Abstract:
In a method for servicing an air conditioning system of a motor vehicle, surrounding areas in which there is a risk of leakage of inflammable coolant is ventilated such that air in the surrounding areas is suctioned out and discharged from the surrounding areas.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method of servicing cooling systems in vehicles, said servicing including suction, cleaning and subsequent adding of coolant to the air conditioning system, said coolant including inflammable coolants, as well as equipment and use thereof. 
     2. Description of the Related Art 
     Today, air conditioning systems in vehicles contain coolants which are not inflammable, and, therefore, servicing, i.e. suction, cleaning and adding of the coolant, may take place without any need for special safety measures. 
     However, these known coolants are a risk to the environment, since, when being discharged, they involve an increased greenhouse effect. 
     Therefore, it is endeavoured to provide alternative coolants which do not increase the greenhouse effect, and coolants are being developed which, however, are inflammable. This means that these new coolants cannot be serviced by the known methods, but require special safety measures in accordance with the ATEX Directive No. 94/9/EU. It is a matter of safety zones in the area around the inflammable vapours which are possibly discharged. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the invention to provide methods which satisfy the ATEX Directive using inflammable media, such as inflammable coolants, and this is achieved according to the invention by a method of servicing, where the areas in which there is a risk of leakage of inflammable agents, such as the area around the engine of the vehicle as well as the service equipment necessary for the servicing, are ventilated, so that the air in these areas is sucked out and discharged from the areas. 
     It is ensured in this manner that the areas in which there is a risk of occurrence of inflammable liquids, vapours, are reduced to comprise solely these inflammable zones, and therefore, it is possible to provide ventilation in a simple manner by suction and thus safe removal of inflammable components, which are discharged outside the service area via channels. Hereby, the safety requirements in the so-called Zone  2  area may be met in accordance with the Directive, thus making it possible in practice to service these inflammable coolants. 
     When the Zone  2  area around the engine of the vehicle is sucked out via a suction chamber or channel disposed below the engine, the safety requirements may be met, without this involving inconvenience to the service work in general. 
     When the Zone  2  area is ventilated around the service equipment, i.e. the equipment which sucks, cleans and adds coolant, and which is enclosed in a cabinet, the interior of this may be ventilated, which ensures that this zone, too, meets the safety requirements, without causing inconvenience to the service work in general. 
     When the method is applied to a filling station, which comprises the equipment necessary for the adding of coolant, and this is encapsulated in a cabinet which is sucked out, the Zone  2  requirements will be met, without the service work being impeded or rendered difficult by this. 
     When the equipment is controlled partly by subjecting it to vacuum, partly to pressure, it is ensured that the system is tight under all pressure conditions. 
     When the service equipment is provided in a ventilated cabinet with the necessary components, and the air is discharged from the cabinet via a hose to the exterior of the service building, an effective suction is achieved, and thereby a safely exhausted Zone  2  area around the service equipment. 
     Finally, it is expedient to use the method for both servicing of air conditioning systems and for adding coolant on a production line. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a system for servicing a vehicle, with the Zone  2  area indicated by hatching. 
         FIG. 2  shows a sectional view of service equipment with incorporated ventilator. 
         FIG. 3  shows adding of coolant on a production line, in which the Zone  2  area is likewise hatched. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The first example is a method of servicing a cooling system in a vehicle  1 , as shown in  FIG. 1 . 
     The vehicle is shown disposed in a space  20  in a service building or the like with a roof  19  and walls  3 . A sprinkler system with nozzles  18  is shown at the top. 
     The vehicle  1  is disposed such that the engine compartment is present above a suction trough  4 . In the example shown, it is a front engine, but, of course, it might also be a rear engine. 
     The suction trough  4  is provided with inlet openings at the top, so that air from the space  20  may be sucked out, as indicated by arrows  5 . 
     The suction takes place via a blower or ventilator  7 , whose outlet side provides discharge of the air outside the wall  3 , as indicated by arrows  8 . 
     In the example shown, the service system is constructed as a wheeled cabinet  9 . At the top of this cabinet, there is a room  10  for the electrical control, etc., at the side a room  12  for the service equipment, such as coupling parts, etc, and beneath a room  11  for components and the like. Various components are shown at the bottom of the system, such as a vacuum pump, a liquid container, etc., and also a differential pressure meter  16 . 
     The cabinet  9  is partly ventilated, as air from the space  20  may be admitted through an opening  17  in the cabinet  9 , as indicated by an arrow  13 , so that the space shown hatched may be evacuated by means of a ventilator  38 , via a suction hose  15 , and the air is discharged from the service space  20 , as indicated by arrows  8  in  FIG. 1 . 
     The service unit, as shown in  FIG. 2 , has a housing configured as a wheeled cabinet  21 , with an interior with an upper  22  and a lower part  23  beneath the upper part  22 , and with a bottom  24 . Inside the cabinet  21 , components are arranged for an emptying mechanism  25  for exhausting coolant or a compressor oil mixture from the cooling system, e.g. a vacuum pump  26 , and components for a filling mechanism  27  for refilling a closed cycle of the cooling system e.g. a compressor  28 . 
     A first air inlet opening  29  is provided on the upper part  22  of the cabinet  21 , and a discharge opening  30  is provided on the lower part  23 . In addition to the first part air inlet opening  29 , a second air inlet opening  31  is provided, which is in front of a waste oil bottle  32 . For instance, an internal cylinder  33  and the compressor  28  are arranged on the bottom  24  in the interior of the cabinet  21 . Also a third inlet opening  34  is arranged in the bottom  24 . 
     The interior of the cabinet  21  is ventilated by a ventilation system, as air from the outside space  20  around the cabinet  21  may be admitted through the air inlet openings  29 ,  31 ,  34  into the interior of the cabinet  21 , as indicated by arrows  35  and  36  and by an arrow  37 . It is also possible that more than three inlet openings may be provided. 
     The ventilation system comprises a ventilator  38  inside the cabinet  21 . The ventilator  38  is arranged in front of the discharge opening  30 . The outside of the cabinet  21  has arranged thereon a flange  39  around the discharge opening  30  for the fastening of a hose  15 . Thereby, the air or inflammable gas or vapours are pressed out of the interior of the cabinet  21  by the blast pressure of the ventilator  38 , as indicated by an arrow  40 . 
     For a better flow of the fresh air behind the inlet opening  29 , there is provided a guide sheet  41 , which separates a zone  42  with electrical components, such as an electrical power supply  43  and the vacuum pump  26 , from the whole area on the upper part  22 . In order to eliminate the zone  42  around the electrical components  43  and the vacuum pump  28 , the flow of fresh air is configured in such a way that fresh air shown by the arrow  35  from the outside of the service unit is sucked into the cabinet  21  through the first inlet opening  29  and thereby passes the electrical components  43  and the vacuum pump  26  in the area  42 , as shown by arrows  45 . In addition, in order to eliminate the inflammable zone around the internal cylinder  33  and the compressor  28  and the waste oil bottle  32 , fresh air, as shown by arrows  36  and  37  are sucked from the outside of the service unit into the interior, thereby passing the components on the bottom  24 , e.g. the internal cylinder  33  and the compressor  28  and the waste oil bottle  32  on the side wall. 
     The discharge opening  30  is connected with a hose  15  for discharging air from the interior of the cabinet  21  outside a service space, as shown by an arrow  8  in  FIG. 1 . The ventilator  38  acts such that fresh air from the outside of the service unit is sucked into the interior of the service unit through the inlet openings  29 ,  31 ,  34  and is pressed out through the discharge opening  30  and through the hose  15  outside a service building. Thereby, air contaminated with inflammable coolant, which may escape in the interior of the service unit  21 , is pressed out of the interior of the service unit  21 . Therefore, the contaminated air inside the cabinet is handled correctly. 
     With this equipment, the method according to the invention may be carried out in a such a manner that the ATEX Directive may be satisfied with the safety requirements which are made, as indicated in the shown example by the hatching, viz. a Zone  2  of minimum 1 meter around the engine and a Zone  2  in the cabinet  9 ,  21 . Inflammable vapours from liquids, which may be ignited, may occur in these zones at servicing and perhaps because of leakages, etc. 
     By means of the ventilation possibilities described, viz. partly below the engine, partly through the cabinet, the requirements of the ATEX Directive may be met, without this causing work-related problems. 
     Now, the equipment shown in  FIG. 3  will be described. 
     In the example shown, an air conditioning system is to be filled with an inflammable coolant in a so-called online production line, where the vehicle  52  is advanced on a belt  51 . 
       FIG. 3  shows a filling station  53  as a suspension for a cabinet comprising an electrical cabinet  55 , a classified and ventilated room  59 , which is hatched to indicate that it is a Zone  2  room, a liquid pump  58  as well as a high pressure line  56  and a low pressure line  57  for a filling adaptor (not shown). 
     It is noted that with this production line there is no Zone  2  around the engine, as the zone is exclusively present inside the ventilated room  59  and the lines  56  and  57 . 
     The Zone  2  area  59  in the cabinet is connected with a ventilation system at the top via a ventilation channel  60 , so that the air present in the cabinet  59  may be sucked out, as indicated by arrows  61 . It is ensured thereby that the cabinet satisfies the safety zone requirements in accordance with the ATEX Directive. 
     The online filling may therefore take place in a safe manner, without this involving any inconvenience to the work. 
     For the control of the system, including the tightness of the couplings, the filling system may be subjected to partly a vacuum, partly a positive pressure with a view to controlling its tightness. Hereby, it is ensured in a simple manner that the system is completely tight under all conditions of operation. 
     The equipment according to the invention may readily be installed in existing service systems, as this does not require material changes, but just installation of the necessary ventilation equipment.