Patent Application
20140060101
This disclosure relates to climate control systems for vehicles.
Climate control systems are used to provide conditioned air to vehicle passenger compartments. The climate control system may cool the passenger compartment in warm conditions and may warm the passenger compartment in cold conditions. For example, air conditioners may be used to provide chilled air and resistance heaters may be used to provide warmed air.
A climate control system is provided for a vehicle. The vehicle includes a passenger compartment, and the climate control system includes a heater circuit, a cooler circuit, and a primary loop. The heater circuit is filled with a first liquid medium and has a heater core selectively in thermal communication with the passenger compartment. The cooler circuit is filled with a second liquid medium and has a cooler core selectively in thermal communication with the passenger compartment.
No portion of the primary loop is within the passenger compartment. The primary loop is filled with a refrigerant medium, and has a compressor and an expansion valve. The heater circuit, the cooler circuit, and the primary loop each have fixed flow directions, such that the flow through the circuits is not reversible.
A liquid-cooled condenser thermally links the heater circuit and the primary loop. A liquid-warmed evaporator thermally links the cooler circuit and the primary loop. Therefore, the primary loop is always in direct heat-exchange communication with one of the first liquid medium of the heater circuit and the second liquid medium of the cooler circuit.
The above features and advantages, and other features and advantages, of the present invention are readily apparent from the following detailed description of some of the best modes and other embodiments for carrying out the invention, which is defined solely by the appended claims, when taken in connection with the accompanying drawings.
Referring to the drawings, like reference numbers correspond to like or similar components wherever possible throughout the several figures.
The climate control system 10 generally includes three closed circuits or loops: a heater circuit 14, a cooler circuit 16, and a primary loop 18. Each of the heater circuit 14, the cooler circuit 16, and the primary loop 18 have fixed flow directions, such that the various fluids within the circuits generally move, if moving, in only one direction. The climate control system 10 does not include any reversing valves, regardless of whether climate control system 10 is cooling the passenger compartment 12, heating the passenger compartment 12, or both heating and cooling the passenger compartment (such as may occur during dehumidification).
While the present invention may be described with respect to automotive or vehicular applications, those skilled in the art will recognize the broader applicability of the invention. Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” et cetera, are used descriptively of the figures, and do not represent limitations on the scope of the invention, as defined by the appended claims. Any numerical designations, such as “first” or “second” are illustrative only and are not intended to limit the scope of the invention in any way.
Features shown in one figure may be combined with, substituted for, or modified by, features shown in any of the figures. Unless stated otherwise, no features, elements, or limitations are mutually exclusive of any other features, elements, or limitations. Any specific configurations shown in the figures are illustrative only and the specific configurations shown are not limiting of the claims or the description. All elements may be mixed and matched between figures.
As used herein, the term “liquid” refers to substances composed of molecules at an appropriate pressure that move freely among themselves but do not tend to separate like those of gases, as opposed to a solid or gas. The terms “gas” or “gaseous” refer to a substance possessing molecular mobility and the property of indefinite expansion, as opposed to a solid or liquid. Both liquids and gases are fluids. The term “refrigerant” refers to a fluid having a reversible phase transition from a liquid to a gas and generally capable of changing phase below and above normal ambient temperature of the environment.
Throughout the figures, some components are illustrated with standardized or basic symbols. These symbols are representative and illustrative only, and are in no way limiting of any specific configuration shown, of combinations between the different configurations shown, or of the claims. All descriptions of componentry are open-ended and any examples of components are non-exhaustive.
The primary loop 18 may also be referred to as a refrigeration loop or a direct expansion loop. Generally, the components of the primary loop 18 form, and operate, as a vapor compression cycle. The primary loop 18 is filled with a refrigerant medium, which operates as a working fluid for the primary loop 18. No portion of the primary loop 18 is within the passenger compartment 12, and the primary loop 18 may be wholly separated from the passenger compartment 12 by structures including a firewall (not shown). The refrigerant medium may be, for example, and without limitation: R32, R410A, R134a, R152a, or other single halogenated hydrocarbons; non-halogenated hydrocarbons, such as propane; ammonia; or carbon dioxide.
The working fluid for the heater circuit 14 is a first liquid medium, as opposed to refrigerant. Similarly, the cooler circuit 16 is filled with a second liquid medium. The first liquid medium and the second liquid medium may or may not be the same substances, but may both be coolants or heat transfer fluids. The first liquid medium and the second liquid medium both flow within the passenger compartment 12, and may, therefore, be more limited due to possible contact with the occupants. Examples of coolant used for the first liquid medium and the second liquid medium may include, without limitation: water or antifreeze solutions of ethylene glycol, diethylene glycol, or propylene glycol in water.
The primary loop 18 includes a compressor 20, which pressurizes the refrigerant and moves it through the primary loop 18. The compressor 20 may be electrically driven or mechanically driven. The compressor 20 generally changes the refrigerant from a gas to a liquid and moves the refrigerant to a liquid-cooled condenser 22. In the liquid-cooled condenser 22, the refrigerant is in direct heat-exchange communication with the first liquid medium of the heater circuit 14.
While in the liquid-cooled condenser 22, the refrigerant condenses from a gas to a liquid form, so that the heat exchange occurring in the liquid-cooled condenser 22 is from the refrigerant to the working fluid in the heater circuit 14, which is a liquid. Therefore, heat exchange in liquid-cooled condenser 22 occurs from gaseous refrigerant to liquid, two-phase refrigerant to liquid, and liquid refrigerant to liquid; with the bulk of the heat exchange occurred due to latent heat release when the refrigerant changes from gas to liquid.
After flowing through the liquid-cooled condenser 22, the refrigerant in the primary loop 18 flows to an expansion valve 24, which is a pressure-lowering device or a metering device. Much, or all, of the refrigerant is changed into two-phase state (both liquid and gas) by the expansion valve 24 and then passes through a liquid-warmed evaporator 26.
The expansion valve 24 may be a thermostatic or thermal expansion valve, and is configured to hold a constant evaporator superheat state as the refrigerant enters the liquid-warmed evaporator 26. There are no electronic devices associated with a conventional thermal expansion valve. The expansion valve 24 may monitor, such as with a sensor or a bulb, the temperature of the refrigerant leaving the liquid-warmed evaporator 26, and may improve the performance of the heat exchange by letting additional or less refrigerant into the liquid-warmed evaporator 26. In the liquid-warmed evaporator 26, the refrigerant, regardless of its phase state, is in direct heat-exchange communication with the second liquid medium of the cooler circuit 16.
The primary loop 18 has a fixed flow direction during normal operations (generally counterclockwise, as diagramed in
The heater circuit 14 has a heater core 30 selectively in thermal communication with the passenger compartment 12. A first pump 32 moves the first liquid medium through the heater circuit 14. The first pump 32, and other pumps described herein, may have fixed or variable displacement and may be driven by coupling to another rotating component or to a dedicated motor (not shown).
A fan or a blower (not shown) may move air over the heater core 30 to transfer heat from the first fluid medium within the heater core 30 to the passenger compartment 12. Alternatively, the first liquid medium may be directed to specific locations within the passenger compartment 12, such as, and without limitation, passenger seats (not shown).
In the climate control system 10, the heater circuit 14 also includes a low-temperature radiator 34, which is in thermal communication with ambient air. The low-temperature radiator 34 is disposed, in the direction of flow of the first liquid medium, between the heater core 30 and the liquid-cooled condenser 22. Ambient air refers to air from outside of the compartment 12. Generally, ambient air is taken from the exterior of the vehicle and directed to some portion of the under hood components.
The liquid-cooled condenser 22 thermally links the heater circuit 14 and the primary loop 18. Therefore, heat generated and pumped by the primary loop 18 is transferred to the heater circuit 14, where the heat may then be communicated to the ambient air outside of the vehicle, to the passenger compartment 12, some combination of both, or to other locations, depending upon the configuration of the climate control system 10.
The heater circuit 14 has a fixed flow direction during normal operations (generally clockwise, as diagramed in
The cooler circuit 16 of the climate control system 10 is filled with a second liquid medium. The first fluid medium in the heater circuit 14 and the second fluid medium in the cooler circuit 16 are both coolants, although they need not be the same type of coolant.
The cooler circuit 16 has a cooler core 40, which is selectively in thermal communication with the passenger compartment 12 and the cooler circuit 16. A second pump 42 moves the first liquid medium through the cooler circuit 16.
The first pump 32 and the second pump 42 may be numerous types of pumping mechanisms or devices. Furthermore, the first pump 32 and the second pump 42 may be driven by numerous power sources, including mechanical drives and electrical motors.
The liquid-warmed evaporator 26 thermally links the cooler circuit 16 and the primary loop 18. As the climate control system 10 operates, the liquid-warmed evaporator 26 may draw heat from the cooler circuit 16 into the primary loop 18. Therefore, the primary loop 18 is always in direct heat-exchange communication with liquid media, as opposed to gaseous media. Particularly, the primary loop 18 is in direct heat-exchange communication with at least one of the first liquid medium and the second liquid medium, which are always in liquid form during normal operations.
Generally, direct heat-exchange communication refers to thermal communication occurring purposefully, and without an intermediary, between the circuits. For example, the cooler circuit 16 and the passenger compartment may be in direct heat-exchange communication through the cooler core 40, but the primary loop 18 and the passenger compartment 12 are not in direct heat-exchange communication. However, the primary loop 18 and the passenger compartment 12 may be placed into indirect heat-exchange communication through the intermediary components of the cooler circuit 16.
The vehicle may also include a battery 44. In the climate control system 10 shown, the cooler circuit 16 includes a battery path 46 linking the cooler circuit 16 and the battery 44. Therefore, the battery 44 may be placed into thermal communication with the cooler circuit 16. The battery 44 illustrated may be a battery pack and may include components associated with the electrical system. The battery path 46 may include valves or switches to selectively control whether the second fluid medium in the cooler circuit 16 is in direct heat-exchange communication with the battery 44. The battery path 46 allows the cooler circuit 16 to cool the battery 44, which also acts as a heat source for the climate control system 10.
The cooler circuit 16 has a fixed flow direction during normal operations (generally clockwise, as diagramed in
In the climate control system 10, the heater core 30 and the cooler core 40 selectively communicate with at least a common air stream 50. The common air stream 50 may be generated by a fan (not shown) within the passenger compartment 12, which may also draw ambient air into the passenger compartment 12, often after passing through a cabin air filter (not shown). With the common air stream 50, it is possible to simultaneously place the cooler core 40 and the heater core 30 into direct heat-exchange communication with the passenger compartment 12. During, for example and without limitation, dehumidification cycles, the climate control system 10 may use the cooler core 40 to condense and remove moisture from the passenger compartment 12 and the heater core 30 reheat the common air stream 50 after it passes through the cooler core 40.
The heater core 30 and the cooler core 40 may also be selectively in communication with separate air streams, such that either the heater core 30 or the cooler core 40 may individually condition the passenger compartment 12. Furthermore the heater core 30 and the cooler core 40 may selectively communicate with other components in the passenger compartment 12, such as seat warmers or seat coolers (not shown).
A control system or controller (not shown) monitors and controls some, or all, of the components of the climate control system 10, including those discussed herein and others. The controller may include one or more components with a storage medium and a suitable amount of programmable memory, which are capable of storing and executing one or more algorithms or methods to effect control of the climate control system 10 and, possibly, other components of the vehicle. The controller may be in communication with numerous sensors and communication systems of the vehicle and the passenger compartment 12.
Each component of the controller may include distributed controller architecture, such as a microprocessor-based electronic control unit (ECU). Additional modules or processors may be present within the controller, and the controller may be only a portion of another control system.
Referring now to
The primary loop 118 includes a compressor 120, which pressurizes the refrigerant and moves it through the primary loop 118 to a liquid-cooled condenser 122, such that the refrigerant is in direct heat-exchange communication with the first liquid medium of the heater circuit 114. The climate control system 110 also includes a front-end subcooler 123, which may selectively place the refrigerant in direct heat-exchange communication with ambient air. The front-end subcooler 123 provides an additional point of heat dissipation for the primary loop 118.
After flowing through the liquid-cooled condenser 122 (and, possibly, the front-end subcooler 123) refrigerant in the primary loop 118 flows to an electronic expansion valve 124, which is a pressure-lowering device or a metering device. The electronic expansion valve 124 may use a motor, stepper motor, or solenoid to adjust pressure settings based upon a signal from a controller (not shown).
The refrigerant is changed into two-phase state by the electronic expansion valve 124 and then passes through a liquid-warmed evaporator 126. In the liquid-warmed evaporator 126, the refrigerant is in direct heat-exchange communication with the second liquid medium of the cooler circuit 116.
The electronic expansion valve 124 may monitor, such as with a sensor, the temperature of the refrigerant leaving the liquid-warmed evaporator 126, and may improve the performance of the heat exchange by adjusting flow of refrigerant into the liquid-warmed evaporator 126. Where the expansion valve 24 of the climate control system 10 likely utilized physical sensing and physical control, the electronic expansion valve 124 uses electronic sensing and control to adjust flow into the liquid-warmed evaporator 126. The electronic expansion valve 124 may include its own processor or controller, or may use the controller for the climate control system 110 as a whole, in order to maintain a constant evaporator superheat into the liquid-warmed evaporator 126.
As the refrigerant in the primary loop 118 returns to the compressor 120, it passes through an accumulator 127 or accumulator bottle. The accumulator 127 is a device configured to store liquid refrigerant and to prevent liquid refrigerant, as opposed to gaseous refrigerant, from returning to the compressor 120. Liquid refrigerant is collected by the accumulator 127 and may be vaporized back into gas before continuing to the compressor 120.
The heater circuit 114 has a heater core 130 selectively in thermal communication with the passenger compartment 112. A first pump 132 moves the first liquid medium through the heater circuit 114, which includes a low-temperature radiator 134 in thermal communication with ambient air. The liquid-cooled condenser 122 thermally links the heater circuit 114 and the primary loop 118 and allows direct heat-exchange communication therebetween.
The cooler circuit 116 of the climate control system 110 is filled with a second liquid medium, and includes a cooler core 140, which is selectively in thermal communication with the passenger compartment 112 and the cooler circuit 116. A second pump 142 moves the second liquid medium through the cooler circuit 116.
The liquid-warmed evaporator 126 thermally links the cooler circuit 116 and the primary loop 118. Therefore, the primary loop 118 is in direct heat-exchange communication with at least one of the first liquid medium through the liquid-cooled condenser 122 and the second liquid medium through the liquid-warmed evaporator 126, which are always in liquid form during normal operations.
The climate control system 110 also communicates with a battery 144 through a battery path 146 linking the cooler circuit 116 and the battery 144. Therefore, the battery 144 may selectively be placed into thermal communication with the cooler circuit 116. The battery path 146 allows the cooler circuit 116 to cool the battery 144, which also acts as a heat source for the climate control system 110. In the climate control system 110, the heater core 130 and the cooler core 140 selectively communicate with a common air stream 150.
Referring now to
The primary loop 218 includes a compressor 220, which pressurizes the refrigerant and moves it through the primary loop 218 to a liquid-cooled condenser 222, such that the refrigerant is in direct heat-exchange communication with the first liquid medium of the heater circuit 214.
After flowing through the liquid-cooled condenser 222 refrigerant in the primary loop 218 flows to an expansion valve 224, which is a pressure-lowering device or a metering device. The expansion valve 224 may be an electronic expansion valve, thermal expansion valve, or another suitable device.
The refrigerant is changed into two-phase by the expansion valve 224 and then passes through a liquid-warmed evaporator 226. In the liquid-warmed evaporator 226, the refrigerant is in direct heat-exchange communication with the second liquid medium of the cooler circuit 216.
The expansion valve 224 may monitor, such as with a sensor, the temperature of the refrigerant leaving the liquid-warmed evaporator 226, and may improve the performance of the heat exchange by adjusting flow of refrigerant into the liquid-warmed evaporator 226.
In the climate control system 210, the primary loop 218 also includes a liquid-gas separator 228 disposed between the liquid-cooled condenser 222 and the expansion valve 224. The liquid-gas separator 228 distributes gaseous portions of the refrigerant medium to the compressor 220 and liquid portions of the refrigerant medium to the liquid-warmed evaporator 226 via the expansion valve 224.
The heater circuit 214 has a heater core 230 selectively in thermal communication with the passenger compartment 212. A first pump 232 moves the first liquid medium through the heater circuit 214, which includes a low-temperature radiator 234 in thermal communication with ambient air. The liquid-cooled condenser 222 thermally links the heater circuit 214 and the primary loop 218 and allows direct heat-exchange communication therebetween.
The cooler circuit 216 of the climate control system 210 is filled with a second liquid medium, and includes a cooler core 240, which is selectively in thermal communication with the passenger compartment 212 and the cooler circuit 216. A second pump 242 moves the first liquid medium through the cooler circuit 216.
The liquid-warmed evaporator 226 thermally links the cooler circuit 216 and the primary loop 218. Therefore, the primary loop 218 is in direct heat-exchange communication with at least one of the first liquid medium through the liquid-cooled condenser 222 and the second liquid medium through the liquid-warmed evaporator 226, which are always in liquid form during normal operations.
The climate control system 210 also communicates with a battery 244 through a battery path 246 linking the cooler circuit 216 and the battery 244. Therefore, the battery 244 may selectively be placed into thermal communication with the cooler circuit 216. The battery path 246 allows the cooler circuit 216 to cool the battery 244, which also acts as a heat source for the climate control system 210. In the climate control system 210, the heater core 230 and the cooler core 240 selectively communicate with a common air stream 250.
In the climate control system 210, the cooler circuit 216 includes a liquid reservoir 252, which is configured to store the second liquid medium, and a reservoir valve 254. The liquid reservoir 252 is shown disposed between the cooler core 240 and the liquid-warmed evaporator 226, and allows the cooler circuit 216 to store thermal mass for later use. However, the liquid reservoir 252 may be disposed in other locations within the cooler circuit 216. The reservoir valve 254 is configured to selectively direct some, or all, of the second liquid medium into the liquid reservoir 252, and is also configured to allow the second liquid medium to flow from the liquid reservoir 252 back into the cooler circuit 216.
The liquid stored in the liquid reservoir 252 may be used to cool the passenger compartment 212 when the primary loop 218 is not operating. Alternatively, the liquid reservoir 252 may be used as an auxiliary heat source for the primary loop 218.
Referring now to
The primary loop 318 includes a compressor 320, which pressurizes the refrigerant and moves it through the primary loop 318 to a liquid-cooled condenser 322, such that the refrigerant is in direct heat-exchange communication with the first liquid medium of the heater circuit 314.
After flowing through the liquid-cooled condenser 322, refrigerant in the primary loop 318 flows to an expansion valve 324, which is a pressure-lowering device or a metering device. The expansion valve 324 may be an electronic expansion valve, thermal expansion valve, or another suitable device.
The refrigerant is changed into two-phase by the expansion valve 324 and then passes through a liquid-warmed evaporator 326. In the liquid-warmed evaporator 326, the refrigerant is in direct heat-exchange communication with the second liquid medium of the cooler circuit 316.
The expansion valve 324 may monitor, such as with a sensor, the temperature of the refrigerant leaving the liquid-warmed evaporator 326, and may improve the performance of the heat exchange by adjusting flow of refrigerant into the liquid-warmed evaporator 326.
The primary loop 318 includes an internal heat exchanger 329, which selectively allows direct heat-exchange communication between refrigerant flowing from the liquid-cooled condenser 322 to the expansion valve 324 and refrigerant flowing from the liquid-warmed evaporator 326 to the compressor 320. The internal heat exchanger 329 may promote delivery of only liquid refrigerant to the expansion valve 324 and only gaseous refrigerant to the compressor 320.
The heater circuit 314 has a heater core 330 selectively in thermal communication with the passenger compartment 312. A first pump 332 moves the first liquid medium through the heater circuit 314, which includes a low-temperature radiator 334 in thermal communication with ambient air.
The heater circuit 314 also includes a bypass path 336 and a bypass valve 338. The bypass path 336 links portions of the heater circuit 314 on either side of the low-temperature radiator 334, and the bypass valve 338 selectively channels the first liquid medium to the bypass path 336. The bypass valve 338 may be an on/off valve or may proportionally divide flow between the low-temperature radiator 334 and the bypass path 336. The bypass valve 338 shown is illustrative only and the type, operation, function, and actuation of the bypass valve 338 may vary greatly. All of the valves shown in the figures are illustrative only and different valves or equivalent components may be substituted or added.
Therefore, when the bypass path 336 is used, some, or all, of the first liquid medium moves between the heater core 330 and the liquid-cooled condenser 322 without passing through the low-temperature radiator 334. The bypass path 336 allows the heater circuit 314 to retain heat instead of expelling it when the ambient air is cold and the heat is desired in the heater circuit 314. Furthermore, when the ambient air is hotter than the first liquid medium, the bypass path 336 allows the heater circuit 314 to avoid picking up additional heat.
The cooler circuit 316 of the climate control system 310 is filled with a second liquid medium, and includes a cooler core 340, which is selectively in thermal communication with the passenger compartment 312 and the cooler circuit 316. A second pump 342 moves the second liquid medium through the cooler circuit 316.
The liquid-warmed evaporator 326 thermally links the cooler circuit 316 and the primary loop 318. Therefore, the primary loop 318 is in direct heat-exchange communication with at least one of the first liquid medium through the liquid-cooled condenser 322 and the second liquid medium through the liquid-warmed evaporator 326, which are always in liquid form during normal operations.
The cooler circuit 316 also includes an auxiliary heat source 348. The auxiliary heat source 348 may be, for example and without limitation: a resistance heater, water from an internal combustion engine, or an exhaust gas heat recirculation heat exchanger. Other configurations of the climate control system 310 may include an auxiliary heater within the heater circuit 314.
In the climate control system 310, the heater core 330 and the cooler core 340 both selectively communicate with a common air stream 350. Therefore, the common air stream 350 may be chilled and dehumidified by the cooler core 340 and then warmed by the heater core 330, such that the passenger compartment 312 is warmed and dehumidified.
The detailed description and the drawings or figures are supportive and descriptive of the invention, but the scope of the invention is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed invention have been described in detail, various alternative designs, configurations, and embodiments exist for practicing the invention defined in the appended claims.
