EP3705823A1 - Service intervention - Google Patents

Abstract

Method for opening a housing in which there is a flammable working fluid of a left-rotating cycle, the housing (6) having an open gas path to the environment protected by an adsorbent (12) for working fluid, the housing (6) having a service opening (14 ) has, which is protected against opening by an unlocking device (16), the service opening (14) has a service connection (15) for a service cartridge (13), the service cartridge (13) contains a pressurized inert gas in an amount which is in relaxed state corresponds at least to the volume of the container (6), the service cartridge (13) has a cartridge neck (19) with a connecting line in the cartridge neck (19) and an external thread (25) on the cartridge neck (19), the service connection (15) Has an internal thread (26) which matches the external thread (25) of the cartridge neck (19), the service connection (15) has a closure cap (21), the closure cap (21) comprises a sealing seal (20) directed towards the outside of the housing (6), furthermore a sealing membrane (23) directed towards the inside of the housing (6), on which a mandrel (22) is arranged towards the outside of the housing (6) is, furthermore a sealing surface (27) on the internal thread (26), characterized by the following work steps: screwing the cartridge neck (19) into the service connection (15), turning further until the mandrel (22) of the sealing membrane (23) the connecting line ( 24) of the service cartridge (13), continue turning until the cartridge neck (19) pushes the sealing membrane (23), emptying the service cartridge (13) into the housing, continuing to turn until the cartridge neck (19) actuates the unlocking device (16), opening the service opening (14).

Description

The invention relates to irregular states in refrigeration circuits in which a working fluid acting as a refrigerant is conducted in a thermodynamic cycle, such as the Rankine cycle, for example. These are mainly heat pumps, air conditioning systems and cooling devices, as are common in residential buildings. Residential buildings are understood to mean private houses, apartment complexes, hospitals, hotel facilities, restaurants and combined residential and commercial buildings in which people live and work permanently, in contrast to mobile devices such as car air conditioning systems or transport boxes, or industrial systems or medical devices. What these cycle processes have in common is that they generate useful heat or useful cooling using energy and form heat displacement systems.

The thermodynamic cycle processes used have been known for a long time, as have the safety problems that can arise when using suitable working fluids. Apart from water, the most popular working fluids of the time are flammable and poisonous. In the past century, they led to the development of safety refrigerants, which consisted of fluorinated hydrocarbons. It turned out, however, that these safety refrigerants damage the ozone layer, lead to global warming, and that their safety-related harmlessness led to constructive inattention. Up to 70% of the turnover was accounted for by the need to refill leaky systems and their leakage losses, which was accepted as long as this was perceived as economically justifiable in individual cases and promoted the need for replacement.

For this reason, the use of these refrigerants was subject to restrictions, for example in the European Union through the F-gas regulation (EU) 517/2014.

• Im Normalbetrieb muss die Anlage absolut dicht sein.
• Weder bei einer Leckage im Kondensator noch bei einer Leckage im Verflüssiger darf Arbeitsfluid in den gekoppelten Nutzwärme- oder Nutzkältekreislauf gelangen.
• Es darf kein Arbeitsfluid aus dem Kältekreislauf unbemerkt entweichen können.
• Im Verdichter darf das Arbeitsfluid nicht durch die Lagerung entweichen.
• Im Entspannungssystem darf das Arbeitsfluid nicht durch den Ventilsitz diffundieren oder durch Kavitation zu Leckagen führen.
• Gekapselte Teile müssen für Wartungs- und Kontrollzwecke zugänglich bleiben.
• In Notfällen dürfen sich keine Gefahren einstellen.
• Die Anlage soll in vorhandene Räumlichkeiten integrierbar sein
• Das Kältemittel soll abgelassen und eingefüllt werden können.

It is therefore extremely problematic, on the one hand, to adopt the design principles for refrigerant-carrying thermodynamic processes, which have apparently proven themselves well with safety refrigerants, and, on the other hand, to use the system concepts from the time before the introduction of the safety refrigerants. This is also due to the fact that individual devices have now become complex systems, which has multiplied the number of possibilities for malfunctions and their consequences. This results in the following requirements for the safety concept, for example:

• In normal operation, the system must be absolutely tight.
• Neither in the event of a leak in the condenser nor in the event of a leak in the condenser, working fluid must not enter the coupled useful heat or useful cooling circuit.
• No working fluid must be able to escape unnoticed from the cooling circuit.
• In the compressor, the working fluid must not escape through the storage.
• In the expansion system, the working fluid must not diffuse through the valve seat or cause leaks due to cavitation.
• Encapsulated parts must remain accessible for maintenance and control purposes.
• In emergencies, there must be no danger.
• The system should be able to be integrated into existing rooms
• It should be possible to drain and fill the refrigerant.

The concept of emergency must be seen broadly. Power outages, earthquakes, landslides, floods, fires, technical errors and extreme climatic conditions are conceivable. If the systems are operated in a network, a power failure or a power failure is also to be regarded as an emergency. Against such dangers or disturbances the device is intended to be inherently safe. But even a failure of the available primary energy can justify an emergency and must not result in a development of danger. All of these emergencies can also occur in combination.

• Haushaltskühlschränke,
• Haushaltsgefrierschränke,
• Haushaltstrockner,
• Haushaltskühl-Gefrierkombinationen,
• Kühlkammern für Hotel- und Gastronomie,
• Gefrierkammern für Hotel- und Gastronomie,
• Klimaanlage für Haus, Hotel- und Gastronomie,
• Warmwassererzeugung für Haus, Hotel- und Gastronomie,
• Beheizung für Haus, Hotel- und Gastronomie,
• Sauna-Schwimmbadanlagen für Haus, Hotel- und Gastronomie,
• Kombinierte Anlagen für die oben genannten Anwendungen,

wobei diese Aufzählung nicht vollständig ist.Here, the various designs and applications for such thermodynamic cycle processes must be considered separately, for example the following for fixed systems for residential buildings:

• Household refrigerators,
• Household freezers,
• Household dryers,
• Household fridge-freezers,
• Cooling chambers for hotel and catering,
• Freezer chambers for hotel and catering,
• Air conditioning for home, hotel and catering,
• Hot water generation for home, hotel and catering,
• Heating for home, hotel and catering,
• Sauna swimming pool systems for home, hotel and catering,
• Combined systems for the above-mentioned applications,

although this list is not exhaustive.

• Erdwärme aus Erdwärmespeichern,
• Geothermische Wärme,
• Fernwärme,
• Elektrische Energie aus allgemeiner Stromversorgung,
• Elektrische Solarenergie,
• Solarwärme,
• Abwärme,
• Warmwasserspeicher,
• Eisspeicher,
• Latentwärmespeicher,
• Fossile Energieträger wie Erdgas, Erdöl, Kohle,
• Nachwachsende Rohstoffe wie Holz, Pellets, Biogas,
• Kombinationen aus den oben genannten Energiequellen,

wobei auch diese Aufzählung nicht vollständig ist.The energy for operating the systems, including the thermal energy to be shifted, can come from various sources:

• Geothermal energy from geothermal storage,
• Geothermal heat,
• District heating,
• Electrical energy from general power supply,
• Electric solar energy,
• Solar heat,
• Waste heat,
• Hot water tank,
• Ice bank,
• Latent heat storage,
• Fossil fuels such as natural gas, oil, coal,
• Renewable raw materials such as wood, pellets, biogas,
• Combinations of the above energy sources,

although this list is not complete either.

The problems that arise in the safety design of such systems are in the WO 2015/032905 A1 clearly described. The lower ignition limit of propane as a working fluid is around 1.7 percent by volume in air, which corresponds to 38 g / m ³ in air. If the refrigeration process is carried out in a surrounding, hermetically sealed, but otherwise air-filled space with the working fluid propane, the problem of recognizing a critical, explosive situation arises after a fault in which the working fluid escapes into this hermetically sealed space. Electrical sensors for detecting critical concentrations are difficult to design with explosion protection, which is why the propane detection by the sensors themselves increases the risk of explosion considerably, with the exception of infrared sensors. Propane is also poisonous; inhalation above a concentration of approx. 2 g / m ³ results in narcotic effects, headaches and nausea. This affects people who are supposed to solve a recognized problem on site before there is a risk of explosion.

Propane is also heavier than air, so in still air it sinks to the floor and collects there. So if some of the propane collects in a low-flow zone of the closed space in which the disturbed unit is located, the local explosion limits can be reached much faster than the quotient of the total volume of the space to the amount of propane that has escaped would suggest. The WO 2015/032905 A1 seeks to solve this problem by integrating a generator for electrical current into the opening or locking of this room and, when activated, in a first step generates and provides the electrical energy with which the sensor is activated, and in the event of an alarm the The lock then does not release, but causes ventilation of the locked room, and only allows unlocking and opening in a second step.

The DE 10 2011 116 863 A1 describes a method for securing a device for a thermodynamic cycle which is operated with a process fluid that contains or consists of at least one environmentally hazardous, toxic and / or inflammable substance. In the event of a leak in the device for a thermodynamic cycle, an adsorbent is brought into contact with the process fluid, in particular ammonia, propane or propene, and the substance is selectively bound by the adsorbent. The adsorbent is regenerated after use. Zeolite, also in combination with imidazole or phosphates, and also CuBTC are proposed as adsorbents; the adsorbent can be in the form of a bed, a molded body, a paint, a spray film or a coating. The support structure of the molded body can consist of a microstructure, lamellar structure, tube bundle, tube register and sheet metal and must be mechanically stable and greatly increase the surface area. The potentially contaminated air is usually circulated continuously, but it can also be initiated by a sensor that switches on the ventilation when a threshold value is reached or when an accident is detected. The adsorption can be carried out inside or outside a closed space.

The DE 195 25 064 C1 describes a refrigeration machine with a gas-tight housing which accommodates all refrigerant-carrying components of the machine, a space connecting the interior of the gas-tight housing with an outlet is provided, and the space is filled with a refrigerant sorbing agent. The amount of sorbent material is dimensioned in such a way that the entire amount of any refrigerant that may escape can be absorbed and kept away from the environment. The space filled with the sorbent material is open to the surroundings. With refrigerants that are heavier than air, the room is open at the bottom, with those that are lighter, it is open at the top, so that a conveying fan is not required. The sorbent is introduced into the housing and completely encloses the refrigeration machine or the refrigerant-carrying devices. On its way to the outside, baffles are provided which prevent short-circuit currents and force escaping gas through the sorbent. A double-walled embodiment in which the sorbent is arranged in the double jacket is also possible. A measuring device for refrigerant can be provided at the exit of the space filled with the sorbent substance to the environment.

The object of the invention is therefore to provide a device that enables service intervention if a leak has occurred and there is possibly still inflammable working fluid inside the housing.

• das Gehäuse einen, durch ein Adsorbens für Arbeitsfluid geschützten, offenen Gasweg zur Umgebung aufweist,
• das Gehäuse eine Serviceöffnung besitzt, die durch eine Entriegelungsvorrichtung gegen Öffnen geschützt ist,
• die Serviceöffnung einen Serviceanschluss für eine Servicepatrone aufweist,
• die Servicepatrone ein unter Druck stehendes Inertgas in einer Menge enthält, welches im entspannten Zustand mindestens dem Volumen des Behälters entspricht,
• die Servicepatrone einen Patronenhals mit einer Verbindungsleitung im Patronenhals und einem Außengewinde auf dem Patronenhals aufweist,
• der Serviceanschluss ein Innengewinde besitzt, welches zu dem Außengewinde des Patronenhalses passt,
• der Serviceanschluss eine Verschlusskappe aufweist, wobei
  • die Verschlusskappe ein zur Außenseite des Gehäuses gerichtetes Dichtsiegel umfasst,
  • ferner eine zur Innenseite des Gehäuses gerichtete Dichtmembran, auf der ein Dorn in Richtung zur Außenseite des Gehäuses angeordnet ist,
  • ferner eine Dichtfläche auf dem Innengewinde.

The invention solves this problem by means of a device for a safe service intervention for a housing in which an inflammable working fluid of a counterclockwise cycle is located, with

• the housing has an open gas path to the environment protected by an adsorbent for working fluid,
• the housing has a service opening which is protected against opening by an unlocking device,
• the service opening has a service connection for a service cartridge,
• the service cartridge contains a pressurized inert gas in an amount which in the relaxed state corresponds at least to the volume of the container,
• the service cartridge has a cartridge neck with a connecting line in the cartridge neck and an external thread on the cartridge neck,
• the service connection has an internal thread that matches the external thread of the cartridge neck,
• the service connection has a cap, wherein
  • the closure cap comprises a sealing seal directed towards the outside of the housing,
  • Furthermore, a sealing membrane directed towards the inside of the housing, on which a mandrel is arranged in the direction of the outside of the housing,
  • also a sealing surface on the internal thread.

• das Gehäuse einen, durch ein Adsorbens für Arbeitsfluid geschützten, offenen Gasweg zur Umgebung aufweist,
• das Gehäuse eine Serviceöffnung besitzt, die durch eine Entriegelungsvorrichtung gegen Öffnen geschützt ist,
• die Serviceöffnung einen Serviceanschluss für eine Servicepatrone aufweist,
• die Servicepatrone ein unter Druck stehendes Inertgas in einer Menge enthält, welches im entspannten Zustand mindestens dem Volumen des Behälters entspricht,
• die Servicepatrone einen Patronenhals mit einer Verbindungsleitung im Patronenhals und einem Außengewinde auf dem Patronenhals aufweist,
• der Serviceanschluss ein Innengewinde besitzt, welches zu dem Außengewinde des Patronenhalses passt,
• der Serviceanschluss eine Verschlusskappe aufweist, wobei
  • die Verschlusskappe ein zur Außenseite des Gehäuses gerichtetes Dichtsiegel umfasst,
  • ferner eine zur Innenseite des Gehäuses gerichtete Dichtmembran, auf der ein Dorn in Richtung zur Außenseite des Gehäuses angeordnet ist,
  • ferner eine Dichtfläche auf dem Innengewinde,
  gekennzeichnet durch die folgenden Arbeitsschritte
• Eindrehen des Patronenhalses in den Serviceanschluss,
• Weiterdrehen bis der Dorn der Dichtmembran die Verbindungsleitung der Servicepatrone aufstößt,
• Weiterdrehen, bis der Patronenhals die Dichtmembran aufstößt,
• Entleeren der Servicepatrone in das Gehäuse,
• Weiterdrehen, bis der Patronenhals die Entriegelungsvorrichtung betätigt,
• Öffnen der Serviceöffnung.

The invention also achieves the object by a method for opening a housing in which there is an inflammable working fluid of a counter-clockwise cycle, wherein

• the housing has an open gas path to the environment protected by an adsorbent for working fluid,
• the housing has a service opening which is protected against opening by an unlocking device,
• the service opening has a service connection for a service cartridge,
• the service cartridge contains a pressurized inert gas in an amount which in the relaxed state corresponds at least to the volume of the container,
• the service cartridge has a cartridge neck with a connecting line in the cartridge neck and an external thread on the cartridge neck,
• the service connection has an internal thread that matches the external thread of the cartridge neck,
• the service connection has a cap, wherein
  • the closure cap comprises a sealing seal directed towards the outside of the housing,
  • Furthermore, a sealing membrane directed towards the inside of the housing, on which a mandrel is arranged in the direction of the outside of the housing,
  • also a sealing surface on the internal thread,
  characterized by the following work steps
• Screwing the cartridge neck into the service connection,
• Continue turning until the mandrel of the sealing membrane pushes open the connection line of the service cartridge,
• Continue turning until the cartridge neck hits the sealing membrane,
• Emptying the service cartridge into the housing,
• Continue turning until the cartridge neck activates the release device,
• Opening the service opening.

• Fig. 1 eine Übersicht über eine Wärmepumpe mit Servicemodul,
• Fig. 2 ein Servicemodul vor seinem Einsatz,
• Fig. 3 das Servicemodul zu Beginn seines Einsatzes,
• Fig. 4 das Servicemodul während seines Einsatzes,
• Fig. 5 das Servicemodul gegen Ende seines Einsatzes.

The invention is explained in more detail below with the aid of 5 basic sketches. Here show:

• Fig. 1 an overview of a heat pump with service module,
• Fig. 2 a service module before its use,
• Fig. 3 the service module at the beginning of its use,
• Fig. 4 the service module during its use,
• Fig. 5 the service module towards the end of its use.

Fig. 1 shows the refrigeration circuit 1 of a heat pump with a compressor 2, a condenser 3, a pressure reducer 4 and an evaporator 5 in a closed housing 6. The housing has a heat source connection 7, a heat source flow 8, a heat sink flow 9 and a heat sink connection 10. The refrigeration circuit 1 is operated in this example with the flammable working fluid propane, which is also known under the designation R290.

In the event of a leak, the propane can be conducted together with the exhaust air 18 through the duct 11 open to the environment and through the activated carbon layer 12, where it is separated out, while inert air components can escape into the environment.

The housing 6 has a service opening 14 which has a service connection 15 for a service cartridge 13. The service opening 14 is secured with an unlocking bolt 16 and sealed with a seal 17. This prevents the service opening 14 from being opened in the event of a leak while an ignitable mixture is inside the housing.

Fig. 2 shows a service module before it is used. The service module is formed from the service cartridge 13, which has a connecting line 24 with a valve and a cartridge neck 19 with an external thread 25, the service connection 15, which has an internal thread 26, a closure cap 21, a sealing membrane 23, a cartridge neck sealing surface 27 , which also covers the first thread turns of the internal thread 26, a sealing seal 20 which protects the internal thread 26 and can be easily pierced, and a mandrel 22 which is attached to the sealing membrane 23. In the service cartridge 13 there is an inert gas under pressure, for example nitrogen. The amount of inert gas stored in the service cartridge 13 corresponds to at least the volume of the housing 6 in the relaxed state.

Fig. 3 shows the service module at the beginning of its use. Here, the seal seal is broken with the cartridge neck 19 of the service cartridge 13 and the external thread 25 of the cartridge neck 19 is screwed into the internal thread 26 of the service connection 15. The sealing surface 27 has the effect that the intermeshing threads are gas-tight. When screwed in, the mandrel 22 pierces the closure of the connecting line 24, which means that the inert gas of the service cartridge 13 can flow out. However, it cannot yet flow into the housing 6.

Prop. 4 shows the service module during its use. After the service cartridge 13 is turned further, the sealing membrane 23 is pierced and the inert gas can flow into the housing through the connecting line 24. In doing so, it displaces the possibly ignitable mixture of air and working fluid through the activated carbon layer 12. Such a process takes about ten seconds.

Fig. 5 shows the service module towards the end of its use. By continuing to turn the emptied service cartridge 13, the unlocking bolt is pushed out of its locking position and the service opening 14 can now be opened.

It goes without saying that this opening can only be carried out with great care, since the inert gas, such as nitrogen or carbon dioxide, can lead to suffocation when inhaled. Ensure that there is good ventilation, including in the installation room. After a service intervention, a new sealing cap 21 must be inserted and the unlocking bolt must be returned to its locked position. If working fluid has leaked, the activated carbon layer 12 must also be changed.

List of reference symbols

1

Refrigeration cycle

2

compressor

3

capacitor

4th

Pressure reduction

5

Evaporator

6th

casing

7th

Heat source connection

8th

Heat source flow

9

Heat sink supply

10

Heat sink connection

11

channel

12

Activated carbon layer

13

Service cartridge

14th

Service opening

15th

Service connection

16

Release bolt

17th

poetry

18th

Exhaust air

19th

Cartridge neck

20th

Sealing seal

21st

Sealing cap

22nd

mandrel

23

Sealing membrane

24

Connecting line

25th

External thread

26th

inner thread

27

Cartridge neck sealing surface

Claims (2)

Device for a safe service intervention for a housing in which there is an inflammable working fluid of a counterclockwise cycle, wherein - The housing (6) has an open gas path to the environment protected by an adsorbent (12) for working fluid, - The housing (6) has a service opening (14) which is protected against opening by an unlocking device (16), - the service opening (14) has a service connection (15) for a service cartridge (13), - The service cartridge (13) contains a pressurized inert gas in an amount which in the relaxed state corresponds at least to the volume of the container (6), - the service cartridge (13) has a cartridge neck (19) with a connecting line (24) in the cartridge neck (19) and an external thread (25) on the cartridge neck (19), - the service connection (15) has an internal thread (26) which matches the external thread (25) of the cartridge neck (19), - The service connection (15) has a closure cap (21), wherein - the closure cap (21) comprises a sealing seal (20) directed towards the outside of the housing (6), - Furthermore, a sealing membrane (23) directed towards the inside of the housing (6), on which a mandrel (22) is arranged towards the outside of the housing (6), - Furthermore, a sealing surface (27) on the internal thread (26). Method for opening a housing in which there is a flammable working fluid of a left-handed cycle, wherein - The housing (6) has an open gas path to the environment protected by an adsorbent (12) for working fluid, - The housing (6) has a service opening (14) which is protected against opening by an unlocking device (16), - the service opening (14) has a service connection (15) for a service cartridge (13), - The service cartridge (13) contains a pressurized inert gas in an amount which in the relaxed state corresponds at least to the volume of the container (6), - the service cartridge (13) has a cartridge neck (19) with a connecting line in the cartridge neck (19) and an external thread (25) on the cartridge neck (19), - the service connection (15) has an internal thread (26) which matches the external thread (25) of the cartridge neck (19), - The service connection (15) has a closure cap (21), wherein - the closure cap (21) comprises a sealing seal (20) directed towards the outside of the housing (6), - Furthermore, a sealing membrane (23) directed towards the inside of the housing (6), on which a mandrel (22) is arranged towards the outside of the housing (6), - Furthermore, a sealing surface (27) on the internal thread (26), characterized by the following work steps - Screw the cartridge neck (19) into the service connection (15), - Keep turning until the mandrel (22) of the sealing membrane (23) pushes open the connecting line (24) of the service cartridge (13), - Continue turning until the cartridge neck (19) hits the sealing membrane (23), - Emptying the service cartridge (13) into the housing, - Continue turning until the cartridge neck (19) actuates the unlocking device (16), - Open the service opening (14).

Images