EP3159628A1 - Heat pump circuit comprising an evaporator - Google Patents

Abstract

In a heat pump cycle having an evaporator to be flown by a refrigerant in a flow direction, switching means for reversing the first flow direction of the refrigerant through the evaporator is provided.

Description

Background of the invention

The invention relates to a heat pump cycle with an evaporator, which is to flow from a cryogen in a flow direction.

A heat pump cycle is a cycle in which a refrigerant in a heat pump flows in a flow direction in a circle. The refrigeration medium is a fluid that absorbs thermal energy at low temperature and low pressure and releases heat energy at higher temperature and pressure. In this case, usually a change in state of the fluid, in particular a change of its state of aggregation. In most cases, the cooling medium changes from a liquid state of aggregation to a gaseous state of aggregation. Usually come as a refrigerant medium hydrofluorocarbons (HFC), natural refrigerants, such as pure hydrocarbons, or inorganic alternatives, such as ammonia, carbon dioxide or water used.

The transition from a liquid state of aggregation to a gaseous state of aggregation takes place in the evaporator. The evaporator absorbs energy from its environment, usually in the form of thermal energy. This energy passes the evaporator to the refrigerant located inside the evaporator. The refrigeration medium stores this energy. This raises the energy level of the refrigerant.

The cooling medium flows in the direction of flow through the evaporator. The flow direction is thus defined from before the evaporator to after the evaporator.

Underlying task

The invention has for its object to achieve in a heat pump cycle an increase in efficiency, measurable by increasing the so-called line number of the heat pump cycle.

Inventive solution

This object is achieved according to the invention with a heat pump cycle with an evaporator, which is to be flowed through by a refrigerant in a flow direction, the evaporator is associated with a switching device for reversing the flow direction of the refrigerant through the evaporator.

In current heat pump cycles, the refrigerant within the evaporator absorbs thermal energy and thereby cools the evaporator. As the evaporator cools, ice forms on the outside of the evaporator. The ice on the evaporator acts to insulate and reduce the ability of the evaporator to pass thermal energy into the cryogen through the ice. The efficiency of the evaporator and thus the efficiency of the heat pump cycle decrease. In order to defrost the ice at the evaporator, the heat pump cycle is currently stopped and it is waited until the ice of the evaporator is defrosted on the outside from the outside. During this waiting period, the heat pump cycle can not be operated. This period of time leads accordingly to an efficiency reduction in the heat pump cycle.

In the solution according to the invention, a heat pump cycle is provided with a switching device for reversing the flow direction of the refrigerant through the evaporator. The switching device is designed so that it is necessary to switch from a normal, first flow direction to a second flow direction. Reversing the flow direction causes a flow of the refrigerant in the evaporator to reverse. In the first flow direction, within the evaporator, taking up thermal energy, the cooling medium changes from a liquid state of aggregation to a gaseous state of aggregation. With the second flow direction according to the invention, the evaporator flows through the refrigerant medium, which has a higher thermal energy or heat. The cooling medium then gives off the thermal energy as it flows through the evaporator. The evaporator is heated from the inside by means of the thermal energy of the refrigerant medium. With the heating of the evaporator from the inside, the ice deposited on the outside of the evaporator is also defrosted from the inside. The period of time to defrost the ice decreases, which leads to an increase in efficiency for the heat pump cycle.

Due to the faster defrosting can often be defrosted often, so the Abtauhäufigkeit be increased, which leads to average lower ice formation on the evaporator. The efficiency of the evaporator and the guide number of the heat pump cycle increase. It is particularly advantageous if, for defrosting, the cold medium is gaseous on entering the evaporator and liquefies as it flows through the evaporator. In this phase transition of the refrigerant medium from gaseous to liquid in particular the thermal energy is given off in the form of heat of condensation.

In a preferred manner, a condenser is also provided in the heat pump cycle according to the invention, which is to be flowed through by the refrigerant in the flow direction, wherein with the switching means and the flow direction is reversible by the liquefier. Within the liquefier, the cooling medium, when flowing through in the conventional, first flow direction, changes from a gaseous state of aggregation into a liquid state of aggregation. The condenser then releases thermal energy. The switching device according to the invention reverses at the condenser this first flow direction to the second flow direction. The condenser is then flowed through in the opposite direction to the normal, first flow direction with the second flow direction. The cooling medium then absorbs thermal energy at the condenser in the second flow direction. The cooling medium can accordingly supply this thermal energy absorbed by the condenser to the evaporator in the second flow direction. Particularly advantageously, the cooling medium is liquid in the second flow direction before it enters the liquefier and then becomes gaseous with the absorption of thermal energy in the liquefier. The condenser acts in this second flow direction exactly the opposite, namely as an evaporator.

Furthermore, a compressor is advantageously provided and the switching device is designed with a first four-way valve arrangement, by means of which in a first switching position of the compressor with the condenser fluidly connected and is connected in a second switching position of the compressor with the evaporator flow-conducting. The compressor compresses or compresses the local cooling medium in the heat pump cycle. This refrigerant is thus compressed by means of the compressor, the pressure rises. The four-way valve arrangement allows switching between the first switching position and the second switching position by means of one or more valves. These are located between four ports, which are the inlets and outlets of the paths leading through the four-way valve assembly. In the first switching position, the connection to which the compressor is connected is connected to the connection to which the condenser is connected in a flow-conducting manner. When changing from the first shift position to the second shift position, the port to which the compressor is connected is connected to the port connected, to which the evaporator is connected. With such a valve circuit, the evaporator and once the condenser can be addressed or flowed particularly easily from the compressor once. Thus, the above-described switching of the flow directions can be realized very inexpensively and effectively.

In a preferred manner, a separator is further provided and the switching means provided with a second four-way valve arrangement, by means of which in a first switching position of the condenser with an input of the separator is flow-connected and in a second switching position, an outlet of the separator with the condenser flow-conducting connected is. The separator separates the liquid refrigerant from the gaseous refrigerant from a mixture of liquid and gaseous cryogen. By means of the second four-way valve arrangement, the flow direction at a second location in the heat pump cycle can be switched. It is switched between a first and second switching position. In the first switching position, the cooling medium flows in said first flow direction and the condenser conventionally operates as a condenser. In the second switching position, however, the evaporator operates as a condenser and the condenser, as explained, as an evaporator. Therefore, in accordance with the invention, by means of the second four-way valve arrangement in the first switching position, refrigerant medium is passed from the condenser to the inlet of the separator. In the separator, the gaseous fraction is separated from this refrigerant as explained. In the second switching position, the refrigerant is passed to the condenser by means of the second four-way valve assembly from the output of the separator, which then acts as an evaporator. At the outlet of the separator only liquid refrigerant emerges, which can then be vaporized correspondingly in the condenser acting as an evaporator. At the entrance of the separator so called mixture of liquid and gaseous refrigerant is supplied. At the exit of the separator exits only the liquid portion of the refrigerant medium. The gaseous cryogen preferably collects in an upper region of the separator and occurs there at a first discharge opening. The liquid refrigerant accumulates advantageous due to gravity in a lower portion of the separator and exits there at a second discharge opening. Such a separator works solely due to the gravity acting on it.

Further advantageously, the compressor is provided in flow communication between the first and second four-way valve assemblies. Such an arrangement of the compressor between the two four-way valve arrangements allows the first and the second four-way valve arrangement to change the flow direction of the refrigerant medium before and after the compressor, but to leave it in the compressor itself equal. Only if the flow direction in the compressor remains the same, it can also act as a compressor. Thus, the flow direction through the compressor can be left very simple unchanged.

According to the invention, the compressor is therefore preferably to flow from the refrigerant in only one flow direction, wherein the flow direction in the first switching position and the second switching position is the same. The compressor is thus always flowed through with the same, identical flow direction. Switching between the first switching position and the second switching position does not influence this flow direction and thus the functioning of the compressor. This aspect, that a part of the heat pump cycle is to flow in spite of switching only in one direction of flow, also applies to the separator. Therefore, the separator is preferably to flow from the refrigerant in only one flow direction, wherein the flow direction in the first switching position and the second switching position is the same. Furthermore, the separator is also advantageously provided in flow-conducting fashion between the first and the second four-way valve arrangement.

Furthermore, a measuring device for measuring a degree of icing of the evaporator is preferably provided. The degree of icing indicates the deposited thickness of ice on the evaporator. So is by means of the measuring device to Determine how thick the ice layer on the evaporator is. The thickness of the ice layer indicates the insulating effect of the ice on the evaporator. Based on the insulating effect can then be decided when a defrosting of the evaporator makes sense.

According to the invention, the measuring device for measuring the degree of icing of the evaporator is furthermore configured to determine a particular electrical power consumption of the compressor. The power consumption of the compressor shows how much time the compressor needs how much power to compress the refrigerant. As the degree of icing of the evaporator increases, so does the power consumption of the compressor. The power consumption can thus be used advantageously as a measure of the degree of icing of the evaporator.

In a preferred manner, a control device for simultaneously switching the first and second four-way valve arrangement is also provided. In the control device, an incoming signal is processed according to a specified condition. If this condition is satisfied, the control device outputs a control signal. The actuating signal is transmitted to the first and second four-way valve assembly at the same time, whereby the simultaneous switching of both four-way valve assemblies takes place. The simultaneous switching thus allows to change at several points simultaneously from the first flow direction to the second flow direction in the heat pump cycle, while at another point the flow direction remains the same.

Furthermore, according to the invention, it is also specifically provided to use such a switching device for reversing the flow direction of the refrigerating medium in a heat pump cycle.

Brief description of the drawings

Fig. 1

eine Übersicht eines Wärmepumpenreislaufs gemäß dem Stand der Technik,

Fig. 2

eine Übersicht eines erfindungsgemäßen Wärmepumpenreislaufs mit einem Abscheider und einer Pumpe,

Fig. 3

eine Übersicht eines erfindungsgemäßen Wärmepumpenreislaufs mit einer Pumpe, die innerhalb des Abscheiders angeordnet ist.

Fig. 4

eine Übersicht des erfindungsgemäßen Wärmepumpenreislaufs gemäß Fig. 3 im Heizbetrieb, mit einer Umschalteinrichtung,

Fig. 5

eine Übersicht des erfindungsgemäßen Wärmepumpenreislaufs mit einer umgeschalteten Umschalteinrichtung, im Abtaubetrieb,

Fig. 6

eine Übersicht des erfindungsgemäßen Wärmepumpenkreislaufs gemäß Fig. 3, bei dem die im Abscheider vorgesehene Pumpe als eine Schieberpumpe ausgeführt ist,

Fig. 7

eine Detailansicht der Schieberpumpe gemäß Fig. 6,

Fig. 8

eine Übersicht des erfindungsgemäßen Wärmepumpenkreislaufs gemäß Fig. 3 bei dem die im Abscheider vorgesehene Pumpe als eine Kolbenpumpe ausgeführt ist,

Fig. 9

eine Detailansicht der Kolbenpumpe gemäß Fig. 8,

Fig. 10

eine Übersicht eines erfindungsgemäßen Wärmepumpenreislauf gemäß Fig. 6 mit zwei Vier-Wege-Ventilanordnungen, und

Fig. 11

eine Detailansicht der Vier-Wege-Ventilanordnung gemäß Fig. 10.

An exemplary embodiment of the solution according to the invention will be explained in more detail below with reference to the attached schematic drawings. It shows:

Fig. 1

an overview of a heat pump cycle according to the prior art,

Fig. 2

an overview of a heat pump cycle according to the invention with a separator and a pump,

Fig. 3

an overview of a heat pump cycle according to the invention with a pump which is disposed within the separator.

Fig. 4

an overview of the heat pump cycle according to the invention according to Fig. 3 in heating mode, with a switching device,

Fig. 5

an overview of the heat pump cycle according to the invention with a switched switching device, in the defrosting operation,

Fig. 6

an overview of the heat pump cycle according to the invention according to Fig. 3 in which the pump provided in the separator is designed as a slide pump,

Fig. 7

a detailed view of the slide pump according to Fig. 6 .

Fig. 8

an overview of the heat pump cycle according to the invention according to Fig. 3 in which the pump provided in the separator is designed as a piston pump,

Fig. 9

a detailed view of the piston pump according to Fig. 8 .

Fig. 10

an overview of a heat pump according to the invention according to Fig. 6 with two four-way valve arrangements, and

Fig. 11

a detailed view of the four-way valve assembly according to Fig. 10 ,

Detailed description of the embodiment

The Fig. 1 As the prior art shows a heat pump cycle 10 and a refrigerant circuit of a heat pump with a low-temperature heat source 12 and a high-temperature heat sink 14. The heat pump cycle 10 is formed with a fluid-conducting, pressure-tight circulation line 16, which is traversed by a refrigerant or fluid 18. In the present case, a so-called safety refrigerant is preferably used as the fluid 18. This is in particular composed without fluorocarbons (CFCs). Particularly preferably, a propane refrigerant is used. The circulation line is divided into a low-pressure region 20 and a high-pressure region 22. The subdivision of the heat pump cycle 10 takes place on a compressor 24, which interrupts the circulation line 16 fluid-conducting. The compressor 24 compresses the cooling medium 18 from the low-pressure region 20 toward the high-pressure region 22 in a flow direction 26. The high-pressure region 22 is further divided from the low-pressure region 20 with a throttle 28 which likewise interrupts the circulation line 16 in a fluid-conducting manner.

The flow direction 26 within the compressor 24 indicates the flow direction of the cooling medium 18 within the heat pump cycle 10.

In the low-pressure region 20, an evaporator 30 is provided, which interrupts the circulation line 16 between the throttle 28 and the compressor 24 fluid-conducting. The evaporator 30 is located at the low-temperature heat source 12 and draws the low-temperature heat source 12 thermal energy. In the high pressure area 22, a condenser 32 is arranged, which interrupts the circulation line 16 between the compressor 24 and the throttle 28 fluidly. The condenser 32 is disposed at the high-temperature heat sink 14 and outputs there thermal energy from this.

In the heat pump cycle 10, the evaporator 30 receives thermal energy from the low temperature heat source 12. In this case, the existing within the evaporator 30 liquid refrigerant 18 is evaporated. The refrigeration medium 18 thus changes its state of aggregation from liquid to gaseous. The then gaseous cooling medium 18 is passed through the circulation line 16 to the compressor 24. The compressor 24 compresses the gaseous cooling medium 18 by means of mechanical work, wherein the gaseous cooling medium 18 is compressed or compressed. The pressure and the temperature of the gaseous cooling medium 18 increase. The energy level of the cooling medium 18 increases. The compressor 24 further determines the flow direction 26 within the heat pump cycle 10 of non-compressed refrigerant medium 18 to compressed refrigerant medium 18. In this case, only gaseous cryogen 18 can be compressed, since liquid cryogen 18 can not be compressed.

The compressed, gaseous refrigerant medium is forwarded to the condenser 32. The condenser 32 releases thermal energy from the cold medium 18 to the high-temperature heat sink 14. With the discharge of the thermal energy from the gaseous cryogen 18, the cryogen 18 liquefies. The cryogen 18 thus changes at the condenser 32, the state of matter from gaseous to liquid. The liquid refrigerant 18 is transported through the circulation line 16 to the throttle 28. At the throttle 28, the pressurized liquid refrigerant medium 18 is released. By means of the throttle 28 so the pressure of the refrigerant medium 18 is reduced in front of the throttle 28 to the pressure downstream of the throttle 28. From the throttle 28, the liquid refrigerant 18 is further to the Evaporator 30 transported. When the refrigerant medium 18 has returned to the evaporator 30, the heat pump cycle 10 is closed.

The Fig. 2 shows a heat pump cycle 10 according to the invention, in which a separator 34 is arranged in front of the compressor 24. The separator 34 separates a liquid fraction 36 of the cold medium 18 from a gaseous fraction 40 of the cold medium 18 by means of earth gravity, the direction of which is indicated by an arrow 38. The separator 34 is designed with a pressure-tight, cylindrical outer shell 42 which extends longitudinally in the direction of earth gravity. The outer sheath 42, a first feed opening or an inlet 44 and a first discharge opening 45 and in the lower region of a second discharge opening or an output 46 are provided in the upper region thereof. Within the outer shell 42, a separating chamber 48 is further formed in the upper region of the separator 34, and a collecting chamber 50 is formed in the lower region of the separator 34. Between the separation chamber 48 and the collecting space 50 is a level or liquid level 52 of the there separated and collected refrigerant medium 18th

A separator line 54, which leads to the first inlet region 55 of a pump 56, is connected to the collecting chamber 50 in a fluid-conducting manner to the second discharge opening 46.

The pump 56 is driven by a drive 58, which is coupled to the pump 56 with a transmission element 60 to transmit torque. The drive 58 is designed in particular as an electric motor.

From the pump 56, the cooling medium 18 flows through an outlet region 61 into a second connecting line 62. The second connecting line 62 then continues to flow the cooling medium 18 to the circulation line 16 between the condenser 32 and the throttle 28. In particular, the throttle 28 is a high-pressure regulator 63 executed. The cold medium 18 is there in the circulation line 16 fed. In the circulation line 16, the liquid fraction 36 of the cooling medium 18 pumped from the separator 34 then mixes with the cooling medium 18, which flows from the high-pressure regulator 63.

In contrast to the heat pump cycle 10 according to Fig. 1 is in the heat pump cycle 10 according to Fig. 2 the separator 34 is disposed after the evaporator 30 and in front of the compressor 24. The separator 34 separates, as already described above, a liquid portion 36 of the refrigerant medium 18 from the otherwise gaseous portion. Thus, only gaseous cooling medium 18 enters the compressor 24. Therefore, it is no longer absolutely necessary with the separator 34 that a complete transition of the state of aggregation of the cooling medium 18 from liquid to gaseous takes place in the evaporator 30. The evaporator 30 according to Fig. 2 Therefore, it can also be designed so that the cooling medium 18 after this evaporator 30 only partially has a gaseous state of aggregation. The cold medium 18 is then there a mixture of liquid portion 36 and gaseous portion 40. This mixture of liquid portion 36 and gaseous portion 40 is separated before the compressor 24 by means of the separator 34. The compressor 24 but, as required, only gaseous refrigerant 18 supplied through the circulation line 16 of the separator 34. The gaseous cryogen 18 then flows as well Fig. 1 described by the compressor 24 in the flow direction 26 in the heat pump cycle 10 on.

The liquid portion 36 of the separated in the separator 34 refrigerant 18 collects in the plenum 50. From there, the refrigerant medium 18 is sucked by the pump 56 through the discharge opening 46 and the separator line 54. The pump 56 transports the refrigerant medium 18 through the second connection line 62 to the circulation line 16. The refrigeration medium 18 is then fed into the circulation line 16 between the throttle 28 and the evaporator 30.

Fig. 3 shows the heat pump cycle 10 according to the invention Fig. 2 with a pump 56 disposed within the separator 34. Advantageously, the pump 56 is disposed within the outer shell 42 of the separator 34, in particular in the collecting space 50. The separator 34 with its integrated pump 56 interrupts the circulation line 16. The inflow of the circulation line 16 is connected to a second feed opening 64 in the outer shell 42 of the separator 34. The sequence of the circulation line 16 is connected to the second discharge opening 46.

The pump 56 is designed with a first pumping area 66 and a second pumping area 68. The first pumping region 66 of the pump 56 is connected to the second supply port 64 through a third connecting line 70. The second pumping area 68 is fluid-conductively connected to the second discharge opening 46 by a fourth connecting line 72. The cooling medium 18, pressurized by the compressor 24, flows to the first pumping area 66. The pressure of the cooling medium 18 acts as a drive for the first pumping area 66, so that the first pumping area 66 functions as a type of expansion motor 74. The expansion motor 74 has for this purpose a first inlet region 76 and a first outlet region 78. The expansion motor 74 is torque-transmitting coupled to the transmission element 60 to the second pumping area 68.

The second pumping area 68 sucks in the cold medium 18 from the collecting space 50 of the separator 34 and pumps it in the flow direction 26 into the circulation line 16.

Before the expansion motor 74, the cooling medium 18 is under higher pressure than after the expansion motor 74. The cooling medium 18 therefore flows there automatically through the expansion motor 74 and puts it in motion.

The Fig. 4 shows the heat pump cycle 10 in heating mode with a switching device 80. The heating operation is the normal operation of the heat pump cycle 10. In the heating mode, as well as Fig. 1 described, thermal energy taken from the low-temperature heat source 12 and delivered to the high-temperature heat sink 14. In the present case, for example, the high-temperature heat sink 14 may be a heater of a building.

Also with the Fig. 1 to 3 the heat pump cycle 10 is in a heating mode. The cooling medium 18 flows as explained in the flow direction 26th

The switching device 80 is formed with a first switching element 82 and a second switching element 84. The first switching element 82 interrupts the circulation line 16 between the evaporator 30 and the separator 34, and the circulation line 16 between the compressor 24 and the condenser 32. The second switching element 84 interrupts the circulation line 16 between the high pressure regulator 63 and the condenser 32 and between the separator 34 and the evaporator 30th

The two switching elements 82 and 84 each have a first terminal 86, a second terminal 88, a third terminal 90 and a fourth terminal 92. The first connection 86 of the first switching element 82 is connected to a fifth connection line 94 leading to the separator 34. The second connection 88 of the first switching element 84 is connected to the circulation line 16, coming from the evaporator 30, connected. The third port 90 of the first switching element 84 is connected to a sixth connecting line 96, coming from the compressor 24, and the fourth port 92 is connected to the circulation line 16 to the evaporator 30 through.

The first connection 86 of the second switching element 84 is connected to a seventh connection line 98, which leads to the second discharge opening 46 from the separator 34. The second connection 88 of the second switching element is connected leading to the circulation line 16 to the evaporator 30 out. The third Terminal 90 of the second switching element 84 is connected to an eighth connecting line 100, which leads to the high-pressure regulator 63. The fourth connection 92 of the second switching element 84 is connected to the circulation line 16, coming from the evaporator 30. The high-pressure regulator 63 is connected to a ninth connecting line 102 with the second feed opening 64 in the outer shell 42 of the separator 34.

Within the two switching elements 82 and 84, a first flow path 104 and a second flow path 106 are formed in each case. After switching the switching elements 82 and 84, respectively, as in Fig. 5 3, a third flow path 108 and a fourth flow path 110 are formed. The first flow path 104 is formed from the first port 86 to the second port 88 and the second flow path 106 from the third port 90 to the fourth port 92.

In the heat pump cycle 10 according to Fig. 4 acts the switching element 82 visible there above as a so-called gas control valve. The switching element 82 can therefore also be replaced by a gas control valve according to the prior art. However, unlike such a prior art gas control valve, the switching element 82 has larger tubular ports 86, 88, 90, 92 in diameter. The terminals 86, 88, 90, 92 are advantageous with a diameter between 12 and 32 mm (in words: twelve and thirty-two millimeters), more advantageously between 17 and 27 mm (in words: seventeen and twenty-seven millimeters), in particular with a diameter of 22 mm (in words: twenty-two millimeters) provided.

In the heat pump cycle 10 according to Fig. 4 the switching element 84 visible there below acts as a so-called liquid valve. The switching element 84 has smaller diameter tubular connections 86, 88, 90, 92 than the switching element 82. The terminals 86, 88, 90, 92 are advantageous with a diameter between 5 and 15 mm (in words: five and fifteen millimeters), particularly advantageous between 7 and 13 mm (in words: seven and thirteen millimeters), in particular with a diameter of 10 mm (in words: ten millimeters), designed.

The switching elements 82, 84 separate the cooling medium 18 in the low-pressure region 20 from the cooling medium 18 in the high-pressure region 22. The low-pressure region 20 advantageously has a pressure between 0.8 and 6.0 bar (in words: zero comma eight and six comma zero bar). Particularly advantageously, the low pressure region 20 a pressure between 1 and 3 bar (in words: one and three bar), in particular of 2 bar (in words: two bar) on. The low-pressure region 20 advantageously has a temperature of up to -40 ° C (in words: minus forty degrees Celsius). Particularly advantageously, the low pressure region 20 a temperature of up to -35 ° C (in words: minus thirty five degrees Celsius), in particular of up to -30 ° C (in words: minus thirty degrees Celsius), on.

The high-pressure region 22 advantageously has a pressure between 2 and 35 bar (in words: two and thirty-five bar). Particularly advantageously, the high-pressure region 22 has a pressure of between 4 and 20 bar (in words: four and twenty bar). The high-pressure region 22 advantageously has a temperature of up to 110 ° C. (in words: one hundred and ten degrees Celsius) in the case of the switching element 82. Particularly advantageously, the high-pressure region 22 in the switching element 84 has a temperature of up to 60 ° C (in words: sixty degrees Celsius).

The Fig. 5 shows the heat pump cycle 10 with the switched switching device 80 in the so-called defrosting operation. This defrost operation is necessary for the following reason: In the illustrated heating operation, in particular also in the heat pump cycle 10 according to Fig. 4 , the evaporator 30 cools due to the absorption of thermal energy by means of the cooling medium 18. At the then cold evaporator 30 can form ice on the outside. This Ice on the evaporator 30 acts as an insulating layer that impedes heat transfer from the outside to the inside of the evaporator 30. The evaporator 30 can then absorb difficult heat from, for example, ambient air as a low-temperature heat source 12 in Fig. 1 shown. In order to remove the insulating layer from the evaporator 30, the ice must be defrosted in the defrosting operation on the evaporator 30.

The switched switching device 80 has the first flow path 104 in FIG Fig. 4 and second flow path 106 in FIG Fig. 4 shown switched to the third flow path 108 and fourth flow path 110. The third flow path 108 is now formed from the second port 88 to the third port 90 and the fourth flow path 110 from the first port 86 to the fourth port 92.

With this change in the flow paths, the first flow direction 26 is changed in parts of the circulation line 16 in a second flow direction 112. The second flow direction 112 is opposite to the first flow direction 26. The flow direction 26 in the connection lines 94, 96, 98, 100 and 102 remains identical. Thus, the flow direction 26 in the compressor, in the separator 34 with its integrated pump 56 and in the high-pressure regulator 63 when the switching device 80 is switched over remains the same. The flow direction in the evaporator 30 and condenser 32, however, changes to the second flow direction 112.

The cooling medium 18 flows according to the heat pump cycle 10 Fig. 5 in defrost mode, no longer, as in heating mode, from the compressor 24 to the condenser 32 in the flow direction 26, but from the compressor 24 to the evaporator 30 with the flow direction 112. The function of the evaporator 30 is changed as follows: The evaporator 30 acts during the Defrosting operation like a condenser. In this case, the evaporator 30 releases thermal energy. The thermal energy gets in particular in the ice formed on it. This heat release the ice thus supports the defrosting of the ice on the outside of the evaporator 30. When switching from heating to defrosting, the flow direction also in the condenser 32 changes from the flow direction 26 to the flow direction 112. In the defrosting operation, the cooling medium 18 flows from the condenser 32 to the separator 34. The condenser 32 acts as an evaporator during the defrost operation. The condenser 32 absorbs thermal energy.

In order to determine when the flow direction 26 is to be changed by means of the switching device 80, a measuring device 113 is provided. The measuring device 113 is formed with a sensor 114, which measures a degree of icing on the evaporator, and a sensor line 115. The measuring device 113 is connected to a control device 116. The control device 116 evaluates a signal of the measuring device 113 and switches by means of a first control line 117, the first switching element 82 of the switching device 80. At the same time, the second switching element 84 of the switching device 80 is switched over by means of a second control line 118. In particular, the sensor 114 of the measuring device 113 can determine the power consumption of the compressor 24.

The measuring device 113 is provided to determine the thickness of the ice on the evaporator 30 and the resulting degree of icing of the evaporator 30. The measuring device 113 is attached to the sensor 114 on the evaporator 30. When the sensor 114, in cooperation with the controller 116, determines that the insulating effect of the ice is too high, the heat pump cycle 10 is switched from the heating operation to the defrosting operation by means of the switching means 80. Which degree of icing triggers a switchover is stored in the control device 116.

In Fig. 6 shows a detailed overview of a heat pump cycle 10 in which the provided in the separator 34 pump 56 is designed as a slide pump 120. The vane pump 120 is shown in detail in FIG Fig. 7 shown.

According to Fig. 7 the spool pump 120 has an ejector 121. The slider pump 120 is further formed with a first rotary valve area or rotary valve chamber 122 and with a second rotary valve area or rotary valve chamber 124. The first rotary valve area 122 and the second rotary valve area 124 are arranged in particular in a housing 126.

The first rotary valve region 122 is formed with a cylindrical hollow body 128, in which a rotor 130 is rotatably mounted on a first shaft 132 in a rotational direction 133. The shaft 132 is arranged eccentrically to the hollow body 128. The rotor 130 almost contacts the inner wall 134 of the hollow body 128 at a contact point 131. The contact point 131 and the opposite point on the inner wall 134 of the hollow body 128 divide the hollow body 128 into a suction region 135 and a pressure region 136.

In the rotor 130 a plurality of guide grooves 138 are excluded, which are arranged radially to the rotor 130. Within the guide grooves 138 rectangular rotary valves 140 are supported. The rotary valve 140 move during operation of the slide pump 120 within the guide grooves 138 by means of a centrifugal force generated by the rotation in the direction of rotation 133 of the rotor 130 to the outside. As a result, the rotary valves 140 seal against the inner wall 134 of the hollow body 128. In particular, the rotary valves 140 are pressed by means of a spring, not shown here in the guide groove 138 to the outside.

In the first rotary valve area 122, in the present case, six guide grooves 138 are formed on the cylinder 130 with six rotary valves 140. These six rotary valves 140 divide the space between the rotor 130 and the hollow body 128 into six chambers 142, 144, 146, 148, 150 and 152. The first chamber 142 is formed downstream of the contact point 131 in the direction of rotation 133 in the suction region 135.

A first inflow opening 154 extends through the housing 126 toward the first chamber. A first outflow opening 156 and a second outflow opening 158 lead out of the fourth chamber 148 and fifth chamber 150, as seen in the direction of rotation 133. The two outflow openings 156 and 158 unite to a common first drain port 160 which penetrates the housing 126. In this case, the two outflow openings 156 and 158 are brought together within the housing 126 to the first outflow opening 160. The drain opening 160 is followed by a first drain line 161. From the sixth chamber 152, viewed in the direction of rotation 133, a connecting line 162 leads to the second rotary valve area 124.

The second rotary valve area 124 is similar to the first rotary valve area 122 configured with a cylindrical hollow body 128 in which a rotor 130 is rotatably mounted on a second shaft 164 in the direction of rotation 133. The first shaft 132 is torque-transmittingly connected in the first rotary valve area 124 to the second shaft 164 in the second rotary valve area. The first shaft 132 and the second shaft 164 thus form a common pump shaft, not shown here.

In contrast to the first rotary valve region 122, not six, but four guide grooves 138 are provided on the rotor 130 with four rotary valves 140 in the second rotary valve region 124. Correspondingly, the four rotary valves 140 divide the space between the rotor 130 and the hollow body 128 into four chambers 166, 168, 170 and 172. The first chamber 166 is formed downstream of the associated contact point 131 in the suction region 135, as viewed in the direction of rotation 133.

Toward the first chamber 166, at a second inlet region 167, the connecting line 162 extends from the first rotary valve region 122. To the second chamber 168 extends at a first inlet region 169 through the housing 126 a second inflow opening 174. The second inflow opening 174 terminates at the other end in the separation chamber 48 of the separator 34 in Fig. 6 shown. In the fourth chamber 172, a second drain opening 176 is formed. The second outflow opening 176 connects in a fluid-conducting manner to the fourth connection line 72.

The fourth connection line 72 is combined with the first discharge line 161 by means of the ejector 121. The ejector 121 is designed for this purpose with a driving tube 178, which ends within the connecting line 72 in a motive nozzle 180. The motive nozzle 180 narrows the associated flow area of the riser 178 to a nozzle orifice 182. The orifice 182 and the reduced flow area of the fourth interconnect 72 form a flow outlet 184.

In the slide pump 120 rotates in each of the two rotary valve areas 122 and 124 in the associated hollow body 128 each one of the two rotors 130 in the direction of rotation 133. In the rotor 130 are the guide grooves 138 in which the rotary valve 140 are supported. The rotary valves 140 are urged radially outwards by the rotor 130 due to the centrifugal force generated by the rotation and bear against the inner wall 134 of the hollow body 128. Thus, 128 chambers form between the rotor 130 and the inner wall 134 of the hollow body. These chambers are limited in the circumferential direction of the rotary valves. Since the rotor 130 is mounted eccentrically to the associated hollow body 128, upon rotation of the rotor 130 in the direction of rotation 133, the volume of each individual chamber changes. The volume of the individual chamber then increases in the suction region 135. In the pressure region 136, the volume of the individual chamber decreases during this rotation in the direction of rotation 133.

In the rotary valve portion 122, which is designed as an expansion motor 74, the pressure medium supplied from the condenser 32 under pressure medium 18 is pressed into the suction region 135 in the first chamber 142 with pressure. The pressurized refrigeration medium 18 thereby causes the associated rotor 130 to rotate in the direction of rotation 133. The cooling medium 18 is then transported from the rotary chamber area 122 in the pressure region 136 of the rotary valve area 122 out of the chamber moved there. The pressure in the discharge medium 136 discharging the cooling medium 18 of this rotary valve region 122 is less than the pressure in the suction medium 135 leading to the cooling medium 18 of this rotary valve region 122.

In the rotary valve area 124, which is designed as a pump 56, likewise takes place a rotation in the direction of rotation 133 by means of the drive 58. The drive 58 is for this purpose advantageously carried out by means of the expansion motor 74. The rotation on the pump 56 causes the cooling medium 18 to be sucked in the suction region 135 of the rotary valve region 124 by enlarging the chambers there during the rotation. By contrast, in the pressure region 134 of this rotary valve region 124, the cold medium 18 is pressed out of the rotary valve region 124 as the chambers are reduced in size.

The Fig. 8 shows a heat pump cycle 10, in which the pump 56 in the separator 34 is designed as a piston pump 190. The piston pump 190 is likewise arranged in the separation chamber 48 of the separator 34.

The Fig. 9 shows the piston pump 190 in detail. The piston pump 190 is formed with a hollow cylinder 192, which is closed at its two open ends in each case with a closure lid 194 and 195. The closure lids 194 and 195 each have a step 196 on their outer edge. The first stage 196 of the closure lids 194 and 195 is adapted to the inner wall 198 of the hollow cylinder 192. The closure cap 194 and 195 are inserted with the step 196 in the hollow cylinder 192 and seal thereon on an inner wall 198 from. For this purpose, a seal, not shown here may be provided. The two closure lids 194 and 195 penetrating each have a feed opening 200 and a discharge opening 202. At the feed opening 200 and at the discharge opening 202 preferably two, not shown here, valves are arranged, acting as check valves, open or close depending on the direction of flow.

The hollow cylinder 192 is divided internally in the middle with a separating disk 204 in two halves. The separating disk 204 extends parallel to the closure lids 194 and at right angles to the inner wall 198. The separating disk 204 thus separates the hollow cylinder 192 into a first chamber 206 and into a second chamber 208. The hollow cylinder 192 penetrates axially directly next to the separating disk 204 toward the first chamber 206 and the second chamber 208 towards a first opening 210 and a second opening 212 formed. At the separating disk 204 itself, an opening 214 is provided in the center thereof.

Within the hollow cylinder 192, a piston 215 is inserted. The piston 215 is formed of a piston rod 216 and two piston discs 218 and 220. The piston rod 216 is movably slidably fitted in the opening 214 of the separation disc 204. The piston rod 216 is sealed by means of a seal, not shown here in the opening 214 and slidably mounted. The piston rod 216 thus extends concentrically in the longitudinal direction of the hollow cylinder 192 and thereby tapers at its two ends depending on a step 217th

At this stage 217, the first piston disc 218 or the second piston disc 220 is positively coupled in each case in a stationary manner. The two piston discs 218 and 220 are thereby slidably against the inner wall 198 of the hollow cylinder 192 with their peripheral side or lateral surface. In the case of both piston disks 218 and 220, a respective groove 221 is formed on the lateral surface facing the hollow cylinder 192. In this groove 221, a sealing ring 222 is inserted around the respective piston disc 218 and 220, which seals the piston discs 218 and 220 to the hollow cylinder 192. The sealing ring 222 is designed to allow sliding in the hollow cylinder 192.

The first piston disc 218 divides the first chamber 206 into a first cylinder chamber 223 and a second cylinder chamber 224. The first cylinder chamber 223 is formed within the hollow cylinder 192 between the closure cap 194 and the first piston disc 218. The second cylinder space 224 is formed between the first piston disk 218 and the separation disk 204.

The second piston disc 220 divides the second chamber 208 into a third cylinder chamber 226 and a fourth cylinder chamber 228. The third cylinder chamber 226 is formed inside the hollow cylinder 192 between the separation disk 204 and the second piston disk 220. The fourth cylinder chamber 228 is formed between the second piston disk 220 and the second closure lid 195. Within the second and third cylinder chamber 224 and 226 is the piston rod 216, which influences the volume of the second cylinder chamber 224 with its outer diameter.

The second cylinder chamber 224 and the third cylinder chamber 226 form the first pumping region 66, which acts as an expansion engine 74, and the first cylinder chamber 223 and the fourth cylinder chamber 228 form the second pumping region 68, which acts as a pump 56.

Into the second cylinder chamber 224 and the third cylinder chamber 226, the refrigerant medium 18 is pressed by the condenser 32 under pressure alternately by means of a (not shown here) valve. The pressed-in refrigeration medium 18 sets according to the associated piston 215 in motion. A cooling medium 18 pressed into the second cylinder space 224 causes the piston 215 within the piston pump 190 to move away from the separation disk 204 in the direction of the closure cover 194.

As a result, at the same time the volume in the first cylinder chamber 222 and in the third cylinder chamber 226 is reduced. From the first cylinder chamber 222 and the third cylinder chamber 226 refrigerant medium 18 is pushed out. At the same time enlarges the volume in the fourth cylinder chamber 228. Refrigerant 18 is thereby sucked into the fourth cylinder chamber 228.

Fig. 9 shows that position, just before the refrigerant medium 18 is pressed into the second cylinder chamber 224.

The Fig. 10 shows a heat pump cycle 10 in which the switching elements 82 and 84 are designed as four-way valve assemblies 240.

Fig. 11 shows such a four-way valve assembly 240 in detail. There two hollow cylindrical housing elements 242 and 244 are arranged substantially parallel to each other. Between the housing member 242 and the housing member 244 tubular spacer lines 248 and 250 are formed in the transverse direction. The spacer lines 248 and 250 also extend substantially parallel to one another and connect the two housing elements 242 and 244 in a fluid-conducting manner with one another. In the middle of the longitudinal extent of the two housing elements 242 and 244 there is arranged an outwardly directed connection element 252 and 254, respectively. Likewise, an outwardly directed connection element 256 and 258 is arranged approximately in the middle of the longitudinal extent of the two spacer lines 248 and 250, respectively. The two spacer lines 248 and 250 are at least as far apart in relation to the longitudinal direction of the housing elements 242 and 244 from each other, as the connecting elements 252 and 254 are wide in this direction.

The distance between the two housing elements 242 and 244 is chosen so large that this distance makes up 1.5 to 2 times, particularly preferably 3 to 5 times, the diameter of the connecting elements 252, 254, 256 and 258. An intermediate space 257 formed in this way between the housing elements 242 and 244 or the spacer lines 248 and 250 is filled with an insulating material (not shown). The arrangement of the housing elements 242 and 244 and the spacer lines 248 and 250 forms in the view according to Fig. 11 a rectangle.

The housing element 242 is sealed at its two ends, each with a closure disk 260 and 262. The closure discs 260 and 262 penetrating each have an access opening 261 and 263 configured.

The closure discs 260 and 262 are sealingly fitted into the housing member 242. Following the shutter discs 260 and 262 toward the middle of the longitudinal extent of the housing member 242, two cylindrical switching elements or valve bodies 264 and 266 are fitted into the housing member 242. The outer diameter of the switching elements 264 and 266 are designed to be slightly smaller than the inner diameter of the housing element 242. This allows a sliding of the switching elements 264 and 266 in the cavity of the housing element 242nd

The access ports 261 and 263 are provided to supply a fluid through them by means of a solenoid valve (not shown). With this fluid can then act on the located in the housing element 242 switching elements 264 and 266 to adjust them. The switching elements 264 and 266 then act as a "working piston" at the same time.

In the case of the switching elements 264 and 266, two circumferential grooves 268 and 270 open towards the outer radius of the switching elements 264 and 266 are formed on the side of the closure disks 260 and 262. In the grooves 268 and 270, a respective annular sealing means 272 and 274 is fitted. The sealants 272 and 274 seal the switching elements 264 and 266 toward the inner wall of the housing member 242.

In the longitudinal direction of the switching elements 264 and 266, a small taper 276 of the outer diameter of the switching elements 264 and 266 is further formed toward the center of the housing element 242 thereafter. The longitudinal extent this taper 276, in which the switching elements 264 and 266 are tapered, is greater than the width, in particular the inner diameter of the two spacer lines 248 and 250th

The two mutually facing radially outer edges of the switching elements 264 and 266 are rounded and form bearing surfaces 280 and 282, by means of which the switching elements 264 can seal against a valve seat 288 and 290, respectively.

The switching element 264 is shown in the illustration Fig. 11 in a position where it is disposed in the housing member 242 at or near the shutter disk 260. In addition to the switching element 264 then opens a through hole 284, which belongs to the distance line 248. The switching element 266 is arranged in this position away from the closure disks 262. Then, a through hole 286 belonging to the clearance line 250 is disposed on the case member 242 so as to be overlapped with the taper 276 of the outer diameter of the switching element 266.

In the center of the housing element 242, this inside is finally reduced circumferentially in phase diameter. This reduction in the inner diameter of the housing member 242 forms two valve seats 288 and 290. The two valve seats 288 and 290 are designed so that they seal at a concern of the respective bearing surfaces 280 and 282 with the associated switching elements 264 and 266. Between the two valve seats 288 and 290 then there is a connection element 252 belonging through opening 292nd

Both switching elements 264 and 266 are connected to the center of the housing member 242 out with a cylindrical connecting rod 294 stationary. The switching elements 264 and 266 and the connecting rod 294 together form a piston element 296. The length of the connecting rod 294 is dimensioned such that, when abutment of the bearing surface 282 of the switching element 266 on the valve seat 290, the switching element 264, the passage opening 284 completely free. The switching element 264 is then as in Fig. 11 shown disposed at the shutter disc 260.

The housing member 244 is according to the Fig. 11 point symmetrical to the housing element 242 designed. Accordingly, there is provided a third switching element or a third valve body 298, which allows a flow between the third port 90 and the fourth port 92. Furthermore, a fourth switching element or a fourth valve body 300 is provided which can prevent a flow between the third port 90 and the second port 88. Preferably, the switching elements 264, 266, 298 and 300 are made of a material having a low thermal conductivity.

With such an arrangement of the housing members 242 and 244 and the spacer lines 248 and 250 spaced therefrom, thermal separation of the flow paths 104, 106, 108 and 110 within the four-way valve assembly 240 is provided. This thermal separation is further enhanced by the low thermal conductivities of the switching elements 264, 266, 298 and 300.

The thermal separation acts as a thermal barrier between the respective active flow paths 104, 106, 108 and 110. Thus, less thermal energy is exchanged between the cold media 18 flowing in the flow paths. This reduces thermal losses, which increases the efficiency in the heat pump cycle 10.

Finally, it should be noted that all the features that are mentioned in the application documents and in particular in the dependent claims, in spite of the formal reference back to one or more specific claims, even individually or in any combination should receive independent protection.

Reference number list

10

Heat pump cycle

12

Low-temperature heat source

14

High temperature heat sink

16

Circuit line

18

cold medium

20

Low pressure area

22

High pressure area

24

compressor

26

flow direction

28

throttle

30

Evaporator

32

condenser

34

separators

36

liquid fraction

38

arrow

40

gaseous portion

42

outer shell

44

feed

45

first discharge opening

46

second discharge opening

48

separating chamber

50

plenum

52

liquid Level

54

Abscheiderleitung

55

inlet area

56

pump

58

drive

60

transmission element

61

outlet

62

second trunk line

63

High pressure regulator

64

second feed opening

66

first pumping area

68

second pumping area

70

third connection line

72

fourth connection line

74

expansion engine

76

inlet area

78

outlet

80

switchover

82

switching

84

switching

86

first connection

88

second connection

90

third connection

92

fourth connection

94

fifth connection line

96

sixth connection line

98

seventh connection line

100

eighth connection line

102

ninth connection line

104

first flow path

106

second flow path

108

third flow path

110

fourth flow path

112

second flow direction

113

measuring device

114

sensor

115

sensor line

116

control device

117

first control line

118

second control line

120

vane pump

121

ejector

122

Rotary vane area

124

Rotary vane area

126

casing

128

hollow body

130

rotor

131

contact point

132

first wave

133

direction of rotation

134

inner wall

135

suction area

136

pressure range

138

guide

140

rotary vane

142

first chamber

144

second chamber

146

third chamber

148

fourth chamber

150

fifth chamber

152

sixth chamber

154

first inflow opening

156

first outflow opening

158

second outflow opening

160

drain opening

161

first drain line

162

connecting line

164

second wave

166

first chambers

167

second inlet area

168

second chambers

169

first inlet area

170

third chambers

172

fourth chambers

174

second inflow opening

176

second drainage opening

178

blowing pipe

180

propelling nozzle

182

nozzle opening

184

flow output

190

piston pump

192

hollow cylinder

194

cap

195

cap

196

step

198

inner wall

200

feed

202

discharge opening

204

Abtrennscheibe

206

first chamber

208

second chamber

210

first opening

212

second opening

214

opening

215

piston

216

piston rod

217

step

218

first piston disc

220

second piston disc

221

groove

222

seal

223

first cylinder space

224

second cylinder space

226

third cylinder room

228

fourth cylinder space

240

Four-way valve assembly

242

housing element

244

housing element

248

distance line

250

distance line

252

connecting element

254

connecting element

256

connecting element

258

connecting element

257

gap

260

sealing washer

261

access opening

262

sealing washer

263

access opening

264

switching element

266

switching element

268

groove

270

groove

272

sealant

274

sealant

276

rejuvenation

280

bearing surface

282

bearing surface

284

Through opening

286

Through opening

288

valve seat

290

valve seat

292

Through opening

294

connecting rod

296

piston element

298

switching element

300

switching element

Claims (10)

Heat pump circuit (10) with an evaporator (30) to flow through by a cooling medium (18) in a flow direction (26),
characterized in that a switching means (80) for reversing the flow direction (26) of the refrigerant medium through the evaporator (30) is provided. Heat pump cycle according to claim 1,
characterized in that a condenser (32) is provided, which is to be flowed through by the cold medium (18) in the flow direction (26), wherein with the switching means (80) and the flow direction (26) through the condenser (32) is reversible , Heat pump cycle according to claim 2,
characterized in that a compressor (24) is provided and the switching means (80) is designed with a first four-way valve assembly (240), by means of which the compressor (24) in a first switching position with the condenser (32) connected in a flow-conducting manner is and in a second switching position of the compressor (24) to the evaporator (30) is connected in flow conduction. Heat pump cycle according to claim 3,
characterized in that the switching device (80) with a second four-way valve assembly (240) is provided, by means of which in a first switching position of the condenser (32) with a first discharge opening (45) of a separator (34) is conductively connected and in a second switching position, a second discharge opening (46) of the separator (34) with the condenser (32) is conductively connected. Heat pump cycle according to claim 4,
characterized in that the compressor (24) is provided in flow communication between the first and second four-way valve assemblies (240). Heat pump cycle according to claim 5,
characterized in that the compressor (24) of the refrigerant medium (18) in a flow direction (26) to flow through, said flow direction (26) in the first switching position and the second switching position is the same. Heat pump cycle according to claim 5 or 6,
characterized in that a measuring device (113) for measuring a degree of icing of the evaporator (30) is provided. Heat pump cycle according to claim 7,
characterized in that the measuring device (113) for measuring the degree of icing of the evaporator (30) is adapted to determine a power consumption of the compressor (24). Heat pump cycle according to one of claims 4 to 8,
characterized in that a control device (116) for simultaneously switching the first and second four-way valve assembly (240) is provided. Use of a switching device (80) for reversing a flow direction (26) of a refrigeration medium (18) according to one of claims 1 to 9 in a heat pump cycle (10).

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