An electrically heated compensated spray evaporation chamber, air intake system and control method thereof

Abstract

The application provides an electric heating compensation type spray evaporation cavity, an air intake system and a control method thereof. The spray evaporation cavity is sequentially provided with an inlet, a high-pressure nozzle, an evaporation cavity and an outlet along an air intake direction. The high-pressure nozzle is used for spraying water mist into the evaporation cavity, and the sprayed water mist has the same velocity component as the air intake direction. A heating array composed of multiple electric heating sheets is arranged in a region where the gas in the evaporation cavity and the water mist are mixed. By using the electric heating compensation type spray evaporation cavity provided by the application in the air intake system, the change range of temperature and humidity can be improved compared with the traditional membrane humidifier, the controllability is increased, so that the low-power operation condition of the fuel cell system is better adapted, and in the high-power operation condition, the electric compensation can be closed, and the heat required for the droplet gasification is completely provided by the high-temperature air at the outlet of the air compressor, so that the energy consumption is further reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to an electric heating compensation type spray evaporation cavity, an air inlet system and a control method thereof. BACKGROUND

[0002] The proton exchange membrane fuel cell is a chemical reactor, hydrogen is decomposed into electrons and protons in the cathode catalyst layer. The protons are transported to the cathode in the form of hydrated hydrogen ions across the membrane, react with oxygen to generate water, and are discharged from the flow channel. The cross-membrane transport of protons requires the proton exchange membrane to maintain a certain humidity, otherwise it will bring a larger proton transfer resistance, affecting the power generation efficiency. Therefore, the reaction gas entering the stack is required to have a certain humidity.

[0003] The current fuel cell system uses a humidifier mainly composed of perfluorosulfonic acid resin membrane humidifier. Although the humidifier can adjust the temperature and humidity of the air entering the stack, the humidifier is bulky, which significantly reduces the volume energy density of the fuel cell engine system. And in the actual engineering application, it is found that it has the problems of poor stability, poor humidity controllability, high performance decay rate and high cost.

[0004] The spray cooling and humidification technology is generally used in heat exchangers, plant humidification and other fields, and is rarely used in fuel cell engine systems. The existing spray evaporation cavity for fuel cells has simple structure, poor humidification effect and low heat exchange efficiency. Especially in low power working conditions, liquid droplets are easily attached and left, and the temperature and humidity change interval is small. Therefore, the spray evaporation cavity needs to be further designed in structure and scheme to adapt to the variable load fluctuation of the fuel cell system and improve the controllability and robustness. SUMMARY

[0005] In view of the above analysis, the present application aims to provide an electric heating compensation type spray evaporation cavity, which improves the temperature and humidity change interval and increases the controllability to better adapt to the low power operating condition of the fuel cell system.

[0006] In a first aspect of the present application, an electric heating compensation type spray evaporation cavity is provided. The spray evaporation cavity is provided with an inlet, a high-pressure nozzle, an evaporation cavity and an outlet in sequence along the air inlet direction. The high-pressure nozzle is connected with a water supply pipeline, which can spray water mist into the evaporation cavity, and the sprayed water mist has the same speed component as the air inlet direction; the region where the inlet gas and the water mist mix in the evaporation cavity is provided with an electric heating array, and the electric heating array is composed of a plurality of electric heating sheets.

[0007] Specifically, the evaporation cavity has a larger inner diameter relative to the inlet and the outlet. Based on this design, the inlet gas slows down in the evaporation cavity and can exchange heat with the water mist more fully.

[0008] Specifically, a plurality of high-pressure nozzles are arranged uniformly on the evaporation cavity, and the jet direction is at an angle of 45 degrees with the air inlet direction.

[0009] Specifically, the electric heating sheet comprises a substrate and a fin vertically connected with the substrate, a heating wire is arranged in the fin, and the substrate is provided with a circuit interface of the heating wire.

[0010] Specifically, the heating wire in the fin is arranged non-uniformly, and the density of the heating wire gradually increases from the root to the end of the fin. Since the heating wire is concentrated at the end of the fin, the heat in the central region of the evaporation cavity is higher, and this region is the main part for droplet evaporation, which makes the present application more energy-saving and efficient, and most of the energy is used to provide the latent heat required for droplet evaporation, thereby improving the temperature stability of the inlet and outlet of the evaporation cavity.

[0011] Specifically, in order to install the electric heating sheet in the evaporation cavity to form an electric heating array, a plurality of insertion slots matching the size of the fin are arranged on the periphery of the evaporation cavity, and the electric heating sheet is inserted into the insertion slot through the fin; the end of the fin of each electric heating sheet forms a central flow channel of the inlet gas.

[0012] In the second aspect of the present application, the present application provides a fuel cell air inlet system based on the foregoing electric heating compensation type spray evaporation cavity, which comprises an air compressor, a spray evaporation cavity, a intercooler and a high-pressure water pump. The spray evaporation cavity is the electric heating compensation type spray evaporation cavity described above. The outlet of the air compressor is in communication with the inlet of the electric heating compensation type spray evaporation cavity. The outlet of the electric heating compensation type spray evaporation cavity is in communication with the inlet of the intercooler. The outlet gas of the intercooler is used to supply to the cathode of the fuel cell stack. The high-pressure water pump is in communication with the high-pressure nozzle of the electric heating compensation type spray evaporation cavity.

[0013] Specifically, the fuel cell stack is a proton exchange membrane fuel cell stack.

[0014] In the third aspect of the present application, the present application further provides a control method of the fuel cell air inlet system based on the foregoing fuel cell air inlet system, which comprises the following steps:

[0015] S1. Detect the power condition of the fuel cell stack, such as in high-power working condition, execute step S2; otherwise, execute step S3;

[0016] S2. Stop the power supply of the electric heating array, and the heat required for water mist gasification is provided by the high-temperature gas input at the inlet of the electric heating compensation type spray evaporation cavity;

[0017] S3. Start the power supply of the electric heating array, and the intercooler functions as a heater at this time.

[0018] Preferably, the method further comprises the following steps after step S2:

[0019] S2’. Detecting the temperature and humidity of the outlet of the electrically heated compensating spay evaporator, and increasing the flow rate of the high pressure nozzle if the temperature is higher than a preset value and the humidity is lower than a preset threshold.

[0020] Based on the above, the electrically heated compensating spay evaporator, the air intake system and the control method thereof have the following advantages:

[0021] 1. Reduced cost: Replacing the expensive perfluorosulfonic acid resin membrane humidifier;

[0022] 2. Increased volume power density of the fuel cell system: Eliminating the bulky membrane humidifier;

[0023] 3. Improved humidification stability: The spray evaporator is only a mechanical structural component, and its stability is higher than that of the almost uncontrollable membrane humidifier;

[0024] 4. High heat exchange efficiency, which can effectively avoid liquid droplet residue under the same working conditions, especially in low power conditions. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures, and in which:

[0026] Figure 1 An electrically heated compensating spray evaporator in an embodiment is shown;

[0027] Figure 2 An electric heating array in an embodiment is shown;

[0028] Figure 3 An electric heating sheet in an embodiment is shown;

[0029] Figure 4 A fuel cell air intake system in an embodiment is shown.

[0030] BRIEF DESCRIPTION OF DRAWINGS DETAILED DESCRIPTION

[0031] Embodiments of the present application will be described below in greater detail with reference to the accompanying drawings. Although embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application is more thoroughly and completely conveyed to those skilled in the art.

[0032] The term "includes," "including," "has," "having," "contains," "containing," or variants thereof herein are open-ended, and include a variety of meanings depending upon the context in which it is used. Unless otherwise noted, the terms "comprises" and "comprising" are open-ended, and include a wide variety of meanings, and are synonymous with "includes" and "including," "has" and "having," "contains" and "containing," and "specifies" and "specifying," as well as other variations. Unless specifically stated otherwise, the term "or" as used herein is intended to be interpreted as "and / or," and not as an exclusive logical or. The terms "based on" and "based upon" are not exclusive and are not intended to be limiting. The terms "one example embodiment" and "an example embodiment" are used interchangeably. The term "another embodiment" is used interchangeably with "at least one other embodiment." The terms "a" and "an" are defined as one or more unless explicitly stated otherwise. The terms "first," "second," and the like are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0033] As shown in Figure 1 The present embodiment provides an electrically heated compensation type spray evaporation chamber, which is provided with an inlet 1, a high-pressure nozzle, an evaporation chamber 5, and an outlet 2 in sequence along the direction of the incoming gas.

[0034] The evaporation chamber 5 has a larger inner diameter relative to the inlet 1 and the outlet 2. Based on this design, the flow rate of the incoming gas is slowed down in the evaporation chamber 5, and the heat exchange with the water mist sprayed by the high-pressure nozzle can be more sufficient.

[0035] In order to facilitate the installation of the high-pressure nozzle, the present embodiment symmetrically provides a plurality of high-pressure nozzle mounting ports 4 on the evaporation chamber 5, so as to detachably install the high-pressure nozzle. Alternatively, the skilled person in the art can also install the high-pressure nozzle in other ways in the evaporation chamber 5, as long as the water mist can be uniformly sprayed into the evaporation chamber. In the present embodiment, four high-pressure nozzles are provided, each of which sprays water mist into the evaporation chamber 5 at an angle of 45 degrees to the direction of the incoming gas.

[0036] In the area where the incoming gas and the water mist are mixed, an electric heating array 3 is provided in the evaporation chamber 5, which is composed of a plurality of electric heating fins according to a specific arrangement rule. In the present embodiment, the plurality of electric heating fins are installed on the periphery of the evaporation chamber 5, forming an electric heating array 3 as shown in Figure 2 .

[0037] The electric heating fins can be installed on the periphery of the evaporation chamber 5 in various ways. In order to facilitate installation and subsequent maintenance, the present embodiment provides the electric heating fins to include a substrate and fins connected perpendicularly to the substrate, and the periphery of the evaporation chamber is provided with a plurality of insertion slots matching the size of the fins, the electric heating fins are inserted into the insertion slots through the fins, and the substrate is stably connected to the evaporation chamber 5 by a conventional fixing method.

[0038] As shown in Figure 3As shown, the circuit interface on the substrate has heating wires, the fins are provided with heating wires, and the heating wires in the fins are arranged non-uniformly, gradually increasing from the root to the end of the fins. Since the fins in the central region of the electric heating array 3 are denser, and the heating wires at the end of the fins are arranged more densely, the temperature in the central region of the array is higher, and at the same time, as Figure 2 As shown, the end of the fins of each electric heating sheet of the electric heating array 3 forms a central flow channel for the inlet gas, which can further strengthen the convective heat transfer effect and avoid the attachment and retention of liquid droplets.

[0039] Figure 4 A fuel cell air intake system based on the above electric heating compensation type spray evaporation cavity is given. The inlet 1 of the electric heating compensation type spray evaporation cavity is communicated with the outlet of the air compressor, and the outlet 2 is communicated with the inlet of the intercooler, and the outlet gas of the intercooler is used to supply to the cathode of the fuel cell stack. The high-pressure nozzle is connected with the high-pressure water pump and the water treatment device.

[0040] The fuel cell air intake system works according to the following method:

[0041] S1. Detect the power condition of the fuel cell stack, such as in high-power working condition, execute step S2; otherwise, execute step S3;

[0042] S2. Stop the power supply of the electric heating array, and the heat required for water mist gasification is provided by the high-temperature gas input at the inlet of the electric heating compensation type spray evaporation cavity;

[0043] S3. Start the power supply of the electric heating array, and humidify the inlet gas by electric heating assisted water mist gasification. The humidified inlet gas enters the cathode of the fuel cell stack through the intercooler, and the intercooler plays a heating role at this time.

[0044] After executing step S2, the following steps are also executed:

[0045] S2'. Detect the outlet temperature and humidity of the electric heating compensation type spray evaporation cavity, and increase the flow of the high-pressure nozzle if the temperature is higher than the preset value and the humidity is lower than the preset threshold.

[0046] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles, practical applications, or improvements to the prior art of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. An electrically heated compensated spray evaporation chamber, characterized in that, The spray evaporation chamber is provided with an inlet, a high-pressure nozzle, an evaporation chamber body, and an outlet in sequence along the air intake direction; wherein... The high-pressure nozzle is used to spray water mist into the evaporation chamber. The sprayed water mist has a velocity component in the same direction as the air intake. An electric heating array is provided in the area of ​​the evaporation chamber where the air intake gas and water mist mix. The electric heating array is composed of multiple electric heating elements. The electric heating element includes a substrate and fins perpendicularly connected to the substrate. A heating wire is disposed inside the fins, and the substrate has a circuit interface for the heating wire. The heating wires inside the fins are arranged non-uniformly, gradually becoming denser from the root to the tip of the fins; The periphery of the evaporation chamber is provided with multiple slots that match the size of the fins, and the electric heating elements are inserted into the slots through the fins; the fin ends of each electric heating element form a central flow channel for the intake gas.

2. The electrically heated compensated spray evaporation chamber according to claim 1, characterized in that, The evaporation chamber has a larger inner diameter relative to the inlet and the outlet.

3. The electrically heated compensated spray evaporation chamber according to claim 1, characterized in that, Multiple high-pressure nozzles are provided and evenly distributed on the evaporation chamber, with the spray direction at a 45-degree angle to the air intake direction.

4. A fuel cell intake system, characterized in that, The intake system includes an air compressor, a spray evaporator chamber, an intercooler, and a high-pressure water pump; wherein... The spray evaporation chamber is selected from the electrically heated compensated spray evaporation chamber according to any one of claims 1-3. The outlet of the air compressor is connected to the inlet of the electrically heated compensated spray evaporation chamber, and the outlet of the electrically heated compensated spray evaporation chamber is connected to the inlet of the intercooler. The outlet gas of the intercooler is used to supply the cathode of the fuel cell stack. The high-pressure water pump is connected to the high-pressure nozzle of the electrically heated compensated spray evaporation chamber.

5. A fuel cell intake system according to claim 4, wherein the fuel cell stack is a proton exchange membrane fuel cell stack.

6. A control method for a fuel cell intake system, characterized in that, The fuel cell intake system is selected from the fuel cell intake system according to any one of claims 4-5, and includes the following steps: S1. Detect the power status of the fuel cell stack. If it is in a high-power condition, proceed to step S2; otherwise, proceed to step S3. S2. Stop the power supply to the electric heating array; the heat required for water mist vaporization is provided by the high-temperature gas input into the inlet of the electric heating compensated spray evaporation chamber. S3. Start the power supply to the electric heating array, and the intercooler will then play a heating role.

7. The control method for a fuel cell intake system according to claim 6, characterized in that, The method performs the following steps after executing step S2: S2'. Detect the outlet temperature and humidity of the electrically heated compensated spray evaporation chamber. If the temperature is higher than the preset value and the humidity is lower than the preset threshold, increase the flow rate of the high-pressure nozzle.

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