EP3692309A1

EP3692309A1 - Refrigerant compressor system

Info

Publication number: EP3692309A1
Application number: EP17780712.0A
Authority: EP
Inventors: Florian BERNHARDT; Jan Revellin
Original assignee: Bitzer Kuehlmaschinenbau GmbH and Co KG
Current assignee: Bitzer Kuehlmaschinenbau GmbH and Co KG
Priority date: 2017-10-04
Filing date: 2017-10-04
Publication date: 2020-08-12
Also published as: CN111164352B; CN111164352A; WO2019068322A1; US20200224940A1; US11353247B2

Abstract

In order to improve safety in a refrigerant compressor system comprising a refrigerant compressor and an electric drive motor for driving the refrigerant compressor and, arranged in a protected manner in an interior of a control housing, an electronic control system comprising electric components or electronic power components for controlling the electric drive motor, according to the invention, during operation of the refrigerant compressor system with combustible refrigerant, the control housing is provided with a refrigerant diversion, which does not impair at least one protection criterion of the control housing, for discharging refrigerant which enters into the interior due to a refrigerant leakage, said refrigerant diversion causing the refrigerant entering into the interior due to the refrigerant leakage to pass out of the interior into the surroundings of the refrigerant compressor system.

Description

REFRIGERANT COMPRESSOR SYSTEM

The invention relates to a refrigerant compressor system, comprising a refrigerant compressor and an electric drive motor for driving the refrigerant compressor and a control electronics arranged in an interior of a control housing control electronics for driving the electronic drive motor having electrical components or electronic power components.

An electronic control system can be a simple motor protection device, which monitors, for example, a temperature of the drive motor and switches off the drive motor at too high a temperature.

In such a refrigerant compressor system, there is the risk that refrigerant leaks refrigerant into an interior of the control housing, creating security problems.

The invention is therefore based on the object to improve the safety of such a refrigerant compressor system.

This object is achieved in a refrigerant compressor system of the type described above according to the invention that during operation of the refrigerant compressor with combustible refrigerant, the control housing for discharging by a refrigerant leakage into the interior eintretendem refrigerant with at least one protection criterion of

Control housing is provided not impairing refrigerant discharge, which causes leakage of refrigerant entering through the refrigerant leakage into the interior of the interior space in an environment of the refrigerant compressor plant. The advantage of the solution according to the invention is thus to be seen in the fact that it can be ensured by the refrigerant discharge that the refrigerant entering through the refrigerant leakage in turn exits through the refrigerant discharge from the interior.

The fact that the refrigerant exits from the interior, there is also an easy way to detect the leaked refrigerant outside the control housing.

The at least one protection criterion of the control housing is dust-tight, which means that the control housing prevents the ingress of dust into the interior.

Preferably, another protection criterion is tightness of the control housing with respect to from outside thereof into the interior space

penetrating fluids.

The solution according to the invention proves to be particularly advantageous if refrigerant-carrying components are provided in the control housing or the control housing is directly adjacent to refrigerant-carrying components.

With regard to the arrangement of the refrigerant discharge no further details were made.

Thus, an advantageous solution provides that the refrigerant discharge opens into a space region of the interior, in which the refrigerant accumulates due to gravity.

That is, when the refrigerant accumulates due to gravity due to its lower density in an upper space portion of the interior, the refrigerant discharge is associated with the upper space portion and opens into it. Since the combustible refrigerants usually have a higher density than air, it is preferably provided that the spatial area of the interior is a gravitationally low-lying spatial area of the same, to which the refrigerant outlet is assigned, which thus opens into it.

With regard to the design of the control housing, no further details have been given in connection with the previous explanation of the solution according to the invention.

Thus, an advantageous solution that housing parts of the control housing to maintain the associated protection criteria are tightly connected with respect to condensed liquids and dustproof, so that in the region of the connection of the housing parts together no significant gas flow can form and also no dust can pass ,

With regard to the design of the refrigerant discharge no further details were made, it was only defined that this must also meet the control housing associated protection criteria.

For this purpose, it is advantageously provided that the refrigerant outlet of the control housing has a filter element, through which passes refrigerant propagating in the interior.

In particular, the filter element of the refrigerant discharge is designed so that it allows gas passage, but prevents the passage of dust particles, so that the at least one protection criterion can be maintained by the refrigerant discharge, the one against

Intrusion of dust particles protected interior calls.

It is even more advantageous if, in addition, the filter element also protects against the ingress of liquids into the interior. In order to discharge liquids condensed out of the interior of the control housing, in particular condensed water, it is preferably provided that the filter element allows condensed water to escape from the interior.

In this case, the filter element is expediently semipermeable, that is to say it allows condensed liquids to escape from the interior, but not dust to enter the interior.

With regard to the design of the filter element, it would be conceivable, for example, to form it in the form of a filter mat or a filter membrane.

The filter element is preferably designed so that it filters out particles that are larger than 100 pm, even better filters out particles that are larger than 50 pm.

A particularly advantageous solution provides, however, that the filter element is designed as a sintered body, which is a rigid in itself and thus in the refrigerant discharge easily fixable body.

Instead of a sintered body, it is also conceivable to provide a labyrinth body.

With regard to the nature of the refrigerant cooling of the control electronics so far no further details have been made.

So provides an exemplary solution that in the interior of the

Control housing a refrigerant-operated cooling unit is arranged for the control electronics.

Already arranging such a refrigerant-operated cooling unit thus creates the risk that a refrigerant leakage occurs in the area of this refrigerant-operated cooling unit. The risk is even higher if, for the supply of the refrigerant-operated cooling unit, refrigerant-carrying components are arranged in the control housing.

Such refrigerant-carrying components are, for example, components of a control cooling branch, such as connecting lines, on-off valves, control valves, temperature sensors and throttles.

But the risk of refrigerant leakage also exists when the interior of the control housing, in particular directly adjacent to the housing of the compressor unit and the housing with in the interior of the

Control housing opening electrical line feedthroughs is provided so that in particular in the field of electrical cable feedthroughs or sensors or control valves, the risk of leakage occurs.

Moreover, the invention relates to a refrigeration system, comprising a refrigerant compressor system according to one of the preceding features, wherein according to the invention the refrigerant compressor system in a closed or unfinished, in particular open in all directions,

Plant space is arranged, in which a monitoring takes place with regard to escaping refrigerant.

Such monitoring with respect to escaping refrigerant takes place, for example, in the case of an unfinished room by a

transportable refrigerant tester or by a near the refrigerant discharge arranged sensor.

However, it is particularly favorable if a refrigerant leak warning device is assigned to the system space and if the refrigerant leakage warning device measures the system space, in particular a closed refrigerant tank

Plant room, constantly monitored by means of a refrigerant sensor. In this case, it is advantageously provided that the refrigerant warning device generates a warning signal when a safety-relevant refrigerant concentration in the system room is exceeded, which may be, for example, an optical or an acoustic, electronic or transmitted via a data transmission warning signal.

Further features and advantages of the invention are the subject of the following description and the drawings of some

Embodiments.

In the drawing show:

Fig. 1 is a schematic representation of a first embodiment of a refrigerant compressor plant according to the invention;

FIG. 2 shows an illustration of a real embodiment of the refrigerant compressor system according to the invention; FIG.

Fig. 3 is a section along line 3-3 in Fig. 2;

4 shows a partial enlargement of a region A in FIG. 3;

Fig. 5 is a schematic representation of a refrigerant compressor plant according to the invention as a component of a refrigeration system arranged in a plant room and

Fig. 6 is a longitudinal section through a second embodiment of a

refrigerant compressor according to the invention. In one, shown in Fig. 1, and designated as a whole by 10 refrigerant circuit is designated as a whole by 30 refrigerant compressor system comprising a refrigerant compressor 32, the compressed refrigerant emits at an output terminal AA, which in turn via a first connecting line 12 with a High-pressure side heat exchanger unit 14 is connected, in which a cooling, for example, a liquefaction of the high-pressure refrigerant is carried out.

This cooled, for example, liquefied refrigerant is designated as a whole by 18 via a second connecting line 16

An expansion element is supplied, in which an expansion of the high-pressure and cooled by the high-pressure side heat exchanger 14 refrigerant takes place, which subsequently enters a low-pressure side heat exchanger 22, in which this is due to its expansion in the expansion member 18 by cooling in a position capable of heat

absorb, for example, to evaporate.

The refrigerant leaving the low-pressure-side heat exchanger unit 22 is then supplied via an additional connecting line 24 to an input connection AE of the refrigerant compressor 32.

The refrigerant compressor 32 is preferably driven by an electric motor 34, wherein in particular the refrigerant compressor 32 and the

Electric motor 34 are arranged in an overall housing 36, as shown in FIG. 2, which on the one hand has a compressor housing 42 for receiving the refrigerant compressor 32 and on the other hand, a motor housing 44 for receiving the electric drive motor 34, which are connected to each other. The drive motor 34 is preferably controlled by a motor controller 52 speed-controlled, the motor controller 52 an electronic

Speed control 54, in particular comprises a frequency converter, the highly temperature-loaded electronic power components 56 which show a high heat development during operation of the electric drive motor 34 with the motor controller 52 and in particular have too short a high lifetime during operation of the electric drive motor 34.

For this reason, as described, for example, in WO 2013/139909 A1, a heat sink 62 is provided for the cooling of the electronic power components, to which the heavily loaded electronics

Power components that can give off heat in these.

For this purpose, the heat sink 62 is active in the refrigerant circuit 10

cooled refrigerant and has for this purpose an input terminal 64 and an output terminal 66, wherein from the input terminal 64, a refrigerant leading cooling channel 68 to the heat sink 62 to

Output terminal 66 interspersed.

The heat sink 62 is part of a control cooling branch, designated as a whole by 70, which comprises a branch line 72 which branches off the refrigerant from the second connection line 16 and supplies it to a switch-on valve 74 of the control cooling branch 70, which switches on the refrigerant supply to the control cooling branch 70 for cooling the heat sink 62 ,

The on-off valve 74 is followed by a thermostatic expansion valve 76 of the control cooling branch 70, which is disposed between the input valve 74 and the input port 64 of the heat sink 62 and connected via a capillary tube 78 to a temperature sensor 82 at the output port 66 of the heat sink. The expansion valve 76, in particular designed as a thermostatic expansion valve thus controls according to the measured by means of a temperature sensor 82 at the output terminal 66 of the heat sink 62

Temperature is the cooling capacity in the heat sink 62.

Further, the output port 66 is connected via a connecting line 92, the control cooling branch 70 in which a evaporation pressure regulator 94 is disposed, with an intermediate pressure port AZ of the refrigerant compressor 32, so that already without control effect of

Evaporating pressure regulator 94, an evaporation pressure in the heat sink 62 is higher than a suction pressure of the refrigerant compressor 32 of the refrigerant circuit 10th

Since the thermostatic expansion valve 76 is not externally controllable, the switch-on valve 74 is for switching off the control cooling branch 70

provided, which is controllable via a controller 100 by means of the motor controller 52.

In addition, for example, the evaporating pressure regulator 94 is connected in parallel to a throttle 98 which is arranged in a bypass line 96 of the control cooling branch 70 and which prevents undesired heating of the electronic power components 56 when the refrigerant compressor starts up, as also described in WO 2013/139909 A1.

As shown in FIGS. 2 and 3, all these components of the control cooling branch 70, together with the electronic power components 56, are arranged in a control housing mounted on the overall housing 36, for example on the motor housing 44 or possibly also on the compressor housing 42 and designated 100 as a whole, formed by on the one hand held on the overall housing 36 base unit 102, for example, carries the heat sink 62 on which the motor controller 52, the inverter 54 and in particular the electronic power components 56, in particular the inverter 54 are arranged cooled. The base unit 102 in turn includes one closed around them

circumferential housing flange 104 on soft a housing cover 110 is placed, wherein the housing cover 10 is also provided with a circumferential flange portion 114 which is placed on the mounting flange 104 of the base unit and thus an interior 120, in which, for example, the control cooling branch 70 and the motor controller 52nd with the inverter 54 and the electronic power components 56

is sealed against an environment of the refrigerant compressor plant 30 and, for example, against mechanical shock, corrosion, corrosive solutions, mold, insects, solar radiation, icing, dust and condensed liquids, tight, so that in particular the motor controller 52, the inverter 54 and the electronic power components 56 and all components of the control cooling branch 70 are protected against such harmful external influences.

However, such a design of the control housing 100 has the disadvantage that when using flammable refrigerant, such as the refrigerants that are low flammable or flammable or highly flammable, for example, according to IS0817 from 2014, a refrigerant leakage of all refrigerant-carrying components in the interior 120 of the control housing 100 in Connection with the interior 120

existing oxygen to form a combustible or even

may cause explosive gas mixture.

For this reason, it is necessary to form the control case 100 so as to discharge refrigerant leaking from the inner space 120 upon refrigerant leakage. If, for example, the refrigerant has a specific weight which causes the refrigerant in the interior 120 to sink in the direction of gravity and forms a coolant accumulation 126 in the area of a deepest spatial area 122 in the direction of gravity, for example above a floor 124, then this room area 122 is a refrigerant outlet 130, which branches off from the lowest-lying spatial area 122

4), for example, the base unit 102 passes through and also has a arranged in the discharge 132 filter element 134, which is constructed for example as a rigid sintered filter body and on the one hand, a reliable discharge of the gaseous refrigerant from the refrigerant accumulation 126 allows On the other hand, however, prevents penetration of dust and liquids, for example in the form of liquid droplets.

It is preferably provided that the filter element 134 filters out particles with a size of more than 100 μm, even better particles with a size of more than 50 μm.

For mounting the filter element 134, a sleeve 136 which can be screwed into the discharge channel 132 is preferably provided, which forms a support 138 for the filter element 134 and can be screwed onto a cover 142, which applies the filter element 134 to the support 138 and which provides air exchange openings 144 is.

With such a refrigerant discharge 130, it is possible to discharge refrigerant from the interior space 120 reliably from the refrigerant accumulation 126 so that it exits into the environment of the refrigerant compressor installation 30. The removal of the refrigerant from the interior 120 is additionally supported by the fact that a refrigerant leakage in the region of the refrigerant-carrying elements in the interior 120 represents a, especially mostly permanent, gas supply to the interior, so that the need exists, especially if an overpressure in the interior 120th to avoid the supplied gas volume again, which takes place via the refrigerant outlet 130, which therefore also due to the gas supply to the interior 120 constantly gas from the interior 120 must derive, this gas in that in the lowest room area 122, the refrigerant accumulation 126th forms, is necessarily refrigerant.

If such a refrigerant compressor system 30 (FIG. 5), for example together with the refrigerant circuit 10, is arranged in a plant space 150 of a refrigeration system, a refrigerant leakage in the control housing 120 due to the refrigerant discharge 130 will result in the interior 120 of the control housing due to the refrigerant leakage entering refrigerant through the refrigerant outlet 130 again emerges from this and thus in the plant room 150, which surrounds the refrigerant compressor plant 30 occurs.

Thus, likewise in the plant space 150, specifically in a gravitationally lowermost region 152 of the plant space 150, a refrigerant accumulation 156, which comprises a plant controller 160 with a refrigerant leakage warning device 162, likewise forms in turn

Refrigerant sensor 164 can detect, wherein the refrigerant leakage warning device 162 measures the concentration of the refrigerant in the air in the installation space 150 and generates a warning signal when a defined threshold value is exceeded. Since the refrigerant cycle 10 is also arranged in the plant space 150 at the same time, the plant controller 160 is thus able to detect a refrigerant leakage in the refrigerant circuit 10 as well as a refrigerant leakage in the control housing 100 of the refrigerant compressor installation 30, thereby ensuring safe operation of both the refrigerant circuit as well as arranged in the control housing 100 refrigerant-carrying components is possible without a flammable or explosive gas mixture in the interior 120 of the control housing 100 or in the plant space 150 can form.

In a second exemplary embodiment of a refrigerant compressor system 30 'according to the invention, illustrated in FIG. 6, the overall housing 36 likewise comprises a compressor housing 42 and a motor housing 44, in which case a scroll compressor is arranged in the compressor housing 42, for example.

The arranged in the motor housing 44 electric drive motor 34 is flowed through by guided to the scroll compressor refrigerant, which preferably enters an inflow 172 of the motor housing 44, which is disposed on a side opposite the scroll compressor side of the electric drive motor 34 and an example frontal housing wall 174th adjacent, which simultaneously represents the base unit 102 for the control housing 100.

Also in this embodiment, the base unit 102 of the

Control housing 100 the circumferential mounting flange 104, on which the housing cover 110 is seated with a flange 114 and sealed with this, so that the interior 120 of the control housing 100 in the same manner as in the first embodiment against the environment and, for example against mechanical shock, corrosion, corrosive Solutions, mold, insects, solar radiation, icing, dust and condensed liquids is protected. In this embodiment as well, the motor control 52 is seated in the control housing 100 with the converter 54 enclosed by it, with its electronic power components 56 sitting directly on the base unit 102, which simultaneously represents the housing wall 174 of the motor housing 44 and cooled by the refrigerant supplied to the inflow space 172 is.

Thus, in the interior 120 'of the control housing 110' no refrigerant-carrying components are present.

However, in the housing wall 174 one or more, typically three, electrical feedthroughs 182, 184, 186, or a multiple feedthroughs to a unit summarizing and incorporated as such a unit provided, which are required to make an electrical connection between the To provide inverter 54 of the motor controller 52 and the electric drive motor 34.

In the area of such electrical feedthroughs 182, 184 and 186 there is also the risk of refrigerant leakage, so that refrigerant from the inflow space 172 along the electrical feedthroughs 182, 184, 186 can enter the interior 120 'of the control housing 110', whereby when using a combustible Refrigerant in the interior 120 'also a combustible or even explosive gas mixture can be formed.

For this reason, a refrigerant outlet 130 is also provided in this embodiment in the deepest gravity in the spatial region 122 'of the interior 120, which is constructed and constructed in the same manner as in the first embodiment and causes that in the refrigerant accumulation 126' in Lowest space portion 122 'by the refrigerant leakage collecting refrigerant via the refrigerant outlet 130 from the interior 120' in the environment of the refrigerant compressor unit 30 'is discharged. If such a refrigerant system 30 'is arranged in the plant space 150 in the same way as in the first exemplary embodiment, then refrigerant entering the interior 120' of the control housing 110 'through refrigerant leakage can also be detected in the plant space 150 by the system controller 160 by means of the sensor 162 ,

However, in both exemplary embodiments it is also possible to detect escaping refrigerant with transportable detection devices from the interior 120 or 120 'and then to generate a warning signal or a warning depending on the measured concentration.

Claims

PATENT APPLICATIONS

A refrigerant compressor unit (30) comprising a refrigerant compressor (32) and an electric drive motor (34) for driving the refrigerant compressor (32) and a control electronics (50) disposed in an interior of a controller housing for driving the electric drive motor (34) having electrical components or electronic power components (56),

characterized in that in operation of the refrigerant compressor system (30) with combustible refrigerant, the control housing (100) for discharging by a refrigerant leakage into the interior (120) entering refrigerant with a least one protection criterion of the control housing (100) not impairing refrigerant discharge (130) is provided effecting leakage of refrigerant entering the inner space (120) through the refrigerant leakage from the inner space (120) to an environment of the refrigerant compressor unit (30).

Second refrigerant compressor installation according to claim 1, characterized in that the refrigerant outlet (130) opens into a space region (122) of the interior space (120), in which the refrigerant accumulates due to gravity.

3. Refrigeration compressor installation according to claim 2, characterized in that the spatial region of the interior space (120) is a gravitational direction of the deepest spatial area (122) thereof.

4. refrigerant compressor system according to one of the preceding

Claims, characterized in that housing elements (102, 110) of the control housing (100) for maintaining the associated protection criteria are tightly interconnected with respect to liquids and dust.

5. refrigerant compressor system according to one of the preceding

Claims, characterized in that the refrigerant outlet (130) of the control housing (100) has a filter element (134) through which passes in the interior (120) spreading refrigerant.

6. refrigerant compressor system according to claim 5, characterized in that the filter element (134) of the refrigerant outlet (130) allows gas passage, but prevents the passage of dust particles.

7. Refrigerant compressor installation according to claim 5 or 6, characterized in that the filter element (134) of the refrigerant outlet (130) allows a gas passage, but prevents the entry of liquids into the interior space (120).

8. refrigerant compressor installation according to one of claims 5 to 7,

characterized in that the filter element (134) filters out particles which are larger than 100 pm.

9. refrigerant compressor installation according to one of claims 5 to 8,

characterized in that the filter element (134) is formed as a sintered body.

10. refrigerant compressor system according to one of the preceding

Claims, characterized in that in the interior (120) of the control housing (100), a refrigerant-powered cooling unit (62) for the control electronics (50) is arranged.

11. Refrigerant compressor installation according to claim 10, characterized in that for supplying the refrigerant-operated cooling unit (62), refrigerant-carrying components (74, 76, 78.82, 92, 94) are arranged in the control housing (100).

12. refrigerant compressor installation according to one of the preceding

Claims, characterized in that the interior (120) of the control housing (100) adjacent to the housing of the compressor unit (32) and that the housing (42) with in the interior (120) of the control housing (100) opening electrical cable feedthroughs (182, 184, 186) is provided.

13. A refrigeration system comprising a refrigerant compressor system according to one of the preceding claims, characterized in that the refrigerant compressor system (30) is arranged in a plant space (150), in which a monitoring takes place with regard to exiting refrigerant.

14. A refrigeration system according to claim 13, characterized in that the system space (150) is assigned a refrigerant leakage warning device (164) and that the refrigerant leakage warning device (164) constantly monitors the system space (150) by means of a refrigerant sensor.

15. Refrigeration system according to claim 14, characterized in that the

Refrigerant leakage warning device generates a warning signal when exceeding a safety-relevant refrigerant concentration in the plant room.