Electrochemical dehumidification device based on screen-type amphoteric ion exchange membrane electrode

Abstract

Disclosed is an electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode, comprising a core dehumidification unit which comprises, sequentially from one side to the other side, an anode air pathway, a screen-type anode electrode, an amphoteric ion exchange membrane, a screen-type cathode electrode and a cathode air pathway. The core dehumidification unit performs active dehumidification when a voltage is applied, and performs passive dehumidification when no voltage is applied. A number of the core dehumidification unit is equal to or more than one, the core dehumidification units are capable of being connected in parallel, in serial or in an overlapping mode; meanwhile, the units may also be used in combination with other dehumidification devices. The device achieves active/passive dehumidification, and is ultra-compact and flexible.

Claims

1. An electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode, comprising a core dehumidification unit wherein the core dehumidification unit comprises, sequentially from one side to the other side, an anode air pathway, a screen-type anode electrode, an amphoteric ion exchange membrane, a screen-type cathode electrode and a cathode air pathway; in a direction from the anode air pathway to the amphoteric ion exchange membrane, the screen-type anode electrode sequentially comprises an anode metal screen structure diffusion layer and an anode catalyst layer; in a direction from the cathode air pathway to the amphoteric ion exchange membrane, the screen-type cathode electrode sequentially comprises a cathode metal screen structure diffusion layer and a cathode catalyst layer; the anode air pathway and the cathode air pathway are both provided with an air inlet and an air outlet; and variable frequency fans are arranged outside the air inlets of the anode air pathway and the cathode air pathway; a first air valve and a first flow sensor are arranged in the anode air pathway, and the air inlet and the air outlet of the anode air pathway are respectively provided with a first temperature and humidity sensor and a second temperature and humidity sensor; a second air valve and a second flow sensor are arranged in the cathode air pathway, and the air inlet and the air outlet of the cathode air pathway are respectively provided with a third temperature and humidity sensor and a fourth temperature and humidity sensor; the screen-type anode electrode and the screen-type cathode electrode are externally connected with an anode and a cathode of an adjustable direct current power supply respectively, and the adjustable direct current power supply is connected with a digital multimeter; and all of the temperature and humidity sensors, all of the flow sensors and the digital multimeter are connected with a computer.

2. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 1, wherein the amphoteric ion exchange membrane is a high-performance electrolyte membrane with a capability of selectively exchanging cations and water molecules at the same time, including a bipolar membrane or an amphoteric membrane; and the amphoteric ion exchange membrane is prepared by a blending method, a copolymerization method or a radiation grafting method.

3. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 1, wherein the anode catalyst layer and the cathode catalyst layer both have contact points in close contact on an interface connected with the amphoteric ion exchange membrane; when a voltage is applied, air in the anode air pathway approaches an active site of the catalyst through the anode metal screen structure diffusion layer, and an electrolytic reaction of water vapor in the air occurs on a side of the amphoteric ion exchange membrane near the anode thereof; and air in the cathode air pathway approaches the active site of the catalyst, through the cathode metal screen structure diffusion layer, and a reduction reaction of generating water by reaction of oxygen and protons occurs on a side of the amphoteric ion exchange membrane near the cathode thereof.

4. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 1, wherein the anode metal screen structure diffusion layer and the cathode metal screen structure diffusion layer are both composed of porous metal screens with a thickness of 0.8 mm to 2 mm, and are made of titanium, titanium alloy or stainless steel; the porous metal screen is provided with a corrosion-resistant conductive coating and has a rigidity required for supporting the amphoteric ion exchange membrane; the porous metal screen facilitates water vapor in the air on an anode side to approach the amphoteric ion exchange membrane and generate an electrolytic reaction, and facilitates rapid removal of the water generated by a reduction reaction on a cathode side at the same time; and by using a screen printing method, a transfer printing method or an injection method, the anode catalyst layer and the cathode catalyst layer are prepared by tightly attaching catalyst particles to a surface of the anode metal screen structure diffusion layer near the anode air pathway side and a surface of the cathode metal screen structure diffusion layer near the cathode air pathway side respectively.

5. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 1, wherein the anode air pathway and the cathode air pathway are both made of insulating and air-tight materials; and a flow mode of air flowing in the anode air pathway and the cathode air pathway comprises a forward flow, a reverse flow or a cross flow.

6. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 1, wherein when the voltage is applied to the core dehumidification unit, an electrolytic reaction occurs to water vapor in the air circulating in the anode air pathway on an anode side of the amphoteric ion exchange membrane to perform active dehumidification; and when no voltage is applied to the core dehumidification unit, the water vapor in the air circulating in the anode air pathway, which is on a high humidity side, permeates through the amphoteric ion exchange membrane to enter a low humidity side to perform passive dehumidification by a vapor partial pressure difference caused by an air humidity difference.

7. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 6, wherein in an active dehumidification process, air to be dehumidified flows through the anode air pathway, and ambient air flows through the cathode air pathway; the temperature and humidity sensor converts temperature and humidity of the air in the anode air pathway and the cathode air pathway into electrical signals and collect the electrical signals into a computer, the computer compares the obtained data with a set value, generates control signals through a control algorithm and sends the control signals to a control output circuit, the control output circuit respectively sends the control signals to an executing mechanism comprising the adjustable direct current power supply and the variable frequency fan, and the executing mechanism completes corresponding adjustment and control actions according to a control command.

8. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 7, wherein the adjustable direct current power supply can swap the anode and the cathode according to the command of the control output circuit, and a voltage can also be adjusted in real time; and a voltage of the adjustable direct current power supply is adjustable in a range of 1.29 V to 10 V.

9. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 1, wherein a number of the core dehumidification unit is equal to or more than one, the core dehumidification units are capable of being connected in of a series mode, a parallel mode, an overlapping mode, a combination mode or a multistage mode, and the core dehumidification units are connected with the adjustable direct current power supply in parallel or series.

10. The electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to claim 1, wherein the one or more of core dehumidification units are used in combination with a set comprising a liquid-desiccant dehumidification device, a rotary-wheel dehumidification device or a cooling dehumidification device, and a connection mode comprises a series connection or a parallel connection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of a core dehumidification unit of an electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment.

(2) FIG. 2a is a working principle schematic diagram of the electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment when a voltage is applied.

(3) FIG. 2b is a working principle schematic diagram of the electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment when no voltage is applied.

(4) FIG. 3 is a schematic diagram of a plurality of core dehumidification units combined in parallel in the electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment.

(5) FIG. 4 is a schematic diagram of the plurality of core dehumidification units combined in series in the electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment.

(6) FIG. 5 is a schematic diagram illustrating dehumidification by a plurality of electrochemical dehumidification devices based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment combined in parallel with a liquid desiccant dehumidification device.

(7) FIG. 6 is a schematic diagram illustrating dehumidification by the plurality of electrochemical dehumidification devices based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment combined in series with the liquid desiccant dehumidification device.

(8) FIG. 7 is a schematic diagram illustrating dehumidification by the plurality of electrochemical dehumidification devices based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment combined in parallel with a rotary dehumidification device.

(9) FIG. 8 is a schematic diagram illustrating dehumidification by the plurality of electrochemical dehumidification devices based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment combined in series with the rotary dehumidification device.

(10) FIG. 9 is a schematic diagram illustrating dehumidification by the plurality of electrochemical dehumidification devices based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment combined in parallel with a cooling dehumidification device.

(11) FIG. 10 is a schematic diagram illustrating dehumidification by the plurality of electrochemical dehumidification devices based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment combined in series with the cooling dehumidification device.

DETAILED DESCRIPTION

(12) The technical solutions of the invention will be clearly and completely described hereinafter with reference to the embodiments and the accompanying drawings, but the invention is not limited thereto.

(13) FIG. 1 shows a core dehumidification unit of an electrochemical dehumidification device based on a screen-type amphoteric ion exchange membrane electrode according to the embodiment, which comprises a core dehumidification unit. The core dehumidification unit comprises, sequentially from one side to the other side, an anode air pathway 6, a screen-type anode electrode, an amphoteric ion exchange membrane 1, a screen-type cathode electrode and a cathode air pathway 7.

(14) The amphoteric ion exchange membrane 1 is a high-performance electrolyte membrane with a capability of selectively exchanging cations and water molecules at the same time, including a bipolar membrane or an amphoteric membrane. The amphoteric ion exchange membrane 1 is prepared by a blending method, a copolymerization method or a radiation grafting method. In the radiation grafting method, polyvinylidene fluoride (PVDF) is used as a base membrane for preparation. In the copolymerization method, a sulfonate is introduced on difluorobenzophenone and a quaternary ammonium group is introduced on bisphenol fluorene, and then the two monomers are copolymerized to prepare the amphoteric ion exchange membrane.

(15) In a direction from the anode air pathway 6 to the amphoteric ion exchange membrane 1, the screen-type anode electrode sequentially comprises an anode metal screen structure diffusion layer 2 and an anode catalyst layer 4. In a direction from the cathode air pathway 7 to the amphoteric ion exchange membrane 1, the screen-type cathode electrode sequentially comprises a cathode metal screen structure diffusion layer 3 and a cathode catalyst layer 5.

(16) The anode metal screen structure diffusion layer 2 and the cathode metal screen structure diffusion layer 3 are both composed of porous metal screens with a thickness of 0.8 mm to 2 mm, and are made of titanium, titanium alloy or stainless steel. The porous metal screen is provided with a corrosion-resistant conductive coating and has a rigidity required for supporting the amphoteric ion exchange membrane 1. The porous metal screen facilitates water vapor in the air on an anode side to approach the amphoteric ion exchange membrane 1 and generate the electrolytic reaction, and facilitates rapid removal of the water generated by the reduction reaction on a cathode side at the same time.

(17) By using a screen printing method, a transfer printing method or an injection method, the anode catalyst layer 4 and the cathode catalyst layer 5 are prepared by tightly attaching catalyst particles to a surface of the anode metal screen structure diffusion layer 2 near the anode air pathway 6 side and a surface of the cathode metal screen structure diffusion layer 3 near the cathode air pathway 7 side respectively. The anode catalyst layer 4 and the cathode catalyst layer 5 both have contact points in close contact on an interface connected with the amphoteric ion exchange membrane 1, when a voltage is applied, air in the anode air pathway 6 approaches an active site of the catalyst through the anode metal screen structure diffusion layer 2, and an electrolytic reaction of water vapor in the air occurs on a side of the amphoteric ion exchange membrane 1 near the anode thereof. Air in the cathode air pathway 7 approaches the active site of the catalyst through the cathode metal screen structure diffusion layer 3, and a reduction reaction of generating water by reaction of oxygen and protons occurs on a side of the amphoteric ion exchange membrane 1 near the cathode thereof.

(18) The screen-type anode electrode and the screen-type cathode electrode are externally connected with an anode and a cathode of an adjustable direct current power supply 17 respectively, and the adjustable direct current power supply 17 is connected with a digital multimeter 16. The adjustable direct current power supply 17 can swap an anode and a cathode according to the command of the control output circuit, and a voltage can also be adjusted in real time. A voltage of the adjustable direct current power supply 17 is adjustable in a range of 1.29 V to 10 V.

(19) The anode air pathway 6 and the cathode air pathway 7 are both provided with an air inlet and an air outlet. A first air valve 8 and a first flow sensor 14 are arranged in the anode air pathway 6, and the air inlet and the air outlet of the anode air pathway 6 are respectively provided with a first temperature and humidity sensor 12 and a second temperature and humidity sensor 10. A second air valve 9 and a second flow sensor 15 are arranged in the cathode air pathway 7, and the air inlet and the air outlet of the cathode air pathway 7 are respectively provided with a third temperature and humidity sensor 11 and a fourth temperature and humidity sensor 13.

(20) Variable frequency fans are arranged outside the air inlets of the anode air pathway 6 and the cathode air pathway 7. The anode air pathway 6 and the cathode air pathway 7 are both made of insulating and air-tight materials. A flow mode of air flowing in the anode air pathway 6 and the cathode air pathway 7 comprises a forward flow, a reverse flow or a cross flow.

(21) All of the temperature and humidity sensors (10, 11, 12 and 13), all of the flow sensors (14 and 15) and the digital multimeter 16 are connected with a computer.

(22) When a voltage is applied to the core dehumidification unit, an electrolytic reaction occurs to water vapor in the air circulating in the anode air pathway 6 on an anode side of the amphoteric ion exchange membrane 1 to perform active dehumidification. When no voltage is applied to the core dehumidification unit, the water vapor in the air circulating in the anode air pathway 6, which is on a high humidity side, permeates through the amphoteric ion exchange membrane 1 to enter a low humidity side to perform passive dehumidification by a vapor partial pressure difference caused by an air humidity difference.

(23) In an active dehumidification process, air to be dehumidified in the core dehumidification unit flows through the anode air pathway 6, and ambient air flows through the cathode air pathway 7. The temperature and humidity sensors (10, 11, 12 and 13) convert temperature and humidity of the air in the anode air pathway 6 and the cathode air pathway 7 into electrical signals and collect the electrical signals into a computer, the computer compares the obtained data with a set value, generates control signals through a control algorithm and sends the control signals to a control output circuit, the control output circuit respectively sends the control signals to an executing mechanism comprising the adjustable direct current power supply 1 and the variable frequency fan, and the executing mechanism completes corresponding adjustment and control actions according to a control command.

(24) A number of the core dehumidification unit is equal to or more than one, the core dehumidification units are capable of being connected in a series mode, a parallel mode, an overlapping mode, a combination mode or a multistage mode, and the amphoteric ion exchange membrane 1 in each core dehumidification unit is connected with the adjustable direct current power supply 1 in parallel mode or series.

(25) The dehumidification device according to the embodiment can be normally operated at a low temperature (0° C. or below) and a low humidity (<5%).

(26) The devices can be used in combination with a set comprising a liquid desiccant dehumidification device, a rotary dehumidification device or a cooling dehumidification device in a single or multiple mode, and a combination mode comprises a series connection or a parallel connection.

Embodiment 1

(27) FIG. 2a and FIG. 2b respectively show working principle diagrams of the device according to the embodiment when a voltage is applied and when no voltage is applied.

(28) As shown in FIG. 2a, when a voltage is applied to a core dehumidification unit, an electrolytic reaction occurs to water vapor in air circulating in an anode air pathway 6 on an anode side of an amphoteric ion exchange membrane 1, which is shown in formula (1):

(29) 2H.sub.2O.fwdarw.4H.sup.++O.sub.2+4e.sup.−, (1). Through the reaction of the formula (1), a humidity of the air in the anode air pathway 6 is reduced. At the moment, hydrogen ions (H.sup.+) generated by the formula (1) reach a cathode side through the amphoteric ion exchange membrane 1, electrons (e.sup.−) reach the cathode side through a circuit of a direct current power supply, and a reaction of formula (2) occurs to consume oxygen and generate water: O.sub.2+4H.sup.++4e.sup.−.fwdarw.2H.sub.2O, (2). The reaction of the formula (2) consumes oxygen and generates water. In this way, water vapor in the air flowing through the anode air pathway is electrolyzed, and water molecules generated by the formula (2) are carried away by the air circulating in the cathode air pathway 7. Through the reactions of the formulas (1) and (2), the humidity of the air in the anode air pathway 6 is reduced to perform active dehumidification.

(30) As shown in FIG. 2b, when no voltage is applied, the water vapor in the air circulating in the anode air pathway 6 (a high humidity side) permeates through the amphoteric ion exchange membrane 1 to enter the cathode air pathway 7 (a low humidity side) by a vapor partial pressure difference caused by an air humidity difference and is carried away by the air circulating in the cathode air pathway 7, so that the humidity of the air in the anode air pathway 6 is reduced to perform passive dehumidification.

Embodiment 2

(31) FIG. 3 and FIG. 4 show diagrams of a plurality of core dehumidification units combined in parallel and series.

(32) FIG. 3 is a diagram of a plurality of core dehumidification units combined in parallel. During the dehumidification process, variable frequency fans, a first air valve 8 and a second air valve 9 are firstly switched on, so that air to be dehumidified respectively flows through anode air pathways 6 of a second core dehumidification unit 18 to an n.sup.th core dehumidification unit 19 in parallel, and then is collected into one stream and sent into a room, while ambient air enters cathode air pathways 7. During operation, a temperature and humidity sensor senses a humidity in the air pathway and converts the humidity into electrical signals and collect the electrical signals into a computer, the computer compares the humidity signal with set temperature and humidity required, judges that active/passive dehumidification is required, generates a series of control signals (comprising a direct current power supply, a voltage and a frequency of the variable frequency fan) through a control algorithm and sends the control signals to a control output circuit.

(33) In the case of active dehumidification, an adjustable direct current power supply 17 is switched on, voltages are applied to two sides of the core dehumidification unit, an electrolytic reaction of water occurs in the anode air pathway 6, a humidity of air in the anode air pathway 6 is reduced, and a humidity of air in the cathode air pathway 7 is increased.

(34) In the case of passive dehumidification, the adjustable direct current power supply 17 is switched off, a humidity of air on a higher humidity side is reduced, and a humidity of air on a lower humidity side is increased by a vapor partial pressure difference of water vapor; the humidity in the air pathway is continuously collected by the temperature and humidity sensor into the computer, and is repeatedly adjusted until a set parameter is reached.

(35) A number of the core dehumidification units, air volumes of dehumidified air and blown air, a voltage of the direct current power supply, etc. are determined by working conditions and dehumidification requirements.

(36) FIG. 4 is a diagram of a plurality of core dehumidification units combined in series, which is different from the parallel combination mode. During the dehumidification process, the air to be dehumidified sequentially flows through the anode air pathways 6 of a plurality of core dehumidification units in series, and then is sent into the room, while the ambient air enters the cathode air pathways 7.

Embodiment 3

(37) FIG. 5 and FIG. 6 are diagrams illustrating dehumidification by a plurality of dehumidification devices combined in parallel and series with a liquid desiccant dehumidification device 20.

(38) FIG. 5 is a diagram illustrating dehumidification by a plurality of dehumidification devices combined in parallel with a liquid desiccant dehumidification device 20. During the dehumidification process, variable frequency fans, a first air valve 8 and a second air valve 9 are firstly switched on, so that air to be dehumidified respectively flows through anode air pathways 6 of core dehumidification units of the plurality of dehumidification devices in parallel, enters the liquid desiccant dehumidification device 20 to be contacted with a solution at the same time, and then is collected into one stream and sent into a room, while ambient air enters cathode air pathways 7. A humidity in the air pathway is continuously collected by a temperature and humidity sensor into a computer, and is repeatedly adjusted until a set parameter is reached. A number of electrochemical dehumidification units, air volumes of dehumidified air and blown air, a voltage of the direct current power supply, etc. are determined by working conditions and dehumidification requirements.

(39) FIG. 6 is a diagram illustrating dehumidification by the plurality of dehumidification devices combined in series with the liquid desiccant dehumidification device 20. Different from the parallel combination mode, the air to be dehumidified sequentially flows through the anode air pathways 6 of the core dehumidification units of the plurality of dehumidification devices in series, enters the liquid desiccant dehumidification device 20 to be contacted with the solution next, and then is sent into the room, while the ambient air enters the cathode air pathways 7.

Embodiment 4

(40) FIG. 7 and FIG. 8 are diagrams illustrating dehumidification by a plurality of dehumidification devices combined in parallel and series with a rotary dehumidification device 21.

(41) FIG. 7 is a diagram illustrating dehumidification by a plurality of dehumidification devices combined in parallel with a rotary dehumidification device 21. During the dehumidification process, variable frequency fans, a first air valve 8 and a second air valve 9 are firstly switched on, so that air to be dehumidified respectively flows through anode air pathways 6 of core dehumidification units of the plurality of dehumidification devices in parallel, enters a dehumidification side of the rotary dehumidification device 21, and then is collected into one stream and sent into a room, while ambient air enters cathode air pathways 7 and a regeneration side of the rotary dehumidification device 21. A humidity in the air pathway is continuously collected by a temperature and humidity sensor into a computer, and is repeatedly adjusted until a set parameter is reached. A number of electrochemical dehumidification units, air volumes of dehumidified air and blown air, a voltage of the direct current power supply, etc. are determined by working conditions and dehumidification requirements.

(42) FIG. 8 is a diagram illustrating dehumidification by the plurality of dehumidification devices combined in series with the rotary dehumidification device 21, which is different from the parallel combination mode. During the dehumidification process, the air to be dehumidified respectively flows through the anode air pathways 6 of the core dehumidification units of the plurality of dehumidification devices in series, enters the dehumidification side of the rotary dehumidification device 21, and then is collected into one stream and sent into the room, while the ambient air enters the cathode air pathways 7 and the regeneration side of the rotary dehumidification device 21.

Embodiment 5

(43) FIG. 9 and FIG. 10 are diagrams illustrating dehumidification by a plurality of dehumidification devices combined in parallel and series with a cooling dehumidification device 22.

(44) FIG. 9 is a diagram illustrating dehumidification by a plurality of dehumidification devices combined in parallel with a cooling dehumidification device 22. During the dehumidification process, variable frequency fans, a first air valve 8 and a second air valve 9 are firstly switched on, so that air to be dehumidified respectively flows through anode air pathways 6 of core dehumidification units of the plurality of dehumidification devices in parallel, enters the cooling dehumidification device to be contacted with a cooling coil, and then is collected into one stream and sent into a room, while ambient air enters cathode air pathways 7. A humidity in the air pathway is continuously collected by a temperature and humidity sensor into a computer, and is repeatedly adjusted until a set parameter is reached. A number of electrochemical dehumidification units, air volumes of dehumidified air and blown air, a voltage of the direct current power supply, etc. are determined by working conditions and dehumidification requirements.

(45) FIG. 10 is a diagram illustrating dehumidification by the plurality of dehumidification devices combined in series with the cooling dehumidification device 22, which is different from the parallel combination mode. During the dehumidification process, the air to be dehumidified respectively flows through the anode air pathways 6 of the core dehumidification units of the plurality of dehumidification devices in series, enters the cooling dehumidification device to be contacted with the cooling coil, and then is collected into one stream and sent into the room, while the ambient air enters the cathode air pathways 7.

(46) The embodiments of the invention are not limited by the embodiments above. Apparently, the embodiments described are only a part of the embodiments of the invention rather than all of the embodiments. Based on the embodiments of the invention, all other embodiments obtained without creative works, such as changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principle of the invention shall be deemed as equivalent replacement methods and included in the protection scope of the invention.