Patent Application
20070000263
This disclosure relates generally to heating, ventilation, air conditioning (HVAC) systems, and more particularly to an assembly design for an HVAC system on a vehicle.
Modem vehicles may be equipped with heating, ventilation, and conditioning (HVAC) systems to control conditioned air supplied, for example, to the cabin of the vehicle. On some vehicle platforms, a component of the HVAC system may be disposed at one location while on other vehicle platforms, the same component of the HVAC system may be disposed at a different location. Additionally, some vehicle platforms may require one kind of HVAC system component while another kind or model of the same component may be required on another vehicle platform. Utilizing another kind or model of the same component may often require alternative connections, fittings, additional vehicle modifications, etc., in order to configure, for example, additional devices to the component. This may provide difficulties in trying to accommodate the component on various vehicle platforms. As a result, inefficiencies may exist in incorporating the component into various platform designs as well as extra expenditures which may be associated with additional efforts to retrofit different component designs.
Another trend in modem vehicle manufacturing may include a rapid increase in the number of components or accessories in the engine compartment of a vehicle. Thus, a resultant decrease in available space within the engine compartment may increase a desirability of combining related components into a compact assembly. Such a combination assembly is compact and often more economical than separate components. In addition, connections between the formerly separate components can often be simplified or eliminated.
Combining related components into a compact assembly has been proposed in an effort to accommodate the needs of a particular type of vehicle. U.S. Pat. No. 3,754,410 issued to Jacobs describes a combination compressor and condenser assembly for a vehicle air conditioning system. While the system of the '410 patent may provide a combined compressor and condenser assembly, the compressor is driven by a pulley-fan member connected to an internal combustion engine via drive belt. Thus, a power outlet of the compressor is tied directly with a drive speed of the engine. The compressor can therefore provide over-cooling or under-cooling to the compartment of the automobile based upon the engine speed of the vehicle. This can result in an inefficient use of vehicle power. Accordingly, additional means may be employed to compensate for the over-cooling or under-cooling effect. However, such means may add undesirable costs.
Methods and systems consistent with certain features of the disclosure are directed to solving one or more of the problems set forth above.
In one embodiment, a heating, ventilation, and air conditioning (HVAC) module for an HVAC system is provided. The HVAC module may include an input port, a compressor connected to the input port, a condenser connected to the compressor, a heat exchanger connected to the compressor, an output port connected to the heat exchanger, and a thermostatic expansion valve connected to the condenser, the compressor, and the heat exchanger.
Another aspect of the present disclosure includes a work machine having a heating and cooling system. The work machine may include an operator cabin and a heating, ventilation, and air conditioning (HVAC) system configured to provide conditioned air to the cabin. The HVAC system may have an HVAC module coupled to an evaporator assembly. The HVAC module may further include an input port, a compressor connected to the input port, a condenser connected to the compressor, a heat exchanger connected to the compressor, an output port connected to the heat exchanger, and a thermostatic expansion valve connected to the condenser, the compressor, and the heat exchanger.
Yet another aspect of the present disclosure includes a method of controlling a heating and cooling system. The method may include circulating a refrigerant, in order, to and through a compressor, to and through a condenser, to and through a heat exchanger, to and through an evaporator assembly and back to the compressor. The method may further include circulating a portion of the refrigerant, in order, from the condenser to and through a first thermostatic expansion valve, to and through the heat exchanger, to and back through the first thermostatic expansion valve, and to the compressor.
Yet another aspect of the present disclosure includes a work machine having an operator cabin, a heating, ventilation, and air conditioning (HVAC) system configured to provide conditioned air to the cabin. The work machine may further include an HVAC system having a containment assembly having an HVAC module including an input port, a compressor connected to the input port, a condenser connected to the compressor, a heat exchanger connected to the compressor, an output port connected to the heat exchanger, and a thermostatic expansion valve connected to the condenser, the compressor, and the heat exchanger.
Yet another aspect of the present disclosure includes a method of controlling a heating and cooling system. The method may include circulating a refrigerant through an input of a compressor, to a condenser, and directly to and out of a heat exchanger. The method may further include diverting a portion of the refrigerant exiting the condenser and indirectly providing the portion through the heat exchanger and back to the compressor for subsequent transfer of the portion to the heat exchanger.
HVAC system 112 may be powered by any appropriate power source. For example, HVAC system may be driven by a generator 114 coupled to an internal combustion engine 110 of the work machine 100. Alternatively, HVAC system 112 may be driven by an alternative power unit, such as a fuel cell or direct electrical connection (not shown), or may be driven directly by the internal combustion engine 110 of the work machine 100. The HVAC system 112 may be configured to supply conditioned air to a desired compartment 102 of the work machine 100. Compartment 102 may include, for example, an operator's cab of the work machine 100, with the conditioned air being delivered to the operator's cab through one or more vents 109.
Referring to
HVAC module 200 may be connected to an evaporator 210 of the work machine 100 to form a closed loop refrigeration circuit 212 for circulating an appropriate conditioning fluid, for example, a refrigerant fluid. Thus, the refrigerant fluid may be subjected to a partial thermodynamic process within the HVAC module 200 and further processing through the evaporator 210 as the refrigerant fluid is converted into a gaseous phase. The evaporator 210 may be configured to be swept by an airflow in order to produce a refrigerated or cooled air supply that may be delivered through one or more vents 109 to compartment 102 of work machine 100 in any conventional manner.
HVAC module 200 may include any variety of plumbing for connecting the components of the HVAC module 200. Such plumbing may include non-limiting items such as connection hoses, piping, and conduits, with appropriate fittings, such as, for example, threaded and/or slip-on type fittings. With respect to the particular plumbing of HVAC module 200, a connection line 214 may be utilized to connect a refrigerant input port 216 of the HVAC module 200 to a first input 270 compressor 202. Condenser 204 may be connected via connection line 218 to the compressor 202. Connection line 220 may be utilized to connect the condenser 206 to a first input 222 of the vapor injection heat exchanger 206. Connection line 224 connects a first output 226 of the vapor injection heat exchanger 206 to a refrigerant output port 228 of the HVAC module 200.
A portion of refrigerant from the condenser 204 may also be supplied to the vapor injection heat exchanger thermostatic expansion valve 208. Connection line 230 may be utilized to couple connection line 220 to a first input 232 of the vapor injection heat exchanger thermostatic expansion valve 208. A connection line 234 may be utilized to couple the vapor injection heat exchanger thermostatic expansion valve 208 back to the vapor injection heat exchanger 206. Thus, connection line 234 may connect a first output 236 of the vapor injection heat exchanger thermostatic expansion valve 208 to a second input 238 of the vapor injection heat exchanger 206. The vapor injection heat exchanger 206 may be connected back to the vapor injection heat exchanger thermostatic expansion valve 208. Connection line 240 may connect a second output 242 of the vapor injection heat exchanger 206 to a second input 244 of the vapor injection heat exchanger thermostatic expansion valve 208. An output of the vapor injection heat exchanger thermostatic expansion valve 208 may be linked to the compressor 202 through connection line 248 extending between a second output 246 of the vapor injection heat exchanger thermostatic expansion valve 208 and a second input 250 of compressor 202.
As noted above, the HVAC module 200 may connect to an evaporator 210 of the work machine 100. In particular, a connection line 252 may connect a first input 254 of an evaporator thermostatic expansion valve 256 to a refrigerant output port 228 of the HVAC module 200. A first output 258 of the evaporator thermostatic expansion valve 256 may be connected to evaporator 210 via connection line 260. The evaporator 210 may be further connected to a second input 262 of the evaporator thermostatic expansion valve 256 via connection line 264. Connection line 266 may connect a second output 268 of the evaporator thermostatic expansion valve 256 to the refrigerant input port 216 of the HVAC module 200. By way of the above described fluid connections, the closed loop refrigeration circuit 212 is formed connecting the compressor 202, condenser 204, vapor injection heat exchanger 206, and vapor injection heat exchanger thermostatic expansion valve 208 of HVAC module 200 with the evaporator thermostatic expansion valve 256 and evaporator 210.
It is understood that an electronic control system (not shown) may be included to facilitate operation of the refrigeration circuit 212. For example, the electronic control system could include a plurality of various sensors for measuring various operational aspects of the refrigeration circuit 212. The sensed information could be provided to a controller for analyzing the received information and generating operation commands for the refrigeration circuit 212.
One or more wiring connection ports 308 may be provided to the HVAC module 200. These wiring connection ports 308 may be utilized to provide power to the HVAC module 200 and/or provide electrical connectors to input and/or output information to the HVAC module 200. The information may be utilized to facilitate operation of the refrigeration circuit 212 in HVAC module 200.
One or more support brackets 310, 312 may be utilized, for example, to provide an amount of protection to a surface of the condenser coil 300. Additionally, the support brackets 310, 312 may be connected to additional components of the HVAC module 200 to provide additional rigid support to the overall structure. In one embodiment, an end of support brackets 310, 312 may be connected to a bottom plate 314 of HVAC module 200. The bottom plate 314 may be designed to accommodate components of the HVAC module 200, for example, as part of the containment assembly 318. For example, the bottom plate 314 may include a generally flat surface having flanged edges around a front and side surfaces. An end of the support brackets 310, 312 may be attached to the bottom plate 314 using fasteners 316 such as a screw and nut assembly. Additional non-limiting fastening means may be employed to attach the support brackets 310, 312 to the bottom plate 314 such as weldments, glues, and other kinds of fasteners. A portion of the side surface of the bottom plate 314 is shown in attachment with rear attachment end 306. Again, appropriate fasteners such as a screw and nut assembly or other attachment means such as weldments may be utilized to secure the bottom plate 314 to the rear attachment end 306. Thus, the condenser coil 300 may be seated within a space defined by an assembly of the bottom plate 314 attached to the rear attachment end 306 and further attached to support brackets 310, 312 as described herein. A surface of the bottom plate 314 may also serve as mounting points for additional equipment to be secured thereto.
Additionally, in some embodiments, a top plate may also be provided as part of the containment assembly 318. The top plate in connection with additional components of the containment assembly 318 may effectively seal and/or provide additional protection to components of the HVAC module 200. The top plate may be connected to another end of the plurality of support brackets 310, 312, and the rear attachment end 306. Additional embodiments of the top plate may include a surface for mounting additional equipment thereto. Additional non-limiting fastening means may be employed to attach the support brackets 310, 312 to the top plate such as weldments, glues, and other kinds of fasteners. Thus, the condenser coil 300 may be seated within a space defined by a containment assembly 318 of the top plate in connection with the rear attachment end 306, support brackets 310, 312 and the bottom plate 314. The bottom plate 314, support brackets 310, 312, rear attachment end 306, and the top plate may include steel sheet metal or other materials known by those skilled in the art to be appropriate.
In some embodiments of the disclosure, the HVAC module 200 includes an electric motor driven compressor 202 and a condenser 204 that are attached together and approximately co-located. The mating portion or connection ports 216, 228 of the HVAC module 200 for engaging an evaporator assembly are configured so that the size of the conduit, the thickness of the wall of the conduit, the number of conduits, and the spacing between the conduits may accommodate a variety of HVAC applications including a demanding environment. Furthermore, a mating portion that is configured to fit the mating portion of connection ports 216, 228 of the HVAC module 200 may be provided to more than one type of evaporator assembly. This standardization of the connection between the HVAC module 200 and the evaporator assembly may be advantageous in certain embodiments, because the mating portions are not required to be reconfigured depending on the type of evaporator assembly or evaporator assembly configuration being utilized. This may further improve a manufacturing efficiency of HVAC systems.
A function of the compressor 202 may include receiving refrigerant fluid, in a gaseous phase, (e.g., first input 270 of compressor 202) and compressing the gas as a cool, low-pressure vapor refrigerant. This, in effect, may cause the refrigerant to become a hot, high-pressure vapor refrigerant. In some embodiments, the compressor 202 may be driven by an electrical power source including, for example, generator 114 and/or an alternate power unit. In some embodiments, a controller may be employed to regulate a desired operational speed of the compressor 202, for instance, in order to achieve a desired temperature within the compartment 102 of the work machine 100. Regulation of the controller may be based upon inputted information to the controller.
A function of the condenser 204 may include transferring heat out of the refrigerant. This may cause the hot, high-pressure vapor entering into the condenser 204 to condense into warm, high-pressure liquid at an exit point of the condenser 204. In an exemplary embodiment, a condenser fan may be provided to blow air over the condenser 204 in order to facilitate heat transfer.
The vapor injection heat exchanger 206 may use a small portion of refrigerant exiting out of the condenser 204 to further sub-cool a majority of refrigerant exiting the condenser and ultimately out of the refrigerant output port 228. To facilitate additional sub-cooling, a re-circulated refrigerant line may be established, for example, to provide additional cooling to the refrigerant as it circulates to and through the refrigerant output port 228. In one embodiment, the re-circulated refrigerant line may include passing a small portion of refrigerant through connection line 230, through the vapor injection heat exchanger thermostatic expansion valve 208, through connection line 234, through vapor injection heat exchanger 206, and into connection line 240. Thus, as refrigerant is circulated from connection line 234 through the vapor injection heat exchanger 206, an additional cooling effect may be incurred upon refrigerant passing through connection line 220, through the vapor injection heat exchanger 206, through connection line 224. Thus, the vapor injection heat exchanger thermostatic expansion valve 208 may be utilized as an expansion device for causing hot liquid exiting the condenser 204 to become a cool two-phase fluid available to enter into the vapor injection heat exchanger 206. The vapor injection heat exchanger thermostatic expansion valve 208 may also be used to meter an amount of flow in a portion of the connection line circuit by sensing a temperature and pressure of the refrigerant as it returns back to the vapor injection heat exchanger thermostatic expansion valve 208 from the vapor injection heat exchanger 206. Thus, an amount of refrigerant may be regulated back to the compressor 202 and, hence, to the condenser 204 to ultimately provide for additional cooling as needed. This design may allow for additional control to increase an efficiency of heat exchange and/or a capacity of heat exchanged by the vapor injection heat exchanger 206 of HVAC module 200.
Those skilled in the art will recognize that the processes described above are exemplary only and not intended to be limiting. Other processes may be created, steps in the described processes may be removed or modified, the order of these steps may be changed, and/or other operation steps may be added without departing from the principle and scope of the disclosed invention.
