FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)


TITLE OF THE INVENTION Vertical tube air-conditioning condenser assembly
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Ho mi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Ranganath kumar S.V, Suresh Babu Tadigadapa and Gopinath
Chandrasekharan all Indian national of TATA MOTORS LIMITED, an Indian
company having its registered office at Bombay House, 24 Homi Mody
Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following Complete specification particularly describes the invention and the
manner in which it is to be performed.

FIELD OF INVENTION
This invention relates to AC condenser assembly used in vehicles and more particularly to vertical tube AC condensers assembly for vehicles/automobiles.
BACKGROUND OF INVENTION
In conventional vapor compression refrigeration system consists of major components such as compressor, condenser, receiver-dryer, expansion valve, evaporator and plumbing which are integrated with each other and operated with fluid called refrigerant to obtain cooling effect at evaporator by giving input power to compressor. The effectiveness of air conditioning depends on all the components selection and sizing to deliver the best cooling capacity for the minimum power consumption. Vapor refrigerant at low pressure and temperature from suction pipe/hose enters into the compressor which is mounted on engine gets compressed to high pressure and temperature. Compressor is driven by crank pulley through belt drive. Damper is in turn driven by engine. The high pressure and temperature vapor refrigerant enters into the condenser through discharge pipe/hose where the heat gets rejected to the atmospheric ambient air there by attain sub cooled liquid at the exit of the condenser. The high pressure and temperature liquid refrigerant travels through receiver-dryer and enters the expansion valve through liquid pipe/hose there by throttle the flow of refrigerant to low pressure and temperature enters into the evaporator in liquid and vapor quality form picks heat from the air by delivering cooling effect. The low pressure and temperature super heated vapor refrigerant enters into the compressor through suction pipe/hose and the cycle repeats.

Receiver dryer bottle acts as a reservoir during relatively low load conditions and dryer acts as moisture absorbent. Also it acts as a separator for liquid and vapor refrigerant and maximum allows liquid refrigerant through outlet. Condenser is one of the very important components among the vapor compression refrigeration cycle which controls the head pressure and temperature there by reducing the power consumption by the compressor from engine. Also condenser condenses the refrigerant from super heated refrigerant to sub cooled refrigerant by rejecting heat to the atmospheric ambient air attains sub cooling state at the exit of the condenser. The advantage of the sub cooling liquid refrigerant is to control the quality of the throttle refrigerant at the inlet to the evaporator which enhances the cooling effect by increasing the liquid quantity of refrigerant. The sizing of condenser is an important process which requires calculations, simulations and validations for optimization.
Presently it is in practice to use multi flow type of integrated receiver-dryer condensers with horizontally aligned tubes in vehicles/automobiles mounted on radiator or intercooler behind the front grille and bumper. The discharge pipe/hose is connected to the inlet port of the condenser. Condenser can be sized for any number of passes/tubes depends on heat rejection and pressure drop of refrigerant across the condenser inlet and out. Normally integrated receiver-dryer condenser is sized for four passes. Normally in practice the tubes are horizontally oriented and brazed/welded between the inlet and outlet ports provision for refrigerant entry and exit. Mainly the four passes are de-super heated pass, condensing pass, liquid pass and sub cooled pass. The high pressure and temperature vapor refrigerant enters into inlet port bared to the header which in turn tubes are bared to the header and interconnected with each other to lay down the path for the refrigerant. The said refrigerant enters de-super heated pass rejects heat to the atmospheric ambient air and attains saturated conditions where condensation starts from vapor to liquid form and

finally attains saturated liquid condition. The saturated liquid refrigerant enters into the receiver-dryer bottle which is integrated into the condenser. Receiver-dryer is brazed to the condenser with inlet and outlet tubes. Receiver-dryer bottle separates the liquid and vapor refrigerant and allows only liquid refrigerant into sub cooled pass where the refrigerant temperature further reduces at constant pressure finally attaining sub cooled condition at the exit of the condenser.
OBJECTS OF INVENTION
The main object of this invention is to provide vertical tube condenser with chassis offset mounting scheme cabin air conditioner which can assist in cabin cooling.
Yet another objective of this is to provide vertical tube condenser with chassis offset mounting scheme cabin air conditioner for vehicles by maintaining required comfort temperature inside the cabin.
Yet another object of this invention is to provide vertical tube condenser with chassis offset mounting scheme cabin air conditioner for vehicles which is simple in construction and cost effective.
Yet further object of this invention is to provide vertical tube condenser with chassis offset mounting scheme cabin air conditioner for vehicles which is easy to service.
BRIEF DESCRIPTION OF INVENTION
Automotive Heating, Ventilation & Air-Conditioning (HVAC) system major components consist of compressor assembly, condenser assembly, HVAC unit assembly and plumbing. The said above components are inter connected to each

other to build a HVAC system to get the desired output in the form of cooling / heating. The functioning of said HVAC system is described as follows. Low temperature and pressure refrigerant vapor from evaporator enters into the compressor inlet through suction pipe, gets compressed to high pressure and temperature in compressor during compression stroke. The high pressure and temperature refrigerant vapor enters into the condenser through inlet port gets condensed to liquid form by rejecting heat to the ram air. The high pressure and temperature liquid refrigerant leaves the condenser through outlet port enters into the liquid pipe and Receiver-Drier bottle and then in turn enters the expansion valve. The refrigerant will then expand from high pressure and temperature liquid to low pressure and temperature liquid and vapor form and enters into the evaporator. The low pressure and temperature liquid refrigerant will absorb heat from the air which needs to be conditioned and converts into the vapor form. The low pressure and temperature vapor form will then enter into the compressor through suction line and then the process is repeated.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig.l - Shows isometric view of refrigerant circuit along with Vertical tube AC condenser assembly for automobiles
Fig.2 - Shows another isometric view of refrigerant circuit along with Vertical tube AC condenser assembly for automobiles
Fig. 3 - Shows front view of AC condenser assembly with vertical tubes for automobiles in accordance with this invention

Fig. 4 - Shows rear view of AC condenser assembly with vertical tubes for automobiles in accordance with this invention
Fig. 5 - Shows sectional view of AC condenser assembly with vertical tubes used in this invention
Fig. 6 - Shows side view of mounting bracket for Vertical tube AC condenser
Fig. 7 - Shows isometric view of refrigerant pipe circuit connecting all AC components on automobiles
Fig. 8 - Shows top view and sectional view of condenser inlet & outlet assembly port used for automobiles
Fig. 9 - Shows isometric view of HVAC unit assembly used for automobiles
Fig. 10 - Shows sectional view of Receiver -Drier used for automobiles Fig.l 1- shows iso metric view of receiver drier mounting assembly.
Fig. 12 -shows sectional view at B-B of receiver drier mounting bracket assembly DETAILED DESCRIPTION OF DRAWINGS
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same,
As shown in Figures 1 & 2, the refrigerant circuit in accordance with an embodiment of the invention comprises a HVAC unit (1), an AC compressor assembly (2), a

condenser assembly (3), a control panel (4) and a piping system (5,6, 7) for interconnection of the above components.
Figures 3-5 describe the vertically mounted condenser assembly in accordance with this invention. Vertical tube (34) AC condenser assembly (3) for automobiles in accordance with this invention comprises of a condenser core (80) with inlet port (19) and outlet port (20), fan assembly (81) and shroud (14) with reinforcement ribs (70). The condenser core (80) is provided with flat tubes (34), horizontally positioned upper tank header (32), horizontally positioned bottom tank header (33), receiver-drier (22) port assembly (52) with mounting (71) provision and connected liquid pipe (41). The assembly of the port assembly is illustrated in Figure 8, which will be discussed below. Said flat tubes (34) are divided into a plurality of rectangular shaped sub channels. Said upper tank header (32) is having perforations on bottom side and bottom tank header (33) is having perforations on top side to insert the flat tubes (34). Said flat tubes (34) are fixed vertically into the said upper tank header (32) and bottom tank headers (33).
The receiver-drier unit is clearly illustrated in Figure 10. Said receiver-drier (22) is a hollow tube (78) having a cover member (79) with mounting provision (76). Said cover member has provision to mount inlet and outlet tubes Said hollow tube consists of a flow tube (74) with inlet, desiccant (72) and filter (73). Said receiver-drier is integrated with said condenser core (80) in vertical direction with inlet pipe (36) and outlet pipe (37) brazed (77) to the bottom tank header (33). Said receiver-drier is mounted on said condenser core with mounting bracket (31) and fasteners (93,94). Receiver-drier (22 is mounted with the help of separate mounting assembly (31) which is illustrated in Figure 11. Said mounting bracket assembly is having left side bracket (91) which holds receiver-drier (22) along with right side bracket (90) by the

fasteners (93). Left side bracket (91) is mounted on condenser side plate (92) by the fastener (94).
The port assembly (52) as shown in figure 8 consists of pressure switch (21), inlet port (19) and outlet port (20) are brazed on upper tank header (32) of said condenser core (80). Said inlet port (19) and outlet port (20) are connected to the refrigerant pipes of both liquid (7) and discharge pipe (6) through pipe connectors (47) having rubber seals (48),
Said fan assembly (81), as shown in Figures 3 - 5, consists of a fan motor (12) with pig tail (43) and a plurality of blades (13) mounted on rear end of the condenser core (80) with the support of shroud (14) and shroud mountings (35) (fig. 3). Said shroud (14) is provided with mesh (42) geometry to allow the ram air across the said condenser core (80). Further, said condenser core, fan assembly, shroud are assembled with fasteners, bolts and nuts. Said condenser assembly is mounted with fasteners, bolts and nuts on mounting bracket (9) with the help of mountings (44) provided on condenser assembly.
Figure 6 illustrates the mounting bracket on which said condenser assembly is mounted according to the present invention. The mounting bracket (9) consists of a main frame (82), an upper supporting rod (40) with mounting provision (62), a bottom supporting rod (39) with mounting provision (50), upper stay rod (10), bottom stay rod (11), locator pin (23), mounting holes (38), fasteners (83), bolts and nuts. Upper supporting rod (40) is welded (61) to the main frame (82) in the form of ' Y' section. Said bottom supporting rod (39) is joined with fasteners (83) to the main frame. Said upper stay rod (10) with mounting (68) provision is joined between the chassis frame (8) and the upper supporting rod (40) with bolts and nuts (84). Said

bottom stay rod (11) with mounting (69) provision is joined between chassis frame (8) and shroud (14) through bolts and nuts (84).
The complete condenser assembly with mounting bracket module is vertically mounted with the help of said locator pin (23) (see figure 4) in the form of cantilever on one side of the vehicle chassis (8) frame in wheel arch area behind the bumper, preferably on the left hand side of the vehicle chassis (8) frame in wheel arch area behind the bumper as shown in the schematic of figure 1. The condenser assembly
(3) and mounting bracket (9) can withstand high vibrations which are directly
transferred from chassis frame of the vehicle.
Said fan assembly (81) may be either push type or pull type; if it is pull type it is mounted on rear side of the said condenser core; if it is push type it is mounted on front side of the condenser.
As can be observed especially in figure 2, the said condenser assembly (3) is connected with HVAC unit assembly (1) and AC compressor assembly (2) through the refrigerant pipes discharge (6), liquid (7) and suction (5). The said HVAC unit assembly (1) is mounted on firewall inside the passenger compartment with support of fasteners provided to the mountings (28).
Figure 9 illustrates the HVAC unit. Said HVAC unit assembly (1) consists of blower assembly (15), evaporator, heater, plastic casings (18), clamps (60), expansion valve housing (53), heater tube housing (54), dampers (56), actuators (55), insulation (58) and fasteners. As already described with reference to figure 1, the HVAC unit assembly (1) and AC compressor assembly (2) are controlled through control panel
(4) connected through wiring harness. Said blower assembly (15) consists of blower

motor (63) (fig. 2), blower plastic casings (85) and scroll (86), fresh air (29) opening and recirculation (30) opening.
The said control panel (4) is used to change the air flow path from HVAC unit in three different modes of vent outlet (16), defrost outlet (17) and foot outlet (59). The air can be regulated to in both the modes at a time with the help of said dampers change in positioning (56).
As shown in figure 2, the said AC compressor assembly (2) is mounted on the engine and driven by a belt through crank pulley. The compressor assembly consists of body shell (87), magnetic clutch (25), mounting lugs (24), inlet port (65) and outlet port (66). The refrigerant liquid pipe (7) is connected from said condenser core (80) outlet port (20) to the thermostatic expansion valve (88) inlet port (57) which is assembled in the said HVAC unit assembly (1). The refrigerant suction pipe (5) is connected from thermostatic expansion valve (88) outlet port (67) which is assembled in the said HVAC unit to AC compressor inlet port (65). The refrigerant discharge pipe (6) is connected from AC compressor outlet port (66) to the said condenser inlet port (19).
Said AC compressor assembly (2) sucks the low pressure and temperature refrigerant (89) from evaporator outlet in superheated vapor condition through refrigerant suction pipe (5) enters into the compressor inlet port (65). The low pressure and temperature refrigerant (89) gets compressed to high pressure and temperature refrigerant vapor leaves the compressor outlet port (66) and then enters to the vertical tube AC condenser core (80) inlet port (19) in desuperheated vapor condition through refrigerant discharge pipe (6). All three refrigerant pipes consist of said liquid, suction and discharge pipes are provided with aluminum tube (26), rubber hose (27).

Rubber hose is crimped (49) to aluminum pipe to avoid refrigerant leak and having flexibility in bending. Liquid and suction pipes are provided with suction charging port (45) and liquid charging port (46).
The high pressure and temperature refrigerant desuperheated vapor passes through said vertical tube AC condenser core (80). The refrigerant vapor passes through certain number of vertical flat tubes (34) brazed to both the upper (32) and bottom tank headers (33) with dividers, in the first pass where desuperheated refrigerant vapor gets converted to saturated vapor by rejecting the heat to the atmosphere ram air. Each flat tube (34) is divided into certain number of rectangular channels to allow refrigerant through in so as to increase the wetted perimeter of the refrigerant for the effective heat rejection by creating turbulence. The refrigerant takes U-turn near divider and passes upwards in the second pass and starts condensing from saturated vapor to saturated liquid during the pass. Thereafter the refrigerant passes downwards by diverting near divider in condenser core third pass and then enters into integrated receiver- drier. Receiver-drier (22) separates the two phase fluid and ensures only liquid refrigerant passed out. Liquid refrigerant from receiver-drier (22) passes upwards in the forth pass to sub cool the liquid refrigerant and leaves the outlet of the condenser core (80) through outlet port (20) and enters the thermostatic expansion valve (88) inlet port (57) through refrigerant liquid pipe (7).
The high pressure and temperature sub cooled liquid refrigerant (89) expands in thermostatic expansion valve (88) and enters into the evaporator as low pressure and low temperature two phase liquid.

Low pressure and temperature two phase liquid refrigerant gets evaporated into low temperature and pressure superheated vapor in the evaporator core by absorbing the heat from the air in the passenger cabin.
The low pressure and temperature superheated refrigerant vapor leaves the evaporator through outlet of expansion valve (88) and enters into the AC compressor(2) through refrigerant suction pipe(5).
Conventionally, automotive AC condensers are mounted on radiator or intercooler behind the vehicle front grille or bumper to effectively dissipate heat to the atmosphere ram air while in running and stationary conditions. Said condenser fan is mounted in front of the condenser core to help the condenser core heat removal. Engine cooling performance will then deteriorates or required optimization to meet the required targets. The same engine cooling performance can be maximized by placing the condenser in other than engine cooling module, so that risk for engine failures or performance worsening can be minimized. Therefore radiator size and fan capacity requirements for engine cooling module can be reduced. One of the possible options for placing the condenser assembly is in "wheel arch area where the space can be utilized for mounting. The challenge for mounting the condenser in wheel arch area is the design of mounting bracket which requires taking lot of vibrations, sudden loads when vehicle moves in off road condition. Another challenge for mounting the condenser assembly in wheel arch area is the retaining of the condenser performance close to the condenser when it is part of engine cooling module. In present invention, said condenser fan is able to suck the atmospheric ram air through the condenser fins effectively either in vehicle stationary condition or in running condition, there by delivering the required cooling performance in passenger cabin while rejecting the sufficient heat to the atmospheric ram air.

The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

WE CLAIM
1. A condenser assembly for a refrigeration circuit in a vehicle comprising:
a condenser core having a horizontally positioned upper tank header and a bottom tank header;
a fan assembly mounted on rear end of said condenser core and supported by a shroud provided with a mesh to allow ram air across said condenser core;
a receiver-drier unit integrated with said condenser core in vertical direction , said receiver-drier unit having inlet pipe and out pipe fixed to said bottom tank header;
a common port assembly fixed on said upper tank header of said condenser core, said common port assembly comprising a pressure switch, an inlet port and an outlet port;
a plurality of flat tubes extending vertically between said upper tank header and said bottom tank header, each of said flat tube being divided into a plurality of rectangular channels to increase the wetted perimeter of a refrigerant passing through said flat tubes for effective heat rejection by creating turbulence; and
said condenser assembly being vertically mounted in the form of cantilever on one side of a vehicle chassis frame in a wheel arch area behind a bumper.
2. The condenser assembly as claimed in claim 1, wherein said upper tank header has perforations on its bottom side and said lower tank header has perforations on its top side to insert and vertically extend said flat tubes.
3. The condenser assembly as claimed in claim 1, wherein said shroud of said fan assembly is reinforced by means of reinforcement ribs.

4. The condenser assembly as claimed in claim 1, wherein said receiver-drier unit is a hollow tube with a cover mounted on its bottom surface having provisions for said inlet and outlet pipe, said hollow tube consists of a flow tube with an inlet, a desiccant and a filter.
5. The condenser assembly as claimed in claim 1, wherein said condenser assembly is vertically mounted on a mounting bracket assembly, said mounting bracket assembly comprising a main frame connected to an upper supporting rod and a bottom supporting rod, an upper stay rod is joined between vehicle chassis frame and said upper supporting rod by fastening means, a bottom stay rod is joined between said chassis frame and said shroud by fastening means.
6. The condenser assembly as claimed in claim 9, wherein said condenser assembly is vertically mounted on said mounting bracket assembly in the form of cantilever by means of a locator pin.
7. The condenser assembly as claimed in claim 1 or 10, wherein said condenser assembly is preferably mounted on the left hand side of the vehicle chassis frame in the wheel arch area behind the bumper.
8. The condenser assembly as claimed in claim 1 , wherein said fan assembly is either a push type fan assembly mounted on front side of said condenser assembly or a pull type fan assembly mounted on rear side of said condenser assembly.
9. A refrigeration circuit comprising:
a HVAC unit;
a compressor assembly;

a control panel to change the air flow path from HVAC unit in three different modes of vent outlet, defrost outlet and foot outlet;
a condenser assembly as claimed in claims 1 to 15; and
piping system for interconnection between said HVAC unit, compressor assembly and condenser assembly to obtain desired cooling or heating.
10. A condenser assembly for a refrigeration circuit in a vehicle as hereinabove described with reference to the accompanying drawings.
Dated this 13th day of January 2009