a method for increasing the level of a vehicle refrigeration system, so that a sufficient distance between the value of the optimal filling amount and the maximum allowable filling amount of the refrigeration system is implemented as part of the vehicle air conditioning and thus at the same time a buffer is provided with the Possible leaks and equipment losses over the vehicle life can be compensated. Another object is to provide a vehicle refrigeration system for carrying out the method.

The first object is achieved by a method for filling level or Füllmengenerhöhung a vehicle refrigeration system with a refrigerant circuit having the features of claim 1.

• – Bereitstellen folgender Komponenten: wenigstens einen Verdampfer, ein Kältemittelverdichter, einen Kältemittelkondensator oder Gaskühler, einen Akkumulator, er und ein dem Verdampfer zugeordnetes Expansionsorgan,
• – Verbinden der Komponenten mittels einer Kältemittelleitung zur Bildung des ein aus der Summe der Einzelvolumina aller Komponenten und Kältemittelleitungen gebildeten Gesamt-Anlagevolumen aufweisenden Kältemittelkreislaufs, wobei der Akkumulator in Strömungsrichtung des Kältemittels dem Verdampfer nachgeschaltet wird,
• – Bestimmen einer optimalen Füllmenge an Kältemittel für das gegebene Gesamt-Anlagevolumen in Abhängigkeit wenigstens einer der Parameter Umgebungstemperatur, Umgebungsfeuchte, Fahrgeschwindigkeit, Sonnenlast, zu konditionierende Luftmenge, Luftklappenstellung,
• – Bereitstellen eines Zusatzvolumens als Puffervolumen in dem Kältemittelkreislauf in Strömungsrichtung des Kältemittels zwischen dem Verdampfer und dem Verdichter,
• – Bestimmen einer optimalen Zusatzfüllmenge an Kältemittel für das Gesamt-Zusatzvolumen, welche unter den Druck- und Temperaturbedingungen der Niederdruckseite des Kältemittelkreislaufes das Zusatzvolumen ausfüllt, und
• – Befüllen des Kältemittelkreislaufes mit einer der Summe aus der optimalen Füllmenge und der optimalen Zusatzfüllmenge entsprechenden neuen optimalen Füllmenge an Kältemittel.

Such a method is characterized by the following method steps:

• Providing the following components: at least one evaporator, one refrigerant compressor, one refrigerant condenser or gas cooler, one accumulator, he and an expander associated with the evaporator,
• Connecting the components by means of a refrigerant line to form a refrigerant circuit having a total investment volume formed from the sum of the individual volumes of all components and refrigerant lines, the accumulator being connected downstream of the evaporator in the flow direction of the refrigerant,
• Determining an optimum charge quantity of refrigerant for the given total investment volume as a function of at least one of the parameters ambient temperature, ambient humidity, driving speed, sun load, air quantity to be conditioned, air damper position,
• Providing an additional volume as a buffer volume in the refrigerant circuit in the flow direction of the refrigerant between the evaporator and the compressor,
• - Determining an optimal additional filling amount of refrigerant for the total additional volume, which fills the additional volume under the pressure and temperature conditions of the low pressure side of the refrigerant circuit, and
• - Filling the refrigerant circuit with one of the sum of the optimal capacity and the optimal additional filling corresponding new optimum refrigerant charge.

With such an additional volume as a buffer volume on the one hand sufficient filling of the refrigeration system and thus buffering of the refrigerant, especially at critical ambient temperatures in the idle state of the refrigeration system of the vehicle is achieved, so that an improved compensation of possible leaks is ensured. On the other hand, due to the realization of the buffer volume on the low pressure side of the refrigerant circuit less refrigerant than optimal additional filling to fill the additional volume required as it would correspond to the value of the additional volume at another point of the vehicle refrigeration system, so that the sum of the given system volume and the optimal additional volume Compared to the new optimum filling quantity (sum of previous optimum filling quantity and the optimal additional filling quantity) disproportionately increases and as a result the limit of currently 250 g / l is significantly undercut, d. H. There is a high distance or difference between the new optimum filling quantity and the new resulting maximum permissible filling quantity for the total system volume increased by the additional volume.

Part of this difference can be selectively used according to training as buffer filling to additionally store refrigerant for a lifetime filling of the refrigeration system, without conflicting with the thermodynamic boundary conditions or the allowable specific capacity in conflict. The new optimum filling quantity for the refrigerant circuit with the additional volume then increases by this buffer filling quantity.

Another advantage of this method according to the invention is that tolerances of the filling and service equipment in production and service are compensated by means of such a buffer filling or that the vehicle refrigeration system is now unsensitive to these tolerances.

According to an advantageous embodiment of the invention, an internal heat exchanger is provided which is arranged on the one hand on the low pressure side of the refrigerant circuit between the accumulator and the compressor and on the other hand on the high pressure side of the refrigerant circuit between the condenser or gas cooler and the expansion element. Such an internal heat exchanger is operated in countercurrent process.

The additional volume is formed according to an embodiment of the invention by an additional container which is connected to a refrigerant line either between the accumulator and the compressor or between the evaporator and the accumulator. Preferably, the auxiliary tank is arranged on the low-pressure side of the refrigerant circuit between the inner heat exchanger and the compressor or between the accumulator and the inner heat exchanger or the evaporator and the accumulator. In this case, the additional container can either be arranged so that it is connected via a line to the refrigerant line and is not actively flowed through by the refrigerant. The installation and its inclination or alignment takes place in such a way that due to the installation position no oil trap is created. The additional container can also be installed in such a way that it is actively flowed through by refrigerant. At the same time, this additional container can be designed as a muffler (silencer) so that acoustic disturbances are damped and compensated.

According to a further advantageous embodiment of the invention, the additional volume can be formed by at least a region-wise cross-sectional enlargement of the refrigerant line between the evaporator and the compressor.

Furthermore, an embodiment of the invention provides that the additional volume is formed by the internal heat exchanger.

Furthermore, according to a further embodiment of the invention, the additional volume can be formed by an extension of the accumulator.

Finally, the additional volume is formed by the compressor according to a last embodiment of the method according to the invention, wherein the additional volume is realized at the refrigerant inlet of the compressor.

The indicated possibilities of realizing the additional volume can also be combined, so that the additional volume is divided into several sub-volumes and integrated in the system section of the vehicle refrigeration system provided for this purpose.

The second object is achieved by a vehicle air conditioning system with the features of claim 10

• – die Komponenten unter Bildung eines gegebenen Gesamt-Anlagenvolumens über Kältemittelleitungen verbunden sind und dem Verdampfer in Strömungsrichtung des Kältemittels nachgeschaltet sind,
• – zur Füllstandserhöhung des Kältemittelkreislaufs ein Zusatzvolumen als Puffervolumen auf der Niederdruckseite des Kältemittelkreislaufs zwischen dem wenigstens einen Verdampfer und dem Verdichter vorgesehen ist, und
• – der Kältemittelkreislauf mit einer Summe aus einer optimalen Füllmenge und einer optimalen Zusatzfüllmenge entsprechenden neuen optimalen Füllmenge an Kältemittel befüllt ist, derart dass die optimale Zusatzfüllmenge gemäß des erfindungsgemäßen Verfahrens bestimmt ist.

Such a vehicle refrigeration system for a vehicle with a refrigerant circuit, which comprises as components at least one evaporator, a refrigerant compressor, a refrigerant condenser or a gas cooler, an accumulator and an evaporator associated with the expansion device, according to the invention is characterized in that

• - The components are connected to form a given total system volume via refrigerant pipes and are downstream of the evaporator in the flow direction of the refrigerant,
• - To fill level increase of the refrigerant circuit, an additional volume is provided as a buffer volume on the low pressure side of the refrigerant circuit between the at least one evaporator and the compressor, and
• - The refrigerant circuit is filled with a sum of an optimal filling quantity and an optimal additional filling amount corresponding new optimal filling amount of refrigerant, such that the optimum additional filling amount is determined according to the inventive method.

Such a vehicle refrigeration system also has the advantages explained in connection with the method according to the invention.

Advantageous embodiments of the vehicle refrigeration system according to the invention are given with the features of the claims 10 to 17.

The invention will now be described in detail by means of embodiments with reference to the accompanying figures. Show it:

1 1 is a block diagram of a refrigerant circuit of a vehicle refrigeration system according to a first embodiment of the invention;

2 a detail of a refrigerant circuit of a vehicle refrigeration system according to a second embodiment of the invention,

3 a detail of a refrigerant circuit of a vehicle refrigeration system according to a third embodiment of the invention,

4 a detail of a refrigerant circuit of a vehicle refrigeration system according to a fourth embodiment of the invention, and

5 a detail of a refrigerant circuit of a vehicle refrigeration system according to a fifth embodiment of the invention.

The 1 to 5 each show a refrigerant circuit 1 with identical basic structure of a vehicle refrigeration system of a vehicle (not shown), wherein in the 2 to 5 only part of this basic structure is shown.

• – einen Verdampfer 2,
• – einen Kältemittelverdichter 3,
• – einen Kältemittelkondensator bzw. Gaskühler 4,
• – ein dem Verdampfer 2 in Strömungsrichtung R des Kältemittels vorgeschaltetes Expansionsorgan 5,
• – einen Akkumulator 6, der die Funktion eines Kältespeichers erfüllt und in Strömungsrichtung R des Kältemittels dem Verdampfer 2 nachgeschaltet ist, und
• – einen inneren Wärmeübertrager 7.

The refrigerant circuit 1 this 1 to 5 includes as a basic structure the following components:

• - an evaporator 2 .
• - a refrigerant compressor 3 .
• - A refrigerant condenser or gas cooler 4 .
• - a the evaporator 2 in the flow direction R of the refrigerant upstream expansion element 5 .
• - an accumulator 6 , which fulfills the function of a cold storage and in the flow direction R of the refrigerant to the evaporator 2 is downstream, and
• - an internal heat exchanger 7 ,

The accumulator 6 (Also called (low-pressure) collector) is used in the refrigerant circuit to separate flowing refrigerant into gaseous and liquid refrigerant. It is also known that accumulator 6 and internal heat exchanger 7 can also be executed as a combined component. This eliminates the refrigerant piping section between the accumulator 6 and the internal heat exchanger 7 and in this case also the option of the simplified interposition of an additional volume.

In the 2 to 5 For the sake of simplicity, they are just the components 6 . 7 and 8th shown.

The listed components 2 . 3 . 4 . 5 . 6 and 7 are for the formation of the refrigerant circuit 1 via a refrigerant line 8th together connected. This results in a given system volume V _{A of} this refrigerant circuit 1 , The refrigerant used is R744 (CO ₂ ).

The internal heat exchanger 7 works in the counterflow principle and is on the low pressure side of the refrigerant circuit 1 between the accumulator 6 and the refrigerant compressor 3 and on the high pressure side of the refrigerant circuit between the gas cooler 4 and the expansion valve 5 connected.

The targeted raising of the total system volume V _{A of} the refrigerant circuit 1 with the components listed above 2 . 3 . 4 . 5 . 6 and 7 by means of a buffer filling quantity of refrigerant to an increasing difference between a new optimum filling quantity m _{opt, new} and a maximum permissible filling quantity m _opt + m _{max, zul,} in this refrigerant circuit 1 is explained below.

Based on the basic structure of the refrigerant circuit described above 1 First of all, the optimum filling quantity m _{opt is} determined for its total system volume V _A. This method for determining the amount of charge is known to the person skilled in the art and is therefore not described in detail.

This optimum filling quantity m _opt for the total system volume V _A is dependent on at least one of the parameters ambient temperature, ambient humidity, driving speed, sun load, conditioning air quantity over the least one evaporator 2 , Air damper position, etc., ideally depending on all of the listed parameters.

As already mentioned, there is also a provision for the maximum permissible filling quantity, which is coupled directly to the total system volume V _A and is specifically for R744 = 250 g / l. This value is currently defined for the system at rest from pressure and temperature of 93 bar at 60 ° C.

Subsequently, an additional volume V _to be provided as a buffer volume, which on the low pressure side of the refrigerant circuit between the evaporator 2 and the refrigerant compressor 3 is realized. The different implementations of such additional volume V _to be in the 1 to 5 shown.

According to the 1 . 2 and 3 is this additional volume V _too as a pressure vessel 9 respectively. 9.1 and 9.11 (see. 1 ), as a pressure vessel 9.2 (see. 2 ), or as a pressure vessel 9.3 (see. 3 ) realized. In analogy to the pressure vessels 9.1 , and 9.11 can the pressure vessels 9.2 or 9.3 similarly repositioned.

According to 1 is the additional volume V _to be realized pressure vessel 9 via a refrigerant line section 8.0 with a section of refrigerant piping 8th between the inner heat exchanger 7 and the refrigerant compressor 3 connected. Alternatively, such pressure vessels 9.1 also between the evaporator 2 and the accumulator 6 , the accumulator 6 and the inner heat exchanger 7 via a refrigerant line section 8.0 with the refrigerant line 8th get connected. Here are these executed in bottle pressure vessel 9 . 9.1 and 9.11 arranged such that they can not be actively flowed through by the refrigerant and represent no oil trap due to the installation position. The design of the pressure vessel 9 . 9.1 and 9.11 can arbitrarily and due to the Packagesituation in their design to the vorzufindenden environment be ideally adapted. Here it means that these pressure vessels 9 . 9.1 and 9.11 standing and above the refrigerant pipe section between the inner heat exchanger 7 and the refrigerant compressor 3 or the accumulator 6 or between the evaporator 2 and the accumulator 6 are arranged.

The likewise executed in a bottle shape pressure vessel 9.2 and 9.3 according to the 2 and 3 are arranged horizontally with a supply line and a drain, so that these components 9.2 and 9.3 be actively flowed through by the refrigerant. Here, these pressure vessels 9.2 and 9.3 be designed as a muffler (damper) to dampen or compensate for acoustic interference. Even with these pressure vessels 9.2 and 9.3 Care must be taken to ensure that there is no oil trap due to the installation position and the position of the outlets.

For all pressure vessels, the respective design used is freely selectable. Basic functional rules are complied with.

The additional volume V _to can on the low pressure side of the refrigerant circuit 1 according to 4 Also be realized in that the refrigerant piping section 8.1 between the internal heat exchanger 7 and the refrigerant compressor 3 and the refrigerant piping section 8.2 between the accumulator 6 and the internal heat exchanger 7 and the refrigerant piping section 8.3 between the evaporator 2 and the accumulator 6 opposite to the other refrigerant pipe sections of the refrigerant circuit 1 Are oversized, ie that their line and / or hose flow cross-sections or the inner diameter are greater than the corresponding values of the refrigerant pipe sections of the refrigerant circuit 1 on the high pressure side, ie between the components internal heat exchanger 7 , Gas cooler 4 and expansion valve 5 ,

In addition to the volume gain, the line cross-sectional enlargement also has a positive effect on the reduction of the flow or pressure losses in the low-pressure side section of the refrigerant circuit 1 , which in turn brings efficiency gains.

Finally, the additional volume V _to on the low pressure side of the refrigerant circuit according to 5 also in the components, namely in the accumulator 6 , the internal heat exchanger 7 and / or the refrigerant compressor 3 to get integrated. Their space requirement or total volume increases thereby.

With regard to the refrigerant compressor 3 the additional volume V _becomes the buffer volume 9.4 ideally integrated into its refrigerant inlet as a volume of muffler (ie with a noise-damping property). Thus, in this case, the additional volume V _becomes into a component of the refrigerant cycle 1 involved.

Also the volume of the accumulator 6 becomes equal to the additional volume V _to with a buffer volume 9.6 elevated. Thus, this accumulator can also 6 as an existing component of the refrigerant circuit 1 used to increase the filling capacity.

The volume of the internal heat exchanger 7 is only on its low pressure side by a buffer volume 9.5 elevated.

Depending on the additional volume V _to the realized buffer volume 8.1 . 8.2 . 9 . 9.1 . 9.11 . 9.2 . 9.3 . 9.4 . 9.5 and 9.6 is to fill an optimal Zusatzfüllmenge m _{opt, to be} determined. In order to "fill in" the additional volume V _to refrigerant due to the realization of the buffer volume is on the low pressure side of the refrigerant circuit 1 less refrigerant than additional charge amount m _opt, required to be equal to the value of the additional volume or elsewhere in the refrigerant circuit 1 the case would be.

Is, for example, the additional volume V _to = 100 ml and is this additional volume as a pressure vessel 9 . 9.2 . 9.3 or as a cross-sectional enlargement by means of the refrigerant pipe section 8.1 If this additional volume was realized, this additional volume could _be filled with approximately 25 g of refrigerant as the maximum permissible additional filling quantity m _{max, zul} , which is determined by the limit value of 250 g / l for R744. Since the additional volume V _to as a buffer volume on the low pressure side of the refrigerant circuit 1 is realized, however, to fill the additional volume V _to only 10 g of refrigerant as optimum additional filling amount m _{opt, to be} required.

The optimal auxiliary-Weight m _{opt to} on the one hand by calculation be determined based on the autogenous pressure and temperature values within the known filling quantity determination to determine the optimum filling amount with the inclusion of the refrigerant material data and the geometric information of the additional volume V _A. Alternatively, the filling quantity determination with a vehicle refrigeration system having the additional volume is carried out again in the vehicle and the new optimum filling quantity m _{opt, new} is consequently determined experimentally by the methods known to the person skilled in the art.

The refrigerant circuit 1 (m _{opt, old} + m _{opt to)} from the original optimum filling amount m _opt with the sum (= m _{opt, old)} and the optimum auxiliary capacity m _{opt to} corresponding amount of refrigerant as a new optimum fill m _{opt, new} basis filled, the new total system volume V _{A, new} has _{to be} increased by the additional volume V, that is, it is V _{A, new} = V _A + V _to.

Since the optimum additional filling quantity m _{opt is too} small than the maximum permissible additional filling quantity m _{max, zul} resulting from the limit value of 250 g / l, the original system volume V _{A increases} to the new value V _{A, again} disproportionately in comparison to the new one optimum filling quantity, which only increases from m _opt to m _{opt, new} = m _opt + m _{opt · to} .

In the example described above with an additional volume of V _to = 100 ml and an optimal additional filling amount m _{opt, to} 10 g of refrigerant, this means that the difference of (m _{max, zul, to} - m _{opt, too} ) = 15 g to the maximum possible m _{max, perm, to} = 25 g of refrigerant is not used. This means that the limit of 250 g / l is exceeded, and yet the vehicle refrigeration system can be operated properly. This difference (m _{max, permissible to} - m _{opt to) to} may be used specifically corresponding partial volume of the additional volume V to a buffer fill m _{PUF to} store in addition _to of refrigerant for a lifetime filling of the refrigeration system, without with the thermodynamic boundary conditions or the permissible specific filling quantity.

The installation location of the pressure vessel 9 according to 1 between the internal heat exchanger 7 and the refrigerant compressor 3 is particularly advantageous because during the process operation here the lowest densities occur, so there the need for mass of the optimal additional filling amount m _{opt, is} the lowest. This also applies to the pressure vessel 9.2 and 9.3 according to the 2 and 3 , This is also the embodiment with respect to the determination of the optimal additional filling quantity m _{opt, for} for an additional volume V _to of 100 ml. If other implementations for the additional volume V _{to be} selected, then in theory, the above example values can be scaled up or down or can be redetermined according to known methods. The positions of the additional volume V _{A change} in the area between the evaporator 2 and compressors 3 Thus, due to other pressures, temperatures, other densities and thus other values for the additional charge quantities m _opt, and, as a result, other resulting buffer charge quantities m _{puf, result} . The basis of the limit value 250 g / l predetermined maximum permissible additional capacity m _{max, permissible to} for the additional volume V _to remain unchanged.

• – die Differenz (m_max,zul.zu – m_opt,zu) zwischen der optimalen Füllmenge m_opt,zu und der aufgrund des Grenzwertes 250 g/l maximal zulässigen Füllmenge m_max,zul.zu wird wesentlich erhöht,
• – wird die optimale Zusatzfüllmenge m_opt,zu vollständig oder mit einem Teil der Differenz (m_max,zul,zu – m_opt,zu) als Pufferfüllmenge m_puf,zu für eine sogenannte Lebensdauerbefüllung erhöht, können mögliche Leckagen kompensiert werden,
• – die optimale Zusatzfüllmenge m_opt,zu, gegebenenfalls zusammen mit einer Pufferfüllmenge m_puf,zu, ermöglicht die Kompensation von Toleranzen der Befüllapparaturen und den Servicegeräten in Produktion und Service, und
• – trotz der optimalen Zusatzfüllmenge m_opt,zu und gegebenenfalls einer Pufferfüllmenge m_puf,zu an Kältemittel wird die Begrenzung von 250 g/l an Kältemittel eingehalten.

In summary, this is based on the 1 to 5 explained method according to the invention for increasing the level of a vehicle refrigeration system with the additional volume V _to and the corresponding optimal additional filling amount m _{opt, the} following advantages:

• - the difference (m _{max, zul.zu} - m _{opt to)} between the optimum filling amount m _{opt to} and substantially increased because of the limit value 250 g / l maximum permissible capacity m _max, is _zul.zu,
• If the optimum additional filling quantity m _{opt is increased too} completely or with a part of the difference (m _{max, zul, to} m _{opt, too} ) as the buffer filling quantity m _puf, for a so-called service life filling, then possible leaks can be compensated.
• - the optimal additional filling quantity m _{opt, to} , if necessary, together with a buffer filling quantity m _{puf, to} , allows the compensation of tolerances of the filling equipment and the service equipment in production and service, and
• - Despite the optimal additional filling quantity m _opt, and if necessary, a buffer filling quantity m _{puf, to} refrigerant is the limitation of 250 g / l of refrigerant complied with.

The new resulting buffer filling quantity m _{puf, res, new} for a with the additional volume V _A to a new total system volume V _{A, newly} increased refrigerant circuit 1 results from the sum of the previous buffer volume m _{puf of} the vehicle refrigeration system in its basic design (ie without additional volume V _A ) and the buffer filling quantity, due to the integrated additional volume V _A and can be described as follows: m _{puf, res, new} = m _puf + m _{puf, too}

The final design of the design of the pressure vessels 9 . 9.1 . 9.11 . 9.2 . 9.3 , in particular the necessary additional volume for each system, a vehicle refrigeration system must be assessed and performed separately.

The basis of the 1 to 5 described invention is independent of the choice of the refrigerant used. In addition to the refrigerant R744 also chemical operating materials, such as R134a and R1234yf, can be used in the above-described refrigeration systems. However, the method according to the invention is advantageous in particular for refrigerants which, in the quiescent state of a refrigeration plant, can move into the supercritical state region due to the adjacent environmental boundary conditions (temperature) and in which an increased mechanical rest load (pressure) can thus result.

In addition to the refrigeration systems with pure cooling functionality, this inventive method for Füllmengenerhöhung example, for systems with heat pump function can be used.

LIST OF REFERENCE NUMBERS

1

Refrigerant circulation

2

Evaporator, internal heat exchanger

3

Refrigerant compressor

4

Refrigerant condenser, gas cooler

5

expansion element

6

accumulator

7

internal heat exchanger

8th

Refrigerant line

8.0

Refrigerant line section

8.1

Refrigerant line section of the refrigerant line 8th

8.2

Refrigerant line section of the refrigerant line 8th

8.3

Refrigerant line section of the refrigerant line 8th

9

Additional volume, additional container

9.1

Additional volume, additional container

9.11

Additional volume, additional container

9.2

Additional volume, additional container

9.3

Additional volume, additional container

9.4

Additional volume of the refrigerant compressor 3

9.5

Additional volume of the internal heat exchanger 7

9.6

Additional volume of the heat exchanger 6

R

Flow direction of the refrigerant

m _{max, zul, too}

maximum allowable filling quantity for additional volume V _to

m _opt

optimal filling quantity for a total system volume V _A

m _{opt, too}

optimal additional filling volume for additional volume V _too

m _{opt, new}

new optimal filling volume for new total system volume V _{A, new}

m _puf

Buffer fill quantity for a total system volume V _A

m _{puf, res, new}

Buffer capacity for a total system volume V _A + V _to

m _{puf, too}

Buffer capacity for additional volume V _too

V _A

Total investment volume

V _{A, new}

new total plant volume

V _too

Additional volume, buffer volume

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007021874 A1 [0009]

Claims (17)

Method for increasing the fill level and filling quantity of a vehicle refrigeration system with a refrigerant circuit ( 1 ), which comprises the following method steps: - providing the following components: at least one evaporator ( 2 ), a refrigerant compressor ( 3 ), a refrigerant condenser ( 4 ) or gas cooler ( 4 ), an accumulator ( 6 ) and the evaporator ( 2 ) associated expansion organ ( 5 ), - connecting the components ( 2 . 3 . 4 . 5 . 6 ) by means of a refrigerant line ( 8th ) for forming the refrigerant circuit (V _A ) having a total of system volumes (V _A ) formed from the sum of the individual volumes of the components and refrigerant pipes ( 1 ), the accumulator ( 6 ) in the flow direction (R) of the refrigerant to the evaporator ( 2 ), determining an optimal filling quantity (m _opt ) of refrigerant for the given total system volume (V _A ) as a function of at least one of the parameters ambient temperature, ambient humidity, driving speed, sun load, air quantity to be conditioned, air damper position, provision of an additional volume ( V _to ) as buffer volume ( 8.1 . 8.2 . 8.3 . 9 . 9.1 . 9.11 . 9.2 . 9.3 . 9.4 . 9.5 . 9.6 ) in the refrigerant circuit ( 1 ) in the flow direction (R) of the refrigerant between the evaporator ( 2 ) and the compressor ( 3 ), - determining an optimal additional filling amount (m _{opt, zu} ) of refrigerant for the additional volume ( 8.1 . 8.2 . 8.3 . 9 . 9.1 . 9.11 . 9.2 . 9.3 . 9.4 . 9.5 . 9.6 ), which under the pressure and temperature conditions of the low-pressure side of the refrigerant circuit ( 1 ) the additional volume ( 8.1 . 8.2 . 8.3 . 9 . 9.1 . 9.11 . 9.2 . 9.3 . 9.4 . 9.5 . 9.6 ), and - filling the refrigerant circuit ( 1 ) with one of the sum of the optimum filling quantity (m _opt ) and the optimal additional filling quantity (m _{opt , zu} ) corresponding new optimum filling quantity (m _{opt, neu} ) of refrigerant. Method according to Claim 1, in which the new optimum filling quantity (m _{opt, new} ) is increased by a buffer filling quantity (m _{puf, to} ) which is less than or equal to the difference (m _{max, zul, to -m opt, to} ) between a maximum permissible additional filling quantity (m _{max, zul, zu} ) related to the additional volume (V _zu ) and the optimal additional filling quantity (m _{opt, zu} ). Method according to Claim 1 or 2, in which an internal heat exchanger ( 7 ) is provided, which on the one hand on the low pressure side of the refrigerant circuit ( 1 ) between the accumulator ( 6 ) and the compressor ( 3 ) and on the other hand on the high pressure side of the refrigerant circuit ( 1 ) between the capacitor ( 4 ) or gas cooler ( 4 ) and the expansion organ ( 5 ) is arranged. A method according to claim 1, 2 or 3, wherein an additional volume through an additional container ( 9 . 9.1 . 9.11 . 9.2 . 9.3 ) formed with a refrigerant line ( 8.0 ) either between the accumulator ( 6 ) and the internal heat exchanger ( 7 ) or between the internal heat exchanger ( 7 ) and the compressor ( 3 ) or between the evaporator ( 2 ) and the accumulator ( 6 ) is connected. Method according to Claim 4, in which the additional container ( 9 . 9.1 . 9.11 . 9.2 . 9.3 ) on the low pressure side of the refrigerant circuit between the internal heat exchanger ( 7 ) and the compressor ( 3 ) or between the accumulator ( 6 ) and the internal heat exchanger ( 7 ) or the evaporator ( 2 ) and the accumulator ( 6 ) is arranged. The method of claim 1, 2 or 3, wherein an additional volume by at least a portion cross-sectional enlargement of the refrigerant line ( 8.1 . 8.2 . 8.3 ) between the evaporator ( 2 ) and the compressor ( 3 ) is formed. Method according to Claim 1, 2 or 3, in which an additional volume ( 9.5 ) through the internal heat exchanger ( 7 ) is formed. Method according to Claim 1, 2 or 3, in which an additional volume ( 9.6 ) through the accumulator ( 6 ) is formed. Method according to Claim 1, 2 or 3, in which an additional volume ( 9.4 ) through the compressor ( 3 ) is formed, wherein the additional volume ( 9.4 ) at the refrigerant inlet of the compressor ( 3 ) is realized. Vehicle refrigeration system for a vehicle with a refrigerant circuit ( 1 ), which as components at least one evaporator ( 2 ), a refrigerant compressor ( 3 ), a refrigerant condenser ( 4 ) or a gas cooler ( 4 ), an accumulator ( 6 ) as well as the evaporator ( 2 ) associated expansion element ( 5 ), wherein - the components ( 2 . 3 . 4 . 5 . 6 ) to form a total plant volume (V _A ) via refrigerant lines ( 8th ) and the accumulator ( 6 ) the evaporator ( 2 ) in the flow direction (R) of the refrigerant is connected downstream, - for increasing the level of the refrigerant circuit ( 1 ) an additional volume (V _to ) as the buffer volume ( 8.1 . 8.2 . 8.3 . 9 . 9.1 . 9.11 . 9.2 . 9.3 . 9.4 . 9.5 . 9.6 ) on the low-pressure side of the refrigerant circuit ( 1 ) between the evaporator ( 2 ) and the compressor ( 3 ), and - the refrigerant circuit ( 1 ) with a sum of an optimal filling quantity (m _opt ) and an optimal additional filling quantity (m _{opt , to} ) corresponding new optimum filling quantity (m _{opt, neu} ) to refrigerant is filled, so that the optimal additional filling quantity (m _{opt, too} ) is determined according to a method according to one of claims 1 to 8. Vehicle refrigeration system according to claim 10, in which an internal heat exchanger ( 7 ) is provided, which on the one hand on the low pressure side of the refrigerant circuit ( 1 ) between the accumulator ( 6 ) and the compressor ( 3 ) and on the other hand on the high pressure side, the refrigerant circuit ( 1 ) between the capacitor ( 4 ) or gas cooler ( 4 ) and the expansion organ ( 3 ) is arranged. Vehicle refrigeration system according to claim 10 or 11, in which an additional container ( 9 . 9.1 . 9.11 . 9.2 . 9.3 ) is provided for the additional volume, which with a refrigerant line ( 8.0 ) between the accumulator ( 6 ) and the and the internal heat exchanger ( 7 ) or the internal heat exchanger ( 7 ) and the compressor ( 3 ) or the evaporator ( 2 ) and the accumulator ( 6 ) is connected. Vehicle refrigeration system according to claim 11 or 12, wherein the additional container ( 9 . 9.1 . 9.11 . 9.2 . 9.3 ) on the low pressure side of the refrigerant circuit ( 1 ) between the internal heat exchanger ( 7 ) and the compressor ( 3 ), between the accumulator ( 6 ) and the internal heat exchanger ( 7 ) ( 6 ) or between the evaporator ( 2 ) and the accumulator ( 6 ) is arranged. Vehicle refrigeration system according to claim 10 or 11, in which an additional volume through at least a regional cross-sectional enlargement of the refrigerant line ( 8.1 . 8.2 . 8.3 ) between the evaporator ( 2 ) and the compressor ( 3 ) is formed. Vehicle refrigeration system according to claim 10 or 11, in which an additional volume ( 9.5 ) through the internal heat exchanger ( 7 ) is formed. Vehicle refrigeration system according to claim 10 or 11, in which an additional volume ( 9.6 ) through the accumulator ( 6 ) is formed. Vehicle refrigeration system according to claim 10 or 11, in which an additional volume ( 9.4 ) through the compressor ( 3 ) is formed, wherein the additional volume ( 9.4 ) at the refrigerant inlet of the compressor ( 3 ) is provided.

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