WO2017013163A1

WO2017013163A1 - Heat pump system

Info

Publication number: WO2017013163A1
Application number: PCT/EP2016/067268
Authority: WO
Original assignee: Glen Dimplex Deutschland Gmbh
Priority date: 2015-07-21
Filing date: 2016-07-20
Publication date: 2017-01-26
Also published as: DE112016003281A5; DE112016003281B4

Abstract

The invention relates to a heat pump system (1), which is used to air-condition a building system (52), and comprises a refrigeration circuit (2), which is connected to a waste heat circuit (36) via a first interface (40) during operation in order to use waste heat from the building system (52) and to a load-side air-conditioning circuit (38) via a second interface (42) in order to air-condition a building area, wherein - the refrigeration circuit (2) has a main branch (4) in which a first load-side heat exchanger (8), a second air-supplied heat exchanger (10), a throttle element (12), and a compressor (14) are arranged, - the first load-side heat exchanger (8) is used as a condenser (8) in a combined waste heat heating mode, and the second air-supplied heat exchanger (10) is used as an evaporator (10), - the load-side air-conditioning circuit (38) is connected to the first heat exchanger (8) during operation in order to transmit heat between the refrigeration circuit (2) and the load-side air-conditioning circuit (38), - the refrigeration circuit (2) has a parallel branch (6) in which a third heat exchanger is integrated into the refrigeration circuit parallel to the second heat exchanger (10), and - the third heat exchanger is used as a waste heat evaporator (30) in the combined waste heat heating mode and is connected to the waste heat circuit (36) in order to transmit heat into the refrigeration circuit (2).

Description

description

heat pump system

The invention relates to a heat pump system with a refrigeration cycle.

Heat pump systems for providing heat or cold for a consumer side are known in principle. For receiving or releasing heat from / to the environment, an air-loaded (lamellar) heat exchanger is frequently used. Alternatively, it is also possible to use a brine / water-charged heat exchanger, for example a soldered plate heat exchanger. In particular, in an air-heated heat exchanger (evaporator) defrosting is regularly required. The heat required for this purpose is usually withdrawn from a consumer connected heating network. This will negatively affect energy efficiency.

Especially in the industrial sector or in commercial or retail areas there are complex requirements with regard to the air conditioning of rooms. Here, an efficient use of energy is sought.

Based on this, the present invention seeks to provide a particularly reversible heat pump system, which is characterized by high efficiency.

The object is achieved according to the invention by a heat pump system with the features of claim 1. Preferred developments are contained in the subclaims. The heat pump system is used to air-condition a building system. The heat pump system has for this purpose a refrigeration cycle, which is connected in operation via a first interface to a waste heat cycle to exploit waste heat from the building system. In the waste heat circulating generally circulates a liquid heat carrier, for example brine or a glycol-water mixture or other heat transfer medium. Hereinafter, the waste heat cycle without limiting the generality as a brine circuit and the heat carrier referred to as brine for the identification of the liquid heat carrier. Via a second interface, the refrigeration cycle is connected to a consumer-side air conditioning circuit for air conditioning of a building area of the building system. The term "air conditioning" is understood herein to mean both the ability to heat and to cool the building area, and thus, suitably, is a reversibly operable heat pump installation Control unit for operating the heat pump system is set up in different operating modes.

The refrigeration cycle has a main branch in which a first, consumer-side heat exchanger and a second air-heated heat exchanger and also a throttle element and at least one compressor are arranged. In a heating mode, in which heat is delivered to the consumer-side air conditioning circuit, the first consumer-side heat exchanger serves as a condenser and the second air-heated heat exchanger as an evaporator. Below - unless otherwise stated - is assumed by such a heating operation and the first consumer-side heat exchanger is referred to as a condenser and the second air-heated heat exchanger as an evaporator.

In operation, the consumer-side air conditioning circuit is connected to the condenser in order to transfer heat into it. Furthermore, the cold run has a parallel branch into which a third heat exchanger is integrated in parallel to the second heat exchanger, that is to say parallel to the evaporator is used in a combined waste heat heating mode as a waste heat evaporator. This waste heat evaporator is used to transfer heat from the waste heat cycle in the refrigeration cycle. Under parallel arrangement is understood that during operation, the two evaporators in parallel - and not serially in succession - are flowed through by refrigerant.

In the combined waste heat heating mode, therefore, heat is absorbed by both the waste heat evaporator and the evaporator of the main branch, which heat can then be released via the condenser to the air conditioning circuit. By this embodiment, the particular advantage is achieved that waste heat from the building system itself is used in addition to the heat from the ambient air for heating the building area. Due to the parallel circuit of the two evaporators, ie the evaporator in the main branch and the waste heat evaporator in the parallel branch, a particularly advantageous interconnection is achieved in order to utilize different heat sources as efficiently as possible. Thus, this special circuit makes it possible to use both evaporators in parallel, only the waste heat evaporator or even only the evaporator of the main branch. The control logic depends in particular on how much heat from the waste heat cycle can be made available. In addition, this special design of the heat pump system also allows the waste heat to be used for de-icing the air-pressurized evaporator.

In particular, a multiplicity of different circuit options is made possible by this heat pump system, which allows efficient utilization of the energy available in the building system for the air conditioning, in particular heating of the building system. The waste heat provided by the building itself is therefore used particularly advantageously for heating. The term "building system" generally refers to a locally connected system with one or several building parts. Specifically, the building complex is an office building, a supermarket, a production facility with offices, a leisure facility. such as swimming pool or wellness area as well as a hotel complex.

The waste heat evaporator connected in parallel serves in particular exclusively to absorb heat from the waste heat cycle. The waste heat evaporator is therefore preferably flowed through in one direction. In contrast, the first and the second heat exchanger of the main branch of the refrigeration cycle are flowed through in a cooling mode in the opposite flow direction to the heating mode.

In combined waste heat heating mode, in which heat is thus absorbed into the refrigeration cycle via both evaporators, the two evaporators have different evaporation temperatures in an expedient embodiment. Specifically, the waste heat evaporator has a higher evaporation temperature than the evaporator. Especially in the use of waste heat for the waste heat evaporator, a certain temperature level within the waste heat cycle it is necessary, which should not be exceeded. Conversely, the evaporation temperature may be lower in the main branch at the air-exposed evaporator. Since it is generally the same refrigerant, which flows only in the various branches of the refrigeration cycle, this is usually required that the waste heat evaporator and the evaporator each have their own expansion valve, so a separate throttle body is connected, in particular a desired overheating is set.

In the combined waste heat heating mode, the power of the waste heat evaporator is regulated in a preferred embodiment as a function of a temperature associated with the waste heat evaporator. This is referred to below as the waste heat temperature. This generally refers to all temperatures which are present in the region of the waste heat evaporator in the waste heat cycle or in the refrigeration cycle. In particular, the power is regulated as a function of a return temperature of the waste heat cycle. Under return temperature is generally understood the temperature of the heat carrier in the waste heat after flowing through the waste heat evaporator. This will in particular This ensures that kept in the waste heat cycle a certain temperature and / or a minimum temperature is not exceeded. The power of the waste heat evaporator, ie the heat transferred per unit time to the refrigeration cycle, varies depending on the heat provided in the waste heat cycle. Overall, it is ensured that the function of the waste heat cycle is not affected by excessive heat extraction. This measure thus serves to ensure the function of the downstream waste heat supplier (eg refrigerated cabinets).

In addition to the control function of the return temperature of the waste heat cycle, it is also possible to make the control in dependence on the evaporation temperature of the waste heat evaporator, and to keep this constant, for example. Since the evaporation temperature also correlates with the pressure, this also corresponds to a regulation as a function of the evaporation pressure. The temperature of the refrigerant (superheat temperature) and the evaporation pressure are preferably measured on the output side of the waste heat evaporator.

As already stated, the overall control is designed such that the transfer of heat in the waste heat evaporator adapts to a waste heat output in the waste heat cycle. In particular, the control is designed such that the already mentioned minimum temperature in the waste heat cycle is not exceeded.

It is preferably provided that the mass flow of the refrigerant flowing through the waste heat evaporator is controlled to control the power of the waste heat evaporator. The higher the thermal power provided by the waste heat cycle, the greater the mass flow conducted via the waste heat evaporator and vice versa.

To control the power of the waste heat evaporator, a control valve is preferably provided, which is arranged downstream of the waste heat evaporator in the flow direction of the refrigerant. To control the power of the waste heat evaporator, in particular an opening degree of the control valve is set. In particular, the mass flow of the refrigerant flowing in the parallel branch and therefore by the waste heat evaporator is also at least implicitly regulated via this degree of opening.

In the case of only a small or reduced waste heat in the waste heat cycle, therefore, an opening degree of the control valve is generally reduced. As a result, the pressure in the previously connected waste heat evaporator is raised at the same time. The control valve therefore generates, depending on the degree of opening a certain pressure jerk, which leads to the pressure increase. The control valve is so far an evaporation pressure regulator. With an increase in pressure is also accompanied by an increase in the evaporation temperature. As a result, a temperature difference between the refrigerant and the waste heat cycle is then reduced overall. By this measure, therefore, the performance of the waste heat evaporator is reduced, both by reducing the mass flow and by reducing the temperature difference between the refrigerant and the waste heat cycle. Preferably, a defined overheating of the refrigerant by a suitable throttling is set by a corresponding regulation of the waste heat evaporator associated expansion valve. A change in the opening degree of the control valve therefore also entails a control of the expansion valve, which leads, in particular in combination, to a change in the mass flow. In particular, it is ensured via the control valve that a minimum return temperature is not undershot, thus securing a limit range in this respect. Outside this limit range, the mass flow is adjusted primarily by the expansion valves in the two branches of the refrigerant circuit.

In an expedient embodiment, the previously mentioned waste heat temperature, especially the return temperature, is used as the controlled variable for the control valve. This ensures in a simple manner a control to a constant return temperature or a control to a return temperature above a minimum return temperature. In particular, if sufficient heat is provided by the waste heat cycle, then another controlled variable for the control valve can be used, for example, the evaporation temperature of the waste heat evaporator. For example, it is regulated to a constant evaporation temperature of the waste heat evaporator.

By varying the degree of opening and the resulting accumulation pressure, this automatically leads to different pressure situations on the one hand on the waste heat evaporator and on the other hand on the evaporator. Due to the different pressure situations, it is therefore due to the change in the opening degree of the control valve also automatically to a change in the distribution of the mass flow of the refrigerant on the one hand to the waste heat evaporator and on the other hand to the evaporator. Therefore, the refrigerant circulated by the compressor is distributed automatically on the one hand to the waste heat evaporator and on the other hand to the evaporator.

With a view to the most cost-effective implementation, it is provided that the at least one compressor is a non-output-controlled compressor. The delivered mass flow is usually at least largely constant. By the at least one compressor, a total mass flow of refrigerant is circulated, which automatically distributed to the two branches (main branch and parallel branch).

Alternatively, to regulate the power of the waste heat evaporator both the main branch and the parallel branch each associated with a power-controlled compressor so that the mass flows in the main branch and in the parallel branch can be set independently via the respective compressor. By a suitable distribution of the mass flows, the control of the individual evaporator services can be made. In this embodiment, the control valve is preferably not used. Again, the control takes place in particular as a function of a waste heat temperature of the waste heat cycle, especially as a function of the return temperature of the waste heat cycle.

With a reduced thermal performance by the waste heat evaporator and a consistently high thermal power requirement on the consumer side in the air conditioning circuit, a reduced thermal performance of the waste heat evaporator must be compensated by an increased thermal performance of the evaporator in the main branch. This is preferably done by a suitable control of a fan, which is arranged to generate an air flow through the evaporator. This fan, that is, the speed of which is thus controlled as a whole preferably in dependence on the waste heat output of the waste heat evaporator. With a reduced waste heat output, therefore, the speed of the fan, ie the air mass flow, increased and vice versa.

When using a control valve, the fan is in particular - at least indirectly - controlled depending on the degree of opening of the control valve. The degree of opening of the control valve is so far a correlated with the performance of the waste heat evaporator size.

Especially with sufficient waste heat in the waste heat cycle, there is the possibility that only the heat provided by the waste heat cycle is used and that therefore in such a heating mode, which is referred to as the sole waste heat heating mode, the evaporator is inactive. Especially in such an operating situation there is a risk that refrigerant is displaced into the non-active evaporator. To avoid this, a check valve is expediently arranged between the parallel branch and the main branch, which avoids such a return flow of refrigerant into the evaporator.

In the sole waste heat heating mode, in addition, in an expedient embodiment, there is an additional extraction of refrigerant, in particular cyclic extraction provided to the (inactive) evaporator, wherein the extracted refrigerant to the active part of the refrigeration cycle, ie in particular the parallel branch is supplied. This embodiment is based on the consideration that due to not completely negligible leakage currents despite a check valve can lead to a refrigerant shift. By the measure of the suction there is the advantage that a required expansion tank for the refrigerant can be made smaller and more compact compared to a design without such suction.

For suction, the parallel branch is preferably switched off for the duration of the suction, so that no refrigerant flows through the parallel branch. Preferably, the throttle element, which is designed as a controllable expansion valve and which is assigned to the evaporator and which is closed in the sole waste heat heating mode, is partially opened. The opening degree is preferably below 15% and more preferably below 10% and especially in the range of 3% to 8% based on a complete opening of the expansion valve. The compressor is simultaneously operated, so that in total this refrigerant is sucked out of the evaporator. After completion of the suction process, the expansion valve is closed again and the parallel branch is activated again. This suction process is preferably repeated cyclically.

As already mentioned, in an expedient embodiment, the heat provided by the waste heat circuit is also used to defrost the air-heated heat exchanger. Conveniently, only the heat from the waste heat cycle is used. This is therefore prioritized. If this heat is insufficient, heat from the consumer-side air conditioning circuit can additionally be used in a manner known per se. That is, in the absence of heat in the waste heat cycle is switched either partially or completely to a heat extraction from the consumer-side air conditioning circuit expediently. In an expedient embodiment, all the components of the refrigeration circuit, that is to say all the components of the main branch as well as those of the parallel branch, are integrated in a common housing. This is therefore a completed unit in which all components are arranged. This unit has the first and the second interface, on the one hand, the waste heat cycle and on the other hand, the air conditioning circuit is connected.

As already mentioned, the waste heat cycle is preferably a brine circuit, and therefore preferably brine or other liquid heat transfer medium is used as the heat transfer medium. The waste heat cycle is expediently connected to a condenser of a further refrigeration circuit, which serves for cooling a cooling area. The waste heat is therefore in particular condensation heat. Within the entire building complex, special areas are often cooled by means of further refrigeration machines with corresponding refrigeration circuits. With this measure, therefore, the heat dissipated by these other chillers via the respective condenser heat is used as waste heat of the waste heat cycle. In this respect, the capacitor of the further refrigeration cycle is coupled to the refrigeration cycle of the heat pump system via the parallel branch.

Such a situation occurs, for example, in supermarkets with refrigerated cabinets, in administrative and office buildings with refrigerated office rooms or even with refrigerated server rooms or generally in larger central air conditioning units. In all these variants, a heat from the capacitor is utilized.

In addition, there is also the possibility that, for example, waste heat from the production process is made available as heat source for the waste heat cycle for heating the office area (via the consumer-side air conditioning cycle) in industrial manufacturing locations with production and office area. Another possible use are spa and bath applications where, for example, sloshing water is used as the heat source. The above-described specific embodiment of the heat pump system with the integration of the heat pump system in a building system, is used in the waste heat from the building to heat other areas of the building, in principle, transferable to other applications. In this respect, the object is further achieved by a heat pump system with the feature combination of claim 21. Thus, the heat required for the waste heat cycle can also be obtained from heat sources outside the building. For example, this is geothermal, which is obtained for example via a suitable probe. The aforementioned specific embodiments of the refrigeration cycle and especially the regulation apply equally to the heat pump system according to claim 21.

An embodiment of the invention will be explained in more detail with reference to FIGS. These show partly in simplified representations:

1 is a circuit diagram of a refrigeration cycle of a heat pump system in a combined waste heat heating mode,

2 shows the circuit diagram according to FIG. 1 in a cooling mode, FIG.

Fig. 3 shows the circuit diagram of FIG. 1 with a defrost mode and

Fig. 4 shows a building system with a heat pump system in a highly simplified schematic representation.

In the figures, like-acting parts are provided with the same reference numerals.

FIGS. 1 to 3 show a heat pump system 1 with a refrigeration cycle 2. The refrigeration cycle 2 can be generally divided into a main branch 4 and a parallel branch 6. FIG. 1 shows the refrigeration cycle 2 in a special operating mode, hereinafter referred to as a combined waste heat heating mode. The parallel branch 6 is active in this mode. In Fig. 1, the parallel branch 6 is indicated by a thickened line. The main branch 4 generally has a first consumer-side heat exchanger 8, which operates as a condenser in the combined waste heat heating mode. Furthermore, the main branch 4 has a second heat exchanger 10, which operates in the combined waste heat heating mode as an evaporator. Hereinafter, the two heat exchangers 8, 10 are referred to as condenser 8 and evaporator 10. Furthermore, the main branch 4 comprises a first throttle element, which in the exemplary embodiment is designed as a first (electronic) expansion valve 12. Furthermore, the main branch 4 has a compressor arrangement with two compressors 14 connected in parallel in the exemplary embodiment. Finally, in the main branch 4 still a collector 16 is arranged for a circulating in the refrigeration circuit 2 refrigerant.

The refrigeration cycle 2 can be reversibly operated, in particular in the main branch 4, i. the direction of flow of the refrigerant through the two heat exchangers 8,10 can be reversed. For this purpose, a suitable flow direction reversing device is arranged in the main branch 4, in the exemplary embodiment in particular a 4-way switching valve 18.

The evaporator 10 is an air-operated evaporator 10, which is traversed by air during operation. For this purpose, at least one fan 20 is arranged, the speed of which is controllable. In the exemplary embodiment, two fans 20 are arranged.

The flow direction of the refrigerant in the combined waste heat heating mode is shown by arrows in FIG. The evaporator 10 is in this case flows through from top to bottom as shown in FIG. The refrigerant is then passed via the 4-way switching valve 18 in a branch line 22 in which a check valve 24 is arranged. The branch line 22 opens at a first branch point 26a into a suction line 28 which leads to the compressors 14. A pressure-side line leads from the compressors 14 back to the 4-way switching valve 18. The refrigerant is passed through a corresponding valve position from there to the condenser 8, flows through this, passes through the Collector 16 to a second branch point 26 b and is returned to the evaporator 10 via the first expansion valve 12.

The parallel branch 6 is connected to the main branch 4 at the two branch points 26a, 26b, specifically directly, so that the refrigerant can flow equally through the fluidic connection between main branch 4 and parallel branch 6 through both branches 4, 6.

In the illustrated combined waste heat heating mode, the parallel branch 6 flows from the second branch point 26b in the direction of the first branch point 26a through the refrigerant, as indicated by the arrowheads. In this parallel branch 6, a third heat exchanger is arranged, which is hereinafter referred to as waste heat evaporator 30. Between the second branch point 26b and the waste heat evaporator 30, a second (electronically) controllable expansion valve 32 is arranged as a second throttle element. In the embodiment of FIG. 1, a preferably also electronically controllable control valve 34 is arranged downstream of the evaporator 10.

Furthermore, the heat pump system 1 comprises a plurality of temperature sensors TO to T2, a plurality of pressure sensors P1, P2 and regulators R1 to R6.

At the waste heat evaporator 30, a waste heat circuit 36 is connected to a liquid heat carrier, such as brine. In the waste heat evaporator 30 is generally a refrigerant-liquid heat exchanger, in particular a plate heat exchanger, as well as in the capacitor 8. The capacitor 8 is the consumer connected to an air conditioning circuit 38. The waste heat cycle 36 is connected via a first interface 40 and the air conditioning circuit 38 via a second interface 42 to the refrigeration cycle 2. All the components between the two interfaces 40, 42 are arranged in particular within a common housing 44 (cf., Fig. 4), so that a total of a heat pump device is provided, which is preferably placed in the outer area and is designed accordingly. The heat pump system 1 is part of a building system 52 (see Fig. 4). The heat pump system 1 shown in the figures can be operated in total in different operating modes. These are:

Combined waste heat heating mode, in which heat is absorbed via the waste heat evaporator 30 and the evaporator 10,

sole waste heat heating mode in which heat is absorbed only via the waste heat evaporator 30,

normal heating mode in which heat is absorbed only via the evaporator 10,

Cooling mode in which heat is removed via the evaporator 10,

Prioritized defrost mode with heat exclusively from the waste heat circuit 34,

Combined defrost mode with heat from the waste heat circuit 34 and from the air conditioning circuit 38,

- Normal defrost mode with heat only from the air conditioning circuit 38 as well

- Mode refrigerant transfer.

Of particular importance here is the combined waste heat heating mode, as shown in Fig. 1 and will be explained in more detail below:

Waste heat from the building system 52 is provided via the waste heat cycle 36. A return temperature of this waste heat circuit 36 is detected via the temperature sensor TO. Depending on the configuration, the minimum return temperature is, for example, minus 10 ° C. and the maximum return temperature is 30 ° C. In a preferred embodiment, a minimum return temperature is for example between 5 and 10 ° C. This must not be exceeded, in order to maintain the functionality of the waste heat circuit 36 and the components cooled above. About the waste heat circuit 36 is generally over time fluctuating waste heat available. At the same time, a predetermined heat is required on the consumer side in the air conditioning circuit 38, which is designed as a heating circuit in the combined waste heat heating mode. borrowed. Inn combined waste heat heating mode is absorbed by both the waste heat evaporator 30 and 10 through the evaporator heat and discharged through the condenser 8 again. Thus, both the main branch 4 and the parallel branch 6 are active.

In the air-pressurized evaporator 10, a significantly lower evaporation temperature than in the waste-heat evaporator 30 will usually set. The higher evaporation temperature in the waste heat evaporator 30 is required because of the (high) minimum return temperature. The evaporation temperature in the evaporator 10 is typically a few degrees below that of the waste heat evaporator 30, for example 5 to 10 K. Due to the different evaporation temperatures are also different pressures in the parallel branch 6 and in the main branch 4 of the respective evaporator 10,30. The pressure difference is typically in the range of a few bar, for example in the range of 2 bar, wherein in the waste heat evaporator 30, the higher pressure prevails. Due to the hydraulic connection of the two branches 4, 6, the same pressures must prevail at the two branch points 26a, 26b.

Essential for the pressure balance is the control valve 34, the degree of opening can be adjusted by motor and in particular continuously. In the exemplary embodiment, the control variable for actuating the control valve 34 is preferably the temperature measured value of the first temperature sensor TO, which detects the return temperature. In principle, the two expansion valves 12, 32 are in operation in the described parallel operation. These are regulated as a function of the temperature measured via the temperature sensors T1, T2 and in dependence on the pressure of the refrigerant measured via the pressure sensors P1, P2 at the respective evaporator outlet. In this case, it is usually regulated to a specific overheating of, for example, several degrees Kelvin (overheating control) in order to ensure complete evaporation. The setpoint value for overheating is, for example, 6 K. By means of these two expansion valves 12, 32, a mass flow of the refrigerant is thus adapted to the power to be transmitted at the respective evaporator 10, 30. At the same time, the control valve 34 is controlled as a function of the return temperature (temperature sensor TO), in particular such that the return temperature does not fall below a minimum value. A reduction of the return temperature, in particular under a defined, predetermined minimum value, is detected by the temperature sensor TO. In this case, the opening degree of the control valve 34 is reduced, resulting in an increase of the pressure in the waste heat evaporator 30 on the refrigerant side. Accordingly, the evaporation temperature also increases, so that the driving temperature difference between the heat carrier in the waste heat circuit 36 and the refrigerant is reduced, whereby the transmitted heat is reduced. As a result, the total thermal power of the waste heat evaporator 30 is reduced or generally controlled via the control valve 34. Specifically, the combination of the control of the control valve 34 with the overheat control of the second expansion valve 32 controls the mass flow of the refrigerant through the waste heat evaporator 30.

At the same time, the mass flow in the refrigeration cycle 2 is largely constant overall, since the compressors 14 are not power-controlled compressors, which thus promote an at least substantially constant mass flow.

Due to the reduction of the mass flow in the parallel branch 6, there is an increase in the mass flow in the main branch 4 and thus via the evaporator 10. In order to ensure a constant thermal performance overall, therefore, the performance of the evaporator 10 must be increased overall. To achieve this, the fans 20 are additionally controlled and in particular their speed is increased. The controlled variable for this, for example, in turn, the return temperature, as indicated in Fig. 1. Since this is also the control variable for the control valve 34 at the same time, therefore, the fans 20 are actuated at least indirectly as a function of the opening degree of the control valve 34. Alternatively or in addition to the use of the control valve 34, it is also possible to control the mass flow via the respective evaporators 10, 34 by means of power-controlled compressors 14. In that case, for example, one compressor 14 would then be connected to the branch line 22 on the suction side and the other compressor on the suction side to the evaporator outlet side of the waste heat evaporator 30. A merger of the two branches 4, 6 would take place after the two compressors 14. In this case, the compressors 14, in particular the compressor 14, which is connected to the waste heat evaporator 30 on the suction side, would then preferably also be regulated as a function of the return temperature of the waste heat circuit 36. Derived from this then, for example, the second compressor 14, which is connected to the suction side of the evaporator 10, regulated. Again, with a reduction in the waste heat output in the waste heat cycle 36, the refrigerant mass flow through the waste heat evaporator 30 is reduced and at the same time the refrigerant mass flow through the evaporator 10 is increased. Again, then the speed of the fans 20 would be increased.

Instead of the control by means of the return temperature can be controlled in both cases, a control on the basis of the outlet temperature of the refrigerant after the waste heat evaporator 30 or on the basis of the prevailing evaporator outlet pressure. In this case, for example, the signals of the temperature sensors T1, T2 and / or the pressure sensors P1, P2 would be used for the control.

If no waste heat is made available by the waste heat circuit 36, the refrigeration cycle 2 can also be operated in a normal heating mode. In normal heating mode, the parallel branch 6 is not active, i. There is no refrigerant flowing through the waste heat evaporator 30. For this example, the second expansion valve 32 is closed.

Conversely, when a sufficient amount of heat is provided by the waste heat loop 36, the refrigeration cycle 2 is operated in a sole waste heat heating mode. In this case, no heat is produced via the evaporator 10 added. The corresponding section of the refrigeration cycle 2 is therefore inactive. For this purpose, for example, the first expansion valve 12 is closed. Decreases the waste heat, it is preferably automatically transferred to the previously described combined waste heat heating mode with the parallel operation of the two evaporators 10,30.

In addition to these three different heating modes in which heat is discharged to the consumer side and thus to the air conditioning circuit 38 (heating circuit), the refrigeration cycle 2 can also be operated in a cooling mode.

In cooling mode, the parallel branch 6 is basically inactive. In general, the parallel branch 6 is therefore flowed through by the refrigerant only with the flow direction shown in FIG.

The cooling mode is shown in FIG. 2. As can be seen, the flow direction of the refrigerant through the first heat exchanger 8 and the second heat exchanger 10 is now reversed, so that the first heat exchanger 8 now act as an evaporator and the second heat exchanger 10 as a capacitor. In this cooling mode, heat from the air conditioning circuit 38 is received via the first heat exchanger 8 and discharged to the ambient air via the second heat exchanger 10. In this case, the air conditioning circuit 38 is formed as a cooling circuit.

In the previously described sole waste heat heating mode with the evaporator 10 shut down, there is basically the risk due to the hydraulic connection between the two branches 4, 6 that refrigerant will be displaced into the evaporator 10. To prevent this at least for the most part, the check valve 24 is arranged in the branch line 22. This check valve 24 prevents at least largely a backflow into the evaporator 10. Even the closed first expansion valve 12 prevents such a backflow at least largely. However, due to certain leakage rates of these two valves, such backflow can not be completely prevented. In order to compensate for this undesirable refrigerant displacement in the evaporator 10 or to reverse, it is expedient to provide a suction of the refrigerant contained in the evaporator 10, which is supplied to the remaining active part of the refrigeration cycle. In this way, a total of a smaller total refrigerant and thus a smaller collector 16 may be provided, compared to a design without such suction.

The functional sequence is as follows: For suction, the parallel branch 6 is separated from the remaining refrigeration circuit 2. This is done in particular by closing the valves required for this purpose. These are the embodiment of FIG. 1, the second expansion valve 32, the control valve 34 and additionally a check valve 46 in a bypass line 48, which is used in a defrosting mode described below. The compressors 14 are still in operation, so that the desired suction and refrigerant return displacement is performed. Preferably, the first expansion valve 12 is additionally opened. Conveniently, only a limited opening degree is set. Preferably, a position with an opening degree of between 3 and 10%, based on a complete opening, is set, in particular a position with an opening degree of 5%. By this slight opening the suction from the evaporator 10 is favored. Due to the only slight opening, the inflowing refrigerant via the first expansion valve 12 is less than the extracted amount of refrigerant.

Such undesirable refrigerant displacement occurs in the case of low outside temperatures and can lead to malfunctions such as decreasing compressor refrigeration capacity or other low pressure disturbances. Such a refrigerant displacement is typically carried out when the outside temperature is lower than the refrigerant temperature in the suction line 28 of the compressor 14. Accordingly, the suction is cyclically, for example, at predefined intervals, switched on, if this condition is met. If, in a heating mode, the evaporator 10 is active, then there is generally the risk of icing of the same. This negatively affects the evaporator performance. Therefore, a defrost of the evaporator 10 is provided by means of a defrosting mode regularly.

A preferred defrost mode is shown in FIG. 3. The heat required for defrosting is taken exclusively from the waste heat circuit 36. The refrigerant flows from the waste heat evaporator 30 through the compressor 14 and the 4-way switching valve 18 through the evaporator 10 therethrough. The first expansion valve 12 is closed, so that on the consumer side, a part of the refrigeration cycle 2 is inactive. The refrigerant is recycled via the aforementioned bypass line 48 to the waste heat evaporator 30. In this case, the necessary pressure adaptation is provided by a capillary tube injection device 50, which opens into the parallel branch 6. Alternatively or in addition, the heat required for defrosting is taken from the air conditioning circuit 38.

The heat pump installation 1 described above is arranged within a building installation 52, as shown by way of example in FIG. 4. The components of the refrigeration cycle 2 are arranged inside the housing 44. The refrigeration circuit 2 is connected via the two interfaces 40,42 on the one hand with the waste heat circuit 36 and on the other hand with the air conditioning circuit 38. The air conditioning circuit 38 is used for air conditioning of building spaces 54. For this purpose, the building spaces 54 are connected via subcircuits 56 with the air conditioning circuit 38. 4, a buffer storage 58 for the heat carrier (for example water) is also shown in the air conditioning circuit 38. In the heating case, the temperature in the air conditioning circuit 38, for example, between 18 ° C minimum and 60 ° C maximum. In the case of cooling, the temperature is, for example, at a minimum of 6 ° C and a maximum of 25 ° C.

The waste heat loop 36 is generally connected to a building-internal waste heat source. In the embodiment of FIG. 4, a capacitor 60 of a further refrigeration circuit 62 is used for this purpose. This further refrigeration cycle 62 is merely indicated in FIG. 4. This additional refrigeration cycle 62 is used for cooling a cooling area 64 of the building system 52. This cooling area 64 is, for example, a preferably passable cooling room or else a further cooling system.

In general, the following application examples for building installations 52 with such an integrated heat pump installation 1 can be stated:

Supermarkets with condensation heat from refrigerated cabinets,

Administrative and office buildings with condensation heat from office cooling or even server room cooling,

Industrial manufacturing sites with manufacturing and office space, where waste heat from the production process is provided as a heat source for the waste heat cycle 36,

Spa and bathing facilities, for example, with sloshing water as the heat source for the waste heat circuit 36,

Central ventilation devices within a building system 52 with simultaneous cooling and heat requirements for air heating, dehumidification and air heating as a heat source for the waste heat cycle 36th

Commercially available refrigerants such as synthetic refrigerants designated "R134a, R404A, R417A" may be used for the refrigerant circuit 2. In addition, natural refrigerants such as propane, butane or isobutane may also be used Preferably, the synthetic refrigerant is R417A or alternatively the natural refrigerant Refrigerant R290 (propane) used.

LIST OF REFERENCE NUMBERS

1 heat tunneling plant

2 refrigeration circuit

4 main branch

6 parallel branch

8 first heat exchanger / condenser

10 second heat exchanger / evaporator

12 first expansion valve

14 compressors

16 collectors

18 4-way diverter valve

20 fans

22 branch line

24 check valve

26a first branch point

26b second branch point

28 suction line

30 waste heat evaporator

32 second expansion valve

34 control valve

36 waste heat cycle

38 air conditioning cycle

40 first interface

42 second interface

44 housing

46 check valve

48 bypass line

50 capillary tube injector

52 building complex

54 building space

56 pitch circle 58 buffer 60 further capacitor 62 further cooling circuit 64 cooling area

T0-T2 Temperature sensors P1 -P2 Pressure sensors R1 -R6 Controller

Claims

claims

1 . Heat pump system (1) for conditioning a building system (52) with a refrigeration circuit (2), which in operation via a first interface (40) to a waste heat circuit (36) for utilizing waste heat from the building system (52) and via a second interface ( 42) is connected to a consumer-side air conditioning circuit (38) for air conditioning of a building area, wherein

- The refrigeration circuit (2) has a main branch (4) in which a first consumer-side heat exchanger (8) and a second air-heated heat exchanger (10) and a throttle body (12) and at least one compressor (14) are arranged,

the first consumer-side heat exchanger (8) is used as a condenser (8) in a combined waste-heat heating mode and the second air-heated heat exchanger (10) is used as the evaporator (10),

- Connected to the first heat exchanger (8) in operation of the consumer-side air conditioning circuit (38) for the transfer of heat between the refrigeration circuit (2) and the consumer-side air conditioning circuit (38),

- The refrigeration circuit (2) has a parallel branch (6), in which parallel to the second heat exchanger (10), a third heat exchanger is integrated into the refrigeration cycle,

- The third heat exchanger in the combined waste heat heating mode is used as a waste heat evaporator (30) and the waste heat circuit (36) for transmitting heat in the refrigeration circuit (2) is connected.

2. Heat pump system (1) according to the preceding claim,

characterized,

the evaporator (10) and the waste heat evaporator (30) have different evaporation temperatures, the waste heat evaporator (30) preferably operating at a higher evaporation temperature than the evaporator (10).

3. Heat pump system (1) according to one of the preceding claims, characterized,

the thermal output of the waste heat evaporator (30) is regulated as a function of a waste heat temperature associated with the waste heat evaporator (30), in particular as a function of a return temperature of the waste heat circuit (36).

4. Heat pump system (1) according to the preceding claim,

characterized,

the power of the waste heat evaporator (30) is regulated as a function of a return temperature of the waste heat circuit (36), in particular in such a way that a minimum temperature in the waste heat circuit (36) is not undershot.

Heat pump system (1) according to one of the two preceding claims,

characterized,

the regulation of the power of the waste heat evaporator (30) is designed such that the heat transfer in the waste heat evaporator (30) adapts to a waste heat output in the waste heat circuit (36).

Heat pump system (1) according to the preceding claim,

characterized,

that a mass flow of the refrigerant flowing through the waste heat evaporator (30) is controlled to control the power.

Heat pump system (1) according to one of the preceding claims,

characterized,

that the waste heat evaporator (30) in the flow direction of the refrigerant in the combined waste heat heating mode - downstream of a control valve (34) for controlling the power downstream.

8. Heat pump system (1) according to the preceding claim,

characterized, that at a reduced waste heat performance in the waste heat circuit (36), an opening degree of the control valve (34) is reduced, whereby the pressure and thus the evaporation temperature in the waste heat evaporator (36) are raised and thus a temperature difference between the refrigerant and the waste heat cycle is reduced.

9. heat pump system (1) according to one of the two preceding claims and according to claim 3,

characterized,

in that the controlled temperature for the control valve (34) is the waste heat temperature, in particular a minimum return temperature in the waste heat circuit (36).

Heat pump system (1) according to one of claims 7 to 9,

characterized,

that as a result of a change in the opening degree of the control valve (34), there is automatically a shift in the distribution of the mass flow of the refrigerant to the waste heat evaporator (30) and to the evaporator (10).

1 1. Heat pump system (1) according to one of the preceding claims,

characterized,

that the compressor (14) is a non-performance-controlled compressor.

12. Heat pump system (1) according to one of the preceding claims,

characterized,

that the main branch (4) and the parallel branch (6) each associated with a power-controlled compressor (14) and the power-controlled compressor (14), the distribution of the mass flows of the refrigerant through the waste heat evaporator (30) and the evaporator to control the power is controlled.

13. Wärmepunnpenanlage (1) according to any one of the preceding claims,

characterized,

that the evaporator is associated with a fan (20) for generating an air flow through the evaporator, wherein the fan (20) is controlled to control the power of the evaporator (10) in dependence on the power of the waste heat evaporator (30).

14. Heat pump system (1) according to the preceding claim and according to one of claims 7 to 10,

characterized,

the fan (20) is controlled as a function of the degree of opening of the control valve (34).

15. Heat pump system (1) according to one of the preceding claims,

characterized,

that between the parallel branch (6) and the main branch (4), a check valve (24) is arranged, which avoids a backflow of refrigerant into the evaporator.

16. Heat pump system (1) according to one of the preceding claims,

characterized,

that in a sole waste heat heating mode, in which only the waste heat evaporator (30) is active and the evaporator (10) is inactive, in particular cyclically refrigerant from the evaporator (10) sucked and an active part of the refrigeration circuit (2) is supplied ,

17. Heat pump system (1) according to the preceding claim,

characterized,

that for sucking off the parallel branch (6) is switched off and at the same time the throttle body (12) is only partially opened.

18. Heat pump system (1) according to one of the preceding claims,

characterized, that heat (10) from the waste heat circuit (36) and / or from the consumer-side air conditioning circuit (38) is used in a defrost mode for the air-charged second heat exchanger, the use of the heat from the waste heat cycle (30) being prioritized and, in the case of insufficient heat Heat in the waste heat circuit (36) automatically heat from the consumer side air conditioning circuit (38) is used.

Heat pump system (1) according to one of the preceding claims,

characterized,

in that all components of the refrigeration circuit (2) are integrated in a common housing (44) which has the first and second interfaces (40, 42) via which the refrigeration circuit (2) to the waste heat circuit (36) and the consumer-side air conditioning circuit (38 ) connected .

Heat pump system (1) according to one of the preceding claims,

characterized,

in that the waste heat circuit (36) is connected to a condenser (60) of a further refrigeration circuit (62), which serves in particular for cooling a cooling area (64) of the building system (52).

Heat pump system (1) for air conditioning of a building system (52) with a refrigeration circuit (2) which is connected in operation via a first interface (40) to a heat source and via a second interface (42) to a consumer-side air conditioning circuit (38),

- The refrigeration circuit (2) has a main branch (4) in which a first consumer-side heat exchanger (8) and a second air-heated heat exchanger (10) and a throttle body (12) and a compressor (14) are arranged,

the first consumer-side heat exchanger (8) is used as a condenser (8) in a combined waste-heat heating mode and the second air-heated heat exchanger (10) is used as the evaporator (10), - Connected to the first heat exchanger (8) in operation of the consumer-side air conditioning circuit (38) for the transfer of heat between the refrigeration circuit (2) and the consumer-side air conditioning circuit (38),