FIELD OF THE INVENTION

This invention relates to a refrigerant recovery and recharge device.

In particular, this invention relates to a refrigerant recovery and recharge device for a refrigeration equipment in a vehicle.

BACKGROUND OF THE INVENTION

A wide range of refrigerant recovery and recharge devices are already known. The refrigerant recovery and recharge device comprises an oil container which is used to recharge oil from the device to refrigeration equipment through the recharge path. The devices known in the prior art use oil recharge methods has two separate recharge paths or a specialized/specified method to recharge two different types of oils without contamination. Generally conventional automobiles have compressors which are lubricated with mineral oil, generally called as PAG oils. Modern automobiles with hybrid concept may utilize electrically driven compressors. The mineral oil used in normal compressors could damage the electrical compressors due to high conductivity and hence non-conductive oil generally called as use POE oils are used in hybrid automobiles. The challenge with this situation to the workshops servicing refrigeration equipments of automobiles using conventional refrigerant recovery and recharge devices is to avoid contamination of the two oils mentioned above. To overcome such challenges non-conventional complicated method are required to be used the objectives of the recharging correct oil in the refrigeration equipments. Non-conventional methods could include dedicated machines for servicing hybrid and conventional automobiles or avoiding oil recharge in automatic mode but with a special fitment onto the refrigerant recovery and recharge device.

ADVANTAGES OF THE INVENTION

The device and method as claimed in the independent claims have the following advantages. The device comprises a valve block comprising a valve having two inlets. A first oil container is in fluid communication with a first inlet and a second oil container is in fluid communication with a second inlet. The first oil container and the second oil container contain two different types of oil. Thus the recharge path for each of the oil is separate. This ensures that there is no contamination of the oil from the two oil containers but still has the advantage of using same refrigerant recharge and recovery device for vehicles using different types of fuel. Prevention of contamination of the oil from the two containers ensures safer operation of the compressor in the refrigeration equipment in vehicles. The method used for recharging oil to the refrigeration equipment reduces the liability of the operator servicing a refrigeration equipment from damaging the vehicle compressor due to contamination caused due to mixing of the two oils.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

Figure 1 illustrates various components of the refrigerant recovery and recharge
device in accordance with this invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 illustrates various components of the refrigerant recovery and recharge device in accordance with this invention. The device 10 comprises a valve block 12. The valve block 12 comprises a plurality of valve which are switched from an off position to an on position and vice versa. When the valve is switched to an on position a fluid communication is established between refrigeration equipment 14 and the device 10 through the valves in the valve block 12. The device 10 comprises a recharge path which is used to recharge refrigerant and oil from the device 10 to the refrigeration equipment 14. A first oil container 16 and a second oil container 18 is provided in the device 10. The valve block 12 further comprises a valve 20. The valve 20 has two inlets, a first inlet and a second inlet. The first oil container 16 is in fluid communication with the first inlet and the second oil container 18 is in fluid communication with the second inlet in the valve 20 of the valve block 12.

Refrigeration equipments 12 are widely used in many applications including air conditioning systems, refrigerators, vehicle air conditioners and the like. A refrigerant equipment 12 makes use of a refrigerant for the purposes of cooling, other liquids such as oil and UV dyes are also used for other applications in the refrigeration equipment. Due to prolonged usage of the refrigeration equipment the ability of the refrigerant to cool reduces and properties of the oil and UV dyes reduce over a period of time. It then becomes necessary to replace the refrigerant and the oil etc with fresh refrigerant and oil.

For the purposes of recovering the refrigerant and the oil and for recharging new refrigerant and oil to the refrigeration equipment a refrigerant recovery and recharge device is used. While servicing the refrigeration equipment the refrigerant recovery and recharge device is connected with the refrigeration equipment. When the refrigerant recovery and recharge device is switched on, depending on the recovery and recharge algorithm which is based on the pressure difference between the refrigeration equipment and the refrigerant recovery and recharge device the refrigerant and oil is recovered and later recharged into the refrigeration equipment.

A conventional refrigerant recovery and recharge device comprises a valve block which is used to establish a fluid communication between the refrigeration equipment and the
refrigerant recovery and recharge device. There exists a recovery path along which the aged refrigerant and oil flow from the refrigeration equipment to the refrigerant recovery and recharge device. There also exists a recharge path along which the fresh refrigerant and oil flow from the refrigerant recovery and recharge device to the refrigeration equipment. The refrigerant to be recharge is stored in a tank while the oil to be recharge is stored in a container. The oil container containing fresh oil is connected in the recharge path. For better understanding of the invention the refrigeration equipment is an air conditioning equipment in a vehicle.

A vehicle using different type of fuel has different requirements and specifications with respect to the type of refrigerant, oil and the like used in the air conditioning equipment. Refrigeration equipments in a fossil fuel vehicle have a compressor which makes use of mineral oils which are conductive oils such as Polyalkylene Glycol Oils popularly known as PAG oils. Refrigeration equipments in a hybrid fuel have an electric compressor which makes use of non-conductive oils such as Polyester Oils popularly known as POE oils. Thus depending on the type of fuel used in the vehicle the oil to be recharged to the refrigeration equipment varies.

While recharging oil from the refrigerant recovery and recharge device 10 to the refrigeration equipment 14 care has to be taken care that the for a fossil fuel car POE oil is not recharged, similarly for a hybrid fuel car PAG oil is not recharged. It is also necessary to take care that the recharge path for the PAG oil and POE oil is not the same. If the recharge path is the same then this leads to contaminations which reduce the efficiency and life of the compressor in the refrigeration recovery and recharge device 10. Due to the harm caused by the contamination of the PAG oil and POE oil it is not possible to merely replace the oil container in the refrigerant recovery and recharge device 10.

A conventional refrigerant recovery and recharge device does not have the capability to accommodate a separate recharge path for two separate oil containers having two different oils. Using a conventional refrigerant recovery and recharge device the only possibility of recharging different oil was by connecting it externally. However, this has the disadvantage that the amount of oil to be recharged cannot be controlled. Another disadvantage is that it is not possible to guarantee that there will be no contamination. Another disadvantage is that there was no possibility of preventing the POE oil bottle being connected in place of the PAG oil bottle and vice versa.

The object of this invention is to be able to recharge oil using the refrigerant recovery and recharge device 10 as claimed depending on the type of fuel used in the vehicle. In accordance with this invention, the device 10 comprises a valve block 12 comprising a plurality of valves which are adapted to be switched from an off position to an on position and vice versa. When the valves are switched to an on position a fluid communication is established between refrigeration equipment 14 and the device 10 through the valves in the valve block 12. When the connection is established then depending on the type of fuel used in the vehicle the oil is recharged to the refrigeration equipment 14. Thus if the vehicle uses fossil fuel then the first oil container 16 containing a PAG oil is connected in the recharge path. If the vehicle uses hybrid fuel then the second container 18 containing POE oil is connected in the recharge path.

The connection between the first oil container 16, the second oil container 18 and the valve 20 is established using a component known as a quick coupler. The first oil container 16 and the second oil container 18 have male and female connectors. The connection between the first oil container 16, the second oil container 18 and the valve 20 in the valve block 14 through the male and female connectors is such that the first oil container 16 cannot be fitted in place of the second oil container 18 and vice versa. If by mistake the operator connects the first oil container 16 in place of the second oil container 18 and the oil recharge is started, the refrigerant recovery and recharge
device 10 will not recharge any oil to the refrigeration equipment in the vehicle. Thus the device 10 has the advantage that it provides a full-proof possibility of recharging oil into the refrigeration equipment of vehicles which use different fuels. Further separate hoses are used to carry the oil from the first oil container 16 and the second oil container 18 to the valve 20. This further ensures that there is no possibility of contamination of the different oils.

The method of recharging oil from the first oil container 16 or the second oil container 18 to the refrigeration equipment 14 can be explained as follows. At one time oil from only one of the oil containers 16 or 18 is recharged to the refrigeration equipment 14. While recharging refrigerant and oil from the refrigerant recovery and recharge device 10 to the refrigeration equipment 14 in the vehicle the operator of the refrigerant recovery and recharge device 10 presses a button on front console of the device 10 to select that the vehicle uses fossil fuel or hybrid fuel. When the operator selects that the refrigeration equipment 14 is one which is used in a fossil fuel vehicle the valve 20 is switched such that only the first oil container 16 containing PAG oil is connected to the recharge path and the oil from the first oil container 16 is recharge to the refrigeration equipment 14. Similarly when the operator selects that the refrigeration equipment 14 is one which is used in a hybrid fuel vehicle the valve 20 is switched such that only the second oil container 18 containing POE oil is connected to the recharge path and the oil from the second oil container 18 is recharged to the refrigeration equipment 14. Thus the advantage of the device 10 in accordance with this invention is that one device 10 can be used to recharge oil and refrigerant to a refrigeration equipment 14 in a vehicle which use different type of fuels.

If at one instant in time the oil is being recharged to a refrigeration equipment 14 of a vehicle using fossil fuel and at a later instant if the operator selects that the oil has now to be recharged to a refrigeration equipment 14 of a vehicle using hybrid fuel, the device does not immediately switch to the other oil container. As some residual oil from
the previous recharge will be stuck in the hose which connects the device 10 and the refrigeration equipment, it is necessary that the residual oil be removed from the recharge path otherwise this may lead to contamination. Thus before switching to the other oil container a small quantity of refrigerant which is stored in the device 10 is circulated along the recharge path such that any residual oil which may be present in the recharge is washed away. Once the residual oil is washed away the other oil container is connected in the recharge path and recharge can be started. Thus the device 10 ensures that any possibility of contamination of the oil is completely prevented.

WE CLAIM:

1. A refrigerant recovery and recharge device (10) comprising:

(i) a valve block (12) adapted to establish fluid communication between said device (10)
and a refrigeration equipment (14);

(ii) a recharge path adapted to recharge oil to said refrigeration equipment (14) through
an outlet in said valve block (12);

Characterized in that

- said device (10) comprising at least a first oil container (16) and a second oil container (18) adapted to recharge oil to said refrigeration equipment through said recharge path;

- said valve block (12) comprising a valve (20) with a first inlet and a second inlet, said first oil container (16) in fluid communication with said first inlet and said second oil container (18) in fluid communication with said second inlet to recharge oil to said refrigeration equipment (14).

2. The device (10) as claimed in claim 1, wherein said refrigeration equipment (14) is a refrigeration equipment in a vehicle.

3. The device (10) as claimed in claim 1, wherein said first oil container (16) and said second oil container (18) contain different oils.

4. The device (10) as claimed in claim 1, wherein said first container (16) contains oil used in the refrigeration equipment (14) of a fossil fuel vehicles.

5. The device (10) as claimed in claim 1, wherein said second oil container (18) contains oil used in the refrigeration equipment (14) of a hybrid vehicle.

6. The device (10) as claimed in claim 1, wherein said valve (20) in said valve block (12) is used to recharge oil from said first oil container (16) or said second oil container (18) to said refrigeration equipment (14).

7. The device (10) as claimed in claim 1, wherein said first oil container (16) and said second oil container (18) have a male connector and a female connector to connect said first oil container (16) and second oil container (18) to said valve (20).

8. A method to recharge oil in a refrigeration equipment (14) using a refrigerant recovery and recharge device (10), said method comprising the following steps:

(i) establishing a fluid communication through a valve block (12);
Characterized in that recharging oil from a first oil container (16) to said refrigeration equipment (14) or recharging oil from a second container (18) to said refrigeration equipment (14) depending on the type of fuel used by said refrigeration equipment.