DEVICE FOR HEATING AIR AND A LIQUID

Description

[0001] The present invention relates to a device for heating air and a liquid.

[0002] It is known in the prior art to extract thermal energy from the combustion of, for example, propane, butane, or diesel fuel converted into the gaseous state and to transfer it to a liquid, e.g., domestic water or room air, via at least one heat exchanger. It is also known to heat air and liquid (see, for example, US 2010 / 0031900 A1 or US 2019 / 0212033 A1).

[0003] DE 11 2018 003 288 T5 discloses a heating device with two separate combustion chambers and two separate heat exchanger transfer units 6, 6A. The first combustion chamber with the associated heat exchanger transfer unit serves to heat the air conveyed in one channel, while the second combustion chamber with the associated second heat exchanger transfer unit serves to heat the liquid in the second channel.

[0004] The object underlying the invention is to propose a device for heating air and a liquid which represents an alternative to the prior art.

[0005] The invention solves the problem by a device for heating air and a liquid, comprising an air inlet, an air outlet, an air interaction zone, an air conveying device, a liquid inlet, a liquid outlet, a liquid interaction zone, a liquid conveying device, an energy unit, a heat exchanger, and a control unit, wherein air to be heated enters the device via the air inlet, wherein heated air leaves the device via the air outlet, wherein liquid to be heated enters the device via the liquid inlet, wherein heated liquid leaves the device via the liquid outlet, wherein the energy unit generates thermal energy, wherein the heat exchanger transfers the thermal energy generated by the energy unit to the air in the air interaction zone and to the liquid in the liquid interaction zone,The air conveying device conveys the air into the air interaction zone, and the liquid conveying device conveys the liquid into the liquid interaction zone. The control unit controls the air conveying device and the liquid conveying device as to whether the device heats only air in one air mode or liquid in another mode. The control unit is configured to control the liquid conveying device upon switching from the air mode to the other mode so that the liquid only enters the liquid interaction zone when a critical temperature of the heat exchanger is below a predeterminable starting value.

[0006] The other mode can be, for example, a liquid mode or a mixing mode.

[0007] The device according to the invention has at least two different operating modes: either only air is heated, or at least also liquid is heated. Depending on the mode, air or liquid is conveyed by the two associated conveying devices to the corresponding interaction areas, where they receive thermal energy from the heat exchanger. The liquid conveying device is, for example, a pump, and the air conveying device is a fan. The control unit switches between the modes. The air is preferably ambient air in a room, and the liquid is, for example, domestic water.

[0008] The fluid is only heated when a certain temperature of the heat exchanger is sufficiently low, and in particular, lower than a predefined starting value. This prevents unwanted noise or pressure surges, for example. The starting value is the temperature at which the fluid mode or the mixed mode (as examples of the other operating mode in which only or also the fluid is heated) is initiated. The critical temperature refers in particular to an area of the heat exchanger whose temperature affects the fluid.

[0009] According to one embodiment, the control unit is configured to control the air conveying device and the liquid conveying device, depending on whether the device heats only air in an air mode or only liquid in a liquid mode. In this embodiment, there are thus two modes, in which only air or only the liquid is heated. In the liquid mode, the small amount of room air that may be heated by providing thermal energy is ignored as a byproduct.

[0010] According to a further embodiment, the control unit controls the air conveying device and the liquid conveying device to determine whether the device heats only air in an air mode, only liquid in a liquid mode, or air and liquid in a mixed mode. In this embodiment, there are three modes. In the different operating modes, either only one medium (air or liquid) or both media (air and water) are heated. Depending on the mode, only one medium or both media are conveyed by the two associated conveying devices to the corresponding interaction areas, where they receive thermal energy from the heat exchanger.

[0011] One embodiment is that the control unit controls the liquid conveying device before the air mode so that the liquid interaction zone is essentially free of liquid. In this embodiment, the liquid is removed from the liquid interaction zone before the air mode and, in particular, is not refilled, so that no liquid is heated in the air mode, and thus only air is heated.

[0012] One embodiment is that the device further comprises a temperature sensor, that the temperature sensor detects a temperature of the heat exchanger, and that the control unit evaluates the temperature detected by the temperature sensor with regard to the critical temperature of the heat exchanger. In this embodiment, the control unit determines whether the heat exchanger has cooled sufficiently based on the measurement signals from a temperature sensor.

[0013] An alternative or supplementary embodiment provides that, when switching from the air mode to the other mode (e.g., liquid mode or mixed mode), the control unit controls the liquid conveying device such that the liquid only reaches the liquid interaction zone after at least a predeterminable cooling period has elapsed after the end of the air mode. The cooling period is the time required by the heat exchanger to cool from a temperature in the air mode to a temperature below the starting value and can be determined from the cooling behavior of the heat exchanger.

[0014] One embodiment is that the energy unit generates thermal energy by burning a fuel-air mixture and / or by converting electrical energy. In this embodiment, the thermal energy is generated by burning a fuel, e.g., combustible gas or diesel fuel converted into a gaseous state, or by converting electrical energy.

[0015] In detail, there are numerous possibilities for designing and developing the device according to the invention. Reference is made, on the one hand, to the claims subordinate to claim 1 and, on the other hand, to the following description of exemplary embodiments in conjunction with the drawing. It shows: Fig. 1 a schematic representation of a device.

[0016] The Fig. 1 shows schematically the structure of a device for heating air and a liquid.

[0017] The air enters the device through the air inlet 1 and leaves it heated through the air outlet 2. The liquid, for example water, enters the device via the liquid inlet 5 and leaves it heated through the liquid outlet 6. In one variant - not shown here - there is a liquid container through which the liquid passes from the liquid inlet 5 to the liquid outlet 6. The thermal energy for the heating is generated by the energy unit 9 in the variant shown through the combustion of a fuel-air mixture. Depending on the mode, the heat exchanger 10 in the design shown transfers this thermal energy to the air, to the liquid, or to both the air and the liquid. For this purpose, two interaction areas are provided for transferring the thermal energy: an air interaction area 3 and a liquid interaction area 7. The air or liquid is used for heating.The liquid is conveyed by the two conveying devices 4, 8 through the respectively assigned interaction zone 3, 7. This is controlled by the control unit 11, which switches between the operating modes. A temperature sensor 12 is provided for this purpose, which records temperature values of the heat exchanger 10. The measurement signals are evaluated by the control unit 11 with regard to a critical temperature for the liquid. Only when the heat exchanger 10 has cooled sufficiently does the liquid conveying device 4 convey the liquid into the liquid interaction zone 3 when switching from one air mode to another.

Claims

1. A device for heating air and a liquid, comprising an air inlet (1), an air outlet (2), an air interaction area (3), an air conveying device (4), a liquid inlet (5), a liquid outlet (6), a liquid interaction area (7), a liquid conveying device (8), an energy unit (9), a heat exchanger (10), and a control unit (11), wherein air to be heated enters the device via the air inlet (1), wherein heated air exits the device via the air outlet (2), wherein liquid to be heated enters the device via the liquid inlet (5), wherein heated liquid exits the device via the liquid outlet (6), wherein the energy unit (9) generates thermal energy, wherein the heat exchanger (10) transfers the thermal energy generated by the energy unit (9) to the air in the air interaction area (3) and to the liquid in the liquid interaction area (7), wherein the air conveying device (4) conveys the air into the air interaction area (3), wherein the liquid conveying device (8) conveys the liquid into the liquid interaction area (7), wherein the control unit (11) is configured to control the air conveying device (4) and the liquid conveying device (8) depending on whether the device heats only air in an air mode or liquid in a different mode, characterized in that in the event of a change from the air mode to the other mode, the control unit (11) is configured to control the liquid conveying device (8) such that the liquid does not enter the liquid interaction area (7) until a critical temperature of the heat exchanger (10) is below a predeterminable starting value.

2. The device according to claim 1, wherein the control unit (11) is configured to control the air conveying device (4) and the liquid conveying device (8) depending on whether the device heats only air in an air mode or only liquid in a liquid mode.

3. The device according to claim 1 or 2, wherein the control unit (11) is configured to control the air conveying device (4) and the liquid conveying device (8) depending on whether the device heats only air in an air mode, only liquid in a liquid mode, or air and liquid in a mixed mode.

4. The device according to any of claims 1 to 3, wherein the control unit (11) is configured to control the liquid conveying device (8) prior to the air mode such that the liquid interaction area (7) is substantially free from the liquid.

5. The device according to any of claims 1 to 4, wherein the device further includes a temperature sensor (12), wherein the temperature sensor (12) detects a temperature of the heat exchanger (10), and wherein the control unit (11) is configured to evaluate the temperature detected by the temperature sensor (12) with regard to the critical temperature of the heat exchanger (6).

6. The device according to any of claims 1 to 5, wherein in the event of a change from the air mode to the other mode, the control unit (11) is configured to control the liquid conveying device (8) such that the liquid does not enter the liquid interaction area (7) until at least a predeterminable cooling time period has elapsed after an end of the air mode.

7. The device according to any of claims 1 to 6, wherein the energy unit (5) generates thermal energy by burning a fuel-air mixture and / or by converting electrical energy.