EP2812638B1 - Heat pump device - Google Patents

Description

The invention relates to a heat pump device according to the preamble of patent claim 1.

A Wärmepumenvorrichtung of the aforementioned type is known from the patent document WO 2010/039682 A2 known.

A heat pump device of this kind is similar even after JP 2001 153482 A known. This consists inter alia of a compressor (in particular screw compressor), which is followed by a condenser (also called a condenser), in turn, a refrigerant collector (also called refrigerant tank) is connected downstream. The refrigerant collector is connected to the intermediate injection of refrigerant into the compressor with this via a refrigerant line.

Furthermore, in the case of this heat pump device, just as in the device according to the invention to be explained, the refrigerant collector is followed by a controllable expansion valve, which in turn is followed by an evaporator, which in turn is followed by the already mentioned compressor. The refrigerant circuit of the JP 2001 153482 A So corresponds to a very classic refrigerant circuit, but added to the refrigerant collector for the intermediate injection of refrigerant in the compressor.

In the solution after the JP 2001 153482 A A refrigerant inflow port of the refrigerant piping leading to the compressor discharges during proper operation of the heat pump device always below the refrigerant level in the refrigerant collector, ie in this solution, liquid refrigerant is always discharged from the refrigerant collector, which opens up the possibility to cool the compressor to lower the hot gas temperature and thus the operating limits of the heat pump device compared to a classic refrigerant circuit without a refrigerant collector expand.

The invention has for its object to further improve a heat pump device of the type mentioned. In particular, the limits of use or the efficiency of such a heat pump device should be even more expanded or enlarged.

This object is achieved by the features listed in the characterizing part of patent claim 1.

According to the invention, it is thus provided that, depending on the setting of the expansion valve, the refrigerant line has a refrigerant inflow opening which selectively opens above and / or below the refrigerant level during operation of the heat pump device, a section of the refrigerant line being arranged in the refrigerant collector and the section having a vertical extension direction ,

In other words, the heat pump device according to the invention is characterized in particular by the fact that via the expansion valve, the refrigerant level in the refrigerant receiver can be adjusted, wherein the refrigerant inflow opening is formed so that it is designed depending on the setting of the expansion valve either above and / or below the refrigerant level ausmündend. The proviso "and / or" means that the refrigerant line is formed with its refrigerant inlet either so that the refrigerant inflow opens either above or below the refrigerant level, or that the refrigerant inflow opening is formed so that it opens both above and below the refrigerant level, which optionally by a correspondingly large Refrigerant inflow or even by a plurality of refrigerant inflow can be realized at the guided into the refrigerant collector refrigerant pipe.

In contrast to the heat pump device mentioned above, it is thus possible with the heat pump device according to the invention to supply optionally pure refrigerant vapor, liquid refrigerant or even refrigerant wet steam to the compressor. In which aggregate state the refrigerant is injected into the compressor, can be determined via the controllable expansion valve and thus on the refrigerant level in the refrigerant collector.

The injection of vaporous refrigerant improves the efficiency and performance of the heat pump device.

The injection of liquid refrigerant, as mentioned above, offers the possibility of cooling the compressor, lowering the hot gas temperature and thus extending the operating limits.

Through the injection of refrigerant wet steam, so the combination of the above two options, can determine the determination of the vapor liquid ratio the advantages Both methods of injection can be used specifically for the current operational situation.

Other advantageous developments of the heat pump device according to the invention will become apparent from the dependent claims.

• Aus der EP 1 965 154 B1 ist eine Wärmepumpenvorrichtung bekannt, bei der ein vergleichsweise kleiner Teil des aus dem Verflüssiger kommenden Kältemittels abgezweigt und zur Entspannung über ein regelbares Expansionsventil geführt wird, dem ein Wärmetauscher (so genannter Economiser) nach geschaltet ist, um Wärme zwischen dem kleinen, bereits entspannten Teil des Kältemittels und dem Rest des vom Verflüssiger kommenden Kältemittels zu übertragen. Nach dem Economiser kann das entspannte Kältemittel dem Verdichter eingespritzt werden, wobei sich über die Einstellung des Expansionsventils festlegen lässt, welchen Aggregatzustand (flüssig, nassdampfförmig oder dampfförmig) das eingespritzte Kältemittel hat. Im Vergleich zur erläuterten erfindungsgemäßen Lösung ist bei der Lösung nach der EP 1 965 154 B1 ein im Vergleich zum Kältemittelsammler hochpreisigerer Wärmetauscher (der Economiser) erforderlich.

For the sake of completeness, reference is made to the following documents:

• From the EP 1 965 154 B1 a heat pump device is known in which a comparatively small part of the coming from the condenser refrigerant is diverted and fed to relax via a controllable expansion valve to which a heat exchanger (so-called economizer) is connected after to heat between the small, already relaxed part of the Refrigerant and the rest of the coming from the condenser refrigerant. After the economizer, the expanded refrigerant can be injected to the compressor, which can be determined by the setting of the expansion valve, which state of aggregation (liquid, wet-vapor or vapor) has the injected refrigerant. Compared to the illustrated inventive solution is in the solution after the EP 1 965 154 B1 a more expensive compared to the refrigerant collector heat exchanger (the economizer) required.

Furthermore, on the DE 33 29 661 A1 pointed out, from the one of the EP 1 965 154 B1 corresponding solution is known, where there the economizer or the heat exchanger is designed as a refrigerant collector. In both cases, however, the coming of the condenser refrigerant before the heat exchanger or divided into two sub-streams before the refrigerant collector, which are brought together again at the compressor.

It will also be on the DE 102010 024986 A1 pointed.

The heat pump device according to the invention including its advantageous developments according to the dependent claims will be explained in more detail with reference to the drawings of various embodiments.

Figur 1

eine Grundausführungsform der erfindungsgemäßen Wärmepumpenvorrichtung mit einem Kältemittelsammler;

Figur 2

eine vergrößerte Darstellung des Kältemittelsammlers gemäß Figur 1;

Figur 3

das Ausführungsbeispiel gemäß Figur 1 mit einem 4/2-Wegeumschaltventil;

Figur 4

ein Ausführungsbeispiel mit einem Sauggaswärmetauscher im Kältemittelsammler sowie einem 4/2-Wegeumschaltventil;

Figur 5

eine vergrößerte Darstellung des Kältemittelsammlers gemäß Figur 4; und

Figur 6

eine Wärmepumpenvorrichtung gemäß dem Stand der Technik ( JP 2001 153482 A ).

It shows schematically

FIG. 1

a basic embodiment of the heat pump device according to the invention with a refrigerant collector;

FIG. 2

an enlarged view of the refrigerant collector according to FIG. 1 ;

FIG. 3

the embodiment according to FIG. 1 with a 4/2-way switching valve;

FIG. 4

an embodiment with a Sauggaswärmetauscher in the refrigerant collector and a 4/2-way switching valve;

FIG. 5

an enlarged view of the refrigerant collector according to FIG. 4 ; and

FIG. 6

a heat pump device according to the prior art ( JP 2001 153482 A ).

The in the FIGS. 1 . 3 . 4 and 6 illustrated heat pump devices consist in a known manner from a compressor 1, in particular a so-called screw or scroll compressor, which is followed by a condenser 2, which is particularly preferably designed as a plate capacitor. This capacitor is a refrigerant collector 3 (also called high-pressure collector) downstream, which is connected to the intermediate injection of refrigerant in the compressor 1 with this via a refrigerant pipe 4. This intermediate injection serves, as already explained, to increase the efficiency of the heat pump device or to expand the application limits of the heat pump device.

Essential for in the FIGS. 1 . 3 and 4 illustrated, heat pump device according to the invention is now that for adjusting the refrigerant level in the refrigerant collector 3 between the condenser 2 and the refrigerant collector 3, an electronically controllable (and reversible working) expansion valve 5 is arranged and that the refrigerant pipe 4 depending on the setting of the expansion valve 5 during operation the heat pump device above and / or below the refrigerant level opening refrigerant inflow opening 6 has.

In FIG. 2 the refrigerant collector 3 is shown enlarged for better understanding. As can be seen, a section 7 of the refrigerant line 4 is arranged in the refrigerant collector 3. The refrigerant inflow opening (s) 6 is (are) arranged on the section 7 of the refrigerant line 4. The section 7 is tubular and in particular formed as a U-shaped piece of pipe. The section 7 further has a vertical extension direction and an open end 8. The open line end 8 forms at least one of the refrigerant inflow openings 6 and is preferably always arranged above the refrigerant level during operation of the heat pump device. How to continue FIG. 2 seen At section 7, a plurality of superposed refrigerant inflow openings 6 are provided.

Like from the FIGS. 1 . 3 and 4 can be seen, it is preferably provided that the refrigerant collector 3 has a connected to the expansion valve 5, during operation of the heat pump device opening out below the refrigerant level refrigerant supply port 9. Furthermore, it is provided that the refrigerant collector 3 has a refrigerant discharge connection 11 connected to a second electronically controllable (and reversibly operating) expansion valve 10, opening out below the refrigerant level during operation of the heat pump device. Via this refrigerant discharge port 11, the refrigerant is discharged to the second expansion valve 10.

In particular from FIG. 2 via the refrigerant supply port 9 refrigerant enters the refrigerant receiver 3. About the electronically controllable expansion valves 5 and 10, which of course with a corresponding, not specifically shown heat pump control device (also called refrigeration circuit controller) is connected set the height of the refrigerant level. At the level according to FIG. 2 can only vapor refrigerant via the refrigerant inlet openings 6 in the section 7, thus reach the refrigerant line 4 and from there to the compressor 1. If the refrigerant level is increased, liquid refrigerant can also pass into the section 7 and thus to the compressor 1 via one or more refrigerant inflow openings 6. This liquid refrigerant mixes with the rest of the rest Refrigerant inlet 6 inflowing refrigerant vapor to a refrigerant wet steam. Finally, if one were to completely flood the refrigerant collector 3, ie to adjust such a refrigerant level at which all the refrigerant inflow openings 6 are positioned in the liquid refrigerant, a completely liquid intermediate injection would occur at the compressor, which, as explained, is particularly desirable when the compressor wants to cool.

Another preferred feature of the solution according to the invention is in turn with reference to FIG. 2 and 5 in that the refrigerant collector 3 is divided into a first and a second chamber 14, 15 by a separating element 13 or partition wall (preferably a perforated plate, metal mesh or the like) having at least one through-opening 12, in particular vertically oriented Chamber 14 of the refrigerant supply port 9 opens and leaving the first chamber 14 of the refrigerant discharge port 11.

Due to the expansion of the refrigerant in the expansion valve 5, the flow in the first chamber 14 is highly turbulent. The proviso of the separating element 13 leads to a calming of the refrigerant in the second chamber 15, in which the portion 7 of the refrigerant pipe 4 is arranged, which in turn is favorable for the desired precise adjustment of the ratio between liquid and vapor refrigerant.

As already explained, the refrigerant collector 3 is followed by a second electronically controllable expansion valve 10, which in turn is followed by an evaporator 16 (in particular a lamella evaporator) connected to the compressor 1 is. With reference to FIG. 4 and 5 another feature of the inventive solution is that in the first chamber 14 of the refrigerant collector 3, a refrigerant-carrying and with the refrigerant in the refrigerant receiver 3 heat exchanging line 17 is arranged, which is connected on the one hand to the evaporator 16 and the other with the compressor 1. This line 17 forms together with the refrigerant collector 3 a so-called Sauggaswärmetauscher for supercooling of the refrigerant, via the already mentioned, not shown heat pump control device and corresponding sensors for measuring Sauggasüberhitzung or subcooling influence on the expansion valves 5 and 10 and thus on the refrigerant level can be taken.

Furthermore, with reference to FIGS. 3 and 4 provided that between the condenser 2 and the expansion valve 5, a (preferably bidirectionally operating) filter 18 (also called filter dryer) is arranged. In addition, a (preferably bidirectionally operating) filter 19 (filter drier) is also arranged between the second expansion valve 10 and the evaporator 16.

In order to use the heat pump device according to the invention both for heating and for cooling purposes, is with reference to FIGS. 3 and 4 a downstream of the compressor 1 switching valve, in particular a 4/2-way switching valve 20 is provided: In the FIGS. 3 and 4 In this case, the heating operation is shown, in which taken over the evaporator 16, for example geothermal and discharged through the condenser 2 to a room of a building to be heated. Would you use the 4/2-way switching valve according to FIGS. 3 and 4 turn 90 ° (both clockwise and anticlockwise), due to the Symmetrical structure of the heat pump apparatus according to the invention is readily possible, the evaporator 16 would be the condenser and the condenser 2 to the evaporator. In this case, heat would be removed via the evaporator, for example, from a room of a building and discharged through the condenser, for example, to the environment of the building.

• Bei der Lösung nach Figur 3 wird gasförmiges Kältemittel über den Verdichter 1 auf ein höheres Druckniveau gebracht, über das 4/2-Wegeumschaltventil dem Verflüssiger 2 zugeführt und dort vollständig kondensiert und unterkühlt. Das flüssige Kältemittel durchläuft den Filter 18 und gelangt danach zum Expansionsventil 5, in dem es auf ein geringeres Druckniveau gebracht wird. Dabei geht ein Teil des Kältemittels in den gasförmigen Zustand über. Das Kältemittel wird danach dem Kältemittelsammler 3 zugeführt, welcher sich in zwei Bereiche unterteilt. Am Kältemittelzufuhranschluss 9 des Kältemittelsammlers 3 ist das Kältemittel aufgrund der hohen Strömungsgeschwindigkeit sehr turbulent. Danach strömt das Kältemittel über Durchgangsöffnung 12 am Trennelement 13 (siehe Figur 2) in den beruhigten Bereich des Kältemittelsammlers 3 (Kammer 15), wo sich der flüssige Anteil aufgrund der Schwerkraft unten absetzt. Über die Kältemittelzuflussöffnung 6, die im oberen Bereich des Kältemittelsammlers 3 endet, wird ausschließlich gasförmiges Kältemittel angesaugt und der Zwischeneinspritzung des Verdichters 1 zugeführt. Das flüssige Kältemittel wird dem Expansionsventil 10 zugeführt, über das der Druck auf Verdampfungsdruckniveau abgebaut wird. Ein Teil des Kältemittels geht dabei in den gasförmigen Zustand über. Danach gelangt das Kältemittel in den Verdampfer 16, wo es vollständig verdampft und überhitzt wird. Über das 4/2-Wegeumschaltventil wird das Kältemittel schließlich dem Verdichter 1 zugeführt. Der Kreislauf schließt sich.

For a better understanding, the functioning of the exemplary embodiments will be described below FIGS. 3 and 4 explained in more detail:

• At the solution after FIG. 3 gaseous refrigerant is brought via the compressor 1 to a higher pressure level, fed via the 4/2-way switching valve to the condenser 2 and there completely condensed and supercooled. The liquid refrigerant passes through the filter 18 and then passes to the expansion valve 5, in which it is brought to a lower pressure level. In this case, a part of the refrigerant goes into the gaseous state. The refrigerant is then supplied to the refrigerant collector 3, which is divided into two areas. At the refrigerant supply port 9 of the refrigerant accumulator 3, the refrigerant is very turbulent due to the high flow velocity. Thereafter, the refrigerant flows through passage opening 12 on the separating element 13 (see FIG. 2 ) in the calmed area of the refrigerant collector 3 (chamber 15), where the liquid fraction settles down due to gravity. Via the refrigerant inflow opening 6, which ends in the upper region of the refrigerant accumulator 3, only gaseous refrigerant is sucked in and fed to the intermediate injection of the compressor 1. The liquid refrigerant is supplied to the expansion valve 10, via which the pressure is reduced to evaporation pressure level. Part of the refrigerant passes into the gaseous state. Thereafter, the refrigerant enters the evaporator 16, where it is completely evaporated and overheated. The refrigerant is finally fed to the compressor 1 via the 4/2-way switching valve. The cycle closes.

Special feature: In order to prevent too high a temperature at the refrigerant outlet of the compressor 1 at operating points with high pressure conditions, it is possible according to the invention to increase the proportion of liquid in the intermediate injection. The liquid components of the refrigerant evaporate in the compressor and thereby absorb heat. To realize this, the suction pipe (refrigerant pipe 7) of the intermediate injection in the refrigerant receiver 3 is designed to pass through the liquid portion. Liquid refrigerant can be drawn in via so-called sniffer bores (refrigerant inflow openings 6) in the pipeline. The proportion of liquid which is drawn in can be regulated by changing the fill level in the refrigerant collector 3 via the expansion valve 5 downstream of the condenser 2. The control variable is the hot gas temperature at the outlet of the compressor 1.

The solution according to FIG. 4 finally differs from the according to FIG. 3 in that there takes place via a pipe coil (line 17), a heat transfer from the warmer refrigerant in the refrigerant header 3 to the colder refrigerant in the coil (keyword: Sauggasüberhitzung). As a result, the gaseous portion of the refrigerant in the refrigerant receiver is partially or completely condensed, whereby the ratio of liquid to gas increases. The line 17 runs from the evaporator 16 via the 4/2-way valve to the first chamber 14 and from there directly to the compressor. 1

LIST OF REFERENCE NUMBERS

1

compressor

2

condenser

3

Refrigerant collector

4

Refrigerant line

5

expansion valve

6

Cold cash opening

7

section

8th

cable end

9

Refrigerant supply port

10

expansion valve

11

Refrigerant discharge port

12

Through opening

13

separating element

14

first chamber

15

second chamber

16

Evaporator

17

management

18

filter

19

filter

20

4/2-way reversing valve

Claims (7)

1. A heat pump device comprising a compressor (1), downstream of which a liquefier (2) is connected, downstream of which a refrigerant collector (3) is connected, which for intermediate injection of refrigerant into the compressor (1) is connected to this via a refrigerant line (4), wherein a controllable expansion valve (5) is arranged between the liquefier (2) and the refrigerant collector (3) in order to set the refrigerant level in the refrigerant collector (3), wherein the refrigerant collector (3) has a refrigerant discharge connection (11) connected to a second controllable expansion valve (10) which opens below the refrigerant level during operation of the heat pump device,
   characterized in that
   depending on the setting of the expansion valve (5) the refrigerant line (4) has a refrigerant feed opening (6) which opens above and/or below the refrigerant level as desired during operation of the heat pump device, wherein a section (7) of the refrigerant line (4) is arranged in the refrigerant collector (3) and wherein the section (7) has a vertical extension direction.
2. The heat pump device according to claim 1,
   characterized in that
   the section (7) has an open line end (8).
3. The heat pump device according to claim 1 or 2,
   characterized in that
   a plurality of refrigerant feed openings (6) arranged one above the other are provided on the section (7).
4. The heat pump device according to any one of claims 1 to 3,
   characterized in that
   the refrigerant collector (3) has a refrigerant feed connection (9) connected to the expansion valve (5) which opens below the refrigerant level during operation of the heat pump device.
5. The heat pump device according to claim 4,
   characterized in that
   the refrigerant collector (3) is configured to be divided into a first and a second chamber (14, 15) by a separating element (13) having at least one through opening (12), wherein the refrigerant feed connection (9) opens into the first chamber (14) and wherein the refrigerant discharge connection (11) leads away from the first chamber (14).
6. The heat pump device according to claim 5, wherein the second controllable expansion valve (10) is connected downstream of the refrigerant collector (3), downstream of the former a vaporizer (16) is connected to the compressor (1),
   characterized in that
   a refrigerant-carrying line (17) which exchanges heat with the refrigerant in the refrigerant collector (3) is arranged in the first chamber (14), which on the one hand is connected to the vaporizer (16) and on the other hand is connected to the compressor (1).
7. The heat pump device according to claim 5 or 6,
   characterized in that
   the section (7) of the refrigerant line (4) is arranged in the second chamber (15).

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