REFRIGERATING SYSTEM AND REFRIGERATING MODULE

Description

[0001] The invention relates to a refrigerant system designed for indoor installation. Such a refrigerant system generally comprises a refrigeration circuit that includes two heat exchangers, namely an evaporator and a condenser, as well as a compressor and an expansion valve. A refrigerant flows through the refrigeration circuit during operation.

[0002] During the service life of refrigerant systems, refrigerant leaks can occur for a variety of reasons. In the case of refrigerant systems installed inside buildings (indoor systems), these leaks can directly affect the installation room. Depending on the installation and use of the refrigerant system, several rooms or even the entire building may be exposed to escaping refrigerant from refrigerant leaks. The escaping refrigerant usually escapes in gaseous form or, in some cases, in liquid form and then becomes gaseous. This can lead to harmful or toxic concentrations for living organisms. The decomposition of some refrigerant gases on hot surfaces can also lead to toxic decomposition products. Furthermore, the use of highly or hardly flammable refrigerants poses the risk of deflagration, explosion, or fire if flammable mixtures with ignition sources are present at the same time.

[0003] DE 10 2016 112 851 A1 describes a refrigerant system in which the refrigeration circuit is arranged within a housing in which a negative pressure is set relative to the ambient pressure. This is intended to prevent the escape of refrigerant gas into the environment.

[0004] According to DE 20 2016 103 305 U1, the refrigeration circuit is also housed in a housing containing a pressure sensor that monitors the internal pressure within the housing. An increase in pressure is identified as a leak in the refrigeration circuit, and an exhaust system draws in outside air for the interior of the housing, while the refrigerant-enriched air is exhausted outside into the surrounding area of the installation room.

[0005] DE 10 2018 113 332 A1 also provides for flushing of a housing of a refrigeration circuit, with an outlet leading into the environment outside the building.

[0006] EP 3 792 572 A1 discloses a safety flushing device for a brine-water heat pump, which has a capsule housing in which the components of the refrigeration circuit are arranged and to which an air duct leading to the outside and / or an internal outlet guided via an adsorber for refrigerant occurring in the event of a leak is attached.

[0007] FR 2 827 948 A1 also describes a heat pump with a housing to which an air duct leading to the outside is connected.

[0008] EP 3 199 883 A1 shows a heat pump with an outdoor unit installed outdoors.

[0009] EP 3 767 186 A1 shows a safety device for an outdoor unit of a heat pump, wherein the cooling circuit is arranged in the outdoor unit and the outdoor unit is connected to the building via hydraulic lines, wherein the hydraulic lines routed outdoors have shut-off valves and a vent.

[0010] Based on this, the invention is based on the object of specifying a refrigerant system which is easy to install and at the same time ensures a high level of protection against refrigerant leakage and against the accumulation of critical refrigerant concentrations in the installation room.

[0011] The object is achieved according to the invention by a refrigerant system for indoor installation with a refrigeration circuit comprising two heat exchangers, namely an evaporator and a condenser, as well as a compressor and an expansion valve, and in which a refrigerant circulates during operation. In the installed state, at least one hydraulic circuit is connected to the refrigeration circuit, in which a liquid carrier medium, in particular a liquid heat transfer medium, typically water, optionally mixed with additives, is circulated. The refrigerant system generally comprises a system housing in which at least some and preferably all components of the refrigeration circuit, as well as other components, are arranged.

[0012] The other components are hydraulic or electrical components that are required and used to operate the refrigerant system. These additional components include, for example, circulation pumps, piping, an expansion tank, valves, or even a storage unit, such as a domestic hot water tank. With regard to the electrical components, this primarily includes a system control system including an operator terminal.

[0013] Furthermore, a sealed control housing is arranged within the system housing, in which the components compressor, expansion valve, and at least one and preferably both heat exchangers of the refrigerant circuit are located. The control housing encloses a control volume, which serves to collect refrigerant that has escaped from the refrigerant circuit. A drain line for the targeted removal of gas from the control volume is also connected to the control housing. When the refrigerant system is installed, the system housing is located in an installation room. The drain line is also in fluid communication with an external area outside the installation room.

[0014] In a preferred embodiment, the drain is connected to a lower section, specifically the lower third of the control housing, and in this area provides a connection to the interior of the control housing. This is based in particular on the consideration that frequently used refrigerants are heavier than atmospheric air and therefore accumulate in the lower section in the event of a leak. The arrangement in the lower section ensures efficient refrigerant drainage.

[0015] A particular advantage of the refrigerant system is that the control housing is arranged as a separate, integral unit within the rest of the system housing, thus forming a separate sub-module of the system. This enables simplified installation, maintenance, and replacement of this separate unit.

[0016] The hermetically sealed control housing, within which the refrigeration circuit is located, also reliably prevents any refrigerant from escaping into the system's installation room. Apart from the drain, the control housing has no other openings that would allow gas exchange with the environment, including any closable openings. This means that the only flow connection is via the drain. In the event of a leak, refrigerant can collect inside the control housing. In the event of a leak, refrigerant is drained from the control housing to the outside area outside the installation room via the connected drain. The refrigerant is therefore reliably drained to a non-critical outside area. No negative pressure is created in the control housing. In particular, the drain ensures a permanently open flow connection to the outside area.

[0017] The outdoor area refers, in particular, to the area outside a building. Alternatively, the outdoor area can also be an area of the building where critical refrigerant accumulation is reliably excluded, for example, through sufficient room size or through secure room ventilation. Overall, this reliably prevents critical refrigerant accumulation in the installation room. Therefore, active ventilation in the installation area of the refrigerant system is also omitted, thus minimizing installation effort.

[0018] The control enclosure creates an explosion-proof area, particularly because there are no effective ignition sources within the enclosure.

[0019] If reference is made here to a refrigerant system, this is generally understood to mean a system in which heat is transported from a heat source to a heat sink by means of a refrigeration circuit, absorbing energy. The refrigerant system is preferably a heat pump system in which heat is provided on a consumer side. Alternatively, it can be a refrigeration system in which cold is provided on the consumer side. Connected to the refrigeration circuit is at least one (first) hydraulic circuit, which is designed as a consumer circuit and in which a carrier medium - depending on the system type, a heat transfer medium or a coolant medium - circulates and supplies at least one consumer with heat (heat sink) or cold (cold sink or heat source for the refrigeration circuit).

[0020] Depending on the system type, a second hydraulic circuit is connected to the installed refrigeration circuit. This can be a water circuit (in a water / water refrigerant system) or a brine circuit. Without loss of generality, both variants will be referred to below as a brine circuit and a brine / water refrigerant system. This second hydraulic circuit is connected to the second heat exchanger, or to the evaporator in the case of a heat pump.

[0021] The second heat exchanger, in one variant, is an air / refrigerant heat exchanger, designed for heat transfer with moist air. Such systems are also referred to below as air / water refrigerant systems.

[0022] Preferably, some of the components of the at least one hydraulic circuit, such as pumps and valves, are already arranged within the system housing. The system housing generally has an interface to which the remaining components of the at least one hydraulic circuit can be connected, specifically piping and at least one consumer. This means that the system housing is a preassembled unit that only needs to be connected to piping, for example, of the consumer circuit.

[0023] When configured as an air / water refrigerant system, in which one of the two heat exchangers is designed as an air / refrigerant heat exchanger, this heat exchanger is preferably arranged within an air duct. In a preferred embodiment, the discharge line opens into this air duct. Since the air duct is usually connected to the outside, specifically to the environment outside the building, this measure ensures a reliable flow connection to the outside with minimal installation effort.

[0024] With regard to reliable discharge of refrigerant in the event of a leak, a preferred embodiment provides for a permanently open flow connection to the outside area via the discharge line. In the event of a leak, refrigerant can therefore automatically flow into the outside area via the discharge line. The discharge line is therefore specifically a passive safety device which reliably discharges the gases independently of any other active measures, such as measuring the concentration of the refrigerant. This achieves a high level of passive system safety. The discharge line is, for example, an open pipe connection. In particular, in a preferred embodiment, the discharge line is free of any built-in components such as flaps or valves. Preferably, no fan is arranged in the discharge line either.

[0025] In a preferred embodiment, the control housing is further provided with no air intake opening. Therefore, apart from the exhaust, there is no possibility of gas exchange with the environment. Therefore, targeted ventilation of the control housing is not possible and is not provided for in the system.

[0026] The at least one heat exchanger is connected to the at least one hydraulic circuit via a connecting line running within the control housing. A gas separator is attached to the connecting line, which is provided for the direct degassing of the fluid carried in the hydraulic circuit into the control housing. This measure enables direct degassing with the aid of the gas separator without the need for an additional degassing line. The gas separator is a conventional gas separator or microbubble separator known per se.

[0027] Fundamentally, there are different types of leaks. On the one hand, continuous, minor leaks, for example in heat exchangers, can lead to the accumulation of refrigerant in the connected hydraulic circuits. These typically contain devices for separating gas components from the liquid carrier medium, so-called gas separators.

[0028] In many systems, a so-called buffer tank is often integrated into the hydraulic circuit. Such a buffer tank is, for example, equipped with a gas separation device so that separated gas can escape, or the buffer tank is designed entirely as a gas separator. The buffer tank is preferably designed as described in EP 4 047 275 A1. In the event of refrigerant overflowing into the hydraulic circuit, refrigerant is therefore discharged via the buffer tank.

[0029] Typically, the hydraulic circuit also includes at least one safety valve, which opens to relieve pressure, particularly in the event of overpressure, allowing the carrier medium flowing in the hydraulic circuit to escape. The safety valve opens particularly in the event of a refrigerant leak, when refrigerant enters the hydraulic circuit. Such a leak leads, for example, to a significant increase in the flow rate and / or system pressure in the hydraulic circuit.

[0030] Preferably, a vent line is connected to a respective device such as a gas separator, buffer tank, or safety valve and is used for the controlled removal of gas components, which may in particular also be refrigerant components, contained in the carrier medium of the hydraulic circuit. In particular, these gas components are led at least indirectly to the outside area via the vent line.

[0031] According to a first variant, such a vent line is routed into the control room. This directs the gas components contained in the hydraulic circuit's carrier medium into the control housing, where they are detected, for example, by a leak detection device. This not only enables direct monitoring of the refrigeration circuit within the control housing, but also allows for overall monitoring of the system, including the hydraulic circuits.

[0032] In an alternative, preferred embodiment, the vent line of the safety valve and / or the buffer tank preferably ends outside the control housing. The vent line preferably opens at least indirectly into the outside area. This prevents the control housing from flooding with refrigerant, in contrast to the previously described embodiment, in which the vent line opens into the control housing. For example, the vent line is routed directly to the outside, ensuring that the gas components are reliably discharged.

[0033] In an air / water refrigerant system and the previously described preferred arrangement of the air / refrigerant heat exchanger in the air duct, the respective vent line preferably opens into this air duct. This ensures that, in the event of a refrigerant leak, the refrigerant is diverted directly through the air duct and from there to the outside.

[0034] In a preferred embodiment, a blocking device, in particular a blocking or sealing flap, is arranged in the hydraulic circuit, which blocks the hydraulic circuit in the event of an increase in pressure and / or an increase in the volume flow above a predetermined limit, in particular in such a way that the circuit is no longer in flow connection with the at least one heat exchanger. The blocking device therefore closes a corresponding hydraulic line as soon as the pressure and / or the volume flow exceeds the defined limit, so that the carrier medium flowing in the hydraulic line during normal operation (e.g. water in a consumer circuit; brine in the brine circuit) no longer circulates. This initially prevents further refrigerant from entering the hydraulic circuit, e.g. via a leak in the heat exchanger.

[0035] Therefore, a heat source / heat sink section of the hydraulic circuit is essentially separated from a refrigeration circuit section and the heat exchanger located there. For this purpose, in addition to the blocking device, a non-return device, specifically a check valve or non-return barrier, is preferably provided.

[0036] A safety valve and / or a gas separator are preferably also located in the refrigeration circuit section. These devices can then reliably remove any refrigerant present. For this purpose, the previously described measures, such as arranging the gas separators within the control housing and / or discharging them via the vent line, are preferably provided.

[0037] The blocking device is preferably a passive blocking element that automatically blocks the hydraulic circuit when the limit value is exceeded and preferably also releases it again when the limit value is undershot. Specifically, the blocking device is a spring-loaded sealing element, such as a sealing valve or sealing flap. The (defined) spring force keeps the sealing element open up to a defined limit value for the pressure or volume flow. The spring force is preferably adjustable. When the limit value is exceeded, the sealing element is pushed into a closed position, which it preferably releases again automatically when the limit value is again undershot.

[0038] This design is based on the consideration that if refrigerant enters the hydraulic circuit, this leads to a displacement of the carrier medium and thus to a higher flow velocity / higher pressure.

[0039] The previously described embodiment variant with the locking device and the automatic hydraulic decoupling of part of the hydraulic circuit, particularly in combination with the arrangement of the safety valve in the refrigeration circuit-side sub-area, is considered an independent invention, even independent of the design with the sealed control housing and the drain. The right to file a divisional application on this aspect remains reserved, i.e., on a refrigerant system with the features of claim 1 without the features of the sealed control housing and the drain, but with the features of claim 7. In preferred developments, such an independent claim is followed by subclaim 8 and / or the previously described special arrangement of the safety valve with a vent line to the outside area.Furthermore, the further dependent claims 2-6 and 9-14 are analogous to such a new claim, in particular also in conjunction with the further advantageous additions and extensions as listed in the description.

[0040] In a preferred embodiment, the downstream line comprises an inner section and an outer section. The inner section is connected to the control housing and leads to an interface on the system housing. The outer section, in turn, is connected to the inner section at this interface, meaning that the two sections of the downstream line can be coupled together.

[0041] This preferably also applies to other components connected to the refrigeration circuit. This applies, for example, to the at least one hydraulic circuit. At least one connecting line is provided for its connection, which is connected on the one hand to the control housing, more precisely to one of the heat exchangers, and on the other hand also leads to the interface on the system housing. Therefore, the hydraulic circuit, or at least parts of it that are not located within the system housing, can be reversibly connected to this interface, for example via appropriate screw connections.

[0042] In case a second hydraulic circuit is provided, another connecting line is routed between the control housing and the interface.

[0043] Preferably, coupling elements are also attached to the control housing for reversibly connecting the control housing and the components located therein, in particular to the inner section of the downstream line and the at least one connecting line. These connecting elements, such as the inner section or the at least one connecting line leading to the interface on the system housing, are therefore designed as connecting pieces between two interfaces, namely, on the one hand, an interface to the control housing and, on the other hand, an interface to the outside of the system housing.

[0044] In addition, coupling elements are preferably provided for reversibly connecting the components arranged inside the control housing to the other components outside the control housing. This may also be an electrical coupling element, for example, via which, for example, a power supply or control of at least one of the components, such as the compressor, is carried out. The coupling element is, in particular, a plug-in connector.

[0045] This measure allows for easy installation of the entire control housing within the system. Specifically, the control housing is replaceable, meaning it can be removed from the system housing as a single unit, along with the components it contains. For this purpose, the control housing is preferably mounted on rails or a support, particularly in a vibration-isolated manner from the rest of the system housing.

[0046] Preferably, the control housing is divided and can be opened. This allows access to the internal components. The at least two, and preferably exactly two, housing shells have a suitable sealing arrangement at their separation point, for example, a sealing element or a suitable wall design, for example, according to the tongue-and-groove principle.

[0047] The system housing is preferably designed as a modular cabinet with multiple housing areas, with different functional modules arranged in the different housing areas. The housing areas for the different functional modules are designed, for example, as independent housing modules. The control housing, in turn, is preferably arranged within a refrigerant module, which forms one of the functional modules and which is arranged in a closed housing area, preferably in its own module housing. The refrigerant module, together with at least one further functional module and its further housing area / module housing, forms the modular cabinet. A storage module with a domestic hot water storage tank is preferably provided as an additional functional module. The refrigerant module and the further functional module are preferably arranged one on top of the other.

[0048] The refrigerant system described here is specifically designed as a heat pump system for buildings, i.e., for providing heat for a building. The heat pump system is specifically designed for heating residential buildings, such as single-family or multi-family homes. The heat pump system has a maximum heating output of up to 10 kW or up to 20 kW, for example.

[0049] In addition to the measures described above, which enable the simplest and most practical installation of such a refrigerant system with a high degree of security against critical refrigerant accumulation in the event of a refrigerant leak, further specific measures are described below that are used to improve the control and monitoring of the system with regard to refrigerant leaks: According to a preferred embodiment, a fan is arranged in the discharge line. This fan makes it possible to actively and selectively discharge refrigerant from the control housing. In principle, the passive and permanently open flow connection via the discharge line is preferably maintained.For this purpose, the fan is preferably designed and configured in such a way that it does not close the discharge line, or at least does not completely close it, so that an open flow connection exists via the fan, even when the fan is not actively operated. In particular, it is intended that the fan can rotate freely even when switched off. This ensures that in the event of a leak, i.e., when increased pressure occurs in the control housing, the gas continues to flow passively via the discharge line. Due to the increased pressure in the control housing, the gas can escape via the discharge line and also past the fan, which merely represents a certain flow resistance but does not act as a flow barrier.

[0050] At the same time, the fan offers the possibility of ensuring that the refrigerant is discharged in a targeted and active manner when necessary and is also controlled accordingly if required.

[0051] Preferably, a device for detecting a leak in the refrigeration circuit is also provided, which device comprises an evaluation unit. The device serves, for example, for the indirect or direct detection of a leak. Preferably, the evaluation unit is also used to determine the extent of the leak and thus the extent of refrigerant leakage and thus the leak rate. Furthermore, countermeasures are initiated with the aid of the evaluation unit, preferably different countermeasures depending on the extent of the refrigerant leakage.

[0052] The evaluation unit is generally designed to monitor the refrigerant system for refrigerant leaks and initiate appropriate safety measures if necessary. The evaluation unit is therefore designed to perform the monitoring and control measures described below.

[0053] Specifically, depending on the detection of a leak, for example, based on the measurement signal from a leak detector or a gas sensor in the control volume, or based on the evaluation of fan parameters, a safety measure is initiated, such as a targeted control of the fan, for example, switching it on or increasing its speed. As a safety measure, depending on the extent of the leak, a safety shutdown of the refrigerant system is also carried out. Depending on the identified leak rate, different measures are therefore taken, ranging from warning messages and / or fan control to an automatic safety shutdown.

[0054] In a preferred embodiment, the evaluation unit is configured to determine whether there is a leak within the refrigeration circuit based on at least one characteristic value of the fan. In this embodiment, the fan, along with suitable sensors, forms the leak detection device.

[0055] This is based on the consideration that in the event of a leak, the flow and pressure conditions within the discharge line and within the control housing change characteristically, and these changes also lead to characteristic changes in the operating parameters of the fan, which are evaluated.

[0056] Preferably, at least one of the following characteristic values is used and evaluated: According to a first embodiment, the fan characteristic curve or at least a current operating point of the fan is evaluated. In this case, the fan characteristic curve refers to the differential pressure curve between a suction side and a pressure side of the fan relative to the conveyed volume flow or relative to the fan speed. The operating point is a specific point on the fan characteristic curve, for example, a defined assignment of a specified volume flow to the differential pressure.

[0057] This analysis is based on the consideration that, due to the hermetic seal of the control housing, the fan characteristic curve varies in steepness depending on the presence of a leak. If there is no leak and therefore no gas is escaping into the control volume, the fan characteristic curve is very steep. Conversely, the fan characteristic curve becomes increasingly flatter as the leak rate increases. Therefore, the current fan characteristic curve or the current operating point can be used to reliably determine whether a leak is present. Preferably, the fan characteristic curve and the operating point are also used to determine the leak rate, so that appropriate countermeasures can be initiated.

[0058] According to an alternative variant, or even in addition, the fan speed is evaluated, especially when the fan is not actively operating. This is fundamentally based on the idea that a refrigerant leak leads to an increase in pressure in the control housing, so that the gas automatically flows out via the discharge line and thus essentially drives the fan. An increase in speed is therefore an indication of a leak, especially an increase in the leak rate. This, too, can be used to draw conclusions about the leak rate.

[0059] Other parameters of the fan that are evaluated are, alternatively or additionally, its electrical current or power consumption as well as vibration values.

[0060] It is generally preferred to use the determined characteristics of the fan to determine the degree of leakage and thus the leakage rate.

[0061] Alternatively or additionally, a gas sensor, in particular a CO2 sensor or alternatively an N2 or O2 sensor, is provided as a device for detecting a leak. In principle, a gas sensor can also be provided which directly detects the refrigerant gas. This gas sensor serves to directly, or at least largely directly, determine whether refrigerant is present in the control volume and, in particular, what the proportion of refrigerant is. The use of a CO2 sensor, or a sensor which measures another component (O2, N2) of the atmosphere, is based on the consideration that in the event of a refrigerant leak, the natural CO2 content (O2, N2 content) is reduced. This reduction then indicates a leak.

[0062] Alternatively or in addition to a gas sensor, a pressure sensor is provided which measures an increase in pressure within the control housing due to a leak.

[0063] Active monitoring is particularly advantageous overall for initiating appropriate countermeasures, i.e., for monitoring the system. Since even non-critical components in the hydraulic circuits can outgas during system operation, thus not leading to critical accumulations of, for example, explosive mixtures, this variant, with the vent line routed into the control housing, is preferably combined with an additional monitoring measure, particularly monitoring using a gas sensor.

[0064] In a preferred embodiment, a leak detector is arranged on the at least one connected hydraulic circuit, which is connected to the evaluation unit. In this case, the evaluation unit receives an (electrical) sensor signal and can consider this for assessing the hazard potential and initiating safety measures.

[0065] According to a first embodiment, a volume flow sensor and / or, according to a second embodiment, a pressure sensor are arranged as the leak detector. The evaluation unit then evaluates the sensor signal of the leak detector with regard to the presence of refrigerant in the carrier medium. In particular, characteristic signal fluctuations are evaluated as an indication of the presence of refrigerant.

[0066] The volume flow sensor is designed, for example, as an ultrasonic sensor, but can also be a vane sensor or based on the Karman vortex street principle. The evaluation of these sensor signals is generally based on the assumption that if refrigerant is present in the liquid carrier medium, the refrigerant is in gaseous form, meaning that gas bubbles are present within the carrier medium. Such gas bubbles lead to characteristic signal variations in both the volume flow sensor and the pressure sensor, which are evaluated by the evaluation unit and used to assess the hazard situation.

[0067] In a preferred embodiment, the refrigerant system has a refrigeration module. The refrigerant module comprises the control housing and the other components connected to the control housing, namely in particular the inner section of the discharge line, the at least one connecting line for connecting the hydraulic circuit, and preferably further hydraulic or electrical components, such as a circulation pump, valves, a control unit, an operating terminal, etc. Components of the at least one hydraulic circuit are preferably already integrated in the refrigerant module. The refrigerant module preferably also has its own module housing, which therefore has the interfaces to which the at least one hydraulic circuit, at least some of its components, especially the consumer, can be connected via the interface.

[0068] Embodiments of the invention are explained in more detail below with reference to the figures, which show, in simplified representations: FIG 1a refrigerant system designed as a heat pump system with a system cabinet as the system housing before the final installation and before the actual installation in an installation room, FIG 2a representation of a refrigerant module with a control housing, which is used in the representation of the Figure 2 is open, FIG 3 a highly simplified representation of a residential building to illustrate the installation of the system housing with a discharge line, FIG 4 a circuit diagram for an air / water heat pump system, FIG 5 a circuit diagram for a brine / water heat pump system, FIG 6 a representation of different fan characteristic curves, FIG 7 a representation of a signal curve of a volume flow sensor and FIG 8 a simplified representation of the curve of a sensor signal of a pressure sensor.

[0069] In the figures, parts with the same function are provided with the same reference symbols.

[0070] One in the Figure 1 A refrigerant system designed as a heat pump system 2 has a system housing 4 designed as a system cabinet. The heat pump system 2 is modular in design and in the exemplary embodiment has two modules, namely a cooling module 6 and a storage module 8. Each of the modules 6, 8 is arranged in its own housing part, in particular in its own module housing. The two module housings are stacked one above the other and form the system housing 4. A storage tank, specifically a domestic hot water tank 10, is arranged in the storage module 8. In the cooling module 6, as it is shown again in a unique position in Figure 2 As shown, a refrigeration circuit 12 is arranged within a control housing 14. This has two housing shells. Figure 2The control housing 14 is open, and only one of the housing shells is shown. In addition, further components are arranged in the cooling module 6, as explained below.

[0071] The control housing 14 is a hermetically sealed housing into which no ambient air can enter. In the exemplary embodiment, the control housing 14 is a two-part housing that can generally be opened, for example, for inspection purposes.

[0072] A discharge line 16, specifically an inner section 16A, is connected to the control housing 14 and is preferably connected in a reversibly removable manner. The term inner section 16A is generally understood to mean a section of the discharge line 16 running within the system housing 4. In some embodiments (compare, for example, the embodiment according to the following description), Figure 4), the inner section 16A forms the entire discharge line. The discharge line 16 is preferably connected to the control housing 14 in a lower section, specifically in the lower third. It generally represents a flow connection to the interior volume of the control housing 14. The discharge line 16 serves to discharge refrigerant in the event of a refrigerant leak.

[0073] In the exemplary embodiment, the control housing 14 is arranged within a separate module housing 18. It is preferably arranged on a separate support 19 and, above this, on a base of the module housing 18, and is arranged in a vibration-decoupled manner. The control housing 14 is preferably made of a plastic, especially a foamed plastic.

[0074] Preferably, at least one connecting line 20 is also connected to the control housing 14, in particular one that is again reversibly removable. The connecting line 20 is connected to a heat exchanger, specifically a condenser, arranged in the control housing 14. If two hydraulic circuits are connected to the refrigeration circuit 12, two connecting lines 20 are arranged. Preferably, an electrical connection, specifically a detachable plug connection, is also provided on the control housing, via which control signals or an electrical power supply for the components arranged within the control housing 14 are provided.

[0075] Both the connecting line 20 and the inner section 16A are led to an interface 22. In the exemplary embodiment, the connecting line 20 and the inner section 16A are arranged on the rear side of the control housing 14 and are led from there to the interface 22. In the exemplary embodiment, this is formed on an upper side of the system housing 4 and specifically of the module housing 18. Via the interface 22, in particular, hydraulic couplings for connecting to further components of hydraulic circuits 64, 66 (cf. Figures 4 , 5 ). Furthermore, a connection is provided as interface 22, via which the inner section 16A can be connected.

[0076] Within the cooling module 6, outside the control housing 14, additional hydraulic and electrical components are arranged. These include, for example, pumps, piping elements, valves if required, and, with regard to the electrical components, in particular a control unit for controlling the heat pump system. Furthermore, an operating element for inputting and operating the control unit is preferably provided.

[0077] Based on the Figure 3 A preferred, exemplary installation of such a heat pump system 2 within a building 24 is shown. The heat pump system 2, specifically the system housing 4 with the components located therein, is arranged within an installation room 26. The discharge line 16 is led into an outdoor area 28, in this case the environment outside the building 24.

[0078] The Figures 4 and 5 show different variants of a heat pump system, whereby the Figure 4For example, an air / water heat pump system 2 and the Figure 5 a brine / water heat pump system 2. The Figures 1 to 5 The reference symbols shown indicate the following components: 2Heat pump system 4System housing 6Cooling module 8Storage module 10Domestic hot water tank 12Refrigeration circuit (if applicable)reversible) 14Control housing (control volume) 16Discharge line (outlet duct) 16AInternal section of the discharge line 16BExternal section of the discharge line 18Module housing 19Support 20Connecting line 22Interface 24Building 28Outdoor area 30Fan / extractor fan (optional) 32Sensors Fan characteristics 34Gas sensor 36Vent line 38Volume flow sensor 40Gas separator / microbubble separator 42Check valve ) 44Pressure sensor 46Circulation pump 48Safety valve 50Expansion vessel 52Consumer (heat consumer heating mode / cold consumer cooling mode) 54Heat source / heat sink 58Buffer storage tank, especially as part of a double differential pressureless distributor 60Air / refrigerant heat exchanger with primary fan 62Air duct 64Consumer circuit 66Brine circuit 68Condenser 70Evaporator 72Coupling element 74Control unit 76Evaluation unit 78Locking device 84Connecting lines 86Duct section .

[0079] In the exemplary embodiments, the refrigeration circuit 12 comprises a compressor, the condenser 68, an expansion valve and the evaporator 70. The components are piped together and a refrigerant is guided in the refrigeration circuit 12. Several of the components, in the exemplary embodiment the Figure 5 all and in the embodiment of the Figure 4 all except the evaporator 70, are arranged within the control housing 14, which leads to the installation room 26 of the system housing 4 ( Figure 3 ) is sealed gas-tight. It is only connected to the outside area 28 via the permanently open discharge line 16.

[0080] Both the brine / water heat pump system 2 according to Figure 5 as well as the air / water heat pump system 2 according to Figure 4a consumer circuit 64 with a consumer 52 is connected to one of the two heat exchangers on the refrigeration circuit 12, namely the condenser 68. The buffer storage 58 is also integrated in the consumer circuit 64. Such a buffer storage 58 is generally known and is typically arranged in series between the refrigeration circuit 12 and the consumer 52. During operation, it is completely or almost completely filled with the carrier medium circulating in the consumer circuit 64, and this medium also flows through it. Typically, no heat exchangers are arranged in the buffer storage 58. Such buffer storages 58 generally have a volume that depends on the intended use and the system output. The volume is typically at least 50 dm 3< , or at least 100 dm 3< or at least several hundred dm 3< and sometimes even more than 1000 dm 3< .Typically, the buffer storage tank 58 has a volume, for example, in the range of 10-50 dm³ / kW and in particular in the range of 20-40 dm³ / kW of the maximum heating output of the heat pump system 2 (maximum rated output of the heat pump system 2). The buffer storage tank 58 is usually a cylindrical pressure vessel with a typically dome-shaped base and lid.

[0081] Furthermore, in the embodiments of the Figures 4 and 5 A passive blocking device 78, specifically in the form of a flap, is integrated in the consumer circuit 64. In particular, this is located directly on the outlet side (cooling water / hot water) of the heat exchanger 68 (condenser). In the variant according to Figure 5Preferably, such a blocking device 78 is also provided in the brine circuit 66. This is also arranged on the outlet side (outlet to the heat source / heat sink) of the other heat exchanger 70 (evaporator).

[0082] In the exemplary embodiments, the blocking device 78 is effective in the direction of flow of the respective carrier medium in the respective hydraulic circuit 64, 66 and closes automatically when a predetermined limit value is exceeded, for example, a predetermined flow velocity and / or a predetermined volume flow and / or a predetermined pressure of the carrier medium. In the exemplary embodiment, the blocking device 78 in the consumer circuit 64 is arranged between the control housing 14 and the buffer reservoir 58 or the consumer 52.

[0083] Furthermore, a check valve 42 is arranged in the respective hydraulic circuit 64, 66 downstream of the heat sink (e.g., consumer 52) or downstream of the heat source (e.g., 54) in the flow direction. The blocking device 78 and the check valve 42 allow a heat sink-side / heat source-side section of the respective hydraulic circuit 64, 66 to be hydraulically separated from a refrigeration-side section of the respective hydraulic circuit 64, 66. This occurs automatically when the blocking device 78 closes when the limit value is exceeded.

[0084] In a preferred variant not shown in detail here, the blocking device 78 is connected via a fluid line, e.g., a capillary tube, to the hydraulic line in the area of the check valve 42, specifically on the side of the check valve 42 facing away from the refrigeration circuit and thus the heat exchanger. The pressure level of the carrier medium in the hydraulic circuit acts at this point. This (pressure) information is preferably applied to the blocking device 78. Specifically, this pressure acts on the blocking device 78 in the opening direction.

[0085] In the example of Figure 5, which shows a brine-to-water heat pump system 2, a second hydraulic circuit, namely a brine circuit 66, is connected to the other heat exchanger, namely the evaporator 70. The hydraulic circuits 64, 66 are each connected to the control housing 14 by means of a coupling element 72, so that a corresponding piping can be connected to the control housing 14. As can also be seen, some essential components of the hydraulic circuits 64, 66 are already connected within the system housing 4. Thus, on the one hand, part of the piping is arranged within the system housing 4, specifically the connecting line 20 is arranged within the system housing 4, which leads to the interface 22. In the illustrated embodiments, outside the system housing 4, there is also external piping, the (optional) buffer tank 58 and the at least one consumer 52, as well as in the variant according to Figure 5the heat source / heat sink 54 is connected, if necessary, with additional components such as valves, pumps, etc. In the variant according to Figure 4 On the system housing, four duct sections 86, namely an intake line and an exhaust line, are connected to air duct 62.

[0086] In the Figure 4 The air-to-water heat pump system 2 shown includes an air duct 62, within which a structural unit 60 consisting of an air / refrigerant heat exchanger (evaporator 70) with a fan is arranged. The air duct 62, in turn, is connected via interfaces 22 to the intake line for outside air and to the exhaust air outlet line, which typically pass through a building wall and extend into the outside area 28. It should be emphasized that the air duct 62 runs within the system housing 4 and is connected via the interfaces 22 to the duct sections 86 leading into the outside area 28.

[0087] Within the system housing 4 there is also a Figures 4 and 5 A control unit 74, shown only in simplified form, is arranged, via which the operation of the heat pump system 2 is controlled. In the exemplary embodiment, this also contains an evaluation unit 76, which is designed to monitor and control the system for refrigerant leaks and to initiate safety measures. For this purpose, the heat pump system 2 has one or more devices for detecting refrigerant leaks.

[0088] In general, it is provided that the discharge line 16, more precisely the inner section 16A, is connected to the control housing 14, preferably via a coupling element 72.

[0089] Within the control housing 14, connecting lines 84 run, which are connected on the one hand to the at least one heat exchanger (condenser 68 and in the embodiment of the Figure 5(also evaporator 70) are connected and lead to the respective coupling element 72, via which the connection to the connecting line 20 is made. The connecting lines 84 are therefore each part of the respective hydraulic circuit (consumer circuit 64 / brine circuit 66). Within the module housing 14, a gas separator 40, for example a microbubble separator, is now attached to a respective hydraulic circuit, specifically to a respective connecting line 84. The particular advantage of this arrangement is that, if necessary, the carrier medium of the hydraulic circuit 64, 66 can be degassed directly into the interior of the control housing 14 via the gas separator 40, and the gas can escape into the outer area 28 via the discharge line 16.

[0090] In both variants, a preferred embodiment provides that no further degassing or venting lines 36 terminate in the control housing 14. Additional venting lines 36, which are connected, for example, to the buffer tank 58 or to a safety valve 48, lead past the control housing 14 at least indirectly into the outer area 28.

[0091] In the example of Figure 4 A total of two vent lines 36, namely one from the buffer tank 58 and one from a safety valve 48, lead into the air duct 62 and open there. In the variant of the Figure 4 the safety valve 48 with the connected vent line 36 is arranged in the refrigeration circuit side section of the consumer circuit 64.

[0092] If - as described above - for example in the event of a refrigerant leak, the consumer-side section is hydraulically separated by closing the blocking device 78, gas and possibly also part of the carrier medium can escape via the safety valve 48 and the connected vent line 36.

[0093] Such a safety valve 48 with connected vent line 36 is, preferably also (deviating from the illustration according to Figure 5 ) in the version of the Figure 5 provided. In this case, the vent line 36 is routed into the outdoor area 28. The vent line 36 connected to the buffer tank 58 is also routed into the outdoor area 28. In the exemplary embodiment, it is connected to the discharge line 16.

[0094] Generally, regardless of the specific design variant, in a preferred embodiment, one or more such vent lines 36 are connected to the discharge line 16. This requires only one passage through the building wall.

[0095] In an (optional) design variant with a fan 30, a fan 30 is arranged within the inner section 16A. A sensor system 32 is assigned to this fan for monitoring and evaluating the characteristics of the fan 30 as well as its fan characteristics and / or the fan characteristic curve. The fan 30 and the sensor system 32 are in the Figure 5 shown as an example. The same applies to the version of the Figure 4Such a fan 30 may be arranged in the discharge line 16, more precisely in the inner section 16A. In alternative embodiments, such a fan is omitted and only an open pipe connection is provided as the discharge line 16 without any internal components.

[0096] Specifically, the sensor system 32 includes pressure sensors, which measure the suction-side pressure and the pressure-side pressure, or at least the differential pressure between the suction side and the pressure side, of the fan 30. Furthermore, the sensor system 32 can, if necessary, measure the speed of the fan 30, the power consumption, or the electrical current consumption of the fan 30. A vibration sensor can also be provided to detect vibrations. Based on the fan characteristics, specifically the fan characteristic curve or operating points, a conclusion can then be drawn about a refrigerant leak, for example.

[0097] Furthermore, a gas sensor 34, specifically a CO2 sensor, is (optionally) arranged within the control housing 14. This sensor at least indirectly measures the refrigerant concentration within the control housing 14, for example, by measuring the CO2 content. In a preferred embodiment, however, such a gas sensor 34 is omitted.

[0098] Furthermore, volume flow sensors 38 and pressure sensors 44 are shown as examples, which can be used to detect whether refrigerant is present in the hydraulic circuits 64, 66. The sensor signals of the respective volume flow sensor 38 and / or pressure sensor 44 are transmitted to the evaluation unit 76 and evaluated there.

[0099] The evaluation of the fan characteristics is based on the Figure 6illustrated. This shows a qualitative progression of the operating points of the fan 30 as a function of the extent of leakage: It shows various fan characteristic curves A, B, C in which the differential pressure Δp (head h) is plotted against the volume flow V / h. Characteristic curve A characterises a condition in which there is no leakage and in which the refrigerant system is sealed against the environment. In this condition, the characteristic curve is very steep. Characteristic curve B characterises a condition in which there is a low leakage rate and characteristic curve C characterises a condition with a high leakage rate. The characteristic curves become increasingly flatter, so that each characteristic curve is characteristic not only of a leak but also of the leakage rate.

[0100] For the evaluation, it is sufficient to record the respective operating points 1, 2, and 3 at a respective current volume flow. This can be derived from the current speed of fan 30. This means that, based on the current speed and knowing the differential pressure Δp, an operating point can be clearly assigned, and from this, a leak rate can be deduced.

[0101] Alternatively or in addition to this analysis, the speed of fan 30 is used, especially when the specified speed remains unchanged and especially in the case of large leaks. For example, fan 30 may be switched off (speed equal to zero) or may be rotating at a low speed and thus only conveying a low volume flow V / h. In the event of a leak, especially a large leak or an abrupt leak, for example in the case of a pipe burst, significant pressure increases typically occur. The leakage mass flow, i.e. the leakage rate (refrigerant mass per unit time) of the escaping refrigerant, can reach up to 100 g / s. This pressure increase causes the speed to be automatically increased. Such a change in speed is evaluated, and the leak rate is determined.

[0102] Finally, alternatively or additionally, a change in the electrical current / power consumption is evaluated, especially when the specified speed remains unchanged. Due to a pressure increase in the event of a leak, the required power and thus the electrical current / power consumption change, with the specified speed remaining otherwise unchanged. In particular, the electrical current consumption decreases because the fan is driven automatically.

[0103] The course of a sensor signal S of the volume flow sensor 38 (volume flow signal) against time t is shown in the Figure 7 illustrated. Figure 7shows the qualitative curve of the sensor signal S over time t as a function of the presence of gas bubbles in the carrier medium. If gas bubbles occur within the hydraulic circuit 64, 66, this leads to a characteristic signal curve. In particular, the usually constant signal curve S, which is present when no gas bubbles are present in the carrier medium, changes, and an unstable zone with strong signal fluctuations occurs when gas bubbles are present in the carrier medium. Figure 7A dashed tolerance range is also shown, which is significantly exceeded in the case of gas bubbles. Based on these signal fluctuations, the proportion of gas bubbles within the carrier medium can be determined. Especially when combined with the gas sensor 34, a statement can then be made about the refrigerant content within the hydraulic circuits 64, 66. However, it is preferable to dispense with an additional gas sensor 34 for detecting escaping gas, specifically for detecting refrigerant. This has the advantage of saving costs for, for example, refrigerant-sensitive sensors.

[0104] The situation is similar with the evaluation of the sensor signal S of the pressure sensor 44, which is shown as an example in the Figure 8 is illustrated. Figure 8shows a qualitative curve of an operating point in the hydraulic circuit 64, 66 over time t. Here, too, gas components within the carrier medium lead to characteristic signal fluctuations, which in turn exceed a tolerance threshold shown in dashed lines of an otherwise largely constant signal S. These evaluations are also combined, for example, with an evaluation of the signal from the gas sensor 34.

[0105] The invention is not limited to the exemplary embodiment described above. Rather, other variants of the invention can also be derived therefrom by those skilled in the art without departing from the scope of the invention. In particular, all individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the scope of the invention.

Claims

1. Refrigerant system with - a refrigerating circuit (12), which has two heat exchangers, to be specific an evaporator (70) and a condenser (68), and also a compressor as well as an expansion valve and in which a refrigerant circulates during operation, wherein at least one hydraulic circuit (64, 66), in which a carrier medium is circulated during operation, is connected to the refrigerating circuit (12) in the installed state, - a system housing (4), which in the installed state is installed in an installation room (26) and in which at least a number of components of the refrigerating circuit (12) and further components, such as hydraulic or electrical components, are arranged, wherein a sealed control housing (14), in which the components comprising the compressor, the expansion valve and at least one of the heat exchangers of the refrigerating circuit (12) are arranged, is arranged inside the system housing (4), and wherein a discharge line (16), which is intended for discharging gas from the control housing (14) and is in flow connection with an external area (28) outside the installation room (26), is connected to the control housing (14), wherein the at least one heat exchanger is connected via a connection line (84), running inside the control housing (14), in the installed state to the at least one hydraulic circuit (64, 66), wherein a gas separator (40), which is intended for the direct degassing of a carrier medium conducted in the hydraulic circuit (64, 66) into the control housing (14), is attached to the connection line (84).

2. Refrigerant system according to the preceding claim, characterized in that one of the two heat exchangers is designed as an air / refrigerant heat exchanger and is arranged in an air duct (62), wherein the discharge line (16) opens out into the air duct (62), wherein the air duct (62) runs in particular inside the system housing (4) and is preferably connected via interfaces (22) to duct sections (86) leading to the external area (28).

3. Refrigerant system according to the preceding claim, characterized in that the discharge line (16) provides a permanently open flow connection to the external area (28), so that escaping refrigerant can automatically flow into the external area (28), wherein the open flow connection is preferably free from internal fittings.

4. Refrigerant system according to one of the preceding claims, characterized in that the control housing (14) has no supply-air opening.

5. Refrigerant system according to one of the preceding claims, characterized in that, on the hydraulic circuit (64, 66) outside the control housing (14) a device, to be specific a safety valve (48) and / or a buffer storage tank (58), is respectively connected to a venting line (36), wherein the venting line (36) opens out at least indirectly into the external area (28) and, in the case of an air / water refrigerant system (2), opens out into an air duct (62), in which an air / refrigerant heat exchanger is arranged.

6. Refrigerant system according to one of the preceding claims, characterized in that arranged in the hydraulic circuit (64, 66) is a shut-off device (78), in particular a shut-off or sealing valve, which in the event of a pressure increase and / or an increase in the volumetric flow beyond a limit value shuts off the hydraulic circuit (64, 66), in particular in such a way that it is no longer in flow connection with the at least one heat exchanger, wherein preferably a heat-sink-side or heat-source-side subregion of the hydraulic circuit (64, 66) is hydraulically disconnected from a refrigerating-circuit-side subregion of the hydraulic circuit (64, 66).

7. Refrigerant system according to the preceding claim, characterized in that the shut-off device (78) is a passive shut-off element which automatically shuts off the hydraulic circuit (64, 66) when the limit value is exceeded and preferably also releases it again when the limit value is no longer exceeded.

8. Refrigerant system according to one of the preceding claims, characterized in that an internal piece (16A) of the discharge line (16) and at least one connecting line (20) for the at least one hydraulic circuit (64, 66) are connected to the control housing (14) and the internal piece (16A) and the at least one connecting line are led to a respective interface (22) of the system housing (4), via which an external piece (16B) of the discharge line (16) and at least parts of the at least one hydraulic circuit (64, 66) can be coupled, wherein, in a preferred configuration, coupling elements (72) intended for connecting, in particular reversibly, to the internal piece (16A) and / or to the at least one connecting line (20), and also preferably to at least one of the further components arranged in the system housing (4), are arranged on the control housing (14).

9. Refrigerant system according to one of the preceding claims, characterized in that the system housing (4) is designed in the manner of a module cabinet and the control housing (14) is arranged inside a refrigerant module (6), wherein preferably a storage module (8) with a service-water storage tank (10) is additionally provided and the refrigerant module (6) and the storage module (8) are in particular arranged one on top of the other.

10. Refrigerant system according to one of the preceding claims, characterized in that a fan (30) is arranged in the discharge line (16).

11. Refrigerant system according to the preceding claim, characterized in that a device for detecting a leakage in the refrigerating circuit (12) is provided and comprises an evaluation unit (76), which is designed in such a way that it infers a leakage within the refrigerating circuit (12) on the basis of at least one characteristic value of the fan (30).

12. Refrigerant system according to the preceding claim, characterized in that at least one of the following characteristic values of the fan (30) is evaluated: - fan characteristic curve or current operating point, - rotational speed, in particular in a state when the fan is not actively operated, - electrical current or power consumption, - vibration, wherein preferably a leakage rate is derived from the characteristic value.

13. Refrigerant system according to one of the preceding claims, characterized in that a device for detecting a leakage in the refrigerating circuit (12) is provided and a gas sensor (34), in particular a CO2 sensor, or a pressure sensor is arranged in the control housing (14) as the device for detecting the leakage.

14. Refrigerant system according to one of the preceding claims, having a refrigerant module with the control housing (14), with an internal piece (16A) of a discharge line (16) connected to it and also with at least one connecting line (20) connected to it, wherein the internal piece (16A) optionally opens out to an interface (22) for the reversible connection of an external piece (16B) of the discharge line (16) or into an air duct (62), wherein the components comprising the compressor, the expansion valve and at least one of the heat exchangers of the refrigerating circuit (12) are arranged in the control housing (14), and wherein the at least one heat exchanger is connected via a connection line (84), running inside the control housing (14), in the installed state to the at least one hydraulic circuit (64, 66), wherein the gas separator (40), which is intended for the direct degassing of a carrier medium conducted in the hydraulic circuit (64, 66) into the control housing (14), is attached to the connection line (84).