DE202020005497U1 - Portable cooling unit - Google Patents

Abstract

Portable cooling unit (1) for transporting temperature-sensitive goods while maintaining a desired cooling temperature, the portable cooling unit (1) comprising
- a multi-stage cascade cooling system which is set up to be operated during the transport of the portable cooling unit (1) and to cool and maintain temperatures of more than 70 K below the ambient temperature,
- a suspension system which is set up and arranged to serve as an elastic bearing for the multi-stage cascade cooling system and / or for components of the multi-stage cascade cooling system,
- a movement limiting system which is set up and arranged to restrict movements of the multi-stage cascade cooling system and / or of components of the multi-stage cascade cooling system,
- a shock protection system which is set up and arranged to dampen collisions between the multi-stage cascade cooling system and other parts of the portable cooling unit (1) and / or between the components of the multi-stage cascade cooling system,
- A lubrication system that enables the lubrication of the components of the multi-stage cascade cooling system for inclinations of at least 10 °, preferably more than 20 °, with respect to the horizontal orientation of the portable cooling unit (1), and
- A monitoring system which is set up to generate an alarm signal in the event of a malfunction of the portable cooling unit (1).

Description

FIELD OF THE INVENTION

The present invention relates to a portable refrigeration unit for transporting temperature sensitive goods while maintaining a desired refrigeration temperature.

GENERAL STATE OF THE ART

Portable cooling units are generally known. Such cooling units, which work with passive cooling by dry ice or liquid nitrogen, cannot, however, be used in connection with highly temperature-sensitive goods due to their unreliability over long periods of time and the dissipation of the limited supply of cooling medium.

In addition, portable refrigeration units based on Stirling refrigeration systems are also not suitable for highly temperature-sensitive goods, since their comparatively low refrigeration capacity prevents rapid restoration of the desired or required refrigeration temperature, for example after a door has been opened.

In general, such portable refrigeration units are unable to cool and maintain temperatures 60 to 70 K lower than room temperature, which makes them unsuitable for the transportation of highly temperature-sensitive goods such as vaccines.

Stationary cooling units, on the other hand, avoid some of the disadvantages mentioned above. However, since stationary systems are only used under controlled conditions, such as indoor laboratories or storage areas, these systems are not suitable for large differences between the ambient temperature and the desired cooling temperature; instead, they are designed to function at certain predetermined ambient temperatures or in narrow ambient temperature bands. This also applies to other environmental conditions, the ambient pressure.

In addition, stationary systems do not allow operation while in a tilted orientation, that is, they are not portable. Instead, such tendencies lead to malfunction or damage to stationary systems.

There is therefore a lack of transportable cooling units for reliably transporting highly temperature-sensitive goods while maintaining a desired cooling temperature of more than 70 K below room temperature under varying environmental conditions.

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a portable refrigeration unit for reliably transporting highly temperature sensitive goods while maintaining a desired refrigeration temperature of more than 70K below ambient temperature under varying ambient conditions and for a longer period of time.

Further objects of the invention emerge from the description of the invention below.

PRESENTATION OF THE INVENTION

• - ein mehrstufiges Kaskadenkühlsystem, das angepasst ist, um während des Transports der tragbaren Kühleinheit zu funktionieren und auf Temperaturen von mehr als 70 K, vorzugsweise mehr als 120 K, unter Umgebungstemperatur abzukühlen und beizubehalten,
• - ein Aufhängungssystem, das dazu angepasst und angeordnet ist, als ein elastisches Lager für das mehrstufige Kaskadenkühlsystem und/oder für Bauteile des mehrstufigen Kaskadenkühlsystems zu dienen,
• - ein Bewegungsbegrenzungssystem, das dazu angepasst und angeordnet ist, Bewegungen des mehrstufigen Kaskadenkühlsystems und/oder von Bauteilen des mehrstufigen Kaskadenkühlsystems einzuschränken,

• - ein Stoßschutzsystem, das dazu angepasst und angeordnet ist, Kollisionen zwischen dem mehrstufigen Kaskadenkühlsystem und anderen Teilen der tragbaren Kühleinheit und/oder zwischen den Bauteilen des mehrstufigen Kaskadenkühlsystems zu dämpfen,
• - ein Schmiersystem, das die Schmierung der Bauteile des mehrstufigen Kaskadenkühlsystems für Neigungen der tragbaren Kühleinheit von mindestens 10°, vorzugsweise mehr als 20°, gegenüber der horizontalen Ausrichtung ermöglicht, und
• - ein Überwachungssystem, das dazu eingerichtet ist, ein Alarmsignal bei Funktionsstörung der tragbaren Kühleinheit zu erzeugen.

An object of the invention is achieved by means of a portable cooling unit for transporting temperature-sensitive goods while maintaining a desired cooling temperature, the portable cooling unit comprising

• - a multi-stage cascade cooling system adapted to function during transport of the portable cooling unit and to cool and maintain temperatures of more than 70 K, preferably more than 120 K, below ambient temperature,
• a suspension system which is adapted and arranged to serve as a resilient bearing for the multi-stage cascade cooling system and / or for components of the multi-stage cascade cooling system,
• - a movement limiting system which is adapted and arranged to restrict movements of the multi-stage cascade cooling system and / or of components of the multi-stage cascade cooling system,

• a shock protection system adapted and arranged to dampen collisions between the multi-stage cascade cooling system and other parts of the portable cooling unit and / or between the components of the multi-stage cascade cooling system,
• - a lubrication system that enables the lubrication of the components of the multi-stage cascade cooling system for inclinations of the portable cooling unit of at least 10 °, preferably more than 20 °, with respect to the horizontal orientation, and
• a monitoring system which is set up to generate an alarm signal in the event of a malfunction of the portable cooling unit.

Because of this particular combination of features, the portable cooling unit avoids all of the disadvantages mentioned above. The multi-stage cascade cooling system used enables sufficient cooling capacity and the realization and maintenance of the desired or required cooling temperature, that is to say the target temperature; the suspension system, the movement limitation system and the shock protection system act as special protection means for the multi-stage cascade cooling system during the transportation of the cooling unit, thereby making the multi-stage cascade cooling system suitable for operation during the transportation of the cooling unit; the lubrication system reliably prevents malfunctions of the multi-stage cascade cooling system in inclined positions, which the portable cooling unit assumes quite often during transport; and the monitoring system ensures the protection of the temperature-sensitive goods in the event of malfunctions in the cooling unit, since it allows the malfunction to be detected at an early stage and countermeasures to be taken quickly.

In the context of the present invention, the term “portable” is to be understood as meaning that the cooling unit can be operated normally during transport, in particular also when the cooling unit is inclined by at least 10 ° with respect to the horizontal orientation.

In a preferred embodiment of the portable cooling unit according to the invention, its weight is 50 kg or less.

This facilitates the handling of the portable cooling unit by the responsible personnel, since high weight would increase the risk of bodily harm or damage and increase the harshness of handling.

In a preferred embodiment of the portable cooling unit according to the invention, it comprises at least one, preferably two handles for easy handling of the portable cooling unit.

This further increases the handling safety and stability of the cooling unit during transport. In particular, the cooling unit can be held in a horizontal orientation more easily, as a result of which the risk of malfunction of the multi-stage cascade cooling system and its components during transport is minimized.

In another preferred embodiment of the portable cooling unit according to the invention, the multi-stage cascade cooling system is designed as a two-stage cascade cooling system.

The use of a two-stage cascade cooling system makes the portable cooling unit particularly efficient for use in conjunction with a wide range of ambient temperatures. While its construction is simple and robust enough to be applied to portable refrigeration units, it allows the desired temperature difference to be divided into two steps by using two standard thermally connected refrigeration systems, for example two vapor compression refrigeration systems, in a first step from ambient temperature To cool ambient air of the cooling unit to an intermediate temperature, also called intercooler temperature, and in a second step from the intermediate temperature down to the target temperature of the cooling unit, also called target temperature. As a result, even with those temperature differences that are relevant for independent portable cooling units, only standard components can be used, which are usually found in the light commercial cooling industry, without sacrificing reliability due to overloads.

In another preferred embodiment of the portable cooling unit according to the invention, a high-temperature cooling circuit of the two-stage cascade cooling system comprises a first compressor, which has a cooling capacity of 60 W at an ambient temperature of 43 ° C on the condenser of the circuit, and an intercooler temperature of -25 ° C the evaporator of the circuit.

In another preferred embodiment of the portable cooling unit according to the invention, a low-temperature cooling circuit of the two-stage cascade cooling system comprises a second compressor which has a cooling capacity of 30 W at an intercooler temperature of -25 ° C at the condenser of the circuit, and a target temperature of -80 ° C at the evaporator of the circuit.

This design of the two-stage cascade cooling system enables the portable cooling unit to rapidly cool the highly temperature-sensitive goods to the target temperature and to maintain the temperature without overloading the cooling cycles (e.g. the two vapor compression cooling systems).

The evaporator of the high-temperature cooling circuit and the condenser of the low-temperature cooling circuit, together with the thermal coupling between them, form the intercooler of the two-stage cascade cooling system. The high temperature cooling circuit can do so designed so that it has a heat dissipation between the condenser and the ambient air of 120 W with a temperature difference of 10 K and a heat absorption at the evaporator (i.e. at the intercooler) of 60 W with a temperature difference of 5 K. The low-temperature cooling circuit, on the other hand, can be designed in such a way that it has a heat dissipation at the condenser (i.e. at the intercooler) of 60 ° with a temperature difference of 5 K, and a heat absorption from the active cooling compartment to the evaporator of 30 W with a temperature difference of 10 K. The cooling compartment is defined as the volume of the portable cooling unit in which the temperature-sensitive goods are stored.

With such a design, the portable cooling unit can quickly restore the target temperature after the cooling process is interrupted, for example after a door of the cooling compartment is opened.

In another preferred embodiment of the portable cooling unit according to the invention, the high-temperature cooling circuit of the two-stage cascade cooling system has propane as the refrigerant, and the low-temperature cooling circuit of the two-stage cascade cooling system has ethane as the refrigerant.

With the combination of these special refrigerants for the high and low temperature cooling circuit, the two-stage cascade cooling system can be operated in a particularly effective way, especially with varying external conditions such as occur during transport.

In another preferred embodiment of the portable cooling unit according to the invention, each compressor of the cooling circuit has a motor-compressor unit which is elastically suspended within the housing of the respective compressor by means of a plurality of springs.

In this way, the transmission of vibrations and noise between the motor-compressor unit and the housing of the compressor can be minimized. In addition, the elastic suspension of the motor-compressor unit within the housing of the respective compressor makes the compressor particularly suitable for portable uses, since different orientations and / or positions of the compressor do not affect the operability of the motor-compressor unit. Since the elastic suspension can also be made possible by a large number of springs which are mounted on the bottom of the compressor housing, these springs are at least partially in this lubricant sump (or oil sump) in the operating state of the compressor in which a lubricant sump (oil sump) covers the floor ) immersed, which further dampens the vibration and sound transmission.

In another preferred embodiment of the portable cooling unit according to the invention, the motor-compressor unit has a plurality of spacing elements made of elastic material, the spacing elements being arranged on a surface of the motor-compressor unit and protruding from the surface towards the housing of the compressor.

The elastic spacing elements serve as special means of protection against collisions between the motor-compressor unit and the housing of the respective compressor. Such protection is necessary if the cooling unit is to be portable, that is, if it is to be able to function normally during transport despite varying orientations and positions that the cooling unit may assume during transport. The spacing elements therefore serve as a shock protection system. The elastic spacing elements can also serve as movement limiting elements, since the dimensions of the spacing elements can be selected in such a way that only a predefined deflection from a rest position of the motor-compressor unit is permitted.

In another preferred embodiment of the portable cooling unit according to the invention, the compressor has a lubricant receptacle which is attached to a crankshaft of the motor-compressor unit in such a way that the lubricant receptacle protrudes at least in sections into the lubricant sump of the compressor.

In this way, constant lubrication of the motor-compressor unit can be guaranteed even when the cooling unit is not in a horizontal orientation. In such situations, the lubricant receptacle still protrudes at least in sections into the lubricant sump which covers the bottom of the compressor housing when the compressor is in operation, and therefore enables a constant supply of lubricant to the critical components that require lubrication. The lubricant can be conveyed from the sump to the critical components by standard means for conveying lubricant, for example through grooves in the surface of the crankshaft, eccentric bores and / or outlet openings within the crankshaft.

In a preferred embodiment, the lubricant can enter the lubricant receptacle and the crankshaft through an inlet opening of the lubricant receptacle and when the crankshaft rotates - which also leads to a rotation of the lubricant receptacle connected to the crankshaft - form a lubricant paraboloid. The lubricant can then into the interior of the rotationally symmetrical hollow area of the crankshaft through an outlet opening which is arranged at the high point of the lubricant paraboloid in the outer surface of the crankshaft, step out. From there, the lubricant can either be directed to critical components of the motor-compressor unit that require lubrication, or it can be fed into further conveying means, for example grooves in the surface of the crankshaft.

Figure list

• 1 eine perspektivische Ansicht einer tragbaren Kühleinheit
• 2 eine schematische Ansicht eines Kompressors eines Kühlkreislaufs des mehrstufigen Kaskadenkühlsystems
• 3 eine perspektivische Ansicht einer tragbaren Kühleinheit während des Transports in einer geneigten Ausrichtung
• 4 eine schematische Ansicht eines Kompressors eines Kühlkreislaufs des mehrstufigen Kaskadenkühlsystems während des Transports in einer geneigten Ausrichtung

There now follows a brief description of the invention using figures of an exemplary embodiment. This shows:

• 1 Figure 3 is a perspective view of a portable cooling unit
• 2 a schematic view of a compressor of a cooling circuit of the multi-stage cascade cooling system
• 3 Figure 3 is a perspective view of a portable cooling unit in an inclined orientation during shipping
• 4th a schematic view of a compressor of a refrigeration circuit of the multi-stage cascade refrigeration system during transportation in an inclined orientation

MODES FOR CARRYING OUT THE INVENTION

1 forms a portable cooling unit according to the invention 1 off, the two handles 2 (of which only one in 1 is visible, see 2 ) on opposite outer surfaces of the body of the cooling unit 1 having. The cooling unit 1 is in an insulated cooling compartment 6th , in which highly temperature-sensitive goods are stored during transport, and a separate machine compartment 7th housing a multi-stage cascade cooling system divided. The cooling compartment 6th is opposite the ambient air through a door 8th closed.

The multi-stage cooling system can be implemented as a two-stage cascade cooling system that comprises two vapor compression cooling systems, which each form a high-temperature cooling circuit and a low-temperature cooling circuit. Each of these cooling circuits includes a compressor which, as in 2 shown is designed.

In 2 is the compressor with a compressor housing 9 and a motor-compressor unit 3 shown being elastic on a floor 10 of the compressor housing 9 by means of several springs 11 forming a suspension system is suspended. The motor-compressor unit 3 has multiple spacers 4th which are made of elastic material, the spacing elements 4th on an outer surface of the motor-compressor unit 3 are set up and from the outer surface towards the compressor housing 9 stick out. These spacers 4th act as a protective system because, due to their elastic design, they cause collisions between the elastically suspended motor-compressor unit 3 and the compressor housing 9 dampen. At the same time, the spacing elements 4th serve as a movement limiting system by changing the dimensions of the spacers 4th can be selected such that only a predefined deflection from the rest position of a motor-compressor unit 3 is possible( 4th ).

In addition, the 2 and 4th schematic representations of a lubricant intake 5 attached to a crankshaft (not shown) of the engine-compressor unit 3 is attached in such a way that the lubricant receptacle 5 into the lubricant sump 12th of the compressor protrudes. This lubricant intake 5 forms a lubrication system, possibly together with other means for conveying lubricant, for example grooves in the surface of the crankshaft, eccentric bores and / or outlet openings within the crankshaft. The lubrication system provides constant lubrication of the motor-compressor unit 3 (or its components) safely, even in situations where the portable cooling unit 1 at an angle α from the horizontal orientation (in 3 and 4th shown) is inclined. While compressors used in stationary refrigeration systems would run the risk of being seriously damaged due to a lack of lubrication on certain slopes, as at least parts of the bottom area of the motor-compressor unit 3 no longer in the lubricant sump 12th would be submerged, the lubricant mount protrudes 5 still in the lubricant sump even with such inclinations 12th into ( 4th ).

As it is essential, the portable cooling unit malfunctions 1 The portable cooling unit encompasses immediate detection and immediate response if it is to be prevented that highly temperature-sensitive goods (e.g. vaccines) are damaged or unusable 1 also a monitoring system which is set up to immediately generate an alarm signal in the event of a malfunction of the portable cooling unit. The alarm signal can be generated, for example, when a specific temperature rise is detected in the cooling compartment and / or a specific inclination angle α is exceeded and / or a specific ambient temperature is exceeded.

List of reference symbols

1

Portable cooling unit

2

Handle

3

Motor compression unit

4th

Spacing elements

5

Lubricant reservoir

6th

Cooling compartment

7th

Machine compartment

8th

Refrigerator compartment door

9

Compressor housing

10

Bottom of the compressor housing

11

feathers

12th

Lubricant sump

Claims (10)

Portable cooling unit (1) for transporting temperature-sensitive goods while maintaining a desired cooling temperature, the portable cooling unit (1) comprising - a multi-stage cascade cooling system which is set up to be operated during the transport of the portable cooling unit (1) and to cool and maintain temperatures of more than 70 K below the ambient temperature, - a suspension system which is set up and arranged to serve as an elastic bearing for the multi-stage cascade cooling system and / or for components of the multi-stage cascade cooling system, - a movement limiting system which is set up and arranged to restrict movements of the multi-stage cascade cooling system and / or of components of the multi-stage cascade cooling system, - a shock protection system which is set up and arranged to dampen collisions between the multi-stage cascade cooling system and other parts of the portable cooling unit (1) and / or between the components of the multi-stage cascade cooling system, - A lubrication system that enables the lubrication of the components of the multi-stage cascade cooling system for inclinations of at least 10 °, preferably more than 20 °, with respect to the horizontal orientation of the portable cooling unit (1), and - A monitoring system which is set up to generate an alarm signal in the event of a malfunction of the portable cooling unit (1). Portable cooling unit (1) according to Claim 1 , characterized in that their weight is 50 kg or less. Portable cooling unit (1) according to Claim 1 or 2 , characterized in that it comprises at least one handle (2) for improved handling of the portable cooling unit (1). Portable cooling unit (1) according to one of the Claims 1 until 3 , characterized in that the multi-stage cascade cooling system is designed as a two-stage cascade cooling system. Portable cooling unit (1) according to Claim 4 , characterized in that a high-temperature cooling circuit of the two-stage cascade cooling system comprises a first compressor which has a cooling capacity of 60 W at an ambient temperature of 43 ° C of a condenser of the circuit and an intercooler temperature of -25 ° C on an evaporator of the circuit. Portable cooling unit (1) according to Claim 4 or 5 , characterized in that a low-temperature cooling circuit of the two-stage cascade cooling system comprises a second compressor, which has a cooling capacity of 30 W at an intercooler temperature of -25 ° C of a condenser of the circuit, and a desired cooling temperature of -80 ° C of an evaporator of the circuit having. Portable cooling unit (1) according to one of the Claims 4 until 6th , characterized in that the high-temperature cooling circuit of the two-stage cascade cooling system has propane as the refrigerant, and the low-temperature cooling circuit of the two-stage cascade cooling system has ethane as the refrigerant. Portable cooling unit (1) according to one of the Claims 1 until 7th , characterized in that a compressor of each cooling circuit has a motor-compressor unit (3) which is elastically mounted within a housing (9) of the respective compressor by means of several springs (11). Portable cooling unit (1) according to Claim 8 , characterized in that the motor-compressor unit (3) has a plurality of spacer elements (4) made of elastic material, the spacer elements (4) being arranged on a surface of the motor compression unit (3) and from this surface towards protrude from the housing (9) of the compressor. Portable cooling unit (1) according to Claim 8 or 9 , characterized in that the compressor has a lubricant receptacle (5) which is attached to a crankshaft of the motor-compressor unit (3) in such a way that the lubricant receptacle (5) protrudes at least in sections into a lubricant sump (12) of the compressor.

Images