Heating and cooling systems for vehicles

Abstract

The heating and cooling system for a vehicle includes a heat transfer assembly (20) having a first heat exchanger (HED2) and a second heat exchanger (HED3) and configured to receive thermal energy at the first heat exchanger, transfer thermal energy from the first heat exchanger to the second heat exchanger, and output thermal energy at the second heat exchanger. The system includes a liquid refrigerant distribution system (22) having a cold tank (24) for a first liquid storage vessel, a hot tank (26) for a second liquid storage vessel, and a network of fluid conduits connecting the cold tank to the first heat exchanger, the hot tank to the second heat exchanger, and the cold and hot tanks to locations within the vehicle that are heated or cooled using liquid from the tanks.

Description

[Technical field]

[0001] Field of Disclosure FIELD OF THE DISCLOSURE This disclosure relates to temperature control within a vehicle, and more particularly, to improving the efficiency of energy use to control temperature within a vehicle. [Background technology]

[0002] Background of the disclosure There is a continuing desire to reduce the environmental impact of transportation. Controlling the interior temperature of a vehicle can consume a significant amount of energy. Summary of the Invention [Means for solving the problem]

[0003] Disclosure Summary The present disclosure provides a heating and cooling system for a vehicle, comprising: a heat transfer assembly having a first heat exchanger and a second heat exchanger and configured to receive thermal energy at the first heat exchanger, transfer thermal energy from the first heat exchanger to the second heat exchanger, and output thermal energy at the second heat exchanger; 1. A liquid refrigerant distribution system comprising: a cryogenic tank for the first liquid storage vessel; a high temperature tank for the second liquid storage vessel; A network of fluid conduits, comprising: The low temperature tank is the first heat exchanger, the hot tank to a second heat exchanger, and Low and high temperature tanks are installed in the vehicle at locations where the liquid from the tanks is used to heat or cool the vehicle. A network of interconnected fluid conduits; a liquid refrigerant distribution system including: The present invention provides a heating and cooling system including:

[0004] The system includes a heat transfer assembly or heat pump in combination with two tanks or storage vessels of liquid. One of the tanks (the "hot tank") is provided for holding liquid at a higher temperature than liquid held in the other tank (the "cold tank"). The heat transfer assembly is operable to transfer thermal energy from the cold tank to the hot tank. The tanks thereby provide a source of liquid heat transfer medium at two different temperatures.

[0005] During operation of the system, the liquid may be used to transfer thermal energy between different components of the system to control the temperature of various areas of the vehicle. By using a liquid (water, water mixed with glycol, or other coolant fluid) as the heat transfer medium, the heat transfer rate may be increased compared to using air instead. The system thereby facilitates improved efficiency of energy usage for temperature control by the vehicle.

[0006] In known temperature control systems for vehicles, air is blown directly onto the evaporator of the air conditioner to provide air cooling. With the present system, thermal energy can be transferred to or extracted from an area of ​​the vehicle using a liquid. Heat transfer can then take place utilizing liquid-air heat exchange within the area of ​​interest and / or heat exchange between the liquid heat transfer medium and the component can take place via direct contact (as opposed to using air circulation).

[0007] The inventors have demonstrated that the amount of energy used to control the temperature of a bus passenger compartment can be comparable to the amount consumed to power the bus, depending on the ambient outside temperature. At the same time, the inventors have recognized that other areas within the bus also require thermal management. For example, an electrically powered bus has electric motors, battery packs, and inverters that require some degree of thermal control for operation and potentially more stringent thermal control to optimize their efficiency.

[0008] For example, in some ambient conditions the passenger compartment of a bus may need to be heated to 15-20°C, while other areas, such as the battery pack, may need to be cooled to 15-5°C.

[0009] Another factor to consider in passenger vehicle temperature control is that each passenger can emit approximately 100 W of heat energy. Thus, a 90-seat double-decker bus can receive up to 9 kW of heat from the passengers in the passenger compartment. The number of passengers a bus carries during a typical day can vary greatly, and so can the heating or cooling demand for the passenger compartment at different times of the day.

[0010] The heating and cooling system according to the present disclosure is capable of managing temperature distribution within a vehicle in a versatile and efficient manner.

[0011] The cryogenic tank may be fluidly connected to the first heat exchanger to allow thermal energy to be transferred from liquid withdrawn from the cryogenic tank to the first heat exchanger, which may then be returned to the cryogenic tank.

[0012] The high temperature tank may be fluidly connected to a second heat exchanger to allow for the transfer of thermal energy from the second heat exchanger to liquid withdrawn from the high temperature tank, which may then be returned to the high temperature tank.

[0013] Either or both of the low temperature and high temperature tanks may be fluidly connected to a location within the vehicle to facilitate cooling and / or heating of the location using liquid from the tanks, which may then be returned to the tank from which it was drawn.

[0014] The system may be configured to selectively circulate liquid from either the low temperature and high temperature tanks (if either cooling or heating is required) to one or more of a number of locations within the vehicle.

[0015] Preferably, the heat transfer assembly comprises: a third heat exchanger having first and second fluid inlets and first and second fluid outlets, the third heat exchanger being positioned to transfer thermal energy from a fluid flowing from the first inlet to the first outlet to a fluid flowing from the second inlet to the second outlet; An expansion device; A compressor; a first loop of fluid conduits arranged to convey liquid from the first outlet of the third heat exchanger through an expansion device to the first heat exchanger and thereafter to the second inlet of the third heat exchanger; a second loop of fluid conduit arranged to convey liquid from the second outlet of the third heat exchanger through the compressor to the second heat exchanger and thereafter to the first inlet of the third heat exchanger; Includes.

[0016] This heat transfer assembly configuration can provide high efficiency heat transfer. The present disclosure provides a heat transfer assembly comprising: a first heat exchanger and a second heat exchanger, the assembly being configured to receive thermal energy at the first heat exchanger, transfer thermal energy from the first heat exchanger to the second heat exchanger, and output thermal energy at the second heat exchanger; a third heat exchanger having first and second fluid inlets and first and second fluid outlets, the third heat exchanger being positioned to transfer thermal energy from a fluid flowing from the first inlet to the first outlet to a fluid flowing from the second inlet to the second outlet; An expansion device; A compressor; a first loop of fluid conduits arranged to convey liquid from the first outlet of the third heat exchanger through an expansion device to the first heat exchanger and thereafter to the second inlet of the third heat exchanger; a second loop of fluid conduit arranged to convey liquid from the second outlet of the third heat exchanger through the compressor to the second heat exchanger and thereafter to the first inlet of the third heat exchanger; There may further be provided a heat transfer assembly comprising:

[0017] Such inclusion of a third heat exchanger may substantially increase (perhaps nearly double) the heat transfer rate achievable by the heat transfer assembly at a given level of power consumption by the heat transfer assembly.

[0018] The expansion device is configured to reduce the fluid pressure and may be in the form of, for example, a capillary tube, a pressure controlled valve, an electrical expansion device, or a thermostatic or thermal expansion valve.

[0019] The heat transfer assembly disclosed herein may be arranged such that the first inlet of the third heat exchanger is higher than the first outlet, and / or the second inlet is lower than the second outlet, which may reduce the possibility that the coolant will exit the first outlet in gas form and / or the coolant will exit the second outlet in liquid form, which tends to improve the efficiency of the heat transfer assembly.

[0020] In a further example, the third heat exchanger may be positioned such that its second inlet is higher than its second outlet, in which case it is preferred that the fluid path between the second outlet and the compressor includes at least a portion at the same height as the second inlet.

[0021] In some implementations, a tank level control conduit may be connected between the cold and hot tanks to transport liquid between the tanks, facilitating adjustment of the liquid level in the tanks as needed.

[0022] The system may include a first liquid-to-air heat exchanger fluidly connected to the cryogenic tank for transferring thermal energy from the atmosphere outside the vehicle to the liquid from the cryogenic tank, such that when the temperature of the liquid in the cryogenic tank drops below a predetermined threshold, its temperature may be increased by drawing thermal energy from the atmosphere.

[0023] A second liquid-to-air heat exchanger may be fluidly connected to the hot tank for transferring thermal energy from the liquid from the hot tank to the atmosphere outside the vehicle, so that when the temperature of the liquid in the hot tank rises above a predetermined threshold, its temperature may be reduced by dissipating thermal energy to the atmosphere.

[0024] In a preferred example, the first fluid-to-air heat exchanger may be fluidly connected to both the cold tank and the hot tank to transport thermal energy from the atmosphere outside the vehicle to the liquid from the cold tank, and to transfer thermal energy from the liquid from the hot tank to the atmosphere.

[0025] The low and high temperature tanks may be fluidly connected to a liquid-to-air heat exchanger for exchanging thermal energy between liquid from the tanks and air within or supplied to an interior region of the vehicle occupied by an occupant of the vehicle, the system thereby facilitating controlling the temperature within the passenger compartment of the vehicle separately from the temperature of other regions of the vehicle.

[0026] The low and high temperature tanks may be fluidly connected to a liquid-to-air heat exchanger for exchanging thermal energy between liquid from the tanks and air within or supplied to an interior region of a vehicle for holding a battery to power the vehicle, the system thereby facilitating controlling the temperature within the battery compartment of a vehicle separately from the temperature of other regions of the vehicle.

[0027] The system may be arranged to supply liquid from the low and / or high temperature tanks for cooling the vehicle's drive motor, whereby the system may control the temperature of the vehicle's drive motor separately from the temperature of other areas of the vehicle. In addition, the system may be used to achieve greater cooling of the motor, thereby improving the performance of the motor, especially when the ambient temperature is high.

[0028] The present disclosure also provides a method of operating a vehicle heating and cooling system as disclosed herein, the method including transferring thermal energy from a low temperature tank to a high temperature tank via a heat transfer assembly, whereby reservoirs of liquid held in the tanks can be maintained at significantly different temperatures to facilitate efficient use of thermal energy for temperature control within the vehicle.

[0029] Methods of operating a vehicle heating and cooling system disclosed herein may include transferring thermal energy from the atmosphere outside the vehicle to a liquid provided to a low temperature tank via a fluid-to-air heat exchanger and / or transferring thermal energy from a liquid from a high temperature tank to the atmosphere outside the vehicle via a fluid-to-air heat exchanger (or the fluid-to-air heat exchanger).

[0030] Methods of operating a vehicle heating and cooling system disclosed herein may include transferring thermal energy from a location within the vehicle to a low temperature tank and / or transferring thermal energy between a location within the vehicle and a high temperature tank.

[0031] Methods of operating a vehicle heating and cooling system disclosed herein may include transferring thermal energy from a vehicle drive motor for driving the vehicle to a low temperature or high temperature tank.

[0032] A method of operating a vehicle heating and cooling system disclosed herein may include transferring thermal energy from an interior region of the vehicle to a low temperature tank for holding a battery for powering the vehicle or transferring thermal energy from a high temperature tank to the interior region.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS Examples of the present disclosure will now be described with reference to the accompanying schematic drawings. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 illustrates a cooling system. [Figure 2A] FIG. 1 illustrates two portions of a heating and cooling system according to an example of the present disclosure. [Figure 2B] FIG. 1 illustrates two portions of a heating and cooling system according to an example of the present disclosure. [Diagram 3] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. [Figure 4] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. [Diagram 5] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. [Figure 6] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. [Figure 7] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. [Figure 8] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. [Figure 9] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. [Figure 10] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. [Figure 11] FIG. 2 illustrates an example of an operational mode of a system according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Detailed Description A cooling system is shown in Figure 1 to illustrate the features of such a system. Refrigerant vapor is fed to a compressor CP1. The compressor then compresses the vapor reducing its volume by a factor of approximately 7 to 12. The compressor is controlled by a dual pressure controller PS1 which monitors the vapor pressure at the inlet and outlet of the compressor. The compressed vapor then passes from the compressor to a condenser C1 where it is condensed from a gas to a liquid. The condenser is cooled by a fan 10 which blows ambient air over the surface of the condenser.

[0036] The liquid discharged by the condenser is fed to a coolant tank RC1, which separates the liquid from any remaining gas. Downstream of the tank RC1 is a service connection SC1, which allows easy monitoring of the coolant pressure and the removal or addition of coolant. Connection SC1 is followed by a filter and dryer FD1, which removes moisture from the coolant and an inspection window through which the condition of the coolant can be inspected.

[0037] The liquid is then fed to an electric expansion device in the form of a thermostatic expansion valve EED1 (TEV), which sprays high pressure liquid into a low pressure evaporator E1 where the refrigerant is vaporized. The TEV is responsive to a temperature sensor T1 downstream of the evaporator. A second fan 12 blows air over the surface of the evaporator which is cooled by the outer surface of the evaporator. A second service connection SC2 is provided downstream of the evaporator. The vapor is then fed to a compressor CP1.

[0038] An example of a heating and cooling system according to the present disclosure is shown in Figures 2A and 2B. The heat transfer assembly or heat pump portion 20 of the system is shown in Figure 2A, and the heat distribution portion 22 of the system is shown in Figure 2B.

[0039] The heat transfer assembly 20 of Fig. 2A is configured to transfer thermal energy from the heat exchange device HED2 to the heat exchange device HED3. These two devices also form part of a distribution system shown in Fig. 2B.

[0040] In the heat transfer assembly of Figure 2A, a refrigerant vapor is fed to a compressor CP1, which then compresses the vapor, reducing its volume by a factor of about 5 to 7.

[0041] The compressor inlet and outlet pipes (VIB1 and VIB2) are preferably vibration absorbing pipes to absorb vibrations of the compressor during its operation. VIB1 and VIB2 are connected in parallel with compressor CP1 and are fluidly connected to each other via a bypass conduit 14 which includes a safety pressure valve SPV1. In addition, another safety pressure valve SPV2 is included upstream of VIB1, which is connected to the atmosphere by an exhaust pipe 16.

[0042] The vapor leaving the compressor is fed to a heat exchanger HED3. The fluid discharged from HED3 (which may consist of 1-10% of fluid in liquid and vapor form) then passes from the heat exchanger HED3 via a pressure sensor SVP2 to a first inlet I1 of another heat exchanger HED1. The liquid leaves the heat exchanger HED1 by a first outlet O1 fluidly connected to the first inlet I1 in HED1.

[0043] A liquid indicator 18 is connected in parallel with the fluid flow from I1 to O1 of HED1 for safety purposes. For example, this may include upper and lower sight glasses, SG2 and SG3 respectively, to indicate the presence or absence of liquid.

[0044] After HED1, the liquid therefore flows through the service valve SSV1 and the sight glass SG1.

[0045] The liquid then flows to an electric expansion device in the form of a thermostatic expansion valve EED1 (TEV). The valve sprays the high pressure liquid into the heat exchanger HED2, where it absorbs thermal energy and vaporizes. The pressure sensor SVP1 and the check valve SSV3 are therefore positioned downstream of HED2. The vapor leaving HED2 is then fed to a second inlet I2 of the heat exchanger HED1. The vapor leaves HED1 through a second outlet O2 and is fed to the compressor CP1.

[0046] The fluid flowing from the first inlet I1 to the first outlet O1 of the HED1 flows in the opposite direction to the fluid flowing from the second inlet I2 to the second outlet O2. The device HED1 facilitates the transfer of thermal energy from the fluid entering through the first inlet I1 to the fluid entering through the second inlet I2.

[0047] Preferably, the fluid conduits interconnecting the components of the heat transfer assembly 20 have a relatively large internal cross-sectional area to reduce resistance to fluid flow, thereby improving the efficiency of the heat transfer assembly. For example, the diameter of the conduits may be about 7 / 8 to 1 3 / 8 inches, and is preferably less than 5 / 8 inches.

[0048] A number of advantages are provided by the configuration of the heat transfer assembly shown in Figure 2A. The inlet I1 of the HED1 is at a higher position than the associated outlet O1. This can help ensure that only liquid is drawn out of the outlet, as liquid will tend to collect at the lower portion of the outlet side of the HED1 due to gravity. This therefore helps separate the liquid from any remaining vapor.

[0049] The heat exchange device HED1 forms another condensation stage between I1 and O1, since thermal energy is extracted from the fluid flowing from a first inlet I1 of HED1 to its outlet O1 by the fluid flowing from a second inlet I2 to a second outlet O2.

[0050] Furthermore, the fluid flowing from the second inlet I2 of the HED1 to its second outlet O2 receives thermal energy from the fluid going from the first inlet I1 to the first outlet O1, so that the HED1 constitutes another evaporation stage between I2 and O2, converting the remaining liquid droplets into steam. Since the second outlet is higher than the second inlet, only the steam tends to leave the HED1 through its outlet O2, because the steam collects by gravity in the upper part of the outlet side of the HED1. This improves the efficiency of the compressor CP1, since it requires a smaller compression ratio (and therefore a higher coefficient of performance) due to the increased vapor pressure as a result of the steam being heated as it passes from I2 to O2 in the HED1. Also, less liquid reaches the compressor, which could otherwise impair its performance and efficiency. Furthermore, the heat transfer realized by the HED1 increases the vapor pressure leaving the outlet O2, which results in less work that the compressor needs to do to compress the refrigerant to the desired temperature.

[0051] In an alternative configuration, the inlet I2 may be higher than the outlet O2. So, in the example shown in Figure 2A, the inlet I2 may be connected to HED1 where O2 is connected in Figure 2A, or vice versa. If the fluid conduit connecting O2 to the compressor CP1 is at or above the same height as inlet I2 at any point, this leveling means that only vapor will tend to reach the compressor, even though the rate of heat transfer through HED1 is reduced during periods when the compressor is not operating.

[0052] This alternative configuration for I2 and O2 may also be desirable if the compressor does not have an oil separator, as it may facilitate the flow of the oil component of the refrigerant back to the compressor. The velocity of the vaporized components of the refrigerant carries the oil out of outlet O2, which tends to lift it up through the higher part of the conduit between HED1 and the compressor. The oil could otherwise accumulate in HED1.

[0053] Preferably, the heat transfer area of ​​HED1 is at least 75% of the heat transfer area of ​​HED2.

[0054] A relatively large heat exchanger is preferably used as HED1. This allows the heat exchanger to provide a high heat exchange rate. It also allows the heat exchanger to store liquid that may accumulate between inlet I1 and outlet O1 and gas that may accumulate between inlet I2 and outlet O2. For example, for every 10 kW of system power, HED1 preferably has an internal volume of at least 1.5 l for each of its two flow paths. The system power may be defined, for example, by the product of the coefficient of performance (COP) and the power rating of the compressor. The internal volume of each side of HED1 may range, for example, from 1 to 10 l for relatively small systems to more than 10 l for larger systems.

[0055] The HED1 is preferably in the form of a plate heat exchanger. The external shape of the heat exchanger may be, for example, suitably contoured to accommodate the available space while at the same time maintaining the required heat exchange area and internal volume.

[0056] The heat distribution mechanism 22 shown in FIG. 2B includes a cold tank 24 and a hot tank 26 for holding respective reservoirs of liquid refrigerant.

[0057] The flow of refrigerant through a network of tubes around the heat distribution mechanism can be controlled by solenoid valves, indicated as SV1-SV27 in Figure 2B. The temperature at various locations is monitored using temperature sensors, indicated as T11-T17.

[0058] The heating and cooling system may include a controller for controlling solenoid valves, pumps and other components of the system in response to signals received from the temperature sensors and other control parameters. The controller may be a dedicated programmable controller or control unit (or may be formed by multiple controllers). The controller may be configured to identify the most appropriate way to operate the system, taking into account the temperature characteristics of various areas of the vehicle, the air temperature and the current temperatures in each compartment of the vehicle, in order to achieve and / or maintain temperatures within the required ranges in those areas.

[0059] Pump P1 is fluidly coupled between the cold tank 24 and the heat exchanger HED2, and the heat distribution mechanism is configured to circulate a refrigerant between the cold tank 24 and HED2. Similarly, pump P2 is fluidly coupled between the hot tank 26 and the heat exchanger HED3, and is positioned to circulate a refrigerant between the hot tank 26 and HED3. Circulation of the refrigerant through HED2 and HED3 by pumps P1 and P2, respectively, as a result of thermal energy transfer from HED2 to HED3 by heat transfer assembly 20 tends to cool the refrigerant held in the cold tank 24 and heat the refrigerant held in the hot tank 26.

[0060] The capacity of each tank may be, for example, about 1.5 to 4 liters. Pump P1 may be capable of delivering, for example, about 40 liters per minute.

[0061] Fluid conduit FAL1 directly interconnects cold tank 24 and hot tank 26. It is configured to transfer refrigerant liquid from one tank to the other if a predetermined level is exceeded in either tank, for example due to a valve failure.

[0062] Each of the low and high temperature tanks 24, 26 are fluidly connected to a common fluid-to-air heat exchanger in the form of a radiator 28. The radiator is exposed to the atmosphere surrounding the vehicle. A fan F1 is configured to blow ambient air over a surface of the radiator.

[0063] When the temperature of the coolant in the cryogenic tank 24 falls below a predetermined threshold, the system may be controlled to circulate the coolant from the tank and into the radiator 28, drawing thermal energy from the atmosphere into the coolant.

[0064] When the temperature of the coolant in the hot tank rises above a predetermined threshold, the system may be controlled to circulate the coolant from the hot tank into the radiator 28 to dissipate thermal energy from the coolant to the atmosphere.

[0065] The heat distribution mechanism 22 is configured to circulate refrigerant from each of the low and high temperature tanks to and from various regions of the vehicle. In the example shown in Figure 2B, three regions are shown: (i) a fluid-to-air heat exchanger located in the driver's seat and passenger compartment, (ii) a fluid-to-air heat exchanger located in the traction battery compartment, and (iii) a traction motor compartment.

[0066] In Fig. 2B, six fluid-to-air heat exchangers are shown for the passenger compartment, namely two heat exchangers 30, 32 for heating or cooling the second floor, two heat exchangers 34, 36 for heating or cooling the driver's seat, a heat exchanger 38 for heating or cooling the first floor area, and a heat exchanger 40 for heating or cooling the rear part of the second floor. Two one-way valves OWV1 and OWV2 are included to facilitate the selection of various combinations of heat exchangers. It should be understood that various heat exchanger configurations suitable for each vehicle may be selected.

[0067] Each of the heat exchangers has a flow regulator (designated FR1-FR6, respectively) associated therewith, which facilitates controlling and / or regulating the relative amount of heat transfer therebetween. The flow regulators may be, for example, capillaries, electrically controlled valves, or thermostatic valves.

[0068] The drive battery compartment houses four batteries 42. The heat distribution mechanism 22 includes respective fluid-to-air heat exchangers BR1-BR4 proximate the corresponding batteries. A pump P3 is provided to pump coolant to the drive battery compartment, which may be capable of pumping up to about 1.8 liters per minute, for example. Each of the heat exchangers BR1-BR4 has a flow regulator associated therewith (designated FR11-FR14, respectively) which facilitates adjusting the relative amount of heat transfer delivered by each heat exchanger.

[0069] The drive motor compartment houses various components that require cooling to drive and operate the vehicle. In Fig. 2B, by way of example only, these include a first motor with a stator 44 and a rotor 46, an associated inverter INV1 and a second motor with a stator 48 and a rotor 50, and an associated inverter INV2. Each motor is adapted to direct a liquid that cools its stator and rotor, for example an APM200 motor manufactured by the applicant. The drive motor compartment may house, for example, further inverters INV_DCDC, INV_24, INV3, an air compressor CP2 and a gearbox G1, etc.

[0070] The flow control devices FR7-FR10 are positioned within the drive motor compartment in the flow of the fluid refrigerant immediately prior to the rotor 46, INV_DCDC, INV_24, and rotor 50, respectively.

[0071] Conduits carrying fluid coolant to and from components within the drive motor compartment extend from an input manifold 60 to an output manifold 62. The temperatures of the manifolds are sensed by respective temperature sensors T16 and T17, thereby facilitating monitoring of the heat dissipation occurring within the drive motor compartment.

[0072] It should be understood that the conduit and valve arrangement shown in Figure 2B is shown by way of example only, and that other configurations could be used to provide similar functionality, for example, three-way valves could be placed in place of some two-way valves at some points, thereby easing fabrication and reducing cost and weight.

[0073] A heating and cooling system constructed in accordance with the present disclosure is capable of managing temperature distribution within a vehicle in a highly efficient and versatile manner. By way of example, the selection of various modes of the exemplary system shown in Figures 2A and 2B will now be described with reference to Figures 3-11.

[0074] Figures 3-11 illustrate various modes of operation of the heat distribution mechanism 22 of Figure 2B, as indicated by the selective opening of the assembly's solenoid valves and the selective operation of the coolant pumps. A lightning bolt symbol is used to indicate that the solenoid valves are actuated open, and a symbol consisting of a circle and crossed diagonal lines is used to identify a closed solenoid valve. Arrows have been added to indicate the flow of coolant.

[0075] 3, heat distribution mechanism 22 is shown operating to (a) cool the drive motor compartment using refrigerant from the hot tank, (b) heat the passenger compartment using refrigerant circulated through the drive motor compartment and heat exchange device HED3, and (c) raise the temperature of refrigerant in the cold tank by circulating it through radiator 28. In this mode, thermal energy extracted from the drive motor compartment can be used directly to heat the passenger compartment.

[0076] In the mode of operation shown in FIG. 4, the heat distribution mechanism (a) heats the passenger compartment with refrigerant drawn from the hot tank via HED3, and (b) cools the drive motor compartment faster in a "fast cool" mode (compared to FIG. 3, where the drive motor compartment is cooled with refrigerant from the hot tank) by circulating refrigerant drawn from the cold tank via HED2 into the drive motor compartment. The refrigerant returning from the drive motor compartment to the cold tank is shown doing so via the radiator 28. In this way, a portion of the thermal energy extracted from the drive motor compartment is released to the atmosphere. Alternatively, the returning refrigerant can be directed back directly to the cold tank without passing through the radiator, thereby retaining a greater portion of the thermal energy extracted from the drive motor compartment within the vehicle for heating other areas of the vehicle. This variation is shown in FIG. 5. Thermal energy can be extracted from the refrigerant in the cold tank via HED2 and then transferred to HED3 (via the heat transfer assembly 20) for heating areas of the vehicle.

[0077] FIG. 6 illustrates a mode in which (a) the passenger compartment and cab are cooled using refrigerant drawn from the low temperature tank, and (b) the motor compartment is cooled by refrigerant drawn from the high temperature tank and returned to the high temperature tank via radiator 28.

[0078] In the configuration shown in FIG. 7, (a) the passenger compartment, cab, and drive motor compartment are cooled using refrigerant drawn from the low temperature tank, and (b) excess thermal energy is dissipated from the system by circulating refrigerant from the high temperature tank through radiator 28.

[0079] In FIG. 8, (a) the drive motor compartment is cooled in a “fast cool” mode by circulating refrigerant from a low temperature tank through HED2 within the drive motor compartment, and (b) excess thermal energy is dissipated from the system by circulating refrigerant from a high temperature tank through radiator 28.

[0080] Figures 9 and 10 show how the heat distribution mechanism 22 can be configured to heat or cool the battery compartment independently from other areas of the vehicle to optimize battery performance and life. In the mode shown in Figure 9, the battery compartment is cooled using refrigerant drawn from the low temperature tank, while in Figure 10, the battery compartment is heated using refrigerant drawn from the high temperature tank.

[0081] FIG. 11 illustrates cooling of the drive motor compartment using refrigerant drawn from the hot tank, with excess thermal energy being dissipated from the system by returning the refrigerant to the hot tank via radiator 28.

Claims

1. 1. A heating and cooling system for a vehicle, comprising: a heat transfer assembly having a first heat exchanger and a second heat exchanger and configured to receive thermal energy at the first heat exchanger, transfer thermal energy from the first heat exchanger to the second heat exchanger, and output thermal energy at the second heat exchanger; 1. A liquid refrigerant distribution system comprising: a cryogenic tank for the first liquid storage vessel; a high temperature tank for the second liquid storage vessel; A network of fluid conduits, comprising: the cryogenic tank to the first heat exchanger; the high temperature tank to the second heat exchanger, and The low and high temperature tanks are placed in locations within the vehicle that will be heated or cooled using liquid from the tanks. A network of interconnected fluid conduits; a liquid refrigerant distribution system including: Heating and cooling systems including:

2. The heat transfer assembly comprises: a third heat exchanger having first and second fluid inlets and first and second fluid outlets, the third heat exchanger being positioned to transfer thermal energy from a fluid flowing from the first inlet to the first outlet to a fluid flowing from the second inlet to the second outlet; An expansion device; A compressor; a first loop of fluid conduits arranged to convey liquid from the first outlet of the third heat exchanger through the expansion device to the first heat exchanger and thereafter to the second inlet of the third heat exchanger; a second loop of fluid conduits arranged to convey liquid from the second outlet of the third heat exchanger through the compressor to the second heat exchanger and thereafter to the first inlet of the third heat exchanger; The system of claim 1 , comprising:

3. 1. A heat transfer assembly comprising: a first heat exchanger and a second heat exchanger, the assembly being configured to receive thermal energy at the first heat exchanger, transfer thermal energy from the first heat exchanger to the second heat exchanger, and output thermal energy at the second heat exchanger; a third heat exchanger having first and second fluid inlets and first and second fluid outlets, the third heat exchanger being positioned to transfer thermal energy from a fluid flowing from the first inlet to the first outlet to a fluid flowing from the second inlet to the second outlet; An expansion device; A compressor; a first loop of fluid conduits arranged to convey liquid from the first outlet of the third heat exchanger through the expansion device to the first heat exchanger and thereafter to the second inlet of the third heat exchanger; a second loop of fluid conduits arranged to convey liquid from the second outlet of the third heat exchanger through the compressor to the second heat exchanger and thereafter to the first inlet of the third heat exchanger; a heat transfer assembly including:

4. The system of claim 2 or the heat transfer assembly of claim 3, wherein the third heat exchanger is positioned such that its first inlet is higher than its first outlet.

5. The system of claim 2 or the heat transfer assembly of claim 3, wherein the third heat exchanger is positioned such that its second inlet is lower than its second outlet.

6. A system or heat transfer assembly as described in claim 4, wherein the third heat exchanger is positioned such that its second inlet is lower than its second outlet.

7. 4. The system of claim 2 or the heat transfer assembly of claim 3, wherein the third heat exchanger is positioned such that its second inlet is higher than its second outlet, and a fluid path defined by the second loop of fluid conduit between the second outlet and the compressor includes a portion that is at least as high as the second inlet.

8. 10. The system of claim 1 including a tank level control conduit connected between said cold and hot tanks for conveying liquid between said tanks.

9. 10. The system of claim 1, including a first liquid-to-air heat exchanger fluidly connected to the cryogenic tank for transferring thermal energy from the atmosphere external to the vehicle to a liquid from the cryogenic tank.

10. 10. The system of claim 1, further comprising a second liquid-to-air heat exchanger fluidly connected to the high temperature tank for transferring thermal energy from a liquid from the high temperature tank to an atmosphere external to the vehicle.

11. 10. The system of claim 9, wherein the first fluid-to-air heat exchanger is also fluidly connected to the hot tank for transferring thermal energy from a liquid from the hot tank to an atmosphere external to the vehicle.

12. 10. The system of claim 1, wherein the low temperature and high temperature tanks are fluidly connected to a liquid-to-air heat exchanger for exchanging thermal energy between liquid from the tanks and air within or supplied to an interior region of the vehicle occupied by an occupant of the vehicle.

13. 10. The system of claim 1, wherein the low temperature and high temperature tanks are fluidly connected to a liquid-to-air heat exchanger for exchanging thermal energy between liquid from the tanks and air within or supplied to an interior region of the vehicle for holding a battery to power the vehicle.

14. 2. A system as claimed in claim 1 arranged to supply liquid from said low temperature and / or high temperature tanks for cooling a vehicle drive motor.

15. 10. A method of operating the system of claim 1 comprising transferring thermal energy from the low temperature tank to the high temperature tank through the heat transfer assembly.

16. 20. A method of operating a system as described in claim 1 or claim 15, comprising the step of transferring thermal energy from the atmosphere external to the vehicle to a liquid provided to the cryogenic tank via a liquid-to-air heat exchanger.

17. 16. A method of operating a system as recited in claim 1 or claim 15, comprising the step of transferring thermal energy from the high temperature tank to the atmosphere external to the vehicle via a liquid-to-air heat exchanger.

18. 20. A method of operating a system as recited in claim 1 or claim 15, comprising the step of transferring thermal energy from a location within the vehicle to the cryogenic tank.

19. 20. A method of operating a system as recited in claim 1 or claim 15, comprising the step of transferring thermal energy between a location within the vehicle and the hot tank.

20. 20. A method of operating a system as recited in claim 1 or claim 15, comprising the step of transferring thermal energy from a vehicle drive motor to the low temperature or high temperature tank.

21. 20. A method of operating a system as described in claim 1 or claim 15, comprising the steps of transferring thermal energy from an interior region of the vehicle to the low temperature tank for holding a battery for powering the vehicle or transferring thermal energy from the high temperature tank to the interior region.

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