CN210489739U

CN210489739U - Heating assembly for fuel cell

Info

Publication number: CN210489739U
Application number: CN201920435471.3U
Authority: CN
Inventors: 王安; 陈宏�; 严启刚; 李骁
Original assignee: Wuhan Troowin Power System Technology Co ltd
Current assignee: Wuhan Troowin Power System Technology Co ltd
Priority date: 2019-04-02
Filing date: 2019-04-02
Publication date: 2020-05-08
Anticipated expiration: 2029-04-02

Abstract

The utility model provides a heating element for fuel cell, include: at least one heating channel arranged between flow field plates of the fuel cell, at least one first pipe, a fluid pump and at least one heater, wherein the heating channel has a first opening and a second opening, two ends of the first pipe are respectively communicated with the first opening and the second opening of the heating channel, so that the first pipe and the heating channel form a heat exchange passage allowing a first heat transfer medium to flow therein, the fluid pump is arranged in the heat exchange passage to drive the first heat transfer medium to circulate in the heat exchange passage, and the heater has a heating cavity, wherein the heating cavity is arranged around the first pipe.

Description

Heating assembly for fuel cell

Technical Field

The utility model relates to a fuel cell especially relates to a heating element for fuel cell, wherein the utility model discloses a heating element for fuel cell can heat fuel cell (or its fuel cell stack) when ambient temperature is low excessively to even make this fuel cell at low temperature environment, also can start the operation smoothly.

Background

Fuel cells, particularly proton membrane exchange fuel cells, can convert chemical energy directly into electrical energy without a heat engine process, and thus have the advantages of high energy conversion efficiency, low noise, low pollution, long service life, and the like, and are increasingly valued by people. However, when the ambient temperature of the fuel cell (or the fuel cell stack thereof) is low, the internal temperature thereof is also low, and even an icing phenomenon occurs. Under the condition of over-low ambient temperature, when the fuel cell is started to operate and generate power, the fuel cell needs to be heated first, so as to avoid that the power generation performance of the fuel cell is not high or the power output is not stable due to uneven internal temperature of the fuel cell, and even the fuel cell cannot be started smoothly. Further, the fuel cell has better power generation performance when it operates in its optimum operating temperature range, and can respond quickly to the power consumption of the load. Therefore, when the temperature of the environment in which the fuel cell is located is too low, the fuel cell is generally heated before starting the operation of the fuel cell to generate electricity, so that it can operate under a preferable temperature condition and its response to the power consumption of the load is improved. Finally, membrane modules of fuel cells, particularly proton membranes of fuel cells, are susceptible to damage when the temperature is too high. Accordingly, the operating temperature of the fuel cell should be controlled below the temperature at which the proton membrane is damaged.

SUMMERY OF THE UTILITY MODEL

The utility model has the main advantages of it provides a heating element for fuel cell, wherein the utility model discloses a heating element for fuel cell can heat fuel cell (or its fuel cell stack) to even make fuel cell under low temperature environment, also can start the operation smoothly.

Another advantage of the present invention is that it provides a heating assembly for a fuel cell, wherein the heating assembly for a fuel cell can heat a fuel cell before the fuel cell starts power generation.

Another advantage of the present invention is that it provides a heating assembly for a fuel cell, wherein the present invention provides a fuel cell stack heating system for a fuel cell that uses compressed, warmed air to heat the fuel cell stack without carrying additional heat transfer media.

Another advantage of the present invention is that it provides a heating assembly for a fuel cell, wherein the heating assembly for a fuel cell heats air as a heat transfer medium, which can be achieved by an air compressor of the fuel cell, without installing additional components or parts.

Another advantage of the present invention is that it provides a heating assembly for a fuel cell, wherein the heating assembly for a fuel cell can be used for an existing fuel cell with only minor modifications to the existing fuel cell.

Another advantage of the present invention is that it provides a heating assembly for a fuel cell, wherein the heating assembly for a fuel cell does not require it to have a complex and precise structure.

The other advantages and features of the invention will be fully apparent from the following detailed description and realized by means of the instruments and combinations particularly pointed out in the appended claims.

According to the utility model discloses, can realize aforementioned purpose and other purposes and advantage the utility model discloses a heating element for fuel cell includes:

at least one heating channel disposed between flow field plates of the fuel cell, wherein the heating channel has a first opening and a second opening;

at least one first pipe, wherein both ends of the first pipe are respectively communicated with the first opening and the second opening of the heating channel, so that the first pipe and the heating channel form a heat exchange passage allowing a first heat transfer medium to flow therein;

a fluid pump, wherein the fluid pump is disposed in the heat exchange path to drive the first heat transfer medium to circulate within the heat exchange path; and

at least one heater, wherein the heater has a heating cavity, wherein the heating cavity is disposed around the first conduit.

Further, the utility model discloses a heating element for fuel cell includes at least one ambient temperature sensor, and wherein this ambient temperature sensor is set up and is used for detecting the temperature of this fuel cell environment.

Further, the present invention provides a heating assembly for a fuel cell including an air compressor and a second pipe, wherein the second pipe is disposed between the air compressor and an air inlet of the heater, so that compressed air generated by the air compressor can be supplied to the heater.

Further, the heating assembly for a fuel cell of the present invention includes an exhaust pipe, wherein the exhaust pipe is communicated with the exhaust port of the heater, so that the air flowing through the heating chamber of the heater can be exhausted.

Preferably, the flow direction of the first heat transfer medium flowing through the heat exchange passage and the flow direction of the second heat transfer medium flowing through the heating chamber are different.

According to another aspect of the present invention, the present invention further provides another heating assembly for a fuel cell, comprising:

at least one fluid pump, wherein the fluid pump is arranged in the heat exchange passage to drive the first heat transfer medium to circulate in the heat exchange passage; and

at least one heater, wherein the heater is disposed in the first conduit.

Further objects and purposes of the present invention will become more fully apparent from the ensuing description and appended drawings.

These and other objects, features and objects of the present invention will become more fully apparent from the following detailed description, the accompanying drawings and the appended claims.

Drawings

Fig. 1 is a schematic structural diagram of a starting system for a fuel cell according to an embodiment of the present invention.

Fig. 2 shows the heat exchange path of the fuel cell starting system for the starting system of the fuel cell according to the embodiment of the present invention, wherein the heat exchange path is configured to heat the fuel cell.

Fig. 3 is another structural diagram of the starting system for a fuel cell according to the embodiment of the present invention.

Fig. 4A is a flowchart of the starting method for the fuel cell according to the embodiment of the present invention.

Fig. 4B is another flowchart of the starting method for the fuel cell according to the embodiment of the present invention.

Fig. 5 shows an alternative implementation of the starting system for a fuel cell according to an embodiment of the present invention.

Fig. 6 shows the heat exchange path of the starting system for a fuel cell according to the embodiment of the present invention, wherein the heat exchange path is configured to heat the fuel cell.

Fig. 7 is another structural diagram of the starting system for a fuel cell according to the embodiment of the present invention.

Fig. 8 shows an alternative implementation of the above-described starting method for a fuel cell according to an embodiment of the present invention.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents and other technical solutions without departing from the spirit and scope of the invention.

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in a generic and descriptive sense only and not for purposes of limitation, as the terms are used in the description to indicate that the referenced device or element must have the specified orientation, be constructed and operated in the specified orientation, and not for the purpose of limitation.

It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.

Referring to fig. 1 to 4B of the drawings, a starting system for a fuel cell according to an embodiment of the present invention is illustrated, wherein the starting system for a fuel cell of the present invention includes a control module or a starting control module 10, at least one ambient temperature sensor 20, a heating channel 30, a first pipeline 40, a fluid pump 50 and a heater 60, wherein the ambient temperature sensor 20 is configured to be electrically connected to the control module 10, so that the control module 10 can receive temperature data generated by the ambient temperature sensor 20, the control module 10 is configured to control the ambient temperature sensor 20 to detect a temperature of an environment where the fuel cell is located according to an ambient temperature detection command, the heating channel 30 is configured between flow field plates of a fuel cell stack of the fuel cell to heat the flow field plates of the fuel cell stack of the fuel cell, wherein the heating channel 30 has a first opening 301 and a second opening 302, both ends of the first pipe 40 are respectively communicated with the first opening 301 and the second opening 302 of the heating channel 30, so that the first pipe 40 and the heating channel 30 form a heat exchange passage 300 allowing a first heat transfer medium to flow therein, wherein the fluid pump 50 is disposed at the heat exchange passage 300, the heater 60 has a heating chamber 600, wherein the heating chamber 600 is disposed around the first pipe 40, so that a second heat transfer medium flowing in the heating chamber 600 can exchange heat with the first heat transfer medium flowing in the heat exchange passage 300, wherein the control module 10 is further electrically connected with the fluid pump 50, and the control module 10 is disposed so that when the ambient temperature detected by the ambient temperature sensor 20 is lower than a preset ambient temperature, the fluid pump 50 is controlled to rotate, thereby driving the first heat transfer medium to circulate in the heat exchange path 300. Preferably, the temperature of the first heat transfer medium is less than the temperature of the second heat transfer medium. As shown in fig. 1 to 3 of the drawings, more preferably, the fluid pump 50 is configured to drive the first heat transfer medium to flow out from the first opening 301 of the heating channel 30, flow in from the second opening 302 of the heating channel 30, and further flow in from the first opening 301 of the heating channel 30 after the first pipeline 40 is heat-exchanged and heated with the heater 60. Accordingly, the first opening 301 of the heating channel 30 forms an inlet for the first heat transfer medium of the heating channel 30, and the second opening 302 of the heating channel 30 forms an outlet for the first heat transfer medium of the heating channel 30. Optionally, the fluid pump 50 is configured to drive the first heat transfer medium out of the second opening 302 of the heating channel 30 and in from the first opening 301 of the heating channel 30.

It is noted that the preset ambient temperature at which the start-up system for a fuel cell of the present invention is started or activated to heat the fuel cell stack of the fuel cell is related to the optimum operating temperature range of the fuel cell and is influenced by the structure of the fuel cell. For example, when the fuel cell is a proton exchange membrane fuel cell, then the preset ambient temperature may be set to 0 ℃, or a lower temperature, for example, -10 ℃. In other words, the start-up system for a fuel cell of the present invention is started or activated to heat the fuel cell stack of the fuel cell when the temperature of the environment in which the fuel cell is located is lower than-10 ℃ (or lower than 0 ℃). However, in practical use, in order to make the fuel cell reach a higher temperature suitable for start-up operation as soon as possible, the preset ambient temperature at which the start-up system for the fuel cell of the present invention is started or activated to heat the fuel cell stack of the fuel cell may be set to a higher temperature, for example, 10 ℃. In other words, the starting system for a fuel cell of the present invention is started or activated to heat the fuel cell stack of the fuel cell when the temperature of the environment in which the fuel cell is located is lower than 10 ℃. Typically, fuel cells, and proton exchange membrane fuel cells in particular, have a minimum temperature for normal start-up of around-10 ℃. Therefore, the preset ambient temperature is preferably set to-10 ℃. And in order to enable faster start-up and better operation, the preset ambient temperature is more preferably set to 0 ℃. Further, when the starting system for a fuel cell of the present invention is started or activated to heat the fuel cell stack of the fuel cell, the fuel cell is heated by the first heat transfer medium, and therefore, the temperature of the first heat transfer medium should not be excessively high so as not to affect the power generation performance of the fuel cell. In actual use, the first heat transfer medium may be heated to 20 ℃ to 110 ℃ by the heater 60. Further, when the fuel cell is a pem fuel cell stack, the maximum temperature of the first heat transfer medium should also take into account the effect on the thermal stability of the pem. Therefore, when the temperature of the environment of the fuel cell, especially the pem fuel cell, is lower than the preset environment temperature, the temperature of the first heat transfer medium is preferably heated to below 100 ℃, so as to prevent the pem of the fuel cell from being damaged due to abrupt temperature changes. Accordingly, the temperature of the first heat transfer medium should not be greater than 100 ℃. More preferably, the first heat transfer medium is heated to 25 ℃ to 90 ℃. Considering that the preferred operating temperature range for most pem fuel cells is 60 ℃ to 80 ℃, the temperature of the first heat transfer medium is most preferably 60 ℃ to 80 ℃. In addition, when the second heat transfer medium is air, the air can be compressed by an air compressor to be heated. The higher the compression ratio of the air compressor is, the greater the energy consumption is. Therefore, when the second heat transfer medium is air, the temperature of the first heat transfer medium is raised as much as possible while taking into account the energy consumption when the second heat transfer medium is compressed. Finally, the melting point of the first heat transfer medium should preferably not be greater than 0 ℃ in order to prevent icing of the first heat transfer medium at low ambient temperatures. Preferably, the first heat transfer medium is water, an aqueous solution or a mixture of water, or other suitable liquid substance. Optionally, the first heat transfer medium is a gaseous substance. The second heat transfer medium is a gas such as air, or other suitable substance.

As shown in fig. 1 to 3 of the drawings, the starting system for a fuel cell according to the embodiment of the present invention further includes an air compressor or air compressor 71, wherein the air compressor 71 is electrically connected to the control module 10, wherein the control module 10 is configured to start compressed air when the ambient temperature is lower than the predetermined ambient temperature, and provide the compressed air with the heated air through a second pipe 72 and an air inlet 601 thereof to the heater 60, and the compressed air is discharged from the heating cavity 600 of the heater 60 through an exhaust port 602 after heat exchange with the first heat transfer medium. In other words, the heating chamber 600 of the heater 60 has an air inlet 601 and an exhaust port 602. Accordingly, the second heat transfer medium is air. In order to heat the fuel cell to a suitable temperature as quickly as possible, it is preferable that the flow direction of the first heat transfer medium flowing in the first pipe 40 and the flow direction of the second heat transfer medium flowing in the heating chamber 600 are different or opposite to each other, so as to improve the heat exchange efficiency therebetween.

As shown in fig. 1 to 3 of the drawings, a starting system for a fuel cell according to an embodiment of the present invention further includes a hydrogen control valve for controlling supply of hydrogen to a fuel cell stack of the fuel cell and an air control valve 90 for controlling supply of air to the fuel cell stack of the fuel cell, wherein the control module 10 is electrically connectable with the hydrogen control valve and the air control valve 90 respectively, wherein the control module 10 is configured to enable when the difference between the temperature T1 (detectable by temperature sensor T1) of the first heat transfer medium flowing through the first opening 301 and the temperature T2 (detectable by temperature sensor T2) of the first heat transfer medium flowing through the second opening 302 is not greater than a start-up temperature difference, the hydrogen control valve and the air control valve 90 are controlled to be opened to supply hydrogen and air to (the fuel cell stack of) the fuel cell. Preferably, the control module 10 controls to close the second pipe 72 supplying compressed air to the heater 60 when the hydrogen control valve and the air control valve 90 are opened to supply hydrogen and air to the fuel cell stack of the fuel cell. Optionally, the control module 10 is configured to provide a fuel cell activation signal when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is not greater than a start-up temperature difference, such that an upper computer or controller controlling the operation of the fuel cell can control the activation of the fuel cell, for example, the supply of hydrogen and air to a fuel cell stack of the fuel cell. It is noted that the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 reflects the temperature of the fuel cell stack of the fuel cell relative to the temperature T1 of the first heat transfer medium flowing through the first opening 301. Therefore, when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is small, it means that the temperature of the fuel cell stack of the fuel cell is high. In practical applications, a fuel cell stack composed of a smaller number of fuel cells can be considered to have been heated to a temperature suitable for start-up when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is less than 5 ℃. A complex fuel cell stack with more fuel cells can be considered to have been heated to a temperature suitable for start-up when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is below a higher temperature value, e.g., 15 ℃. Therefore, the utility model discloses the start-up temperature difference is preferred 0 ℃ -15 ℃. More preferably, the utility model discloses the start temperature difference is 0 ℃ -5 ℃.

As shown in fig. 1 to 3 of the drawings, a starting system for a fuel cell according to an embodiment of the present invention further includes an air supply line 91 for supplying air to the fuel cell, wherein the air control valve 90 is disposed in the air supply line 91 to control the supply of air to a fuel cell stack of the fuel cell. Further, the air compressor 71 is provided to supply air to the fuel cell stack of the fuel cell through the air supply pipe 91. As shown in fig. 1-4B of the drawings, when the difference between the temperature T1 of the first heat-transfer medium flowing through the first opening 301 and the temperature T2 of the first heat-transfer medium flowing through the second opening 302 is not greater than a start-up temperature difference, the control module 10 controls the air compressor 71 to stop providing or supplying compressed air to the second pipe 72 via a control valve. At the same time, the control module 10 controls the air control valve 90 to be opened so that the air compressor 71 can supply air to the fuel cell stack of the fuel cell through the air supply line 91. Preferably, the control module 10 controls to stop the operation of the fluid pump 50 when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is not greater than a start temperature difference.

As shown in fig. 1 to 3 of the accompanying drawings, the first pipe 40 of the starting system for a fuel cell according to the embodiment of the present invention includes a first pipe 41, wherein the heater 60 is disposed outside the first pipe 41, such that the first pipe 41 is disposed between the heat exchange path 300 and the heating chamber 600 and forms a heat transfer medium between the first heat transfer medium and the second heat transfer medium. Further, since the temperature of the first heat transfer medium is lower than that of the second heat transfer medium, it can be considered that the second heat transfer medium heats the first heat transfer medium through the first pipe 41 of the first pipe 40. Preferably, the first tube 41 is made of a material with a high heat transfer coefficient, such as a metal or alloy material with high heat transfer performance, such as gold, silver, copper, aluminum, etc. However, the first tube 41 may be made of a non-metallic material having a high heat transfer coefficient. In practical applications, a material with a thermal conductivity above 115W/(m.k), such as gold, silver, copper, aluminum or an alloy thereof, can better realize the heating of the first heat transfer medium by the second heat transfer medium through the first pipe 41.

As shown in fig. 1 to 3 of the drawings, a heat exchange passage 300 for a starting system of a fuel cell according to an embodiment of the present invention may be further used as a cooling passage of a cooling system or a part thereof. Preferably, the heat exchange path 300 of the starting system for a fuel cell of the present invention forms one cooling branch of the cooling path of the cooling system for the fuel cell, which is communicated with the other cooling branch 80 of the cooling path of the cooling system for the fuel cell, thereby forming a complete cooling path with the cooling branch 80. Preferably, both ends of the cooling branch 80 of the cooling passage of the cooling system of the fuel cell communicate with the cooling channel of the fuel cell and the first pipe 40, respectively. Preferably, a radiator 73 of the cooling system of the fuel cell is provided in the cooling branch 80 to cool down the first heat transfer medium flowing in the cooling passage of the cooling system of the fuel cell after the fuel cell is normally operated for a certain period of time. In other words, the first heat transfer medium can be used both for heating and for cooling the fuel cell stack of the fuel cell.

As shown in fig. 1 to 3 of the drawings, the starting system for a fuel cell according to the embodiment of the present invention further includes an air temperature detector or temperature sensor 61 disposed at the exhaust port 602 of the heater 60, wherein the air temperature sensor 61 is configured to detect the temperature of the second heat transfer medium flowing through the exhaust port 602 of the heater 60, and wherein the control module 10 is further configured to control the opening of the hydrogen control valve and the air control valve 90 to supply hydrogen and air to the fuel cell stack of the fuel cell (or to provide a fuel cell start signal) when the temperature of the second heat transfer medium flowing through the exhaust port 602 of the heater 60 is not less than a start exhaust temperature value T row. It is understood that the compression ratio of the air by the air compressor 71, the heat exchange efficiency between the first heat transfer medium and the air flowing in the heating chamber 600, the temperature T2 of the first heat transfer medium flowing through the second opening 302 determine the temperature of the second heat transfer medium at the discharge port 602 of the heater 60. Thus, for a particular fuel cell, the compression ratio of air by the air compressor 71 determines the magnitude of the start exhaust temperature value Trow.

It is noted that the control module 10 is further configured to control to increase the rotation speed of the fluid pump 50 to increase the heating efficiency of the fuel cell stack of the fuel cell when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating passage 30 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating passage 30 is greater than a heating temperature difference. A greater difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating channel 30 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating channel 30 means that at least part of the internal structure of the fuel cell stack of the fuel cell is still cooler through at least one heating cycle of the first heat transfer medium, and needs to be strengthened, at least to maintain the heating of the fuel cell stack of the fuel cell. Alternatively, the heating of the fuel cell may also be enhanced by controlling to increase the flow rate of the second heat transfer medium flowing within the heating chamber 600 of the heater 60, or to increase the temperature of the second heat transfer medium. For example, the compression ratio of the compressed air is increased to achieve enhanced heating of the fuel cell stack of the fuel cell. However, by controlling the rotational speed of the fluid pump 50 to be increased, the heating of the fuel cell stack of the fuel cell is enhanced in such a manner that the flow rate of the first heat transfer medium in the heat exchange path 300 is increased, and the fuel cell stack is made more gentle. In particular, the proton exchange membrane is not easy to damage.

As shown in fig. 1 to 4B of the drawings, according to an embodiment of the present invention, the present invention further provides a heating device for a fuel cell, which is used to heat a fuel cell stack of the fuel cell and enable the fuel cell to start and operate smoothly even in a low temperature environment when an ambient temperature is too low, wherein the heating device for a fuel cell comprises a control module or start control module 10, at least one ambient temperature sensor 20, a heating channel 30, a first pipeline 40, a fluid pump 50 and a heater 60, wherein the ambient temperature sensor 20 is configured to be electrically connected to the control module 10, so that the control module 10 can receive temperature data generated by the ambient temperature sensor 20, the control module 10 is configured to control the ambient temperature sensor 20 to detect a temperature of an environment where the fuel cell is located according to an ambient temperature detection command, the heating channel 30 is disposed between flow field plates of the fuel cell (or a fuel cell stack thereof) to heat the flow field plates of the fuel cell stack of the fuel cell, wherein the heating channel 30 has a first opening 301 and a second opening 302, both ends of the first pipe 40 are respectively communicated with the first opening 301 and the second opening 302 of the heating channel 30, so that the first pipe 40 and the heating channel 30 form a heat exchange passage 300 allowing a first heat transfer medium to flow therein, wherein the fluid pump 50 is disposed at the heat exchange passage 300, the heater 60 has a heating chamber 600, wherein the heating chamber 600 is disposed around the first pipe 40 to enable a second heat transfer medium flowing in the heating chamber 600 to exchange heat with the first heat transfer medium flowing in the heat exchange passage 300, wherein the control module 10 is further electrically connected with the fluid pump 50, and the control module 10 is configured to control the fluid pump 50 to rotate when the ambient temperature detected by the ambient temperature sensor 20 is lower than a preset ambient temperature, so as to drive the first heat transfer medium to circulate in the heat exchange path 300. Preferably, the temperature of the first heat transfer medium is less than the temperature of the second heat transfer medium. As shown in fig. 1 to 3 of the drawings, more preferably, the fluid pump 50 is configured to drive the first heat transfer medium to flow out from the first opening 301 of the heating channel 30, flow in from the second opening 302 of the heating channel 30, and further flow out from the first opening 301 of the heating channel 30 after the first pipeline 40 is heat-exchanged and heated with the heater 60. Accordingly, the first opening 301 of the heating channel 30 forms an outlet of the first heat transfer medium of the heating channel 30, and the second opening 302 of the heating channel 30 forms an inlet of the first heat transfer medium of the heating channel 30. Optionally, the fluid pump 50 is configured to drive the first heat transfer medium out of the second opening 302 of the heating channel 30 and in from the first opening 301 of the heating channel 30.

As shown in fig. 1 to 4B of the drawings, according to an embodiment of the present invention, the present invention further provides a heating assembly for a fuel cell, comprising a heating channel 30, a first pipe 40, a fluid pump 50 and a heater 60, wherein the heating channel 30 is disposed between flow field plates of a fuel cell stack of the fuel cell to heat the flow field plates of the fuel cell stack of the fuel cell, wherein the heating channel 30 has a first opening 301 and a second opening 302, both ends of the first pipe 40 are respectively communicated with the first opening 301 and the second opening 302 of the heating channel 30, so that the first pipe 40 and the heating channel 30 form a heat exchange passage 300 allowing a first heat transfer medium to flow therein, wherein the fluid pump 50 is disposed in the heat exchange passage 300, the heater 60 has a heating cavity 600, wherein the heating chamber 600 is arranged around the first pipe 40 to enable the second heat transfer medium flowing in the heating chamber 600 to exchange heat with the first heat transfer medium flowing in the heat exchange path 300, wherein the fluid pump 50 is arranged to drive the first heat transfer medium to circulate in the heat exchange path 300. The heating assembly for a fuel cell of the present invention further includes an exhaust pipe, wherein the exhaust pipe is communicated with the exhaust port 602 of the heater 60 to enable the second heat transfer medium (e.g., air) flowing through the heating chamber 600 of the heater 60 to be exhausted.

As shown in fig. 1 to 4B of the drawings, according to an embodiment of the present invention, the present invention further provides a starting method for a fuel cell, which includes the following steps:

(a) detecting the temperature of the environment in which the fuel cell is located; and

(b) if the temperature of the environment in which the fuel cell is located is below a predetermined ambient temperature, a first heat transfer medium is driven to flow in a first predetermined direction in a heat exchange channel 300, and a second heat transfer medium is driven to flow in a second predetermined direction in a heating chamber, wherein the heating chamber 600 is disposed around the heat exchange channel 300, the heat exchange channel 300 forming a heating channel 30 disposed between flow field plates of the fuel cell, wherein the temperature of the first heat transfer medium is less than the temperature of the second heat transfer medium. Preferably, the first heat transfer medium is a liquid such as water, an aqueous solution, or a mixed solution of water. Optionally, the first heat transfer medium is a gaseous substance. The second heat transfer medium is a gas such as air, or other suitable substance.

As shown in fig. 1 to 4B of the accompanying drawings, before the fuel cell is started to operate and generate power, the temperature of the environment where the fuel cell is located is automatically detected according to a self-test instruction or an ambient temperature detection instruction, so as to prevent the fuel cell from failing to start or not preheating, i.e., starting to operate and generate power under a low-temperature environment, and therefore, the stable power output of the fuel cell is affected, the response to the power consumption of a load is slow, and even the service life of the fuel cell is prolonged. If the temperature of the environment in which the fuel cell is located is detected to be below a predetermined ambient temperature, a first heat transfer medium is driven to flow in a first predetermined direction in a heat exchange channel 300, and a second heat transfer medium is driven to flow in a second predetermined direction in a heating chamber 600, wherein the heating chamber 600 is arranged around the heat exchange channel 300, the heat exchange channel 300 forming a heating channel 30 arranged between flow field plates of the fuel cell, wherein the temperature of the first heat transfer medium is lower than the temperature of the second heat transfer medium. In other words, if the temperature of the environment in which the fuel cell is located is lower than the preset ambient temperature, the starting method for the fuel cell of the present invention will heat the first heat transfer medium flowing in the heat exchange path of the fuel cell through the second heat transfer medium having a higher temperature, so that the first heat transfer medium can heat the fuel cell.

As shown in fig. 1 to 4B of the accompanying drawings, when the fuel cell is heated for an appropriate time, the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating passage 30 of the heat exchange passage 300 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating passage 30 are further detected, and if the difference between the temperature T1 and the temperature T2 is greater than a heating temperature difference, the flow rate of the first heat transfer medium flowing in the heat exchange passage 300 is increased to enhance the heating of the fuel cell. Generally speaking. When the difference between the temperature T1 and the temperature T2 is large, it reflects uneven heating of the first heat transfer medium in the heat exchange path 300 or low internal temperature of the fuel cell stack of the fuel cell. In order to ensure uniform temperature inside the fuel cell stack of the fuel cell and that the temperature of the fuel cell stack is heated to a suitable temperature, the heating of the fuel cell should be enhanced, at least the heating of the fuel cell should be maintained. Alternatively, the heating of the fuel cell may also be enhanced by controlling to increase the flow rate of the second heat transfer medium flowing within the heating chamber 600 of the heater 60, or to increase the temperature of the second heat transfer medium. For example, by increasing the compression ratio of the compressed air, enhanced heating of the fuel cell stack of the fuel cell is achieved. Preferably, the present invention enhances heating of the fuel cell by increasing the flow rate of the first heat transfer medium flowing within the heat exchange path 300. By controlling the rotational speed of the fluid pump 50 to be increased, the flow rate of the first heat transfer medium in the heat exchange path 300 is increased, thereby enhancing the heating of the fuel cell stack of the fuel cell, and making the fuel cell stack more mild. In particular, the proton exchange membrane is not easy to damage. Finally, when the second heat transfer medium (air) is heated or pressurized by compressing air with the air compressor to increase the flow rate or temperature of the second heat transfer medium, the energy consumed by the air compressor will increase greatly, and the increase of the flow rate of the first heat transfer medium in the heat exchange passage 300 is increased, especially when the first heat transfer medium is liquid, for example, when the first heat transfer medium is water, aqueous solution or mixed liquid of water, the increase of the energy consumed by the fluid pump is relatively small. Therefore, by increasing the flow rate of the first heat transfer medium in the heat exchange path 300, intensive heating of the fuel cell stack of the fuel cell is achieved, and it is also possible to consume less energy.

Therefore, preferably, the starting method for the fuel cell of the present invention further comprises the following steps:

(c) further detecting the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating passage 30 of the heat exchange passage 300 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating passage 30; and

(d) if the difference between the temperature T1 and the temperature T2 is greater than a heating temperature difference, the flow rate of the first heat transfer medium flowing within the heat exchange passage 300 is increased.

Optionally, the present invention provides a starting method for a fuel cell, further comprising the steps of:

(f) if the difference between the temperature T1 and the temperature T2 is greater than a heating temperature difference, the flow rate of the second heat transfer medium flowing within the heating chamber 600 is increased.

(g) if the difference between the temperature T1 and the temperature T2 is greater than a heating temperature difference, the temperature of the second heat transfer medium flowing within the heating chamber 600 is increased.

As shown in fig. 1 to 4B of the drawings, after the fuel cell is heated for an appropriate time, the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating passage 30 of the heat exchange passage and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating passage 30 are further detected, and if the difference between the temperature T1 and the temperature T2 is not greater than a heating temperature difference, the control stops the flow of the second heat transfer medium in the heating chamber to stop the heating of the fuel cell. Generally speaking. A smaller difference between the temperature T1 and the temperature T2 reflects less heat exchange between the first heat transfer medium in the heat exchange path and the fuel cell stack of the fuel cell, a higher stack internal temperature of the fuel cell, or at least a smaller temperature difference from the first heat transfer medium. At this time, the temperature of the fuel cell stack of the fuel cell may be regarded as satisfying the temperature requirement for starting the operation to generate electricity. Preferably, the start-up temperature difference is between 0 ℃ and 15 ℃. More preferably, the start-up temperature difference is between 0 ℃ and 5 ℃.

(c) further detecting the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating channel 30 of the heat exchange passage and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating channel 30; and

(h) if the difference between the temperature T1 and the temperature T2 is not greater than a start temperature difference, control stops the flow of the second heat transfer medium in the heating chamber.

Alternatively, it is also possible to determine whether the temperature of the fuel cell stack of the fuel cell can satisfy the temperature requirement for starting operation to generate electricity by detecting the temperature of the second heat transfer medium flowing through the discharge port of the heating chamber. For example, it may be controlled to stop the flow of the second heat transfer medium in the heating chamber when the temperature T of the second heat transfer medium flowing through the discharge opening of the heating chamber is not less than a start-up exhaust air temperature value tset. If the temperature T is high, it means that the heat exchange between the second heat transfer medium and the first heat transfer medium is small, at which time, it can be regarded that the temperature of the fuel cell stack of the fuel cell has satisfied the temperature requirement for starting operation to generate electricity.

Therefore, optionally, the starting method for the fuel cell of the present invention further comprises the following steps:

(m) further detecting a temperature of the second heat transfer medium flowing through the exhaust port of the fuel cell; and

(n) controlling to stop the flow of the second heat transfer medium in the heating chamber if the temperature T of the second heat transfer medium flowing through the outlet port of the second heat transfer medium is not less than a start-up exhaust temperature value tsel.

Referring to fig. 5 to 8 of the drawings, an alternative implementation of a starting system for a fuel cell according to an embodiment of the present invention is illustrated, wherein the starting system for a fuel cell of the present invention includes a control module or starting control module 10, at least one ambient temperature sensor 20, a heating channel 30, a first pipeline 40, a fluid pump 50 and a heater 60A, wherein the ambient temperature sensor 20 is configured to be electrically connected with the control module 10, so that the control module 10 can receive temperature data generated by the ambient temperature sensor 20, the control module 10 is configured to control the ambient temperature sensor 20 to detect the temperature of the environment where the fuel cell is located according to an ambient temperature detection command, the heating channel 30 is configured between flow field plates of the fuel cell (or a fuel cell stack thereof), to heat flow field plates of a fuel cell stack of a fuel cell, wherein the heating channel 30 has a first opening 301 and a second opening 302, both ends of the first pipeline 40 are respectively communicated with the first opening 301 and the second opening 302 of the heating channel 30, so that the first pipe 40 and the heating channel 30 form a heat exchange path 300 allowing a first heat transfer medium to flow therein, wherein the fluid pump 50 is disposed at the heat exchanging path 300, the heater 60A is disposed at the first pipe 40, wherein the control module 10 is further configured to control the rotation of the fluid pump 50 when the ambient temperature is less than a predetermined ambient temperature, thereby driving the first heat transfer medium to circulate in the heat exchange path 300, and controlling the heater 60A to operate to heat the first heat transfer medium flowing in the heat exchange path 300. Preferably, the heater 60A is an electric heater. Accordingly, the electric heater 60A heats the first pipe 41 of the first pipe 40 by means of a heating wire or plate, thereby heating the first heat transfer medium flowing in the first pipe 40. As shown in fig. 5 to 7 of the drawings, more preferably, the fluid pump 50 is configured to drive the first heat transfer medium to flow out from the first opening 301 of the heating channel 30, flow in from the second opening 302 of the heating channel 30, and further flow out from the first opening 301 of the heating channel 30 after the first pipeline 40 is heat-exchanged and heated with the heater 60A. Accordingly, the first opening 301 of the heating channel 30 forms an inlet for the first heat transfer medium of the heating channel 30, and the second opening 302 of the heating channel 30 forms an outlet for the first heat transfer medium of the heating channel 30. Optionally, the fluid pump 50 is configured to drive the first heat transfer medium out of the second opening 302 of the heating channel 30 and in from the first opening 301 of the heating channel 30.

As shown in fig. 5 to 7 of the drawings, an alternative implementation of the starting system for a fuel cell according to the embodiment of the present invention further includes a hydrogen control valve for controlling the supply of hydrogen to the fuel cell stack of the fuel cell and an air control valve 90 for controlling the supply of air to the fuel cell stack of the fuel cell, wherein the control module 10 is electrically connected to the hydrogen control valve and the air control valve 90, respectively, wherein the control module 10 is configured to control the opening of the hydrogen control valve and the air control valve 90 to supply hydrogen and air to the fuel cell stack when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is not greater than a starting temperature difference. Preferably, the control module 10 controls to close the second pipe 72 that supplies the compressed air to the heater 60A when the hydrogen control valve and the air control valve 90 are opened to supply hydrogen and air to the fuel cell stack of the fuel cell. Optionally, the control module 10 is configured to provide a fuel cell activation signal when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is not greater than a start-up temperature difference, such that an upper computer or controller controlling the operation of the fuel cell can control the activation of the fuel cell, for example, the supply of hydrogen and air to a fuel cell stack of the fuel cell.

It is noted that the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 reflects the temperature of the fuel cell stack of the fuel cell relative to the temperature T1 of the first heat transfer medium flowing through the first opening 301. Therefore, when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is small, it means that the temperature of the fuel cell stack of the fuel cell is high. In practical applications, a fuel cell stack composed of a smaller number of fuel cells can be considered to have been heated to a temperature suitable for start-up when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is less than 5 ℃. In a complex fuel cell stack with more fuel cells, the temperature of the fuel cell stack of the fuel cell may be considered to have been heated to a temperature suitable for start-up when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 is higher, for example, 15 ℃. Therefore, the utility model discloses the start-up temperature difference is preferred 0 ℃ -15 ℃. More preferably, the utility model discloses the start temperature difference is 0 ℃ -5 ℃. Further, the control module 10 is configured to control to increase the rotation speed of the fluid pump 50 to increase the heating efficiency of the fuel cell stack of the fuel cell when the difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating passage 30 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating passage 30 is greater than a heating temperature difference. A greater difference between the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating channel 30 and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating channel 30 means that at least part of the internal structure of the fuel cell stack of the fuel cell is still cooler through at least one heating cycle of the first heat transfer medium, and needs to be strengthened, at least to maintain the heating of the fuel cell stack of the fuel cell. Alternatively, the heating of the fuel cell may be intensified by increasing the output power of the heater 60A. However, by controlling the rotational speed of the fluid pump 50 to be increased, the heating of the fuel cell stack of the fuel cell is intensified in such a way that the flow rate of the first heat transfer medium in the heat exchange path is increased, which makes the fuel cell stack more gentle. In particular, the proton exchange membrane is not easy to damage.

As shown in fig. 5 to 8 of the drawings, according to an embodiment of the present invention, the present invention further provides a heating device for a fuel cell, which heats a fuel cell stack of the fuel cell and enables the fuel cell to start and operate smoothly even in a low temperature environment when an ambient temperature is too low, wherein the heating device for a fuel cell comprises a control module or start control module 10, at least one ambient temperature sensor 20, a heating channel 30, a first pipeline 40, a fluid pump 50 and a heater 60A, wherein the ambient temperature sensor 20 is configured to be electrically connected to the control module 10, so that the control module 10 can receive temperature data generated by the ambient temperature sensor 20, the control module 10 is configured to control the ambient temperature sensor 20 to detect a temperature of an environment where the fuel cell is located according to an ambient temperature detection command, the heating channel 30 is disposed between flow field plates of the fuel cell (or a fuel cell stack thereof) to heat the flow field plates of the fuel cell stack of the fuel cell, wherein the heating channel 30 has a first opening 301 and a second opening 302, two ends of the first pipe 40 are respectively communicated with the first opening 301 and the second opening 302 of the heating channel 30, so that the first pipe 40 and the heating channel 30 form a heat exchange passage 300 allowing a first heat transfer medium to flow therein, wherein the fluid pump 50 is disposed in the heat exchange passage 300, the heater 60A is disposed in the first pipe 40, wherein the control module 10 is further configured to control the fluid pump 50 to rotate when an ambient temperature is lower than a preset ambient temperature, so as to drive the first heat transfer medium to circulate in the heat exchange passage 300, and controlling the heater 60A to operate to heat the first heat transfer medium flowing in the heat exchange path 300. As shown in fig. 5 to 7 of the drawings, more preferably, the fluid pump 50 is configured to drive the first heat transfer medium to flow out from the first opening 301 of the heating channel 30, flow in from the second opening 302 of the heating channel 30, and further flow out from the first opening 301 of the heating channel 30 after the first pipeline 40 is heat-exchanged and heated with the heater 60A. Accordingly, the first opening 301 of the heating channel 30 forms an inlet for the first heat transfer medium of the heating channel 30, and the second opening 302 of the heating channel 30 forms an outlet for the first heat transfer medium of the heating channel 30. Optionally, the fluid pump 50 is configured to drive the first heat transfer medium out of the second opening 302 of the heating channel 30 and in from the first opening 301 of the heating channel 30.

As shown in fig. 5 to 8 of the drawings, according to an embodiment of the present invention, the present invention further provides another starting method for a fuel cell, which includes the following steps:

(b) driving a first heat transfer medium to flow in a first predetermined direction in a heat exchange channel if the temperature of the environment in which the fuel cell is located is below a predetermined ambient temperature, and controlling a heater to operate to heat the first heat transfer medium flowing in the heat exchange channel, wherein the heater is arranged around the heat exchange channel, wherein the heat exchange channel forms a heating channel 30 arranged between flow field plates of the fuel cell. Preferably, the first heat transfer medium is a liquid substance such as water, an aqueous solution, or a mixed solution of water.

As shown in fig. 5 to 8 of the attached drawings, before the fuel cell is started to operate and generate power, the temperature of the environment where the fuel cell is located is automatically detected according to a self-test instruction or an environment temperature detection instruction, so as to prevent the fuel cell from failing to start or not preheating, i.e. starting to operate and generate power under a low-temperature environment, and therefore, the stable power output of the fuel cell is influenced, the response to the power consumption of a load is slow, and even the service life of the fuel cell is prolonged. Driving a first heat transfer medium to flow in a first predetermined direction in a heat exchange channel if the temperature of the environment in which the fuel cell is located is detected to be below a predetermined ambient temperature, and controlling a heater to be activated to heat the first heat transfer medium flowing in the heat exchange channel, wherein the heater is arranged around the heat exchange channel, wherein the heat exchange channel forms a heating channel 30 arranged between flow field plates of the fuel cell. In other words, if the temperature of the environment where the fuel cell is located is lower than the preset ambient temperature, the start-up method for the fuel cell of the present invention will heat the first heat transfer medium flowing in the heat exchange path of the fuel cell by the heater, so that the first heat transfer medium can heat the fuel cell.

As shown in fig. 5 to 8 of the drawings, when the fuel cell is heated for an appropriate time, the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating passage 30 of the heat exchange passage and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating passage 30 are further detected, and if the difference between the temperature T1 and the temperature T2 is greater than a heating temperature difference, the flow rate of the first heat transfer medium flowing in the heat exchange passage is increased to enhance the heating of the fuel cell. Generally speaking. When the difference between the temperature T1 and the temperature T2 is large, the uneven heating of the first heat transfer medium in the heat exchange path or the internal temperature of the fuel cell stack of the fuel cell is reflected to be low. In order to ensure uniform temperature inside the fuel cell stack of the fuel cell and that the temperature of the fuel cell stack is heated to a suitable temperature, the heating of the fuel cell should be enhanced, at least the heating of the fuel cell should be maintained. Alternatively, the heating of the fuel cell may be enhanced by increasing the output of the heater. Preferably, the present invention enhances heating of the fuel cell by increasing the flow rate of the first heat transfer medium flowing within the heat exchange path. The heating of the fuel cell stack of the fuel cell is enhanced by controlling the increase of the rotational speed of the fluid pump 50, thereby increasing the flow rate of the first heat transfer medium in the heat exchange path, which is more gentle to the fuel cell stack. In particular, the proton exchange membrane is not easy to damage.

(d) if the difference between the temperature T1 and the temperature T2 is greater than a heating temperature difference, the flow rate of the first heat transfer medium flowing within the heat exchange path is increased.

(f) if the difference between the temperature T1 and the temperature T2 is greater than a heating temperature difference, the output power of the heater is increased.

As shown in fig. 5 to 8 of the drawings, when the fuel cell is heated for an appropriate time, the temperature T1 of the first heat transfer medium flowing through the first opening 301 of the heating passage 30 of the heat exchange passage and the temperature T2 of the first heat transfer medium flowing through the second opening 302 of the heating passage 30 are further detected, and if the difference between the temperature T1 and the temperature T2 is not greater than a heating temperature difference, the control stops the heating of the fuel cell by the heater. Generally speaking. A smaller difference between the temperature T1 and the temperature T2 reflects less heat exchange between the first heat transfer medium in the heat exchange path and the fuel cell stack of the fuel cell, a higher stack internal temperature of the fuel cell, or at least a smaller temperature difference from the first heat transfer medium. At this time, the temperature of the fuel cell stack of the fuel cell may be regarded as satisfying the temperature requirement for starting the operation to generate electricity. Preferably, the start-up temperature difference is between 0 ℃ and 15 ℃. More preferably, the start-up temperature difference is between 0 ℃ and 5 ℃.

(h) if the difference between the temperature T1 and the temperature T2 is not greater than a startup temperature difference, control stops heating of the first heat transfer medium in the heat exchange path by the heater.

It will be understood by those skilled in the art that the embodiments of the present invention as described above and shown in the drawings are given by way of example only and are not limiting of the present invention.

The objects of the present invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the embodiments without departing from the principles, embodiments of the present invention may have any deformation or modification.

Claims

1. A heating assembly for a fuel cell, comprising:

2. The heating assembly of claim 1, further comprising at least one ambient temperature sensor, wherein the ambient temperature sensor is configured to detect a temperature of an environment in which the fuel cell is located.

3. The heating assembly of claim 1, further comprising an air compressor and a second conduit, wherein the second conduit is disposed between the air compressor and the air inlet of the heater such that compressed air generated by the air compressor can be provided to the heater.

4. The heating assembly of claim 2, further comprising an air compressor and a second conduit, wherein the second conduit is disposed between the air compressor and the air inlet of the heater such that compressed air generated by the air compressor can be provided to the heater.

5. A heating assembly as claimed in claim 3, further comprising an exhaust duct, wherein the exhaust duct is in communication with the exhaust outlet of the heater to enable exhaust of air flowing through the heating chamber of the heater.

6. A heating assembly as claimed in claim 4, further comprising an exhaust duct, wherein the exhaust duct is in communication with the exhaust outlet of the heater to enable exhaust of air flowing through the heating chamber of the heater.

7. The heating assembly of claim 1 wherein a direction of flow of the first heat transfer medium through the heat exchange pathway and a direction of flow of the second heat transfer medium through the heating chamber are different.

8. The heating assembly of claim 6 wherein the direction of flow of the first heat transfer medium through the heat exchange pathway and the direction of flow of the second heat transfer medium through the heating chamber are different.

9. A heating assembly for a fuel cell, comprising:

at least one heater, wherein the heater is disposed in the first conduit.

10. The heating assembly of claim 9, further comprising at least one ambient temperature sensor, wherein the ambient temperature sensor is configured to detect a temperature of an environment in which the fuel cell is located.