Method for controlling pathogens in vehicle heat pump systems

Abstract

The present invention relates to a control system (100) for controlling a vehicle heat pump system (200, 300), the vehicle heat pump system (200, 300) being operable in a heating mode at a first pressure, the control system (100) including one or more controllers (110) configured to: receive a moisture signal indicative of moisture on a surface of a first heat exchanger (210, 310) of the vehicle heat pump system (200, 300); determine the need for moisture removal in response to the moisture signal; and output a control signal (155) to control the vehicle heat pump system (200, 300) to operate at a second pressure higher than the first pressure, thereby heating the surface of the first heat exchanger (210, 310) and removing moisture from the surface.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Aspects of the invention relate to a control system, a vehicle heat pump system, a vehicle, a method, and computer readable instructions. [Background technology]

[0002] It is known to control the temperature of a vehicle cabin using a heat pump capable of operating in a heating mode and a cooling mode. In the heating mode, a heat exchange unit of the heat pump is heated and air is blown into the vehicle cabin through the heated heat exchange unit, warming the air and warming the vehicle cabin. In the cooling mode, the same heat exchange unit may be cooled, cooling the air blown through the heat exchange unit. The heat pump system provides heating or cooling air conditioning functions for the vehicle. Summary of the Invention [Problem to be solved by the invention]

[0003] A common problem associated with vehicle air conditioning systems is moisture accumulation on the surface of the heat exchange unit. This occurs particularly frequently after the heat exchange unit has been cooled to provide air conditioning. This occurs because the surface temperature of the heat exchange unit is lower than the surrounding area. Moisture on the surface of the heat exchange unit can create an environment conducive to bacterial growth. Prolonged use of the air conditioning unit can lead to unpleasant odors and pathogens entering the vehicle cabin. Therefore, heat pump system maintenance may be required to keep the surface of the heat exchange unit clean, prevent odor generation, and maintain air quality when the air conditioning system is in use. Reducing the presence of pathogens, in particular, is an important part of vehicle maintenance.

[0004] Attempts to dry the surface of a heat exchange unit, which may be located under the hood of a conventional vehicle, without removing the heat exchange unit from the vehicle or manually accessing the heat exchange unit's location have been known. For example, a dedicated heating element, such as a conductive filament heater, can be placed near the surface of the heat exchange unit to heat and dry the surface. Another approach involves directing airflow to carry heat from a heat source, such as a vehicle engine, and blowing the heated air across the surface of the heat exchange unit. However, such approaches have drawbacks, such as increased part count and difficulty in manufacturing and installation, because they require additional dedicated components, such as heating elements, fans, blowers, or airflow directing elements, which may block the desired airflow direction or prevent heat exchange between the heat exchange unit and the surrounding air, thereby disrupting proper operation of the vehicle's temperature control system.

[0005] SUMMARY OF THE INVENTION It is an object of the present invention to overcome one or more disadvantages associated with the prior art. [Means for solving the problem]

[0006] Aspects and embodiments of the present invention provide a control system, a vehicle heat pump system, a vehicle, a method, and computer readable instructions as set out in the accompanying claims.

[0007] According to one aspect of the present invention, there is provided a control system for controlling a vehicle heat pump system, the vehicle heat pump system being operable in a heating mode at a first pressure, the control system including one or more controllers and configured as follows: receiving a moisture signal indicative of moisture on a surface of a first heat exchanger of the vehicle heat pump system; Determining the need to remove moisture in response to the moisture signal; and A control signal is output to control the vehicle heat pump system to operate at a second pressure greater than the first pressure, thereby heating a surface of the first heat exchanger to remove moisture therefrom.

[0008] Advantageously, the control system may control the vehicle heat pump system to operate in a heating mode at a pressure higher than the normal operating pressure to remove moisture from the surface of the first heat exchanger. Advantageously, removing moisture from the surface of the first heat exchanger inhibits bacterial and pathogen growth and maintains a clean vehicle environment. By utilizing the heating mode of the vehicle heat pump system but operating at a second pressure higher than the first pressure, moisture can be removed without the need for dedicated components, such as a heating element, for removing moisture. As a result, the vehicle heat pump system may be simplified because dedicated components for drying the surface of the first heat exchanger are not required.

[0009] In some examples, the control signal controls the vehicle heat pump system to operate in a heating mode at the second pressure to heat the surface of the first heat exchanger. Advantageously, an existing mode of the vehicle heat pump system can be used to heat the surface of the first heat exchanger. Heating the surface of the first heat exchanger can inactivate or destroy bacteria or pathogens present on the surface.

[0010] In some examples, the moisture signal indicates at least one of a temperature or humidity near the first heat exchanger, a usage history of the vehicle heat pump system indicating that the vehicle heat pump system was previously operating in a cooling mode, a user input to remove moisture from the surface of the first heat exchanger, and an identification that the vehicle including the vehicle heat pump system has completed a journey. Advantageously, the control system can control the vehicle heat pump system to operate in a heating mode at the second pressure to remove moisture from the surface of the first heat exchanger when moisture is likely to be present. In some cases, moisture may accumulate on the surface after the first heat exchanger cools during cooling operation. Advantageously, the efficiency of the vehicle heat pump system is maintained by operating to remove moisture only when moisture is likely to be present.

[0011] In some examples, the control system is configured to control the vehicle heat pump system to operate in a heating mode at the second pressure for a predetermined time to dry the surface of the first heat exchanger. Advantageously, the vehicle heat pump system can operate in the heating mode at the second pressure for the predetermined time until the surface is dry, and then be turned off to improve system efficiency.

[0012] In some examples, the control system is configured to control the vehicle heat pump system to operate in a heating mode in response to humidity or temperature information received from the at least one sensor until a predetermined humidity or temperature threshold is reached, advantageously preventing the vehicle heat pump system from operating unnecessarily and improving efficiency.

[0013] In some examples, the control system is configured to, in response to determining whether moisture needs to be removed, send an output instruction to a user requesting user confirmation, and, in response to receiving the user confirmation, output a control signal for controlling the vehicle heat pump system to operate at the second pressure. Advantageously, requesting user confirmation based on the moisture signal may allow the user to postpone operation to a more convenient time, such as after the last trip of the day. Additionally, if the moisture signal indicates user input, the output to the user may serve as an additional confirmation procedure.

[0014] In some examples, the control system is configured to receive a signal indicating that the vehicle has completed a journey, and the control system is configured to postpone outputting a control signal for controlling the vehicle heat pump system to operate at the second pressure until the control system receives the signal indicating that the vehicle has completed a journey. In this manner, the system can wait to control the vehicle heat pump system to operate at the second pressure until the vehicle is no longer in use, thereby avoiding discomfort to the driver. In examples in which the control system is configured to send an output indication to a user, the control system can postpone outputting an indication to the user requesting user confirmation until the control system receives the signal indicating that the vehicle has completed a journey.

[0015] In some examples, the second pressure is between 14 bar and 20 bar. Advantageously, the temperature of the surface of the first heat exchanger may be increased to at least 50°C or 60°C.

[0016] In some examples, the first pressure is up to 14 bar.

[0017] In some examples, the control system is configured to control the vehicle heat pump system to operate in a heating mode at the second pressure such that the temperature of the surface of the first heat exchanger increases to at least 50° C. Advantageously, the surface of the first heat exchanger can be effectively dry at 50° C.

[0018] In some examples, the control system is configured to control the vehicle heat pump system to operate in a heating mode at the second pressure such that a temperature of the surface of the first heat exchanger is increased to at least 60° C. In some examples, the temperature is 69° C. Advantageously, bacteria or pathogens present on the surface may be destroyed.

[0019] Advantageously, a temperature sufficient to remove moisture from the surface of the first heat exchanger can be achieved when the second pressure is 14 bar, and a temperature sufficient to directly destroy or inactivate bacteria or pathogens can be achieved when the second pressure is about 20 bar.

[0020] According to another aspect of the present invention, there is provided a vehicle heat pump system operable in a heating mode at a first pressure, the vehicle heat pump system including a first heat exchanger and a control system.

[0021] In some examples, a vehicle heat pump system includes a compressor configured to compress a fluid to heat the fluid.

[0022] In some examples, the vehicle heat pump system includes a control valve configured to control the direction of fluid flow around the vehicle heat pump system, thereby operating the vehicle heat pump system in a heating mode or a cooling mode. Advantageously, the vehicle heat pump system is operable in a heating mode and a cooling mode to provide efficient heating and cooling to the vehicle.

[0023] In some examples, the vehicle heat pump system includes a thermal expansion valve connected between the compressor and the first heat exchanger and configured to control a flow rate of the compressed fluid to control the expansion of the compressed fluid, thereby cooling the fluid in a cooling mode.

[0024] In some examples, the vehicle heat pump system includes a second heat exchanger connected between the compressor and the thermal expansion valve.

[0025] In some examples, in a heating mode the first heat exchanger can operate as a condenser, and in a cooling mode the first heat exchanger can operate as an evaporator.

[0026] In some examples, in the heating mode the second heat exchanger can operate as an evaporator, and in the cooling mode the second heat exchanger can operate as a condenser.

[0027] In some examples, the vehicle heat pump system includes an accumulator connected between the first heat exchanger and the compressor.

[0028] In some examples, the fluid is a refrigerant.

[0029] In some examples, the thermal expansion valve is configured to cool the fluid by throttling.

[0030] In some examples, the control system is configured to output a control signal to control the vehicle heat pump system to operate at the second pressure in a heating mode such that the temperature of the surface of the first heat exchanger increases to at least 50°C. Advantageously, the surface of the first heat exchanger may be effectively dried at 50°C. In some examples, the control system is configured to output a control signal to control the vehicle heat pump system to operate at the second pressure in a heating mode such that the temperature of the surface of the first heat exchanger increases to at least 60°C. In some examples, the temperature is 69°C. Advantageously, bacteria or pathogens present on the surface may be destroyed.

[0031] In some examples, the vehicle heat pump system includes a control valve configured to control the direction of fluid flow around the vehicle heat pump system, thereby operating the vehicle heat pump system in a heating mode or a cooling mode. The control valve includes a three-way valve configured to selectively connect the compressor to the first heat exchanger via the thermal expansion valve and to selectively connect the compressor to the second heat exchanger. The three-way valve is configured to selectively bypass the second heat exchanger such that hot fluid is circulated through the compressor, the three-way valve, the thermal expansion valve, and the first heat exchanger. Advantageously, the vehicle heat pump system can be operated in a heating mode or a cooling mode by controlling the direction of fluid flow around the vehicle heat pump system to heat or cool the first heat exchanger.

[0032] In some examples, the vehicle heat pump system includes a valve operable to open or restrict to selectively contain fluid in the first heat exchanger, and the control system is configured to output a control signal in response to receiving a moisture signal to control the valve to restrict to contain the hot fluid in the first heat exchanger. Advantageously, the hot refrigerant can circulate through the first heat exchanger without being cooled by passing through the second heat exchanger, thereby improving the efficiency of operation of the vehicle heat pump system in a heating mode at the second pressure.

[0033] In some examples, the valve includes a second thermal expansion valve.

[0034] In some examples, the vehicle heat pump system includes at least one of a temperature sensor configured to detect a temperature near the first heat exchanger or a humidity sensor configured to detect a humidity near the first heat exchanger, and the moisture signal includes at least one of the detected temperature or the detected humidity. Advantageously, the vehicle heat pump system can determine when moisture is present on a surface of the first heat exchanger and operate in a heating mode at the second pressure as needed. Furthermore, the vehicle heat pump system can determine when moisture has been successfully removed or when a target temperature on the surface of the first heat exchanger has been achieved and cease operation.

[0035] In some examples, the vehicle heat pump system includes a blower configured to blow air across a surface of the first heat exchanger, and the control system is configured to control the fan to operate at a low speed to blow air across the surface of the first heat exchanger when it is determined that the surface of the first heat exchanger is dry. Advantageously, this can dissipate moisture in the air surrounding the first heat exchanger, accelerating moisture removal from the surface, while simultaneously reducing power consumption of the blower.

[0036] According to another aspect of the present invention, a vehicle including a control system or a vehicle heat pump system is provided.

[0037] According to another aspect of the present invention, there is provided a method for removing moisture from a surface of a first heat exchanger of a vehicle heat pump system operable in a heating mode at a first pressure, the method comprising: receiving a moisture signal indicative of moisture on a surface of the first heat exchanger; determining the need to remove moisture in response to the moisture signal; and outputting a control signal to control the vehicle heat pump system to operate at a second pressure higher than the first pressure, thereby heating a surface of the first heat exchanger to remove moisture from the surface; Includes:

[0038] In some examples, the second pressure is between 14 bar and 20 bar.

[0039] In some examples, the moisture signal indicates at least one of a usage history of the vehicle heat pump system indicating that the vehicle heat pump system previously operated in a cooling mode, a user input to remove moisture from the surface of the first heat exchanger, and an identification that the vehicle including the vehicle heat pump system has completed a journey. Advantageously, the control system can control the vehicle heat pump system to operate in a heating mode at the second pressure to remove moisture from the surface of the first heat exchanger when moisture is likely to be present. In some cases, moisture may accumulate on the surface after the first heat exchanger cools during cooling operation. Advantageously, the efficiency of the vehicle heat pump system is maintained by operating to remove moisture only when moisture is likely to be present.

[0040] In some examples, the method includes detecting a temperature proximate the first heat exchanger or a humidity proximate the first heat exchanger, and the moisture signal includes at least one of the detected temperature or the detected humidity. Advantageously, the vehicle heat pump system can determine when moisture is present on a surface of the first heat exchanger and operate in a heating mode at the second pressure as needed. Additionally, the vehicle heat pump system can determine when moisture has been successfully removed or a target temperature on the surface of the first heat exchanger has been achieved and cease operation.

[0041] In some examples, the method includes controlling the vehicle heat pump system to operate in a heating mode for a predetermined time to dry a surface of the first heat exchanger.

[0042] In some examples, the method includes controlling the vehicle heat pump system to operate in a heating mode until a predetermined humidity or temperature threshold is reached.

[0043] In some examples, the method includes controlling the vehicle heat pump system to operate in a heating mode at the second pressure such that the temperature of the surface of the first heat exchanger is increased to at least 50°C, or controlling the vehicle heat pump system to operate in a heating mode at the second pressure such that the temperature of the surface of the first heat exchanger is increased to at least 60°C. Advantageously, moisture is effectively removed from the surface when the surface is heated to 50°C. Advantageously, bacteria or pathogens present on the surface of the first heat exchanger are destroyed or inactivated when the surface is heated to at least 60°C.

[0044] According to another aspect of the invention, computer readable instructions are provided that, when executed by a computer, are configured to carry out this method.

[0045] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives, particularly individual features thereof, described in the preceding paragraphs, claims, and / or the following description and drawings, may be employed independently or in any combination. That is, all embodiments and / or features of embodiments may be combined in any manner and / or combination, unless such features are incompatible. The applicant reserves the right to modify the originally filed claims and to submit new claims accordingly, including the right to amend the originally filed claims to depend on and / or incorporate features of other claims, even if not originally claimed as such.

[0046] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings. [Brief explanation of the drawings]

[0047] [Figure 1] FIG. 1 shows a block diagram of a control system according to one embodiment of the present invention. [Figure 2] FIG. 2 shows a block diagram of a vehicle heat pump system according to one embodiment of the present invention. [Figure 3] FIG. 3 shows a block diagram of a vehicle heat pump system according to one embodiment of the present invention. [Figure 4] FIG. 4 is a flow chart illustrating a method for drying a surface of a heat exchanger in a vehicle heat pump system according to one embodiment of the present invention. [Figure 5] FIG. 5 shows a vehicle according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0048] The present disclosure relates to a vehicle heat pump system and a method of operating the vehicle heat pump system to dry heat exchanger surfaces. As described in more detail with respect to Figures 2 and 3, a heat pump typically includes a compressor, two heat exchange units operable as a condenser and an evaporator, and at least one expansion device. A fluid, such as a refrigerant, is compressed by the compressor and passes through one of the heat exchange units, the expansion device, a second heat exchange unit, and then back to the compressor. During this process, the temperature of the fluid changes due to the throttling effect of the expansion device and the compression of the fluid in the compressor. The direction of fluid flow may be reversible, or the fluid flow path may be rerouted to switch between heating and cooling modes, such that a heat exchange unit adjacent to the airflow into the vehicle cabin is heated or cooled by the fluid passing therethrough, thereby heating or cooling the vehicle cabin.

[0049] A control system 100 according to one embodiment of the present invention will now be described with reference to accompanying Figure 1. Figure 1 shows a block diagram of a control system 100 according to one embodiment of the present invention.

[0050] 1 , control system 100 includes one or more controllers 110. In use, control system 100 may be communicatively coupled to a vehicle heat pump system operable in a heating mode at a first pressure, and control system 100 may be configured to control the operation of the vehicle heat pump system.

[0051] The control system 100 is configured to receive a moisture signal indicative of moisture on a surface of a first heat exchanger of the vehicle heat pump system. The heat exchanger is also referred to as a heat exchange unit. In response to the moisture signal, the control system 100 determines the need to remove moisture from the surface of the first heat exchanger. The control system 100 then outputs a control signal 155 to control the vehicle heat pump system to operate in a heating mode at a second pressure. The second pressure can be higher than the first pressure. In some examples, the second pressure is between 14 bar and 20 bar. The first pressure, which is the maximum operating pressure during normal operation of the vehicle heat pump system to heat or cool the vehicle cabin, is approximately 14 bar; however, it should be understood that the vehicle heat pump system can operate at other pressures depending on the heating or cooling required. It should be understood that the maximum pressure that the system can achieve may be limited by physical constraints of the system components, as illustrated in FIG. 2 . However, the control system 100 may control the vehicle heat pump system to operate in a heating mode at a second pressure that is higher than the system's normal operating pressure in a normal heating mode to heat the vehicle cabin. The control system 100 may further receive information 165 indicative of a detected temperature or humidity near the first heat exchanger from one or more sensors 160 and determine a need to remove moisture in response to the received information 165. In some examples, the temperature or humidity information may be included in the moisture signal.

[0052] When the vehicle heat pump system is operated in a heating mode at the second pressure, the temperature of the surface of the first heat exchanger may increase above the normal operating temperature, sufficient to remove moisture from the surface of the first heat exchanger. The surface temperature of the first heat exchanger is related to the pressure of the vehicle heat pump system in the heating mode. For example, when the vehicle heat pump system is operated in a heating mode at 14 bar, the surface temperature of the first heat exchanger may increase to approximately 50°C. When the vehicle heat pump system is operated in a heating mode at 20 bar, the surface temperature of the first heat exchanger may increase to approximately 60°C or 69°C in some examples. The vehicle heat pump system may operate at a first pressure during normal use of the vehicle heat pump system to heat the vehicle cabin. The first pressure may be up to 14 bar in some examples. Advantageously, heating the surface of the first heat exchanger to approximately 50°C may remove moisture from the surface of the first heat exchanger by evaporation. It is understood that removing moisture from the heat exchanger surfaces may inhibit bacterial growth on the heat exchanger surfaces and may also reduce pathogen load. Advantageously, heating the first heat exchanger surface to about 60°C or 69°C should evaporate moisture from the first heat exchanger surface and inactivate or destroy any bacteria or pathogens present on the first heat exchanger surface or in the air near the first heat exchanger. The pressure of the vehicle heat pump system may be controlled by at least one of the compressor and the expansion device.

[0053] 1 includes one controller 110, it will be understood that this is for illustrative purposes only. The controller 110 includes a processing means 120 and a memory means 130. The processing means 120 is one or more electronic processing devices 120 that operatively execute computer-readable instructions. The memory means 130 is one or more memory devices 130. The memory means 130 is electrically connected to the processing means 120. The memory means 130 is configured to store instructions, and the processing means 120 is configured to access the memory means 130 and execute the instructions stored therein.

[0054] The controller 110 includes an input 140 and an output 150. The input 140 may include an electrical input 140 of the controller 110. The output 150 may include an electrical output of the controller 110. The input 140 is configured to receive a moisture signal. The input 140 may also be configured to receive at least one of a temperature signal 165 or a humidity signal 165 from a temperature sensor 160 or a humidity sensor 160. The moisture signal, the temperature signal 165, and the humidity signal 165 may be electrical signals indicative of moisture present on the surface of the first heat exchanger, the temperature detected by the temperature sensor 160, and the humidity detected by the humidity sensor 160, respectively. While the sensor 160 is shown external to the controller 110, the controller 110 may include the sensor 160 as an integrated module. The output 150 is configured to output a control signal 155 for controlling the vehicle heat pump system to operate in a heating mode at the second pressure. The control signal 155 may be output to the vehicle heat pump system by the output 150.

[0055] The controller 110 may be communicatively coupled to one or more additional sensors (not shown in FIG. 1 ) or a vehicle communication network to determine information about the vehicle heat pump system. The controller 110 may also be communicatively coupled to a vehicle control system, such as a system including a vehicle communication bus that can relay information and control signals between various components and systems of the vehicle. For example, the controller 110 may receive a moisture signal via the vehicle control system. The controller 110 may also receive a control signal corresponding to a user input on a user interface module within the vehicle.

[0056] The moisture signal may indicate moisture on the surface of the first heat exchanger of the vehicle heat pump system. In some examples, the moisture signal may indicate a usage history of the vehicle heat pump system, indicating that the vehicle heat pump system previously operated in a cooling mode. That is, the vehicle heat pump system may operate in a cooling mode to cool the vehicle cabin and provide air conditioning functions for the vehicle cabin. During the cooling mode, the first heat exchanger is cooled by a cold fluid passing through the first heat exchanger. Because the first heat exchanger is cooler than the ambient air, moisture may accumulate on the surface of the first heat exchanger. Therefore, if the control system 100 determines that the vehicle heat pump system is operating in a cooling mode, it may determine to operate the vehicle heat pump system in a heating mode at a second pressure to remove moisture from the surface of the first heat exchanger and / or destroy bacteria and pathogens on the surface of the first heat exchanger. Removing moisture from the heat exchanger surface reduces bacterial growth on the heat exchanger surface, which benefits from a moist environment. For example, a determination may be made to initiate a drying process when it is determined that the vehicle heat pump system has operated in a cooling mode for a predetermined period of time. When the control system 100 determines that the vehicle has completed its journey, it can decide to operate the vehicle heat pump system in a heating mode at a second pressure so as not to interfere with the user's desired heating or cooling functions.

[0057] In another example, the moisture signal may be received in response to a user request to dry the surface of the first heat exchanger. The moisture signal may include a user request to dry the surface of the first heat exchanger. In some examples, the moisture signal may be an unrequested display signal, and in response to receiving the display signal, the control system 100 may output an indication to the user recommending that the vehicle heat pump system or the vehicle HVAC system be sanitized to reduce the presence of bacteria or pathogens. To this end, the control system 100 may output instructions recommending a process corresponding to a process for removing moisture from the vehicle heat pump system. The user may confirm that they wish to initiate the process. In response to the user's confirmation, the control system outputs a control signal to the vehicle heat pump system. In some examples, the recommendation may be provided to the user based on the time since the last execution of the drying process exceeding a predetermined threshold or based on use of the vehicle heat pump system in a cooling mode. The user may also decide to initiate the drying process even if a recommendation is not output. Alternatively, or in addition, the control system 100 may determine to remove moisture from the surface of the first heat exchanger in response to temperature or humidity information 165 received from at least one sensor 160. For example, the at least one sensor 160 may be provided near the first heat exchanger and measure at least one of the temperature or humidity near the first heat exchanger. If the measured temperature or humidity exceeds a predetermined threshold, it is determined that moisture needs to be removed from the first heat exchanger.

[0058] In some examples, the control system may determine that moisture needs to be removed from the first heat exchanger while the vehicle is still in use. While the vehicle is in use, the user may want to maintain the temperature of the vehicle heat pump until the journey is complete. Therefore, the control signal may be configured to receive a signal indicating that the journey is complete and output the control signal upon receiving the signal. In other words, the control system may be configured to postpone outputting the control signal for controlling the vehicle heat pump system to operate at the second pressure until receiving a signal indicating that the vehicle has completed the journey.

[0059] In some examples, if it is determined that moisture needs to be removed from the surface of the first heat exchanger, the vehicle heat pump system may operate in a heating mode at the second pressure for a predetermined time. In another example, the vehicle heat pump system may operate in a heating mode at the second pressure until a temperature or humidity value measured by at least one sensor 160 reaches a predetermined value.

[0060] Figure 2 illustrates a vehicle heat pump system 200 according to one embodiment of the present invention. The vehicle heat pump system 200 may include a control system 100, such as that shown in Figure 1, but which is not shown in Figure 2. For example, the vehicle heat pump system 200 may operate under the control of the control system 100 of Figure 1.

[0061] Vehicle heat pump system 200 is comprised of first heat exchanger 210, second heat exchanger 220, expansion device 230, accumulator 240, compressor 250, and control valve 260. However, it should be understood that not all of these components are required, and one or more components may be omitted, such as omitting at least accumulator 240. A fluid, such as a refrigerant or coolant, is conducted around vehicle heat pump system 200 via conduit 270. Air sources inside and outside the vehicle including vehicle heat pump system 200 are drawn through vehicle heat pump system 200 to heat or cool the air.

[0062] The first heat exchanger 210 and the second heat exchanger 220 may comprise heat exchange units configured to exchange thermal energy with ambient air. The heat exchangers 210 and 220 may also be referred to as heat exchange units, heat exchangers, or heat exchange units. It should be understood that any suitable type of heat exchanger may be used, including a shell-and-tube heat exchanger, a plate heat exchanger, a plate-and-shell heat exchanger, a plate-fin heat exchanger, a fin-tube heat exchanger, a pillow plate heat exchanger, a microchannel heat exchanger, and a coil heat exchanger. The type of heat exchanger used may be determined based on the maximum operating temperature or pressure of the heat exchanger. The first heat exchanger 210 and the second heat exchanger 220 are configured to control the passage of fluid through the first heat exchanger 210 and the second heat exchanger 220 and facilitate the exchange of thermal energy between the fluid in the first heat exchanger 210 and the second heat exchanger 220 and the ambient air.

[0063] The compressor 250 is configured to compress the fluid. The compressor 250 may include any suitable type of compressor. The compressor 250 may be configured to compress the fluid to a first pressure during normal operation of the vehicle heat pump system 200 in a heating mode or a cooling mode. The first pressure may be up to 14 bar in some examples. However, it is contemplated that the compressor 250 may be configured to compress the fluid to a pressure lower than the first pressure during operation, or that the first pressure may vary depending on the temperature requirements of the vehicle heat pump system 200 based on control of the desired vehicle cabin temperature by the user or the vehicle. The pressure referred to here is the pressure of the fluid within the first heat exchanger 210. It should be understood that the pressure of the fluid varies between different locations within the vehicle heat pump system 200 as the vehicle heat pump system 200 operates to perform heating and cooling functions, as described below. The pressure of the vehicle heat pump system 200 may be determined by the temperature required to remove moisture from the surface of the first heat exchanger 210. That is, if one wishes to remove moisture from the surface of the first heat exchanger 210, the target temperature to be achieved on the surface of the first heat exchanger 210 is 50°C and the pressure is about 14 bar, whereas if one wishes to directly destroy pathogens on the surface of the first heat exchanger 210, the target temperature is 69°C and the pressure is about 20 bar.

[0064] The control valve 260 includes a valve configured to control the direction of fluid flow around the vehicle heat pump system 200. In some examples, the control valve 260 may include a three-way valve, a T-valve, or a reversing valve. The control valve 260 is configured to control the direction of fluid flow around the vehicle heat pump system 200 under the control of a controller, such as the control system 100 of FIG. 1 . The direction of fluid flow around the vehicle heat pump system 200 determines whether the vehicle heat pump system 200 operates in a heating mode or a cooling mode. That is, when fluid is directed in a first direction around the vehicle heat pump system 200, the hot fluid passing through the first heat exchanger 210 heats the first heat exchanger 210, and air blown across the first heat exchanger by a fan (shown by an arrow in FIG. 2 ) is heated and supplied to the vehicle cabin, thereby warming the vehicle cabin. The control valve 260 can redirect the fluid flow to a second flow direction in which the cool fluid passes through the first heat exchanger 210 and cools the air blown against the first heat exchanger 210 before being supplied to the vehicle cabin, thereby cooling the vehicle cabin. It should be understood that the conduits 270 and control valve 260 in FIG. 2 show a simplified configuration of the fluid path, and that the control valve 260 can redirect the fluid flow around the vehicle heat pump system 200 by directing the fluid to other conduits (not shown). However, it should be understood that the present invention is not limited to the exact configuration of the vehicle heat pump system 200 shown in FIG. 2 , and that the present invention can be practiced using any heat pump system capable of operating in heating and cooling modes.

[0065] Accumulator 240 comprises a vessel or container that holds a fluid awaiting compression by compressor 250 .

[0066] The expansion device 230 is configured to control the flow rate of the fluid through the expansion device 230 and create a cooling effect on the fluid through a throttling effect. The expansion device 230 is also referred to as a thermal expansion valve or a metering device. For example, the expansion device 230 may include a capillary tube or a pressure control valve. The expansion device 230 restricts the flow of the fluid through the expansion device 230, reducing the pressure of the fluid and allowing the fluid to isenthalpic expand from a liquid phase to a vapor phase at a lower temperature. This reduces the temperature of the fluid as it passes through the expansion device 230.

[0067] One or more conduits 270 are provided to connect between first heat exchanger 210, second heat exchanger 220, expansion device 230, accumulator 240, compressor 250, and control valve 260. Conduit 270 may comprise a continuous channel or multiple channel sections and is configured to contain a fluid and control the flow of the fluid between components of vehicle heat pump system 200.

[0068] The basic operation of the vehicle heat pump system 200 in cooling mode is as follows. In cooling mode, fluid flows counterclockwise around the vehicle heat pump system 200 of FIG. 2. First, the fluid is compressed to a high-pressure, high-temperature gas state in the compressor 250. The fluid passes through the control valve 260 and enters the second heat exchanger 220, which functions as a condenser in cooling mode. The fluid exchanges thermal energy with the surrounding air and is partially cooled and condensed into a high-pressure liquid fluid. The high-pressure liquid fluid passes through the expansion device 230, where at least a portion of the fluid undergoes isenthalpic expansion back to a gaseous state. Due to the flow restriction of the expansion device 230 and the resulting pressure differential, the fluid loses temperature as it passes through the expansion device 230. During this stage, the fluid may undergo adiabatic flash evaporation. The cooler fluid (which may include a mixture of liquid and vapor) then passes through the first heat exchanger 210, exchanging thermal energy with the surrounding air. As shown by the arrows in Figure 2, a fan can blow air over the surface of the first heat exchanger 210 to provide cool air to the vehicle cabin. In cooling mode, the first heat exchanger 210 functions as an evaporator, and fluid passing through the first heat exchanger 210 evaporates to a gaseous state. The fluid then returns to the compressor 250 via the accumulator 240, and the cycle begins again.

[0069] During the cooling mode, moisture may accumulate on the surface of the first heat exchanger 210 because the surface temperature is lower than the temperature of the surrounding air. This moisture accumulation and the resulting damp environment can lead to bacterial growth and the associated increase in odors and pathogens, which may be undesirable. Therefore, the control system 100 or the vehicle heat pump system 200 can receive a moisture signal indicative of moisture on the surface of the first heat exchanger 210 and determine whether the moisture needs to be removed. If a determination is made to remove the moisture, the vehicle heat pump system 200 can operate in a heating mode at a second pressure, thereby heating the surface of the first heat exchanger 210 and removing the moisture. As explained above, the second pressure may be higher than the first pressure, which is the normal operating pressure of the vehicle heat pump system 200, and therefore the surface of the first heat exchanger 210 may reach high temperatures. The second pressure may be between 14 bar and 20 bar in some examples, which corresponds to a surface temperature of the first heat exchanger 210 between 50°C and 69°C. As described above with respect to FIG. 1, the moisture signal or determination of the need to remove moisture can be based on several factors, including the usage history of the vehicle heat pump system 200 in cooling mode, identification of the end of a vehicle journey, a user request, a scheduled maintenance cycle, or temperature or humidity information.

[0070] Vehicle heat pump system 200 of Figure 2 may include second expansion device 235. Second expansion device 235 may be similar or identical to first expansion device 230 and may be provided to enable vehicle heat pump system 200 of Figure 2 to operate in either direction, allowing vehicle heat pump system 200 to operate in either a heating mode or a cooling mode. That is, when vehicle heat pump system 200 operates in a heating mode, second expansion device 235 may operate in the same manner as first expansion device 230 in the cooling mode described above.

[0071] To operate vehicle heat pump system 200 in a heating mode, the direction of fluid flow around vehicle heat pump system 200 is reversed by control valve 260. As explained above, FIG. 2 may depict a simplified configuration of control valve 260 and conduit 270 for ease of understanding, and it should be understood that any alternative configuration of a heat pump system capable of operating in cooling and heating modes may be used. In the example of FIG. 2, in heating mode, fluid passes clockwise around vehicle heat pump system 200: from compressor 250 to second expansion device 235, to first heat exchanger 210 to heat first heat exchanger 210, through expansion device 230 to second heat exchanger 220, through control valve 260, and back to compressor 250. It should be understood that in this case, the roles of first heat exchanger 210 and second heat exchanger 220 are reversed compared to operation of vehicle heat pump system 200 in a cooling mode. In this case, the second expansion device 235 may perform the same operation as the first expansion device 230 in the cooling mode to ensure condensation of the fluid upstream of the accumulator 240 .

[0072] In response to the moisture signal indicating the presence of moisture on the surface, the vehicle heat pump system 200 or the control system 100 can determine whether the surface of the first heat exchanger 210 needs to be dried. To dry the surface, the vehicle heat pump system 200 can be operated in a heating mode at a second pressure higher than the normal operating pressure of the vehicle heat pump system 200. While the vehicle heat pump system 200 is operating in a heating mode at the second pressure to dry the surface of the first heat exchanger 210, a blower (not shown) can optionally be controlled to blow air onto the surface of the first heat exchanger 210. The airflow delivered by the blower dissipates moisture from the environment surrounding the first heat exchanger 210, thereby accelerating the removal of moisture from the surface of the first heat exchanger 210, in combination with the heating provided by the operation of the vehicle heat pump system 200 as described above. The operation of the blower can be determined by the surface temperature requirements of the first heat exchanger 210. The blower may be controlled by the control system 100, and more particularly, by the controller 110. A cooling fan or blower (not shown) may also be provided, positioned to direct air over the surface of the second heat exchanger 220.

[0073] Figure 3 shows a block diagram of a vehicle heat pump system 300 according to one embodiment of the present invention. The vehicle heat pump system 300 operates similarly to the vehicle heat pump system 200 of Figure 2, and therefore a detailed description of common components will be omitted. In particular, the heat exchanger, compressor, expansion device, and accumulator operate similarly in Figures 2 and 3.

[0074] Vehicle heat pump system 300 of FIG. 3 differs from vehicle heat pump system 200 of FIG. 2 in that an alternative path for fluid to circulate in a heating cycle is provided via conduit 370. Vehicle heat pump system 300 also includes check valve 380 and second expansion device 335. Check valve 380 of FIG. 3 may include a one-way valve configured to permit fluid flow in one direction and prevent fluid flow in the opposite direction. While second expansion device 335 is shown in FIG. 3, it should be understood that second expansion device 335 may be omitted or an alternative valve may be provided in its place, as described below.

[0075] Vehicle heat pump system 300 can operate in a cooling mode similar to vehicle heat pump system 200 of Figure 2, with fluid passing from compressor 350 through control valve 360, second heat exchanger 320, check valve 380, expansion device 330, first heat exchanger 310, and accumulator 340 before returning to compressor 350. As explained above, second expansion device 335 may be omitted.

[0076] The control valve 360 controls the direction of fluid flow, as indicated by the arrows showing the path through the conduits 370 around the vehicle heat pump system 300, to operate the vehicle heat pump system 300 in a heating mode. In this example, the fluid does not pass through the second heat exchanger 320 but instead circulates between the compressor and the first heat exchanger 310. Thus, hot fluid can be continuously and efficiently supplied to the first heat exchanger 310 to heat the surface of the first heat exchanger 310 and remove moisture, thereby drying the surface. The check valve 380 and the control valve 360 prevent fluid from entering the second heat exchanger 320. The vehicle heat pump system 300 can operate in a heating mode at the second pressure to dry the surface of the first heat exchanger 310, for example, in response to receiving a moisture signal indicating moisture on the surface of the first heat exchanger 310, as described above.

[0077] The vehicle heat pump system 300 of FIG. 3 also includes a second expansion device 335. While an expansion device similar to the first expansion device 330 is shown, it should be understood that other components, such as a valve suitable for restricting fluid flow, can be used in place of the second expansion device 335. The second expansion device 335 is configured to restrict the flow of fluid exiting the first heat exchanger 310, thereby containing the hot fluid within the first heat exchanger 310. Advantageously, the energy consumption of the vehicle heat pump system 300 operating in a heating mode at the second pressure to dry the surfaces of the first heat exchanger 310 can be improved by providing the second expansion device 335, since the hot fluid may be contained within the first heat exchanger 310. As a result, the need to continuously pump fluid around the vehicle heat pump system 300 is reduced, while maintaining the temperature of the first heat exchanger 310 at a high temperature. As previously mentioned, in some examples, when the pressure of the fluid in the vehicle heat pump system 300 is about 14 bar, the surface of the first heat exchanger 310 is heated to at least 50° C., and when the pressure is about 20 bar, the surface is heated to at least 60° C. In some examples, when the pressure is about 20 bar, the surface of the first heat exchanger 310 is heated to about 69° C.

[0078] FIG. 4 illustrates a method 400 according to an embodiment of the present invention. The method 400 may be a method of the control module 100 of a vehicle 500, such as the vehicle 500 illustrated in FIG. 5, or a vehicle heat pump system 200, 300. In particular, the method 400 is a method of removing moisture from a surface of a first heat exchanger of a vehicle heat pump system capable of operating in a heating mode at a first pressure. The method 400 may be performed by the control system 100 illustrated in FIG. 1 or the vehicle heat pump system 200, 300 illustrated in FIG. 2 or 3. In particular, the memory means 130 may include computer-readable instructions that, when executed by the controller 110, perform the method 400 according to an embodiment of the present invention. The method 400 may be performed by the vehicle heat pump system 200, 300 illustrated in FIG. 2 or 3, but it should be understood that the method 400 is not limited thereto. The method 400 may be performed by any heat pump system capable of operating in a heating mode.

[0079] At block 410, the method includes receiving a moisture signal indicating moisture on a surface of the first heat exchanger. In some examples, the moisture signal indicates a usage history of the vehicle heat pump system and indicates that the vehicle heat pump system was previously operating in a cooling mode. That is, the vehicle heat pump system may operate in a cooling mode to cool the vehicle cabin and provide air conditioning functions for the vehicle cabin. During the cooling mode, the first heat exchanger is cooled by a cold fluid passing through the first heat exchanger. Because the first heat exchanger is cooler than the ambient air, moisture may accumulate on the surface of the first heat exchanger. In some examples, the moisture signal may indicate that the vehicle heat pump system has been operating in a cooling mode for a predetermined period of time. The usage history may also include the number of times the vehicle heat pump has operated in a cooling mode. In some examples, the moisture signal may also indicate that the vehicle heat pump system is not operating or that the vehicle has finished traveling.

[0080] In another example, the moisture signal is received in response to a user request to dry the surface of the first heat exchanger. The moisture signal may include a user request to dry the surface of the first heat exchanger. In some examples, the moisture signal is any of the instruction signals described above, and in response to receiving the instruction signal, the control system may output an instruction to the user recommending that moisture be removed from the vehicle heat pump system. The user may confirm that the drying process should be initiated. In some examples, the recommendation is provided to the user based on the time since the last execution of the drying process exceeding a predetermined threshold or based on using the vehicle heat pump system in a cooling mode. The user may also decide to initiate the drying process even if a recommendation is not output. In some examples, the moisture signal may be received based on a predefined maintenance schedule.

[0081] Alternatively or additionally, the moisture signal may be received in response to temperature or humidity information received from at least one sensor. For example, the at least one sensor may be provided near the first heat exchanger and measure at least one of the temperature or humidity near the first heat exchanger. If the measured temperature or humidity exceeds a predetermined threshold, the moisture signal may be received.

[0082] The moisture signal may be received from a vehicle control system, a vehicle user interface, or at least one sensor, or may be determined by a controller in a control module of the vehicle heat pump system.

[0083] At block 420, the method includes determining a need to remove moisture in response to the moisture signal. The method may include identifying the moisture signal and determining, based on the moisture signal, that moisture is likely to be present on a surface of the first heat exchanger. As described above, the method may include receiving a moisture signal in block 410 that includes information related to vehicle usage history, temperature or humidity information, or information corresponding to a user input, and determining whether the surface of the first heat exchanger needs to be dried in response to the received information. For example, the method may include determining, based on the moisture signal, that moisture is likely to be present on a surface of the first heat exchanger. For example, the method may include comparing the detected temperature or humidity to a threshold value.

[0084] At block 430, the method includes outputting a control signal to control the vehicle heat pump system to operate in a heating mode at a second pressure greater than the first pressure such that a surface of the first heat exchanger is heated to remove moisture from the surface. The method may include controlling a compressor and / or a control valve of the vehicle heat pump system to compress the fluid to the second pressure and controlling a flow direction of the fluid around the vehicle heat pump system to operate the vehicle heat pump system in the heating mode and pass the hot fluid through the first heat exchanger.

[0085] The method can include operating the vehicle heat pump system in a heating mode at the second pressure for a predetermined time. Alternatively, or additionally, the vehicle heat pump system can operate in the heating mode at the second pressure until a temperature or humidity measurement proximate the first heat exchanger reaches a predetermined value.

[0086] The method may include operating a fan of the vehicle heat pump system to blow air across a surface of the first heat exchanger to dissipate moisture from the air surrounding the first heat exchanger.

[0087] The method may include determining to operate the vehicle heat pump system in a heating mode at a second pressure when it is determined that the vehicle has completed a journey so as not to interfere with a user's desired heating or cooling function.

[0088] In some examples, the second pressure is between 14 bar and 20 bar, and the first pressure is up to 14 bar. In some examples, the surface of the first heat exchanger is heated to at least 50°C, at least 60°C, or at least 69°C. At 50°C, the surface of the first heat exchanger is effectively dried. In some examples, at 60°C or 69°C, bacteria or pathogens present on or around the surface of the first heat exchanger may be destroyed or inactivated.

[0089] After the vehicle heat pump system operates in the heating mode at the second pressure for a predetermined time, or until the temperature or humidity value reaches a predetermined threshold, the method ends. It should be understood that method 400 of FIG. 4 may be performed after the user exits the vehicle.

[0090] Figure 5 illustrates a vehicle 500 according to one embodiment of the present invention. The vehicle 500 of Figure 5 may include the control system 100 of Figure 1, the vehicle heat pump system 200 of Figure 2, or the vehicle heat pump system 300 of Figure 3. The vehicle 500 may perform the method 400 of Figure 4.

[0091] The vehicle 500 may include a heat pump system and a vehicle cabin in which one or more users can travel. The vehicle heat pump system may be used to heat or cool the vehicle cabin depending on whether the vehicle heat pump system is operating in a heating mode or a cooling mode. The vehicle heat pump system may be operated in a heating mode at a pressure higher than the normal operating pressure to dry the surface of the first heat exchanger.

[0092] Advantageously, implementing the present invention to dry the surface of the first heat exchanger does not require the inclusion of additional components in the vehicle or vehicle heat pump system, and can be applied to any existing vehicle heat pump system. This simplifies manufacturing, installation, and maintenance. Furthermore, unlike conventional approaches, the presence of additional components does not affect the normal operation of the vehicle heat pump system. Heating the surface of the first heat exchanger can effectively dry the surface and prevent or reduce bacterial growth on the surface, which can cause unpleasant odors in the vehicle cabin. Furthermore, operating the vehicle heat pump system at a higher pressure can heat the surface of the first heat exchanger to a temperature higher than normal operation, potentially high enough to destroy or inactivate bacteria or pathogens on or near the surface. The decision to dry the surface may be made based on various factors to determine the potential presence of moisture on the surface, and the drying process may be performed after the journey is completed to avoid interfering with the desired vehicle cabin temperature control.

[0093] It will be understood that various changes and modifications can be made to the present invention without departing from the scope of the invention.

Claims

1. 1. A control system for controlling a vehicle heat pump system, the vehicle heat pump system being operable in a heating mode at a first pressure, the control system including one or more controllers, the control system being configured as follows: receiving a moisture signal indicative of moisture on a surface of a first heat exchanger of the vehicle heat pump system; determining the need to remove moisture in response to the moisture signal; and A control signal is output to control the vehicle heat pump system to operate at a second pressure higher than the first pressure, thereby heating a surface of the first heat exchanger to remove moisture therefrom.

2. 10. The control system of claim 1, wherein the moisture signal is indicative of at least one of the following: the temperature or humidity near the first heat exchanger; a usage history of the vehicle heat pump system indicating that the vehicle heat pump system has previously operated in a cooling mode; a user input to remove moisture from a surface of the first heat exchanger; and Identifying that a vehicle including the vehicle heat pump system has completed a journey.

3. the control system, in response to determining the need to remove moisture, sends an output instruction to a user requesting user confirmation; 3. The control system of claim 1 or 2, configured to output the control signal for controlling the vehicle heat pump system to operate at the second pressure in response to receiving a user confirmation.

4. 4. The control system of claim 1, wherein the control system is configured to receive a signal indicating that the vehicle has completed traveling, and wherein the control system is configured to postpone outputting the control signal for controlling the vehicle heat pump system to operate at the second pressure until the control system receives the signal indicating that the vehicle has completed traveling.

5. A control system according to any one of claims 1 to 4, wherein the second pressure is between 14 bar and 20 bar.

6. 1. A vehicle heat pump system operable in a heating mode at a first pressure, comprising: a first heat exchanger; and A vehicle heat pump system comprising a control system according to any one of claims 1 to 5.

7. 7. The vehicle heat pump system of claim 6, wherein the control system is configured to output the control signal for controlling the vehicle heat pump system to operate in the heating mode at the second pressure so that the temperature of a surface of a first heat exchanger is increased to at least 50°C, optionally at least 60°C.

8. a control valve configured to control a direction of fluid flow around the vehicle heat pump system to operate the vehicle heat pump system in a heating mode or a cooling mode; the control valve includes a three-way valve configured to selectively connect the compressor and the first heat exchanger via a thermal expansion valve and to selectively connect the compressor and the second heat exchanger; 8. The vehicle heat pump system of claim 6 or 7, wherein the three-way valve is configured to selectively direct fluid to bypass the second heat exchanger, thereby circulating hot fluid through the compressor, the three-way valve, the thermal expansion valve, and the first heat exchanger.

9. a valve operable between an open state and a restricted state to selectively contain fluid within the first heat exchanger; 9. The vehicle heat pump system of claim 6, wherein the control system is configured to output a control signal in response to receiving the moisture signal to control the valve to restrict and contain high-temperature fluid within the first heat exchanger.

10. at least one of a temperature sensor configured to detect a temperature near the first heat exchanger or a humidity sensor configured to detect humidity near the first heat exchanger; The vehicle heat pump system of any one of claims 6 to 9, wherein the moisture signal includes at least one of a sensed temperature or a sensed humidity.

11. A vehicle comprising the control system according to any one of claims 1 to 5 or the vehicle heat pump system according to any one of claims 6 to 10.

12. 1. A method for removing moisture from a surface of a first heat exchanger of a vehicle heat pump system operable in a heating mode at a first pressure, the method comprising: receiving a moisture signal indicative of moisture on a surface of the first heat exchanger; determining the need to remove moisture in response to the moisture signal; and Outputting a control signal to control the vehicle heat pump system to operate at a second pressure higher than the first pressure, thereby heating a surface of the first heat exchanger to remove moisture therefrom.

13. 13. The method of claim 12, wherein the moisture signal is indicative of at least one of the following: a usage history of the vehicle heat pump system indicating that the vehicle heat pump system has previously operated in a cooling mode; a user input to remove moisture from a surface of the first heat exchanger; and Identifying that a vehicle including the vehicle heat pump system has completed a journey.

14. detecting a temperature or humidity near the first heat exchanger; 14. The method of claim 12 or 13, wherein the moisture signal includes at least one of a sensed temperature or a sensed humidity.

15. Computer readable instructions configured to, when executed by a computer, carry out the method of any one of claims 12 to 14.

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