The invention pertains to a vehicle cabin climate control system.

In particular in electric vehicles, the vehicle cabin climate control system consumes a considerable amount of energy.

Several solutions have been proposed to reduce the amount of energy needed for vehicle cabin climate control. For example, DE102015115196 discloses a system which comprises a peripheral heat exchanger. In this peripheral heat exchanger, air that is introduced into the vehicle cabin climate control system from outside the vehicle flows through one side of the peripheral heat exchanger and air that is expelled from the vehicle cabin flows through the other side of the peripheral heat exchanger. This way, heat exchange takes place between the incoming air and the outgoing air, therewith pre-heating or pre cooling the incoming air is obtained, depending on whether the temperature in the vehicle cabin of the vehicle in which the vehicle cabin climate control system is arranged is above or below the temperature of the outside air. This way, the heating or cooling that has to be done by the vehicle cabin climate control system is reduced, and therewith, the energy consumption is reduced.

However, the effect of this system on the total energy consumption of the vehicle cabin climate control system is limited.

The invention aims to provide an energy efficient vehicle cabin climate control system.

This object is obtained by a vehicle cabin climate control system which comprises:

- an air discharge, which comprises an air discharge inlet and an air discharge outlet, wherein the air discharge inlet is adapted to receive a discharge air flow and the air discharge outlet is adapted to discharge the discharge air flow, and

- a heat exchanger, which heat exchanger has a first side passage and a second side passage, wherein the first side passage and the second side passage are arranged to allow heat transfer between an air flow within the first side passage and an air flow within the second side passage, wherein the second side passage has an upstream end which is in fluid communication with the air discharge inlet and a downstream end which is in fluid communication with the air discharge outlet, wherein the vehicle cabin climate control system further comprises:

- an air humidifier, which is adapted to add moisture to the discharge airflow, which air humidifier comprises a water release device which is arranged at the air discharge, upstream of the downstream end of the second side passage of the heat exchanger.

The vehicle cabin climate control system according to the invention further comprises an air discharge, which comprises an air discharge inlet and an air discharge outlet. The air discharge is or comprises for example an air exhaust line. The air discharge inlet is adapted to receive a discharge air flow. The discharge air flow for example comprises cabin air to be discharged, i.e. air that is to be discharged from the cabin of the vehicle in which the vehicle cabin climate control system is arranged. Optionally, the discharge air flow also is to be discharged from the vehicle in which the vehicle cabin climate control system is arranged.

The air discharge outlet is adapted to discharge the discharge air flow, e.g. discharge it from the vehicle in which the vehicle cabin climate control system is arranged.

“Downstream” and “upstream” are related to the direction that the discharge air flow flows through the vehicle cabin climate control system.

The vehicle cabin climate control system according to the invention further comprises a heat exchanger. The heat exchanger has a first side passage and a second side passage. The first side passage and the second side passage are arranged to allow heat transfer between an air flow within the first side passage and an air flow within the second side passage.

The second side passage of the heat exchanger has an upstream end which is in fluid communication with the air discharge inlet and a downstream end which is in fluid communication with the air discharge outlet.

“Downstream” and “upstream” are related to the direction that the discharge air flow flows through the vehicle cabin climate control system.

The heat exchanger is for example a peripheral heat exchanger of the vehicle cabin climate control system. For example, the air flow through the first side passage of the heat exchanger is an inlet air flow.

Optionally, the heat exchanger is or comprises an enthalpy exchanger. Optionally, the peripheral heat exchanger is or comprises an enthalpy exchanger.

The vehicle cabin climate control system according to the invention further comprises an air humidifier, which is adapted to add moisture to the discharge air flow. The air humidifier comprises a water release device which is arranged at the air discharge, upstream of the downstream end of the second side passage of the heat exchanger. “Downstream” and “upstream” are related to the direction that the discharge air flow flows through the vehicle cabin climate control system.

In the vehicle cabin climate control system according to the invention, the air humidifier adds moisture to the discharge air flow before the discharge air flow leaves the second side passage of the heat exchanger. Moisture is for example added in the form of water, water droplets, water spray and/or water aerosol.

The added moisture evaporates in the discharge air flow, which withdraws energy from the discharge air flow. By the cooling of the discharge air flow, the air flow in the first side passage of the heat exchanger is cooled to a larger extent without the use of additional energy.

Therewith, the overall energy efficiency of the vehicle in which the vehicle cabin climate control system according to the invention is arranged is improved.

In an embodiment of the vehicle cabin climate control system according to the invention, the water release device is arranged upstream of the second side passage of the heat exchanger or within the second side passage of the heat exchanger.

This way, it is ensured that moisture is added to the discharge air flow by the water release device before the discharge air flow leaves the second side passage of the heat exchanger.

In an embodiment of the vehicle cabin climate control system according to the invention, vehicle cabin climate control system further comprises a water collector which is adapted to collect water that is generated by the vehicle cabin climate control system. The air humidifier comprises a water inlet which is fluidly connected or fluidly connectable to the water collector. So, the water inlet is arranged to receive water from the water collector.

For example, water is formed in the first side passage of the same heat exchanger as the one through which the discharge flow passes via the second side passage, e.g. when an inlet air flow passes through the first side passage and is cooled in order to dehumidify the inlet air flow.

For example, water is formed in an air cooler of an air treatment device within the vehicle cabin climate control system. Such an air cooler is often used to dehumidify an inlet air flow before the inlet air flow enters the cabin of the vehicle in which the vehicle cabin climate control system is mounted. In this dehumidification process, moisture is extracted from the inlet airflow. In this embodiment, the extracted moisture is at least partly, and optionally entirely, collected in the form of water in the water collector. In an embodiment of the vehicle cabin climate control system according to the invention, the vehicle cabin climate control system further comprises an air inlet system and a primary cabin air inlet.

The air inlet system comprises an air inlet. The air inlet system is adapted to allow outside air to enter the vehicle climate cabin control system and to generate an inlet air flow into the vehicle cabin climate control system. The inlet air flow is generated from outside air entering the vehicle cabin climate control system via the air inlet. Optionally, the air inlet system further comprises a flow device, to actively generate the air flow and/or to provide a required flow rate for the inlet air flow. The flow device is or comprises for example a fan.

The primary cabin air inlet is arranged to receive an air flow and to introduce at least a part of that airflow into a vehicle cabin.

In this embodiment, the first side passage of the heat exchanger is arranged downstream of the air inlet and upstream of the primary air cabin inlet.

In this embodiment, the inlet air flow passes through the first side passage of the same heat exchanger as the one through which the discharge flow passes via the second side passage. Optionally, the heat exchanger in this embodiment is a peripheral heat exchanger.

In an embodiment of the vehicle cabin climate control system according to the invention, the vehicle climate control system further comprises an air discharge humidifier control system. The air discharge humidifier control system is adapted to activate the air humidifier when the temperature of the air flow in the second side passage of the heat exchanger is below the temperature of the air flow in the first side passage of the heat exchanger.

The air humidifier is most effective in terms of energy efficiency when the discharge air flow that passes through the second side passage cools the air flow (for example the inlet air flow) that passes through the first side passage of the heat exchanger. In this embodiment, the air humidifier is activated only when it is most effective in terms of energy efficiency.

Optionally, in this embodiment, the air discharge humidifier control system is adapted to activate the air humidifier when the temperature of the air flow in the second side passage of the heat exchanger is below the temperature of the air flow in the first side passage of the heat exchanger by at least a predetermined temperature difference threshold.

In an embodiment of the vehicle cabin climate control system according to the invention, the vehicle cabin climate control system further comprises:

- an air treatment device, comprising: - an air cooler comprising an air cooler inlet for receiving an air flow, which air cooler is adapted to generate a cooled air flow from the air flow that is received through the air cooler inlet, the air cooler being arranged downstream of the air inlet,

- an air heater comprising an air heater inlet for receiving an air flow, which air heater is adapted to generate a heated air flow from the air flow that is received through the air heater inlet, the air heater being arranged downstream of the air cooler. Optionally, in this embodiment, the air cooler comprises a water discharge which is connected or connectable to a water collector. The water collector which is adapted to collect water that is generated by the vehicle cabin climate control system, e.g. by the air cooler of the are treatment device. The air humidifier comprises a water inlet which is fluidly connected or fluidly connectable to the water collector.

Optionally, in a variant of this embodiment, the air heater inlet of the air treatment device is arranged to receive a first portion of the cooled air flow. In addition, in this variant, the vehicle climate control system further comprises a cold air discharge. The cold air discharge is arranged to receive a second portion of the cooled air flow that is generated by the air cooler and to discharge the second portion of the cooled air flow to a location outside a vehicle cabin. The cold air discharge is arranged to keep the second portion of the cooled air flow outside the air heater. The cold air discharge is arranged to provide the second portion of the cooled air to the air discharge, upstream of the upstream end of the second side passage of the heat exchanger.

In an embodiment of the vehicle cabin climate control system according to the invention, the water release device is or comprises at least one of an atomizer, a vaporizer, a wick, a porous element, a capillary.

The porous element is for example made of terracotta or of a sintered material, e.g. a sintered ceramic material.

In an embodiment of the vehicle cabin climate control system according to the invention, the water release device of the air humidifier is adapted to release the water in the form of a spray of droplets and/or in the form of an aerosol.

Droplets and aerosols evaporate easily due to their relatively large surface area.

The invention further pertains to a vehicle comprising a vehicle cabin climate control system according to the invention.

The invention further pertains to a method for operating a vehicle cabin climate control system, wherein the method comprises the following steps: - generating a discharge air flow from air that is extracted from a cabin of a vehicle,

- passing the discharge air flow through a second side passage of a heat exchanger,

- adding moisture to the discharge air flow upstream of a location at which the discharge air flow leaves the second side passage of the heat exchanger,

- making at least a part of the added moisture evaporate in the discharge air flow,

- after passing the discharge air flow through a second side passage of the heat exchanger, discharging the discharge air flow from the vehicle.

The method according to the invention is for example carried out using a vehicle cabin climate control device according to the invention.

In an embodiment, the method comprises the further steps of:

- dehumidifying an air flow, and therewith generating water,

- collecting at least a part of the generated water in a water collector,

- in the step of adding moisture to the discharge air flow upstream of a location at which the discharge air flow leaves the second side passage of the heat exchanger, adding at least a part of the collected water as moisture to the discharge air flow.

The invention will be described in more detail below under reference to the drawing, in which in a non-limiting manner exemplary embodiments of the invention will be shown. The drawing shows in:

Fig. 1: schematically, a first embodiment of the vehicle cabin climate control system according to the invention,

Fig. 2: schematically, a first variant of the embodiment of fig. 1.

Fig. 1 schematically shows a first embodiment of a vehicle cabin climate control system according to the invention.

In the embodiment of fig.1, the vehicle cabin climate control system is arranged into vehicle 1 , for example a passenger car, a truck, a van, a plane, a bus, a tram, a train or any other means of public transport, or the like. The vehicle 1 comprises a vehicle cabin 2, in which a driver and optionally one or more passengers can be present. The dashed lines in fig. 1 schematically indicate the boundaries of the vehicle 1 and the vehicle cabin 2.

In the embodiment of fig. 1 , the vehicle cabin climate control system comprises an air inlet system. The air inlet system comprises an air inlet 50 and an inlet line 51.

The air inlet system is adapted to allow outside air to enter the vehicle climate cabin control system and to generate an inlet air flow into the vehicle cabin climate control system. The inlet air flow is generated from outside air entering the vehicle cabin climate control system via the air inlet 50.

In this example, the air inlet system further comprises a flow device 52, to actively generate the air flow and/or to provide a required flow rate for the inlet air flow. The flow device is or comprises for example a fan.

In the embodiment of fig. 1 , the vehicle cabin climate control system further comprises a primary cabin air inlet 30, which is arranged to receive an air flow and introduce at least a part of that received airflow into the vehicle cabin 2.

In the embodiment of fig. 1 , the air flow that is received by the primary cabin air inlet comprises at least a part of the inlet air flow.

In the embodiment of fig. 1, the vehicle cabin climate control system comprises an air discharge 48, which comprises an air discharge inlet 46 and an air discharge outlet 47. The air discharge 48 is or comprises for example an air exhaust line 42. The air discharge inlet 46 is adapted to receive a discharge air flow. In the embodiment of fig. 1, the discharge air flow comprises cabin air to be discharged, i.e. air that is to be discharged from the cabin of the vehicle in which the vehicle cabin climate control system is arranged. In the embodiment of fig. 1 , the discharge air flow also is to be discharged from the vehicle in which the vehicle cabin climate control system is arranged. The air discharge outlet 47 is adapted to discharge the discharge air flow, e.g. discharge it from the vehicle 1 in which the vehicle cabin climate control system is arranged. In the embodiment of fig. 1, the air discharge inlet 46 is directly connected to a primary cabin air outlet 43.

In the embodiment of fig. 1 , the vehicle cabin climate control system further comprises a heat exchanger, which in this embodiment is a peripheral heat exchanger 60. The peripheral heat exchanger 60 has a first side passage 63 and a second side passage 64. The first side passage 63 and the second side passage 64 are arranged to allow heat transfer between an air flow within the first side passage 63 and an air flow within the second side passage 64.

The first side passage 63 is arranged downstream of the air inlet 50 and upstream of the air treatment device 10. “Downstream” and “upstream” are related to the direction of the air flow through the vehicle cabin climate control system.

So, air enters the vehicle cabin climate control system via the air inlet 50, and flows to the cabin 2, via the first side passage 63 of the peripheral heat exchanger 60 or via the heat exchanger bypass 65. Optionally, a further flow path is additionally present. In the embodiment of fig. 1 , the vehicle cabin climate control system further comprises an air humidifier 110, which is adapted to add moisture to the discharge airflow in the air discharge 48. The air humidifier 110 comprises a water release device 111 which is arranged at the air discharge 48 , upstream of the downstream end of the second side passage 64 of the heat exchanger 60.

“Downstream” and “upstream” are related to the direction that the discharge air flow flows through the vehicle cabin climate control system.

In the embodiment of fig. 1, the air humidifier 110 adds moisture to the discharge air flow before the discharge air flow leaves the second side passage 64 of the peripheral heat exchanger 60. Moisture is for example added in the form of water, water droplets, water spray and/or water aerosol by the water release device 111.

In the embodiment of fig. 1 , the water release device 111 is arranged upstream of the second side passage 64 of the peripheral heat exchanger 60. Alternatively or in addition, the water release device 111 is arranged within the second side passage 64 of the peripheral heat exchanger 60.

This way, it is ensured that moisture is added to the discharge air flow by the water release device 111 before the discharge air flow leaves the second side passage 64 of the peripheral heat exchanger 60.

In the embodiment of fig. 1 , the water release device 111 for example is or comprises at least one of an atomizer, a vaporizer, a wick, a porous element, a capillary.

The porous element is for example made of terracotta or of a sintered material, e.g. a sintered ceramic material.

Optionally, in the embodiment of fig. 1 , the water release device 111 of the air humidifier 110 is adapted to release the water in the form of a spray of droplets and/or in the form of an aerosol.

In the embodiment of fig. 1, optionally the vehicle climate control system further comprises an air discharge humidifier control system 114. The air discharge humidifier control system 114 is adapted to activate the air humidifier 110 when the temperature of the air flow in the second side passage 64 of the peripheral heat exchanger 60 is below the temperature of the air flow in the first side passage 63 of the peripheral heat exchanger 60.

Optionally, air discharge humidifier control system 114 is adapted to activate the air humidifier when the temperature of the air flow in the second side passage 64 of the peripheral heat exchanger 60 is below the temperature of the air flow in the first side passage 63 of the peripheral heat exchanger 60 by at least a predetermined temperature difference threshold.

Fig. 2 shows, schematically, a first variant of the embodiment of fig. 1.

In the variant of fig. 2, the vehicle cabin climate control system further comprises an air treatment device 10. The air treatment device 10 comprises an air cooler 11 and an air heater 112. The air heater 12 is arranged downstream of the air cooler 11 , downstream being related to the direction of the air flow through the air treatment device 10. So, the air flows through the air cooler 11 before at least a part of the air flows through the air heater 12.

The air cooler 11 of the air treatment device 10 comprises an air cooler inlet 14 for receiving an air flow. This air flow for example is comprised of at least a part of the inlet air flow, the entire inlet air flow, a combination of a part of the inlet air flow with recirculated air from the vehicle cabin or the entire inlet air flow in combination with recirculated air from the vehicle cabin.

The air cooler 11 is arranged downstream of the air inlet, downstream being related to the direction of the air flow through the vehicle cabin climate control system.

The air cooler 11 is adapted to generate a cooled air flow from the air flow that is received through the air cooler inlet 14. The air cooler 11 for example is or comprises an evaporator.

The air treatment device of the variant of fig. 2 further comprises an air heater 12 which is arranged downstream of the air cooler 11 , downstream being related to the direction of the air flow through the air treatment device 10. So, the air flows through the air cooler 11 before the air flows through the air heater 12.

The air heater 12 of the air treatment device 10 comprises an air heater inlet 15 which is arranged to receive an air flow.

The air heater 12 of the air treatment device 10 is adapted to generate a heated air flow from the air flow that is received through the air heater inlet 15.

In the variant as shown in fig. 2, the vehicle cabin climate control system further comprises a recirculation line 40 which is connected to a primary cabin air outlet 4. The recirculation line 40 is arranged to remove cabin air from the cabin 2 and recirculate the cabin air back into the cabin 2. In variant as shown in fig. 2, the recirculated air enters the cabin 2 after treatment in the air treatment system 10 and after being mixed with the inlet air flow. In this example, the air discharge inlet 46 is connected to and/or arranged in fluid communication with the recirculation line 40. In the example of fig. 2, a flow device 41 is present in the recirculation line 40 to ensure the required level of air flow through the recirculation line.

In the variant of fig. 2, the vehicle cabin climate control system further comprises a water collector 112 which is adapted to collect water that is generated by the vehicle cabin climate control system. The air humidifier 110 comprises a water inlet 113 which is fluidly connected or fluidly connectable to the water collector 112. So, the water inlet 113 is arranged to receive water from the water collector 112. A valve may be present to control the flow of water from the water collector 112 to the water release device 111.

In the variant of fig. 2, water may for example be formed in the air cooler 11 of the air treatment device 10 of the vehicle cabin climate control system. Such an air cooler 11 is often used to dehumidify an inlet air flow before the inlet air flow enters the cabin 2 of the vehicle 1 in which the vehicle cabin climate control system is mounted. In this dehumidification process, moisture is extracted from the inlet airflow. In this embodiment, the extracted moisture is at least partly, and optionally entirely, collected in the form of water in the water collector 112.

In the variant of fig. 2, the air cooler 11 comprises a water discharge which is connected or connectable to the water collector 112. A valve may be present to control the flow of water from the air cooler 11 to the water collector 112.

In addition, water may be formed in the first side passage 63 of the same heat exchanger 60 as the one through which the discharge flow passes via the second side passage 64, e.g. when an inlet air flow passes through the first side passage 63 and is cooled in order to dehumidify the inlet air flow.

Therefore, the variant of fig. 2, the water collector 112 is connected or connectable to the peripheral heat exchanger 60, in order to collect water that is formed in the peripheral heat exchanger 60 during cooling of an air flow, e.g. during cooling of the inlet air flow. It can also be used to collect water that is formed during cooling of the discharge air flow, which water is then stored in the water collector 112 for later use in the water release device 111.

Optionally, but shown in fig. 2, the air heater inlet 15 of the air treatment device 10 is arranged to receive a first portion of the cooled air flow. In addition, optionally, in this variant, the vehicle climate control system further comprises a cold air discharge 20. The cold air discharge is arranged to receive a second portion of the cooled air flow that is generated by the air cooler 11 and to discharge the second portion of the cooled air flow to a location outside a vehicle cabin 2. The cold air discharge 20 is arranged to keep the second portion of the cooled air flow outside the air heater. The cold air discharge is arranged to provide the second portion of the cooled air to the air discharge 48, upstream of the upstream end of the second side passage 64 of the peripheral heat exchanger 60.

In the variant of fig. 2, the water release device 111 is or comprises at least one of an atomizer, a vaporizer, a wick, a porous element, a capillary.

The porous element is for example made of terracotta or of a sintered material, e.g. a sintered ceramic material.

In the variant of fig. 2, optionally the water release device 111 of the air humidifier 110 is adapted to release the water in the form of a spray of droplets and/or in the form of an aerosol.