Patent Application
20190168581
This disclosure relates to electric and hybrid electric drive vehicles, and in particular it relates to a climate control system arrangement and method utilizing a heat pump for such vehicles.
A full electric wheeled vehicle, such as a car or truck, is propelled solely by one or more electric motors, sometimes referred to as a traction motor. A hybrid electric wheeled vehicle is propelled by one or more electric motors or traction motors, in conjunction with another power source, such as an internal combustion engine, as a non-limiting example. The traction motor draws electric current from an on-board source of electricity, such as a battery or capacitor bank. Presently, the storage capacity of such batteries or capacitor banks is limited, such that the vehicle has a range of travel when operating under electric propulsion that is limited not only by how it is driven and the physical characteristics of the geographical area within which it travels, but also by the amount of on-board stored energy that the onboard source of electricity can deliver to the motor.
Because the propulsion system of a full electric wheeled vehicle lacks an internal combustion engine, and therefore also lacks an engine cooling system through which liquid coolant circulates, hot liquid coolant is unavailable for heating the interior of the cabin, cab, or passenger compartment. Similarly, the propulsion system of a hybrid electric wheeled vehicle may operate for significant periods of time without operation of the internal combustion engine, so that insufficient heat is provided by the circulating liquid coolant of the engine coolant system for heating the interior of the cabin, cab, or passenger compartment. Nevertheless, heating of the cabin, cab, or passenger compartment is necessary, not only for the comfort of the occupants, but also for the purpose of defrosting the vehicle windows. Therefore, it is known to provide another source of heat, such as electric heaters, within the vehicle Heating Ventilation and Air Conditioning (HVAC) system. Additionally, air conditioning in conventional non-electric vehicles is generally provided by an air conditioning compressor that is mechanically driven by the internal combustion engine. Because a full electric wheeled vehicle lacks an internal combustion engine, and because the internal combustion engine of a hybrid electric vehicle may be turned off for significant periods of time, it is necessary to provide an alternate source of cooling for the cab, cabin, or passenger compartment for such vehicles when air conditioning is desired.
Electric heaters used to heat the cab, cabin, or passenger compartment of full electric or hybrid electric vehicles typically draw electric current from the same on-board source of electricity that supplies current to the traction motor that propels the vehicle. Similarly, any electrically operated alternate source of cooling for the cab, cabin, or passenger compartment of a full electric or hybrid electric vehicle also typically draws electric current from the same on-board source of electricity that supplies current to the traction motor that propels the vehicle. Therefore, heating and cooling of the cab, cabin, or passenger compartment of a full electric or hybrid electric vehicle, including defrosting of the vehicle windows, is accomplished at the expense of limiting the vehicle's range of travel under electric power, due to the finite quantity of electrical energy that is stored in the on-board source of electricity. Furthermore, independent of battery chemistry, battery cycle life is typically a non-linear function of repeated depth-of-discharge, and therefore is a non-linear indirect function of HVAC system efficiency. For example, for an AGM battery system, a 20% increase in the efficiency, or Coefficient of Performance (COP), of a battery operated engine-off HVAC system may result in a 50% increase in overall battery charge-discharge cycle life.
Accordingly, there is an unmet need for a system and method for providing energy efficient heating and cooling of the cabin, cab, or passenger compartment of a full electric or hybrid electric wheeled vehicle, in order to conserve electric power within the on-board source of electricity and extend the range of travel of the full electric or hybrid electric wheeled vehicle.
According to one embodiment of the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump, an electric or hybrid electric vehicle has a climate control system. The basic climate control system as shown in
According to another embodiment of the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump, a climate control system of an electric or hybrid electric vehicle includes a heat pump having a refrigerant compressor, a condenser heat exchanger, an expansion valve, and an evaporator heat exchanger. The condenser heat exchanger exchanges heat between refrigerant and working fluid within a hot fluid chamber. The evaporator heat exchanger exchanges heat between refrigerant and working fluid within a cold fluid chamber. An insulated fluid reservoir may selectively be placed in fluid communication with the cold fluid chamber. The insulated fluid reservoir has a PTC heater that may be powered by a drivetrain battery unit or a shore power source. A cold fluid chamber to outside heat exchanger may also selectively be placed in fluid communication with the cold fluid chamber.
According to another embodiment of the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump, a method of providing climate control in an occupant compartment of an electric or hybrid electric vehicle includes several steps. The first step is providing a heat pump having a refrigerant compressor, a condenser heat exchanger, an expansion valve, and an evaporator heat exchanger. The second step is exchanging heat between refrigerant and working fluid within a hot fluid chamber by way of the condenser heat exchanger, and exchanging heat between refrigerant and working fluid within a cold fluid chamber by way of the evaporator heat exchanger. The third step is selectively placing an insulated fluid reservoir in fluid communication with the cold fluid chamber using an insulated fluid reservoir to cold fluid chamber pump, and/or selectively placing the insulated fluid reservoir in fluid communication with the hot fluid chamber using an insulated fluid reservoir to hot fluid chamber pump. The fourth step is selectively heating working fluid within the insulated fluid reservoir using a PTC heater by selectively powering the PTC heater from a drivetrain battery unit by way of a drive train battery connector or from a shore power source by way of a shore power contactor. The fifth step is selectively placing the hot fluid chamber in fluid communication with at least one cabin heat exchanger using a hot fluid chamber to cabin heat exchanger pump, with at least one defrost/defog combination fluid heat exchanger PTC heater using a hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump, and/or with at least one ambient air heat exchanger using a hot fluid chamber to ambient air heat exchanger pump. The sixth step is selectively placing the cold fluid chamber in fluid communication with at least one vehicle interior cooling module using a cold fluid chamber to vehicle interior cooling modules pump. The seventh step is selectively placing a liquid cooled heat sink in fluid communication with the cold fluid chamber or the hot fluid chamber using a liquid cooled heat sink pump and at least one control valve, the liquid cooled heat sink being connected to an electric drive motor of the vehicle and/or power electronics connected to the electric drive motor. The eighth step is selectively placing a cold fluid chamber to outside heat exchanger in fluid communication with the cold fluid chamber using a cold fluid chamber to outside heat exchanger pump.
Embodiments described herein relate to a Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump and methods for the use thereof. The system and method may be applied to various types of electric and hybrid electric vehicles, such as highway or semi-tractors, straight trucks, busses, fire trucks, agricultural vehicles, rail travelling vehicles, and etcetera. The several embodiments of the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump and method for the use thereof presented herein are employed on vehicles having an electric drivetrain, but this is not to be construed as limiting the scope of the system and method, which may be applied to vehicles and engines of differing construction.
In at least one embodiment, this disclosure introduces a climate control system for the interior of a cabin of a wheeled vehicle that is propelled by an electric traction motor that draws electricity from an on-board source of electricity. The basic climate control system as shown in
While the heat pump is operated by its own electric motor that draws electric current from the same on-board source of electricity as the electric traction motor when the vehicle is being driven, the heating efficiency of a heat pump is significantly greater than that of an electric heater, and its cooling efficiency is significantly greater than that of the typical air conditioning system of a vehicle propelled by a fuel burning prime mover. Current heat pump technology can provide a COP (coefficient of performance) in the range of about 3.5, meaning that for one watt of energy input, the heat pump can provide about 3.5 watts of heat output for heating and a similar cooling output for cooling. Heat pump performance can also be characterized by an EER (energy efficiency rating), calculated by dividing the BTU heating or cooling output by the power input in watts.
When used for heating, the COP of an air sourced heat pump decreases as the outside temperature decreases. For example, when the heat pump is being used for heating, and the ambient temperature is 70 degrees Fahrenheit, the COP of the heat pump may be in the range of 4.0. As the ambient temperature decreases, the COP of the heat pump decreases in a linear relationship. When the ambient temperature is about zero degrees Fahrenheit, the COP of the heat pump may be no greater than that achievable using resistive heating, i.e.—having a COP equal to 1.0. At zero degrees Fahrenheit, the ambient temperature is nearly at the boiling point of the refrigerant, so that gaseous refrigerant is being produced at low volume and pressure, causing the drop in efficiency at the heat pump and reduced overall system efficiency. Nevertheless, sufficient refrigerant boiling to increase efficiency over resistive heating occurs at about 10 to 20 degrees Fahrenheit.
By adding heat to the system using a Positive Temperature Coefficient (PTC) heater, which may be a resistive heating device, the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump and methods for the use thereof raises the COP of the heat pump under low temperature conditions for the purpose of delivering cabin heat and improving efficiency of the system during cold ambient environmental conditions, i.e.—ambient temperatures that are less than 30 degrees Fahrenheit. For example, using a PTC heater, the system and method sacrifices a COP of 1, but obtains a heat pump COP of 2.5, instead of the COP of 1 attainable using the PTC heater alone. In other words, in this example, the system and method expends 1 watt in order to get 2.5 watts of heating. This may be accomplished by heating a working fluid, as will be explained further. This further allows for stabilizing the COP of the heat pump, thereby enabling the selection of a heat pump compressor of more efficient size. Ultimately, this may result in a markedly increased battery cycle life according to the principle discussed previously wherein battery cycle life is a non-linear indirect function of HVAC system efficiency.
In a conventional heat pump arrangement, such as for example a residential heat pump arrangement, when operating in heating mode the evaporator draws heat directly from the ambient air and the condenser rejects heat directly to the heated inside air. When operating in cooling mode, the evaporator draws heat directly from the conditioned inside air and the condenser rejects heat directly to the ambient air. As noted previously, however, when the evaporator temperature falls far enough, the refrigerant approaches its evaporation temperature, reducing the efficiency of the system. In the several embodiments of the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump and method for the use thereof presented herein, each of the evaporator and the condenser is situated within a chamber having a working fluid such as water or an alcohol and water mix, in order to avoid freezing. The chamber containing the evaporator becomes, therefore, the cold fluid chamber, and the chamber containing the condenser becomes the hot fluid chamber.
In order raise the overall efficiency of the system when operating in a heating mode, the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump and method for the use thereof may use several methods to raise the fluid temperature of the cold fluid chamber containing the evaporator. This may be accomplished using heat extracted from the ambient air. This may further be accomplished using waste heat, such as heat rejected by electronic and electro-mechanical components of the full electric or hybrid electric vehicle, for non-limiting example heat rejected by the electric drive motor and/or its power electronics. The system and method may further increase operating efficiency by raising the fluid temperature of the cold fluid chamber or evaporator reservoir using heated fluid stored in an insulated fluid reservoir. The fluid stored in the insulated fluid reservoir may be preheated in a preconditioning operation while the vehicle is plugged into shore power. Alternately, the fluid stored in the insulated fluid reservoir may even be heated using the vehicle on-board source of electricity. In each case, the resulting climate control system will deliver a higher COP than a conventional air sourced heat pump or by vehicle interior heating using conventional electrical resistance heaters. This results in less energy needed for heating and cooling operations, and mitigates driving range reduction often resulting from HVAC system operation.
For example, COP decreases linearly with decreasing temperature, so that a baseline COP may be 4.2 at 70 degrees Fahrenheit, and may be 1.0 at 0 degrees Fahrenheit. Under an ambient condition of 40 degrees Fahrenheit, an air sourced heat pump may have a COP of 2.8. For a 40,000 BTU/Hr (11.71 Kw) delivered capacity heat pump at 70 degrees Fahrenheit, at 40 degrees Fahrenheit the delivered capacity becomes 26,667 BTU/Hr and the power input is 2.79 Kw. If the compressor capacity is increased to bring the delivered output to 40,000 BTU/Hr at 40 degrees Fahrenheit, then the system electrical input must be increased to 4.19 Kw. However, if supplemental heat is added to the cold fluid chamber or evaporator reservoir of the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump, the total electrical input becomes 3.72 Kw and the COP of the system becomes 3.16. Consequently, for 40,000 BTU/Hr delivered under these conditions, the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump uses 2S% less energy.
Furthermore, under an ambient condition of 20 degrees Fahrenheit, the system COP of an air sourced heat pump decreases to 1.87 requiring a power input of 2.78 Kw. To maintain 40,000 BTU/Hr at 20 degrees Fahrenheit, the compressor input of an air sourced heat pump must be increased to 6.25 Kw. However, if supplemental heat is added to the cold fluid chamber or evaporator reservoir of the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump, the total electrical input becomes 4.92 KW and the resulting system COP becomes 2.38. Consequently, for 40,000 BTU/Hr delivered under these conditions, the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump uses 21% less energy.
The Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump is further capable of preconditioning the vehicle cabin interior and defrosting vehicle windows under cold weather conditions using a PTC heater and an insulated fluid reservoir. This preconditioning involves adding heat to the insulated fluid reservoir via the PTC heater, which draws its power from a shore power source, and helps to raise the COP of the system. When the vehicle is disconnected from utility power, heated fluid stored in the insulated fluid reservoir is pumped to the cold fluid chamber or evaporator reservoir, in order to maintain the increased COP of the system. Preconditioning by using shore power to heat the working fluid in the insulated cold fluid reservoir helps to maintain a reasonable cabin temperature in advance of vehicle operation, and avoids high energy usage during initial cabin heating during cold ambient conditions.
The fluid stored in the insulated fluid reservoir, as well as the fluid stored in the cold fluid chamber or evaporator reservoir, may further be precooled in the preconditioning operation while the vehicle is plugged into shore power under hot weather conditions. In this preconditioning operation, outside air and cabin air temperatures may be measured, and if a specified differential temperature is exceeded, an HVAC recirculation system may operate to remove hot air from the vehicle interior, in exchange for cooler air taken from the exterior environment. The recirculation fans of the HVAC recirculation system may be powered by variable speed motors, so that power used by the recirculation fans may be controlled to avoid excessive battery discharge over a given time period. For example, the power to be used by the recirculation fans may be set to correspond to a 20% discharge of the drive train battery unit over six hours of operation, thereby insuring that the vehicle battery system will retain enough charge to start the vehicle engine, if applicable.
When the vehicle is subsequently operated with air conditioning active, the precooled fluid in the insulated fluid reservoir, as well as the precooled fluid in the cold fluid chamber or evaporator reservoir, is utilized by the vehicle interior cooling module in initially cooling the interior of the vehicle cabin. This further avoids high energy usage during initial cabin cooling, or “pull down,” during high temperature ambient conditions upon initial vehicle start-up. Specifically, storing and utilizing precooled fluid in the insulated fluid reservoir and in the cold fluid chamber or evaporator reservoir reduces electrical power demand from the drive train battery unit, since the cold fluid is capable of absorbing approximately one BTU per pound degree Fahrenheit. Additionally, the precooled fluid in the insulated fluid reservoir and in the cold fluid chamber or evaporator reservoir may be further utilized to control the temperatures of drive train traction motors, drive train power electronics, and/or the drive train battery unit.
Preconditioning may take place automatically whenever the vehicle is plugged in to shore power, or may be initiated by the driver, for example by the driver using a remote device such as a remote fob or cell phone to call for the vehicle to be ready to operate at a given time of day. Preconditioning in fleet vehicles, such as school transportation vehicles, may be initiated by a timer. In either case, as a non-limiting example, the vehicle system controller would then calculate the BTUs that should be added or removed from the cabin in order to obtain a temperature and humidity condition that is within the comfort zone of the driver at the specified time. Similarly, the drivetrain battery unit may be heated or cooled as necessary. For example, lithium ion batteries lose operational capacity at low temperatures, so that preheating is appropriate under low ambient temperature conditions. Depending upon ambient temperatures, battery precooling may be appropriate in anticipation of temperature control during upcoming high demand operation under high ambient temperature conditions.
Referring now to
An insulated fluid reservoir 400 is in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of an insulated fluid reservoir to cold fluid chamber line 402 and a cold fluid chamber line to insulated fluid reservoir return line 406. Working fluid may be selectively circulated between the insulated fluid reservoir 400 and the cold fluid chamber or evaporator reservoir 100 using an insulated fluid reservoir to cold fluid chamber pump 404. Similarly, the insulated fluid reservoir 400 may be in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of an insulated fluid reservoir to hot fluid chamber line 410 and a hot fluid chamber line to insulated fluid reservoir return line 414. Working fluid may be selectively circulated between the insulated fluid reservoir 400 and the hot fluid chamber or condenser reservoir 300 using an insulated fluid reservoir to hot fluid chamber pump 412.
Working fluid within the insulated fluid reservoir 400 may be selectively heated by an insulated fluid reservoir Positive Temperature Coefficient (PTC) heater 612. The insulated fluid reservoir PTC heater 612 is connected to a shore power source 600 by way of a shore power line 602 having a shore power contactor 604. When the shore power contactor 604 is closed, the insulated fluid reservoir PTC heater 612 draws power from the shore power source 600, and when the shore power contactor 604 is open, the insulated fluid reservoir PTC heater 612 is isolated from the shore power source 600. The insulated fluid reservoir PTC heater 612 is also connected to a drive train battery unit 608 by way of a drive train battery line 616 having a drive train battery contactor 610. When the drive train battery contactor 610 is closed, the insulated fluid reservoir PTC heater 612 draws power from the drive train battery unit 608, and when the drive train battery contactor 610 is open, the insulated fluid reservoir PTC heater 612 is isolated from the drive train battery unit 608. A charging system 606 selectively connects the drive train battery unit 608 to the shore power source 600 as needed for recharging.
At least one cabin heat exchanger 310 is in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of at least one hot fluid chamber to cabin heat exchanger line 306 and at least one cabin heat exchanger to hot fluid chamber return line 312. Working fluid may be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one cabin heat exchanger 310 using at least one hot fluid chamber to cabin heat exchanger pump 308. Similarly, at least one defrost/defog combination fluid heat exchanger PTC heater 318 is in fluid communication with the hot fluid chamber 300 by way of at least one hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater line 314 and at least one defrost/defog combination fluid heat exchanger PTC heater to hot fluid chamber return line 320. Working fluid may be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one defrost/defog combination fluid heat exchanger PTC heater 318 using a hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316. The use of at least one defrost/defog combination fluid heat exchanger PTC heater 318, which may be a combination heat exchanger and electrical resistance heater, may allow the vehicle to comply with windshield defrosting requirements, while still enabling the selection of a VFD heat pump refrigerant compressor 200 sized for maximum efficiency.
At least one outside heat exchanger 326 is also in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of at least one hot fluid chamber to outside heat exchanger line 322 and at least one outside heat exchanger to hot fluid chamber return line 328. Working fluid may be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one outside heat exchanger 326 using a hot fluid chamber to outside heat exchanger pump 324. Similarly, at least one vehicle interior cooling module 114 may be in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of at least one cold fluid chamber to vehicle interior cooling modules line 108 and at least one vehicle interior cooling modules to cold fluid chamber return line 112. Working fluid may be selectively circulated between the cold fluid chamber or evaporator reservoir 100 and the at least one vehicle interior cooling module 114 using a cold fluid chamber to vehicle interior cooling modules pump 110.
The climate control system 10, which is illustrated in
Each of the VFD heat pump refrigerant compressor 200, the insulated fluid reservoir to cold fluid chamber pump 404, the insulated fluid reservoir to hot fluid chamber pump 412, the shore power contactor 604, the drive train battery contactor 610, the cold fluid chamber to vehicle interior cooling modules pump 110, the hot fluid chamber to cabin heat exchanger pump 308, the hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316, and the hot fluid chamber to outside heat exchanger pump 324 are controlled directly or indirectly by a system controller 12. The system controller 12 is connected to the VFD heat pump refrigerant compressor 200 by way of a compressor VFD control output 16, which is connected to a refrigerant compressor VFD control input 204 of a refrigerant compressor variable frequency drive control 202, which is in turn connected to the VFD heat pump refrigerant compressor 200. The refrigerant compressor variable frequency drive control 202 also receives power from the drive train battery unit 608 by way of a battery output to refrigerant compressor 614, which is connected to the refrigerant compressor variable frequency drive control 202 by way of a refrigerant compressor battery input 212.
The system controller 12 is connected to the insulated fluid reservoir to cold fluid chamber pump 404, to the insulated fluid reservoir to hot fluid chamber pump 412, to the cold fluid chamber to vehicle interior cooling modules pump 110, to the hot fluid chamber to cabin heat exchanger pump 308, to the hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316, and to the hot fluid chamber to outside heat exchanger pump 324 by way of pump control outputs 20. The system controller 12 is connected to the shore power contactor 604 and to the drive train battery contactor 610 by way of contactor outputs 18. In order to properly manage the climate control system 10, the system controller 12 is further provided with temperature inputs 14 and solenoid valve outputs 22, the purpose and operation of which will be explained in further detail.
As shown in
Alternately, because efficiency may not be as high of a concern during preconditioning, the insulated fluid reservoir to hot fluid chamber pump 412 may be active, circulating working fluid between the insulated fluid reservoir 400 and the hot fluid chamber or condenser reservoir 300 directly. In either case, the at least one hot fluid chamber to cabin heat exchanger pump 308 and/or the at least one hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316 may be active, using the heated working fluid in the hot fluid chamber or condenser reservoir 300 passing through the at least one cabin heat exchanger 310 and/or through the at least one defrost/defog combination fluid heat exchanger PTC heater 318 to heat the interior of the vehicle and/or to defrost the vehicle windows. The cold fluid chamber to vehicle interior cooling modules pump 110 and the hot fluid chamber to outside heat exchanger pump 324 remain inactive.
Turning now to
An insulated fluid reservoir 400 is again in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of an insulated fluid reservoir to cold fluid chamber line 402 and a cold fluid chamber line to insulated fluid reservoir return line 406. Working fluid may again be selectively circulated between the insulated fluid reservoir 400 and the cold fluid chamber or evaporator reservoir 100 using an insulated fluid reservoir to cold fluid chamber pump 404. The insulated fluid reservoir is again in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of an insulated fluid reservoir to hot fluid chamber line 410 and a hot fluid chamber line to insulated fluid reservoir return line 414. Working fluid may again be selectively circulated between the insulated fluid reservoir 400 and the hot fluid chamber or condenser reservoir 300 using an insulated fluid reservoir to hot fluid chamber pump 412.
Working fluid within the insulated fluid reservoir 400 may again be selectively heated by an insulated fluid reservoir PTC heater 612. The insulated fluid reservoir PTC heater 612 is again connected to a shore power source 600 by way of a shore power line 602 having a shore power contactor 604. As before, when the shore power contactor 604 is closed, the insulated fluid reservoir PTC heater 612 draws power from the shore power source 600, and when the shore power contactor 604 is open, the insulated fluid reservoir PTC heater 612 is isolated from the shore power source 600. The insulated fluid reservoir PTC heater 612 is again also connected to a drive train battery unit 608 by way of a drive train battery line 616 having a drive train battery contactor 610. As before, when the drive train battery contactor 610 is closed, the insulated fluid reservoir PTC heater 612 draws power from the drive train battery unit 608, and when the drive train battery contactor 610 is open, the insulated fluid reservoir PTC heater 612 is isolated from the drive train battery unit 608. A charging system 606 again selectively connects the drive train battery unit 608 to the shore power source 600 as needed for recharging.
At least one cabin heat exchanger 310 is again in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of at least one hot fluid chamber to cabin heat exchanger line 306 and at least one cabin heat exchanger to hot fluid chamber return line 312. Working fluid may again be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one cabin heat exchanger 310 using a hot fluid chamber to cabin heat exchanger pump 308. As before, at least one defrost/defog combination fluid heat exchanger PTC heater 318 is in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of at least one hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater line 314 and at least one defrost/defog combination fluid heat exchanger PTC heater to hot fluid chamber return line 320. Working fluid may again be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one defrost/defog combination fluid heat exchanger PTC heater 318 using a hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316.
At least one outside heat exchanger 326 is again in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of at least one hot fluid chamber to outside heat exchanger line 322 and at least one outside heat exchanger to hot fluid chamber return line 328. Working fluid may again be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one outside heat exchanger 326 using a hot fluid chamber to outside heat exchanger pump 324. As before, at least one vehicle interior cooling module 114 is in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of at least one cold fluid chamber to vehicle interior cooling modules line 108 and at least one vehicle interior cooling modules to cold fluid chamber return line 112. Working fluid may again be selectively circulated between the cold fluid chamber or evaporator reservoir 100 and the at least one vehicle interior cooling module 114 using a cold fluid chamber to vehicle interior cooling modules pump 110.
The full electric or hybrid electric vehicle (not shown) includes an electric drive motor 500 and associated power electronics (not shown), which is heated and/or cooled using a liquid cooled heat sink 502. Another similar liquid cooled heat sink (not shown) may function to heat and/or cool the drivetrain battery unit 608. Such cooling of the electric drive motor 500 and associated power electronics using the liquid cooled heat sink 502 may be required, as the net efficiency of the electric drive motor 500 and its associated power electronics may be in the range of ninety percent under a wide range of ambient conditions. The liquid cooled heat sink 502 is in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of a heat sink pump to cold fluid chamber line 514 and a cold fluid chamber to heat sink return line 518. The liquid cooled heat sink 502 is also in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of a heat sink pump to hot fluid chamber line 508 and a hot fluid chamber to heat sink return line 512.
Working fluid may be selectively circulated between the liquid cooled heat sink 502 and the cold fluid chamber or evaporator reservoir 100 by opening a heat sink pump to cold fluid chamber control valve 516 and using a liquid cooled heat sink pump 506. Working fluid may also be selectively circulated between the liquid cooled heat sink 502 and the hot fluid chamber or condenser reservoir 300 by opening a heat sink pump to hot fluid chamber control valve 510 and using the liquid cooled heat sink pump 506. The liquid cooled heat sink pump 506 may be variable capacity, or may be operated in an on-off mode. If present, the liquid cooled heat sink (not shown) that functions to heat and/or cool the drivetrain battery unit 608 may similarly be provided with fluid circuits and a pump connecting it to the cold fluid chamber or evaporator reservoir 100 and/or the hot fluid chamber or condenser reservoir 300. The pump circulating working fluid from the cold fluid chamber or evaporator reservoir 100 to the liquid cooled heat sink that functions to heat and/or cool the drivetrain battery unit 608 may be a positive displacement pump, and may be capable of circulating fluid at a controlled rate, in order to control the rate of heat transfer from the drivetrain battery unit 608.
Each of the VFD heat pump refrigerant compressor 200, the insulated fluid reservoir to cold fluid chamber pump 404, the insulated fluid reservoir to hot fluid chamber pump 412, the shore power contactor 604, the drive train battery contactor 610, the cold fluid chamber to vehicle interior cooling modules pump 110, the hot fluid chamber to cabin heat exchanger pump 308, the hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316, the hot fluid chamber to outside heat exchanger pump 324, the liquid cooled heat sink pump 506, the heat sink pump to hot fluid chamber control valve 510, and the heat sink pump to cold fluid chamber control valve 516 are again controlled directly or indirectly by a system controller 12. The system controller 12 is again connected to the VFD heat pump refrigerant compressor 200 by way of a compressor VFD control output 16, which is again connected to a refrigerant compressor VFD control input 204 of a refrigerant compressor variable frequency drive control 202, which is in turn connected to the VFD heat pump refrigerant compressor 200. The refrigerant compressor variable frequency drive control 202 again receives power from the drive train battery unit 608 by way of a battery output to refrigerant compressor 614, which is connected to the refrigerant compressor variable frequency drive control 202 by way of a refrigerant compressor battery input 212.
The system controller 12 is again connected to the insulated fluid reservoir to cold fluid chamber pump 404, to the insulated fluid reservoir to hot fluid chamber pump 412, to the cold fluid chamber to vehicle interior cooling modules pump 110, to the hot fluid chamber to cabin heat exchanger pump 308, to the hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316, to the hot fluid chamber to outside heat exchanger pump 324, and to the liquid cooled heat sink pump 506 by way of pump control outputs 20. Alternately, the liquid cooled heat sink pump 506 may utilize a closed loop control, in order to separately maintain the liquid cooled heat sink 502 and the electric drive motor 500 and associated electronics in a temperature range calculated to result in optimum efficiency of the electric drive motor 500 and associated power electronics. The system controller 12 is again connected to the shore power contactor 604 and to the drive train battery contactor 610 by way of contactor outputs 18. The system controller 12 is connected to the heat sink pump to hot fluid chamber control valve 510 and to the heat sink pump to cold fluid chamber control valve 516 by way of solenoid valve outputs 22. In order to properly manage the climate control system 10, the system controller 12 is again provided with temperature inputs 14 that are connected to a cold fluid chamber temperature sensor 106, to a hot fluid chamber temperature sensor 304, to an insulated fluid reservoir temperature sensor 408, and to a liquid cooled heat sink temperature sensor 504.
As shown in
The VFD heat pump refrigerant compressor 200 may be running, thereby pumping heat from the evaporator heat exchanger 102 to the condenser heat exchanger 302, cooling the working fluid in the cold fluid chamber or evaporator reservoir 100 and heating the working fluid in the hot fluid chamber or condenser reservoir 300. By warming the cold fluid chamber or evaporator reservoir 100 with heated working fluid from the insulated fluid reservoir 400, boiling of refrigerant in the evaporator heat exchanger 102 is increased, and the heat pump 50 of the climate control system 10 maintains a COP of greater than one, despite the fact that the insulated fluid reservoir PTC heater 612 itself only has a COP of one.
The at least one hot fluid chamber to cabin heat exchanger pump 308 and/or the at least one hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316 may be active, using the heated working fluid in the hot fluid chamber or condenser reservoir 300 passing through the at least one cabin heat exchanger 310 and/or through the at least one defrost/defog combination fluid heat exchanger PTC heater 318 to heat the interior of the vehicle and/or to defrost the vehicle windows. Additionally, the heat sink pump to hot fluid chamber control valve 510 may be open and the liquid cooled heat sink pump 506 may be active, thereby circulating working fluid between the hot fluid chamber or condenser reservoir 300 and the liquid cooled heat sink 502, and preheating the electric drive motor 500 and associated power electronics. In this way, the electric drive motor 500 and associated power electronics are maintained within a temperature range that assures best efficiency when the power train begins to operate. This preconditioning operation may also include circulating working fluid between the hot fluid chamber or condenser reservoir 300 and the drive train battery unit 608 in order to raise the drive train battery unit 608 to a temperature suited for efficient operation under cold ambient temperature conditions.
The heat sink pump to cold fluid chamber control valve 516 may remain closed, the insulated fluid reservoir to hot fluid chamber pump 412 may remain inactive, and the hot fluid chamber to outside heat exchanger pump 324 may remain inactive. Overall, the climate control system 10 exhibits a much higher energy efficiency than that of an electric heater alone, and avoids the decrease in COP often associated with an air sourced heat pump operating in cold ambient temperatures, which typically need to be supplemented directly using PTC based electric heat.
As shown in
The insulated fluid reservoir to cold fluid chamber pump 404 may be active, thereby circulating working fluid between the cold fluid chamber or evaporator reservoir 100 and the insulated fluid reservoir 400, for the purpose of storing cooled working fluid in the insulated fluid reservoir 400 for later use during operation. The insulated fluid reservoir to hot fluid chamber pump 412 remains inactive. Additionally, the heat sink pump to cold fluid chamber control valve 516 is open and the liquid cooled heat sink pump 506 may be active, thereby circulating working fluid between the cold fluid chamber or evaporator reservoir 100 and the liquid cooled heat sink 502, and precooling the electric drive motor 500 and associated power electronics. The heat sink pump to hot fluid chamber control valve 510 remains closed.
As shown in
The insulated fluid reservoir to hot fluid chamber pump 412 may be active and the insulated fluid reservoir to cold fluid chamber pump 404 inactive, thereby circulating working fluid between the hot fluid chamber or condenser reservoir 300 and the insulated fluid reservoir 400, now for the purpose of using the cooled working fluid in the insulated fluid reservoir 400 previously stored for later use during operation as an additional heat sink. This arrangement lowers the pressure of the refrigerant in the condenser, and increases the efficiency or COP of the heat pump 50. Alternately, the insulated fluid reservoir to cold fluid chamber pump 404 may be active and the insulated fluid reservoir to hot fluid chamber pump 412 inactive, thereby circulating working fluid between the cold fluid chamber or evaporator reservoir 100 and the insulated fluid reservoir 400, now for the purpose of using the cooled working fluid in the insulated fluid reservoir 400 previously stored for later use during operation to further cool the working fluid in the cold fluid chamber or evaporator reservoir 100. This arrangement reduces the boiling of the refrigerant in the evaporator, and also increases the efficiency or COP of the heat pump 50 when in the cooling mode. The system and method may further choose whether to circulate working fluid between the hot fluid chamber or condenser reservoir 300 and the insulated fluid reservoir 400, or between the cold fluid chamber or evaporator reservoir 100 and the insulated fluid reservoir 400, depending on the present temperature of the working fluid in the insulated fluid reservoir 400. In either arrangement, the increased efficiency of the heat pump 50 reduces overall power consumption of the climate control system 10 and helps to preserve the state of charge of the drive train battery unit 608.
The heat sink pump to cold fluid chamber control valve 516 may be open and the liquid cooled heat sink pump 506 may be active, thereby circulating working fluid between the cold fluid chamber or evaporator reservoir 100 and the liquid cooled heat sink 502, and cooling the operating electric drive motor 500 and associated power electronics. Consequently, the operating electric drive motor 500 and associated power electronics are maintained within a temperature range that assures best efficiency. The heat sink pump to hot fluid chamber control valve 510 remains closed.
As shown in
The at least one hot fluid chamber to cabin heat exchanger pump 308 and/or the at least one hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316 may be active, using the heated working fluid in the hot fluid chamber or condenser reservoir 300 passing through the at least one cabin heat exchanger 310 and/or through the at least one defrost/defog combination fluid heat exchanger PTC heater 318 to heat the interior of the vehicle and/or to defrost the vehicle windows. The cold fluid chamber to vehicle interior cooling modules pump 110 and the hot fluid chamber to outside heat exchanger pump 324 remain inactive. The heat sink pump to cold fluid chamber control valve 516 may be open and the liquid cooled heat sink pump 506 may be active, thereby circulating working fluid between the cold fluid chamber or evaporator reservoir 100 and the liquid cooled heat sink 502, now for the purpose of recouping heat from the operating electric drive motor 500 and associated power electronics. This helps to further raise the temperature of the evaporator heat exchanger 102 and raise the COP of the heat pump 50 when in the heating mode. The heat sink pump to hot fluid chamber control valve 510 remains closed.
Turning now to
An insulated fluid reservoir 400 is again in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of an insulated fluid reservoir to cold fluid chamber line 402 and a cold fluid chamber line to insulated fluid reservoir return line 406. Working fluid may again be selectively circulated between the insulated fluid reservoir 400 and the cold fluid chamber or evaporator reservoir 100 using an insulated fluid reservoir to cold fluid chamber pump 404. The insulated fluid reservoir is again in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of an insulated fluid reservoir to hot fluid chamber line 410 and a hot fluid chamber line to insulated fluid reservoir return line 414. Working fluid may again be selectively circulated between the insulated fluid reservoir 400 and the hot fluid chamber or condenser reservoir 300 using an insulated fluid reservoir to hot fluid chamber pump 412.
Working fluid within the insulated fluid reservoir 400 may again be selectively heated by an insulated fluid reservoir PTC heater 612. The insulated fluid reservoir PTC heater 612 is again connected to a shore power source 600 by way of a shore power line 602 having a shore power contactor 604. As before, when the shore power contactor 604 is closed, the insulated fluid reservoir PTC heater 612 draws power from the shore power source 600, and when the shore power contactor 604 is open, the insulated fluid reservoir PTC heater 612 is isolated from the shore power source 600. The insulated fluid reservoir PTC heater 612 is again also connected to a drive train battery unit 608 by way of a drive train battery line 616 having a drive train battery contactor 610. As before, when the drive train battery contactor 610 is closed, the insulated fluid reservoir PTC heater 612 draws power from the drive train battery unit 608, and when the drive train battery contactor 610 is open, the insulated fluid reservoir PTC heater 612 is isolated from the drive train battery unit 608. A charging system 606 again selectively connects the drive train battery unit 608 to the shore power source 600 as needed for recharging.
At least one cabin heat exchanger 310 is again in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of at least one hot fluid chamber to cabin heat exchanger line 306 and at least one cabin heat exchanger to hot fluid chamber return line 312. Working fluid may again be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one cabin heat exchanger 310 using a hot fluid chamber to cabin heat exchanger pump 308. As before, at least one defrost/defog combination fluid heat exchanger PTC heater 318 is in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of at least one hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater line 314 and at least one defrost/defog combination fluid heat exchanger PTC heater to hot fluid chamber return line 320. Working fluid may again be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one defrost/defog combination fluid heat exchanger PTC heater 318 using a hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316. Also, at least one outside heat exchanger 326 is again in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of at least one hot fluid chamber to outside heat exchanger line 322 and at least one outside heat exchanger to hot fluid chamber return line 328. Working fluid may again be selectively circulated between the hot fluid chamber or condenser reservoir 300 and the at least one outside heat exchanger 326 using a hot fluid chamber to outside heat exchanger pump 324.
As before, at least one vehicle interior cooling module 114 is in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of at least one cold fluid chamber to vehicle interior cooling modules line 108 and at least one vehicle interior cooling modules to cold fluid chamber return line 112. Working fluid may again be selectively circulated between the cold fluid chamber or evaporator reservoir 100 and the at least one vehicle interior cooling module 114 using a cold fluid chamber to vehicle interior cooling modules pump 110. Similarly, at least one outside heat exchanger 120 is in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of at least one cold fluid chamber to outside heat exchanger line 116 and at least one outside heat exchanger to cold fluid chamber return line 122. Working fluid may be selectively circulated between the cold fluid chamber or evaporator reservoir 100 and the at least one outside heat exchanger 120 using a cold fluid chamber to outside heat exchanger pump 118.
The full electric or hybrid electric vehicle (not shown) includes an electric drive motor 500 and associated power electronics, which is heated and/or cooled using a liquid cooled heat sink 502. The liquid cooled heat sink 502 is in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of a heat sink pump to cold fluid chamber line 514 and a cold fluid chamber to heat sink return line 518. The liquid cooled heat sink 502 is also in fluid communication with the hot fluid chamber or condenser reservoir 300 by way of a heat sink pump to hot fluid chamber line 508 and a hot fluid chamber to heat sink return line 512. Working fluid may be selectively circulated between the liquid cooled heat sink 502 and the cold fluid chamber or evaporator reservoir 100 by opening a heat sink pump to cold fluid chamber control valve 516 and using a liquid cooled heat sink pump 506. Working fluid may also be selectively circulated between the liquid cooled heat sink 502 and the hot fluid chamber or condenser reservoir 300 by opening a heat sink pump to hot fluid chamber control valve 510 and using the liquid cooled heat sink pump 506.
As with the climate control system 10 illustrated in
Furthermore, the climate control system 10 illustrated in
Each of the VFD heat pump refrigerant compressor 200, the insulated fluid reservoir to cold fluid chamber pump 404, the insulated fluid reservoir to hot fluid chamber pump 412, the shore power contactor 604, the drive train battery contactor 610, the cold fluid chamber to vehicle interior cooling modules pump 110, the hot fluid chamber to cabin heat exchanger pump 308, the hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316, the hot fluid chamber to outside heat exchanger pump 324, the liquid cooled heat sink pump 506, cold fluid chamber to outside heat exchanger pump 118, the heat sink pump to hot fluid chamber control valve 510, and the heat sink pump to cold fluid chamber control valve 516 are again controlled directly or indirectly by a system controller 12. The system controller 12 is again connected to the VFD heat pump refrigerant compressor 200 by way of a compressor VFD control output 16, which is again connected to a refrigerant compressor VFD control input 204 of a refrigerant compressor variable frequency drive control 202, which is in turn connected to the VFD heat pump refrigerant compressor 200. The refrigerant compressor variable frequency drive control 202 again receives power from the drive train battery unit 608 by way of a battery output to refrigerant compressor 614, which is connected to the refrigerant compressor variable frequency drive control 202 by way of a refrigerant compressor battery input 212.
The system controller 12 is again connected to the insulated fluid reservoir to cold fluid chamber pump 404, to the insulated fluid reservoir to hot fluid chamber pump 412, to the cold fluid chamber to vehicle interior cooling modules pump 110, to the hot fluid chamber to cabin heat exchanger pump 308, to the hot fluid chamber to defrost/defog combination fluid heat exchanger PTC heater pump 316, to the hot fluid chamber to outside heat exchanger pump 324, to the liquid cooled heat sink pump 506, and to the cold fluid chamber to outside heat exchanger pump 118 by way of pump control outputs 20. The system controller 12 is again connected to the shore power contactor 604 and to the drive train battery contactor 610 by way of contactor outputs 18. The system controller 12 is again connected to the heat sink pump to hot fluid chamber control valve 510 and to the heat sink pump to cold fluid chamber control valve 516 by way of solenoid valve outputs 22. In order to properly manage the climate control system 10, the system controller 12 is again provided with temperature inputs 14 that are connected to a cold fluid chamber temperature sensor 106, to a hot fluid chamber temperature sensor 304, to an insulated fluid reservoir temperature sensor 408, and to a liquid cooled heat sink temperature sensor 504.
As shown in
In order to extract heat from the ambient environment under certain conditions and raise the COP of the heat pump 50, an outside heat exchanger 120 is in fluid communication with the cold fluid chamber or evaporator reservoir 100 by way of a cold fluid chamber to outside heat exchanger line 116 and an outside heat exchanger to cold fluid chamber return line 122. A cold fluid chamber to outside heat exchanger pump 118 circulates working fluid between the outside heat exchanger 120 and the cold fluid chamber or evaporator reservoir 100, thereby raising the temperature of the evaporator heat exchanger 102. This increases boiling of refrigerant in the evaporator heat exchanger 102 and increases the efficiency of the heat pump 50. The certain conditions under which the outside heat exchanger 120 may be used to extract heat from the ambient environment may occur when the outside or ambient air temperatures are equal to or greater than approximately 40 degrees Fahrenheit and may further extend up to equal to or lesser than approximately 60 degrees Fahrenheit. Specifically, this range of outside or ambient air temperatures may include the temperatures wherein the COP of the heat pump 50 would be greater than approximately 3.0. Therefore, in this arrangement the embodiment of the climate control system 10 heat energy is recovered both from the operating electric drive motor 500 and associated power electronics and from the ambient air by way of the outside heat exchanger 120. It is noted that although in
The shore power contactor 604 is open and the drive train battery contactor 610 may be open, so that the insulated fluid reservoir PTC heater 612 and the insulated fluid reservoir to cold fluid chamber pump 404 may be inactive. In this configuration, the embodiment of the climate control system 10 shown in
While the Vehicle Climate Control System with Heat Recovery Utilizing a Heat Pump, and methods for the use thereof, has been described with respect to at least one embodiment, the system and method can be further modified within the spirit and scope of this disclosure, as demonstrated previously. This application is therefore intended to cover any variations, uses, or adaptations of the system and method using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which the disclosure pertains and which fall within the limits of the appended claims.
| Number | Date | Country | |
|---|---|---|---|
| 62609526 | Dec 2017 | US | |
| 62623884 | Jan 2018 | US | |
| 62593514 | Dec 2017 | US |
