Hvac-apu Systems For Battery Electric Vehicles

Abstract

A HVAC-APU system is provided for a battery electric vehicle. The system includes, but is not limited to a refrigerant fluid. A power cycle loop section, a cabin heating cycle loop section, and a cabin refrigeration cycle loop section are in selective fluid communication with each other to advance the refrigerant fluid through the system. A compressor-expander train includes, but is not limited to a reversing compressor-expander and a high-pressure pump that are operably connected by a shaft. The high-pressure pump pressurizes the refrigerant fluid to form a high-pressure refrigerant fluid. An auxiliary fuel cell and combustion unit heats a heat transfer fluid. A heat exchanger transfers heat from the heated transfer fluid to the high-pressure refrigerant fluid to form a heated high-pressure refrigerant fluid. The reversing compressor-expander expands the heated high-pressure refrigerant fluid to rotate the shaft in a first direction to drive the high-pressure pump.

Description

TECHNICAL FIELD

[0001] The technical field relates generally to heating, ventilation and air-conditioning (HVAC) and auxiliary power unit (APU) systems for use in vehicles, and more particularly relates to HVAC and APU systems for use in battery electric vehicles.

BACKGROUND

[0002] Internal combustion engine powered vehicles have been commercially marketed for over a century and dominate the vehicle industry. Despite their widespread use, gasoline fueled internal combustion engines have been associated with a number of issues. First, due to the finite size and limited regional availability of fossil fuels, major price fluctuations and a generally upward pricing trend in the cost of gasoline are common, both of which can have an impact at the consumer level. Second, fossil fuel combustion has been associated with environmental problems, such as, for example, exhaust emissions including concerns over emissions of carbon dioxide, a greenhouse gas, and a contributor to global warming. Accordingly, considerable effort has been spent on finding alternative drive systems for use in both personal and commercial vehicles.

[0003] Battery electric vehicles offer a promising alternative to vehicles that use internal combustion drive trains. A battery electric vehicle is a type of electric vehicle (EV) that uses chemical energy stored in rechargeable battery, e.g., rechargeable battery packs, to provide electric power to an electric motor, instead of an internal combustion engine, for propulsion. However, there are two main issues with using a battery electric vehicle.

[0004] The two main issues are concerns about the drivable range before running out of a battery charge, which is commonly referred to as range anxiety, and what to do if the battery packs do run out of energy. Typical drivable ranges for battery electric vehicles are about 70 miles. However, these ranges depend considerably upon the age of the battery packs, the driving conditions and the driving habits of the driver. Moreover, many battery electric vehicles are unsuitable for towing due to potential damage that can occur to the transmission if the vehicle is towed. In such cases, a battery electric vehicle that becomes stranded on a roadside may require the use of a flatbed truck to transport the battery electric vehicle to the nearest available power outlet for recharging the battery packs.

[0005] Concerns over range anxiety and what to do if the battery packs do run out of energy are further exacerbated when a battery electric vehicle is driven in an environment that calls for on-demand heating and/or cooling within the passenger cabin to provide occupant comfort and/or safety. This is because the HVAC system for a battery electric vehicle typically operates using electrical energy from the battery packs, and the energy necessary to keep the passenger cabin comfortable in relatively extreme conditions can be on par with the same energy requirements needed to move the battery electric vehicle down the road.

[0006] For example, operating the heating mode of an HVAC system for a battery electric vehicle at 10.degree. F. outside conditions can reduce the drivable range of the battery electric vehicle from about 70 miles to about 35 miles. Moreover, if the energy charge does run out of the battery packs and the battery electric vehicle is stranded on a roadside, there is no electrical energy from the battery packs to operate the HVAC system while the occupants wait to be transported to the nearest available power outlet for recharging the battery packs.

[0007] Accordingly, it is desirable to provide an HVAC system for a battery electric vehicle that is operational when the energy charge runs out of the battery packs. Moreover, it is desirable to provide a battery electric vehicle with extended range capability to reduce range anxiety. Also, it is desirable to provide a battery electric vehicle with better options and less expense if the battery packs do run out of energy and the vehicle needs to be transported to the nearest available power outlet for recharging the battery packs. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.

SUMMARY

[0008] HVAC-APU systems for battery electric vehicles that have passenger cabins are provided herein. In an exemplary embodiment, a HVAC-APU system comprises a refrigerant fluid. A power cycle loop section is configured to advance the refrigerant fluid. A cabin heating cycle loop section is in selective fluid communication with the power cycle loop section and is configured to advance the refrigerant fluid. A cabin refrigeration cycle loop section is in selective fluid communication with the power cycle loop section and the cabin heating cycle loop section and is configured to advance the refrigerant fluid with the power cycle loop section and the cabin heating cycle loop section. A compressor-expander train comprises a reversing compressor-expander, a high-pressure pump and a shaft that operably couples the reversing compressor-expander with the high-pressure pump. The high-pressure pump is disposed along the power cycle loop section and is configured to pressurize the refrigerant fluid to form a high-pressure refrigerant fluid. An auxiliary fuel cell and combustion unit contains a heat transfer fluid and is configured to heat the heat transfer fluid to form a heated transfer fluid. A heat exchanger is disposed along the power cycle loop section to receive the high-pressure refrigerant fluid and is in fluid communication with the auxiliary fuel cell and combustion unit to receive the heated transfer fluid. The heat exchanger is configured to transfer heat from the heated transfer fluid to the high-pressure refrigerant fluid to form a heated high-pressure refrigerant fluid. The reversing compressor-expander is in selective fluid communication with the heat exchanger to receive the heated high-pressure refrigerant fluid and is configured to expand the heated high-pressure refrigerant fluid to rotate the shaft in a first direction to drive the high-pressure pump.

[0009] In accordance with another exemplary embodiment, a HVAC-APU system for a battery electric vehicle that has a passenger cabin is provided herein. The HVAC-APU system is configured to receive an auxiliary fuel cell and combustion unit that contains a heat transfer fluid and which is operable to heat the heat transfer fluid to form a heated transfer fluid. The system comprises a refrigerant fluid. A power cycle loop section, a cabin heating cycle loop section, and a cabin refrigeration cycle loop section are in selective fluid communication with each other to advance the refrigerant fluid through the system to provide various operating modes. A compressor-expander train comprises a reversing compressor-expander, a high-pressure pump and a shaft that operably couples the reversing compressor-expander with the high-pressure pump. The high-pressure pump is disposed along the power cycle loop section and is configured to pressurize the refrigerant fluid to form a high-pressure refrigerant fluid. A heat exchanger is disposed along the power cycle loop section to receive the high-pressure refrigerant fluid. The heat exchanger is configured for fluid communication with the auxiliary fuel cell and combustion unit to receive the heated transfer fluid and to transfer heat from the heated transfer fluid to the high-pressure refrigerant fluid to form a heated high-pressure refrigerant fluid. The reversing compressor-expander is in selective fluid communication with the heat exchanger to receive the heated high-pressure refrigerant fluid and is configured to expand the heated high-pressure refrigerant fluid to rotate the shaft in a first direction to drive the high-pressure pump.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Embodiments of the present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:

[0011] FIG. 1 is a schematic depiction of a HVAC-APU system for a battery electric vehicle in a heating mode in accordance with an exemplary embodiment;

[0012] FIG. 2 is a schematic depiction of a HVAC-APU system for a battery electric vehicle in a refrigeration mode in accordance with an exemplary embodiment;

[0013] FIG. 3 is a schematic depiction of a HVAC-APU system for a battery electric vehicle in a heating mode and a power generation mode in accordance with an exemplary embodiment;

[0014] FIG. 4 is a schematic depiction of a HVAC-APU system for a battery electric vehicle in a refrigeration mode and a power generation mode in accordance with an exemplary embodiment; and

[0015] FIG. 5 is a schematic depiction of a HVAC-APU system for a battery electric vehicle in a demisting mode and a power generation mode in accordance with an exemplary embodiment.

DETAILED DESCRIPTION

[0016] The following Detailed Description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding Background or the following Detailed Description.

[0017] Various embodiments contemplated herein relate to HVAC-APU systems for a battery electric vehicle. The system has a power cycle loop section, a cabin heating cycle loop section, and a cabin refrigeration cycle loop section that are in selective fluid communication with each other to direct a refrigerant fluid through the system to provide various HVAC and/or APU operating modes. In particular, the power cycle loop section is configured for supporting a power generation mode for producing electrical energy that may be stored in the battery packs to extend the vehicle's drivable range, or alternatively, that may be directed to the vehicle's electric motor to be used as an emergency range extender to propel the vehicle without the assistance of electrical energy from the battery packs. The cabin heating cycle loop section is configured for supporting a cabin heating mode for heating the passenger cabin of the battery electric vehicle, and the cabin refrigeration cycle loop section is configured for supporting a cabin cooling mode for cooling the passenger cabin. The cabin heating mode and/or the cabin cooling mode may be performed using electrical energy from the battery packs, or alternatively, may be performed in conjunction with the power generation mode without using electrical energy from the battery packs.

[0018] In an exemplary embodiment, the APU portion of the system includes a removable auxiliary fuel cell and combustion unit and a compressor-expander train that is integrated with the HVAC portion of the system. The compressor-expander train has a reversing compressor-expander, a high-pressure pump, a shaft and preferably a motor generator. The shaft operably couples the reversing compressor-expander to the high-pressure pump and the motor generator. The high-pressure pump is disposed along the power cycle loop section and is configured to pressurize the refrigerant fluid to form a high-pressure refrigerant fluid. The auxiliary fuel cell and combustion unit contains a heat transfer fluid that is heated by combusting fuel that is stored in the unit.

[0019] A heat exchanger is disposed along the power cycle loop section to receive the high-pressure refrigerant fluid and is in fluid communication with the auxiliary fuel cell and combustion unit to receive the heated transfer fluid. The heat exchanger transfers heat from the heated transfer fluid to the high-pressure refrigerant fluid to form a heated high-pressure refrigerant fluid. In an exemplary embodiment, the heated high-pressure refrigerant fluid is fluidly communicated to and expanded by the reversing compressor-expander to rotate the shaft to drive the high-pressure pump, and further, to drive the motor generator to generate electrical energy for the power generation mode.

[0020] In another exemplary embodiment, the cabin heating mode is performed without using electrical energy from the vehicle's battery packs. In particular, the heated high-pressure refrigerant fluid from the heat exchanger is fluidly communicated to a cabin evaporator that is disposed along the cabin heating cycle loop section. The cabin evaporator extracts heat from the heated high-pressure refrigerant fluid to provide heat to the passenger cabin for the cabin heating mode.

[0021] In another exemplary embodiment, the cabin cooling mode is performed without using electrical energy from the vehicle's battery packs. In particular, the heated high-pressure refrigerant fluid from the heat exchanger is advanced through a linear solenoid injector AC pump, which is in fluid communication with the cabin refrigeration cycle loop section, causing a pressure drop across the cabin refrigeration cycle loop section. An expansion valve and a cabin condenser are disposed along the cabin refrigeration cycle loop section, and the pressure drop causes the refrigerant fluid in the cabin refrigeration cycle loop section to advance through the expansion valve and the cabin condenser, expanding and cooling the refrigerant fluid to provide cooling to the passenger cabin for the cabin cooling mode.

[0022] Thus, the HVAC-APU system is operational to perform the cabin heating and/or cooling modes without using electrical energy from the vehicle's battery packs, such as, for example, when the energy charge runs out of the battery packs. Moreover, electrical energy produced during the power generation mode may be stored in the battery packs to extend the vehicle's drivable range to reduce range anxiety. Furthermore, energy produced during the power generation mode may be directed to the vehicle's electric motor to be used as an emergency range extender to propel the vehicle to the nearest available power outlet if the battery packs run out of energy without otherwise having the expense of transporting the vehicle, e.g., via a flatbed truck or the alike.

[0023] Referring to FIG. 1, a schematic depiction of an exemplary embodiment of the HVAC-APU system 10 for a battery electric vehicle operating in a cabin heating mode using battery stored electrical energy is provided. The system 10 includes a HVAC portion 12 and a partially integrated APU portion 14. The HVAC portion 12 is charged with refrigerant fluid and is configured to preferably operate under Rankine cycle conditions as is well known in the art so that the refrigerant fluid is typically expanded in a gas phase and pumped in a liquid phase. The APU portion 14 includes an auxiliary fuel cell and combustion unit 15, and various functioning elements integrated into the HVAC portion 12 along a compressor-expander train 16. The compressor-expander train 16 includes a reversing compressor-expander 18, a high-pressure pump 20, a motor generator 22 and a shaft 24 that operably couples the high-pressure pump 20 and the motor generator 22 with the reversing compressor-expander 18. The various functioning elements of the APU portion 14 integrated along the compressor-expander train 16 include a fluid expander function of the reversing compressor-expander 18, the high-pressure pump 20 and the electric generator function of the motor generator 22 as will be explained in greater detail below.

[0024] As illustrated, the system 10 is operating in a cabin heating mode where the refrigerant fluid is advanced along a heating cycle loop 26 indicated by lines 1, 2, 3, 4 and 5, and a cabin heating cycle loop section 28 that are illustrated in bold. In particular, the motor generator 22 is driven by electrical energy provided from the battery packs 30 to rotate the shaft 24 in a direction (e.g., compression direction) that drives the reversing compressor-expander 18 to compress the refrigerant fluid that is provided from line 1 to form a compressed-heated refrigerant fluid. The compressed-heated refrigerant fluid is passed along line 2 to a mode selection valve 32 that directs the compressed-heated refrigerant fluid to the cabin heating cycle loop section 28 via line 3 and the mode selection valve 34.

[0025] Dispose along the cabin heating cycle loop section 28 are a cabin evaporator 36 and an expansion valve 38. As is known in the art, the cabin evaporator 36 extracts heat from the compressed-heated refrigerant fluid, and air passing over the cabin evaporator 36 carries at least a portion of the heat into the passenger cabin. The expansion valve 38 expands the refrigerant fluid that is then fluidly communicated through a condenser 40, which is also referred to as the primary loop condenser, a recuperating heat exchanger 42, a liquid-gas separator 44, a bypass valve 46, a linear solenoid injector AC pump 48 and the reversing compressor-expander 18 via lines 4, 5 and 1, respectively, to complete the heating cycle loop 26.

[0026] Referring to FIG. 2, a schematic depiction of an exemplary embodiment of the HVAC-APU system 10 operating in a cabin cooling mode using battery stored electrical energy is provided. As illustrated, the refrigerant fluid is advanced along a refrigeration cycle loop 50 indicated by lines 1, 2, 3, 6, 4 and 7, and a cabin refrigeration cycle loop section 52 that are illustrated in bold. In particular, the motor generator 22 is driven by electrical energy provided from the battery packs 30 to rotate the shaft 24 in the compression direction, driving the reversing compressor-expander 18 to compress the refrigerant fluid provided from line 1 to form the compressed-heated refrigerant fluid. The compressed-heated refrigerant fluid is passed along line 2 to the mode selection valve 32 that directs the compressed-heated refrigerant fluid to the condenser 40 via mode selection valve 34 and line 6. Some of the heat is removed from the compressed-heated refrigerant fluid in the condenser 40 and the recuperating heat exchanger 42 to form a compressed heat-depleted refrigerant fluid prior to being introduced to the cabin refrigeration cycle loop section 52 via line 4 and the liquid-gas separator 44. Dispose along the cabin refrigeration cycle loop section 52 is an expansion valve 54 and a cabin condenser 56. As is well known in the art, the expansion valve 54 and the cabin condenser 56 expand and cool the compressed heat-depleted refrigerant fluid, and air passing over the cabin condenser 56 is cooled and directed into the passenger cabin for cooling. The expanded refrigerant fluid is passed from the cabin refrigeration cycle loop section 52 through the recuperating heat exchanger 42 to remove some of the heat from the counter flowing compressed-heat depleted refrigerant fluid, and then is fluidly communicated to the reversing compressor-expander 18 via line 7, the linear solenoid injector AC pump 48 and line 1, respectively, to complete the refrigeration cycle loop 50.

[0027] Referring to FIG. 3, a schematic depiction of an exemplary embodiment of the HVAC-APU system 10 for a battery electric vehicle operating in a cabin heating mode and a power generation mode is provided. In this embodiment, the HVAC portion 12 and the APU portion 14 cooperate to generate electrical energy for the power generation mode. In particular, the auxiliary fuel cell and combustion unit 15 includes a fuel cell 58 that is in fluid communication via line 62 with a combustor 60 to provide fuel for combustion. The auxiliary fuel cell and combustion unit 15 is removably connected to the system 10 by a plurality of quick connects 64 that sealingly coupled together to complete the transfer fluid loop 66. A circulating pump 68 is dispose along the transfer fluid loop 66 to circulate heat transfer fluid through the transfer fluid loop 66. The combustor 60 generates heat by burning fuel from the fuel cell 58 to heat the heat transfer fluid to a temperature of from preferably about 200 to about 300.degree. C.

[0028] As illustrated, the system 10 is operating in both the cabin heating mode and the power generation mode. For the power generation mode, the refrigerant fluid is advanced along a power cycle loop 70 indicated by lines 1, 8, 6, 4 and 9, and a power cycle loop section 72 that are illustrated in bold. Dispose along the power cycle loop section 72 are the high pressure pump 20, an economizer heat exchanger 74 and a refrigerant-to-heat transfer fluid heat exchanger 76. The high pressure pump 20 pressurizes the refrigerant fluid to form a high-pressure refrigerant fluid that is fluidly communicated to the economizer heat exchanger 74, which moderately increases the temperature of the high-pressure refrigerant fluid with the counter flowing refrigerant fluid in line 8 for overall system efficiency, before being introduced to the refrigerant-to-heat transfer fluid heat exchanger 76. The refrigerant-to-heat transfer fluid heat exchanger 76, which is in fluid communication with the auxiliary fuel cell and combustion unit 15, transfers heat from the heated transfer fluid to the high-pressure refrigerated fluid to form a heated high-pressure refrigerant fluid.

[0029] The reversing compressor-expander 18 is in fluid communication with the power cycle loop section 72 via line 9. The reversing compressor-expander 18 receives and expands the heated high-pressure refrigerant fluid to rotate the shaft 24 in a power generation direction (e.g., opposite the compression direction), driving the high-pressure liquid pump 20, the circulating pump 68 and a motor generator 22. The motor generator 22 generates electrical energy in response to being driven by the shaft rotating in the power generation direction. The generated electrical energy, for example, may be stored in the battery packs 30 to extend the vehicle's drivable range, or alternatively, may be directed to the vehicle's electric motor 78 to be used as an emergency range extender to propel the vehicle without the assistance of electrical energy from the battery packs 30.

[0030] For the cabin heating mode performed in conjunction with the power generation mode, the mode selection valves 32 and 34 direct a portion of the heated high-pressure refrigerant fluid from the refrigerant-to-heat transfer fluid heat exchanger 76 to the cabin heating cycle loop section 28 via lines 2 and 3. The cabin evaporator 36 extracts heat from the heated high-pressure refrigerant fluid, and air passing over the cabin evaporator 36 carries some of the heat into the passenger cabin. The expansion valve 38 expands refrigerant fluid that is then fluidly communicated to the power cycle loop 70.

[0031] Referring to FIG. 4, a schematic depiction of an exemplary embodiment of the HVAC-APU system 10 operating in a cabin cooling mode and a power generation mode is provided. The HVAC portion 12 and the APU portion 14 cooperate to generate electrical energy for the power generation mode as discussed in the foregoing paragraphs in relation to FIG. 3.

[0032] For the cabin cooling mode performed in conjunction with the power generation mode, the mode selection valves 32 and 34 are set so as to not direct the refrigerant fluid through the cabin heating cycle loop section 28. The linear solenoid ejector AC pump 48 is in fluid communication with the cabin refrigeration cycle loop section 52 and the refrigerant-to-heat transfer fluid heat exchanger 76 to receive two feed streams including the refrigerant fluid from the cabin refrigeration cycle loop section 52 and the heated high-pressure refrigerant fluid via lines 7 and 11, respectively. With the two feed streams, the linear solenoid ejector AC pump 48 functions as a thermal compressor having the heated high-pressure refrigerant fluid as a high energy motive fluid running through an acceleration nozzle (e.g., a venturi effect produced from a narrow to large diffusion nozzle) at supersonic speed such that the slower adjacent refrigerant fluid from the cabin refrigeration cycle loop section 52 is sucked in and mixes with the heated high-pressure refrigerant fluid to produce a pressure drop across line 7 and the cabin refrigeration cycle loop section 52. The refrigerant fluid mixture expands and exits the linear solenoid ejector AC pump 48 at a relatively low velocity and high pressure. The exiting refrigerant fluid mixture is combined with the refrigerant fluid exiting the reversing compressor-expander 18 at line 8. The linear solenoid ejector AC pump 48 may be modulated so that the exiting refrigerant fluid mixture is at about the same pressure and temperature, e.g., about 100 to about 120.degree. C., as the refrigerant fluid stream from the reversing compressor-expander 18 along line 1. The combined refrigerant fluid mixture is then fluidly communicated to the cabin refrigeration cycle loop section 52 through the economizer heat exchanger 74, line 6, the condenser 40, the recuperating heat exchanger 42, line 4 and the liquid-gas separator 44.

[0033] The pressure drop across the cabin refrigeration cycle loop section 52 accelerates the refrigerant fluid, which is at a relatively high pressure, through the expansion valve 54 and the cabin condenser 56 to expand and cool the refrigerant fluid. Air passing over cabin condenser 56 is cooled by the cooled refrigerant fluid and is directed into the passenger cabin for cooling.

[0034] Referring to FIG. 5, a schematic depiction of an exemplary embodiment of the HVAC-APU system 10 operating in a cabin demisting mode and a power generation mode is provided. The HVAC portion 12 and the APU portion 14 cooperate to generate electrical energy for the power generation mode as discussed in the foregoing paragraphs in relation to FIG. 3.

[0035] For the cabin demisting mode performed in conjunction with the power generation mode, both the cabin heating mode and the cabin cooling mode as discussed in relation to FIGS. 3 and 4 are performed contemporaneously by directing fluid communication between the power cycle loop section 72, the cabin heating cycle loop section 28 and the cabin refrigeration cycle loop section 52 such that the cabin evaporator 36 is heated by the heated high-pressure refrigerant fluid, and the relatively high pressure refrigerant fluid from the linear solenoid ejector AC pump 48 and the reversing compressor-expander 18 is accelerated through the expansion valve 54 and the cabin condenser 56 to cool the cabin condenser 56. An air stream is directed over the cooled cabin condenser 56, which cools and dehumidifies the air, and is subsequently directed over the heated cabin evaporator 36, which returns heat back into the cool-dried air, to form a warm-dry air stream directed towards the passenger cabin for demisting.

[0036] Accordingly, HVAC-APU systems for battery electric vehicles have been described. The various embodiments comprise a power cycle loop section, a cabin heating cycle loop section, and a cabin refrigeration cycle loop section that are in selective fluid communication with each other to direct a refrigerant fluid through the system to provide various HVAC and/or APU operating modes. In particular, the power cycle loop section is configured for supporting a power generation mode for producing electrical energy that may be stored in the battery packs to extend the vehicle's drivable range, or alternatively, that may be directed to the vehicle's electric motor to be used as an emergency range extender to propel the vehicle without the assistance of electrical energy from the battery packs. The cabin heating cycle loop section is configured for supporting a cabin heating mode for heating the passenger cabin of the battery electric vehicle, and the cabin refrigeration cycle loop section is configured for supporting a cabin cooling mode for cooling the passenger cabin. The cabin heating mode and/or the cabin cooling mode may be performed using electrical energy from the battery packs, or alternatively, may be performed in conjunction with the power generation mode without using electrical energy from the battery packs. Thus, the HVAC-APU system is operational to perform the cabin heating and/or cooling modes without using electrical energy from the vehicle's battery packs, such as, for example, when the energy charge runs out of the battery packs. Moreover, electrical energy produced during the power generation mode may be stored in the battery packs to extend the vehicle's drivable range to reduce range anxiety. Furthermore, energy produced during the power generation mode may be directed to the vehicle's electric motor to be used as an emergency range extender to propel the vehicle to the nearest available power outlet if the battery packs run out of energy without otherwise having the expense of transporting the vehicle, e.g., via a flatbed truck or the alike.

[0037] While at least one exemplary embodiment has been presented in the foregoing Detailed Description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing Detailed Description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of as set forth in the appended Claims and their legal equivalents.

Claims

1. A HVAC-APU system for an electric vehicle, the system comprising: a refrigerant fluid; a power cycle loop section configured to advance the refrigerant fluid; a cabin heating cycle loop section in selective fluid communication with the power cycle loop section and configured to advance the refrigerant fluid; a cabin refrigeration cycle loop section in selective fluid communication with the power cycle loop section and the cabin heating cycle loop section and configured to advance the refrigerant fluid with the power cycle loop section and the cabin heating cycle loop section; a compressor-expander train comprising a reversing compressor-expander, a high-pressure pump and a shaft that operably couples the reversing compressor-expander with the high-pressure pump, the high-pressure pump disposed along the power cycle loop section and configured to pressurize the refrigerant fluid to form a high-pressure refrigerant fluid; an auxiliary fuel cell and combustion unit containing a heat transfer fluid and configured to heat the heat transfer fluid to form a heated transfer fluid; and a heat exchanger disposed along the power cycle loop section to receive the high-pressure refrigerant fluid and is in fluid communication with the auxiliary fuel cell and combustion unit to receive the heated transfer fluid, the heat exchanger configured to transfer heat from the heated transfer fluid to the high-pressure refrigerant fluid to form a heated high-pressure refrigerant fluid, wherein the reversing compressor-expander is in selective fluid communication with the heat exchanger to receive the heated high-pressure refrigerant fluid and is configured to expand the heated high-pressure refrigerant fluid to rotate the shaft in a first direction to drive the high-pressure pump.

2. The system according the claim 1, wherein the compressor-expander train further comprises a motor generator operably coupled to the reversing compressor-expander by the shaft, and wherein the motor generator is configured to be driven by the shaft rotating in the first direction to generate electrical energy to define a power generation mode.

3. The system according to claim 2, further comprising a battery configured to store the electrical energy generated during the power generation mode.

4. The system according to claim 2, further comprising an electric motor configured to operably drive the electric vehicle during the power generation mode with the electrical energy.

5. The system according to claim 2, further comprising a cabin evaporator disposed along the cabin heating cycle loop section that is in selective fluid communication with the heat exchanger and configured to receive the heated high-pressure refrigerant fluid, the cabin evaporator further configured to extract heat from the heated high-pressure refrigerant fluid for heating a passenger cabin of the electric vehicle.

6. The system according to claim 5, wherein the system is operable in a cabin heating mode and the power generation mode when the power cycle loop section and the cabin heating cycle loop section are in fluid communication.

7. The system according to claim 5, further comprising: a primary loop condenser in fluid communication with the reversing compressor-expander and configured to receive the refrigerant fluid; an expansion valve disposed along the cabin refrigeration cycle loop section that is in selective fluid communication with the primary loop condenser to receive the refrigerant fluid; a cabin condenser disposed along the cabin refrigeration cycle loop section that is in selective fluid communication with the primary loop condenser to receive the refrigerant fluid, the expansion valve and the cabin condenser cooperatively configured to expand and cool the refrigerant fluid for cooling the passenger cabin; and a linear solenoid ejector AC pump in selective fluid communication with the heat exchanger and the cabin refrigeration cycle loop section and configured to receive the heated high-pressure refrigerant fluid and the refrigerant fluid, the linear solenoid ejector AC pump further configured to advance the heated high-pressure refrigerant fluid and the refrigerant fluid producing a pressure drop across the cabin refrigeration cycle loop section to advance the refrigerant fluid through the expansion valve and the cabin condenser.

8. The system according to claim 7, wherein the system is operable in a cabin cooling mode and the power generation mode when the power cycle loop section and the cabin refrigeration cycle loop section are in fluid communication.

9. The system according to claim 7, wherein the system is operable in a cabin demisting mode and the power generation mode when the power cycle loop section, the cabin heating cycle loop section and the cabin refrigeration cycle loop section are in fluid communication.

10. The system according to claim 7, wherein the motor generator is configured to be driven by battery stored electrical energy to rotate the shaft in a second direction in a non-power generation mode when the reversing compressor-expander is not in fluid communication with the heat exchanger of the power cycle loop section, and wherein the reversing compressor-expander is configured to compress the refrigerant fluid when rotated by the shaft in the second direction to form a compressed refrigerant fluid.

11. The system according to claim 10, wherein the cabin evaporator is configured to extract heat from the compressed refrigerant fluid for heating the passenger cabin when the cabin evaporator of the cabin heating cycle loop section is not in fluid communication with the heat exchanger of the power cycle loop section but is in fluid communication with the reversing compressor-expander to receive the compressed refrigerant fluid.

12. The system according to claim 10, wherein the expansion valve and the cabin condenser are cooperatively configured to expand and cool the compressed refrigerant fluid for cooling the passenger cabin when the linear solenoid ejector AC pump is not in fluid communication with the heat exchanger of the power cycle loop section but the primary loop condenser is in fluid communication with the reversing compressor-expander to receive the compressed refrigerant fluid.

13. The system according to claim 1, further comprising a circulation pump in fluid communication with the heat transfer fluid and operably coupled to the shaft to advance the heated transfer fluid from the auxiliary fuel cell and combustion unit to the heat exchanger in response to the shaft rotating in the first direction.

14. The system according to claim 1, wherein the auxiliary fuel cell and combustion unit is removably connected to the system.

15. A HVAC-APU system for a battery electric vehicle that has a passenger cabin, the HVAC-APU system configured to receive an auxiliary fuel cell and combustion unit that contains a heat transfer fluid and which is operable to heat the heat transfer fluid to form a heated transfer fluid, the system comprising: a refrigerant fluid; a power cycle loop section, a cabin heating cycle loop section, and a cabin refrigeration cycle loop section that are in selective fluid communication with each other to advance the refrigerant fluid through the system to provide various operating modes; a compressor-expander train comprising a reversing compressor-expander, a high-pressure pump and a shaft that operably couples the reversing compressor-expander with the high-pressure pump, the high-pressure pump disposed along the power cycle loop section and configured to pressurize the refrigerant fluid to form a high-pressure refrigerant fluid; and a heat exchanger disposed along the power cycle loop section to receive the high-pressure refrigerant fluid, the heat exchanger configured for fluid communication with the auxiliary fuel cell and combustion unit to receive the heated transfer fluid and to transfer heat from the heated transfer fluid to the high-pressure refrigerant fluid to form a heated high-pressure refrigerant fluid, wherein the reversing compressor-expander is in selective fluid communication with the heat exchanger to receive the heated high-pressure refrigerant fluid and is configured to expand the heated high-pressure refrigerant fluid to rotate the shaft in a first direction to drive the high-pressure pump.

16. The system according to claim 15, wherein the compressor-expander train further comprises a motor generator operably coupled to the reversing compressor-expander by the shaft, and wherein the motor generator is configured to be driven by the shaft rotating in the first direction to generate electrical energy to define a power generation mode.

17. The system according to claim 15, further comprising a cabin evaporator disposed along the cabin heating cycle loop section that is in selective fluid communication with the heat exchanger to receive the heated high-pressure refrigerant fluid, the cabin evaporator configured to extract heat from the heated high-pressure refrigerant fluid for heating the passenger cabin.

18. The system according to claim 15, further comprising: a primary loop condenser in fluid communication with the reversing compressor-expander to receive the refrigerant fluid; an expansion valve and a cabin condenser that are disposed along the cabin refrigeration cycle loop section that is in selective fluid communication with the primary loop condenser to receive the refrigerant fluid, the expansion valve and the cabin condenser cooperatively configured to expand and cool the refrigerant fluid for cooling the passenger cabin; and a linear solenoid ejector AC pump in selective fluid communication with the heat exchanger and the cabin refrigeration cycle loop section to receive the heated high-pressure refrigerant fluid and the refrigerant fluid, respectively, the linear solenoid ejector AC pump configured to advance the heated high-pressure refrigerant fluid and the refrigerant fluid therethrough so as to cause a pressure drop across the cabin refrigeration cycle loop section to advance the refrigerant fluid through the expansion valve and the cabin condenser.

19. The system according to claim 15, further comprising a circulation pump operably coupled to the shaft and configured for fluid communication with the heat transfer fluid to advance the heated transfer fluid from the auxiliary fuel cell and combustion unit to the heat exchanger in response to the shaft rotating in the first direction.

20. The system according to claim 15, further comprising a plurality of quick connects for removably connecting the auxiliary fuel cell and combustion unit to the system.