Fuel cell cogeneration system and control method thereof

Abstract

The application discloses a fuel cell combined heat and power system and a control method thereof. The control method comprises the following steps: determining a target adjustment amount which does not meet a corresponding outlet temperature threshold value from an outlet temperature of a hot side of a first heat exchanger and an outlet temperature of a cold side of the first heat exchanger, and determining the corresponding outlet temperature threshold value as a target outlet temperature threshold value; determining a feedback flow value of the cold side of the first heat exchanger based on the target adjustment amount and the target outlet temperature threshold value; determining a feedforward flow value of the cold side of the first heat exchanger based on a thermal model of the first heat exchanger; correcting the feedforward flow value based on the feedback flow value to obtain a target flow value of the cold side of the first heat exchanger; and controlling the flow of the cold side of the first heat exchanger based on the target flow value so that the target adjustment amount meets the target outlet temperature threshold value. Thus, the purpose of meeting power supply demand and heat supply demand can be achieved to a certain extent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of combined heat and power, and in particular to a fuel cell combined heat and power system and a control method thereof. BACKGROUND

[0002] Combined heat and power (CHP), refers to the simultaneous use of electrical and thermal energy generated by an energy source, thereby improving the efficiency of energy utilization. At present, the combined heat and power system can not only use traditional fuel engines or gas turbines, but also use renewable or semi-renewable energy. Compared with the combined heat and power system based on heat engines, the combined heat and power system based on fuel cells has higher efficiency, quieter operation process and simpler daily maintenance requirements.

[0003] The fuel cell combined heat and power system can simultaneously generate electricity and provide heat efficiently, which helps to reduce primary energy consumption, greenhouse gas emissions and air pollution. The main idea of the fuel cell combined heat and power system to recover heat energy is to use the cooling water (usually at 70-80℃) flowing out of the electric pile to exchange heat with the heat-using equipment to realize the utilization of heat energy. For example, the cooling water can be used to heat kitchen water, toilet water and other domestic water.

[0004] However, the conventional fuel cell combined heat and power system usually has a bias in the priority of heat supply and power supply. Either the power supply demand is prioritized, the outlet temperature of the heat exchanger hot end is stabilized to ensure the stable output power of the fuel cell. But it will cause the relatively poor stability of the outlet temperature of the heat exchanger cold end, and then affect the stability of heat supply. In order to meet the heat demand of the heat-using equipment, other heat supply equipment is usually needed to compensate for the heat demand of the heat-using equipment, which will increase the investment cost and use cost. Or the heat supply demand is prioritized, but it is easy to appear the condition of frequently adjusting the output power of the fuel cell, which affects the service life of the fuel cell. Therefore, the conventional fuel cell combined heat and power system needs to be improved in terms of meeting the power supply demand and the heat supply demand. SUMMARY

[0005] In view of the above problems existing in the prior art, the present application provides a control method of a fuel cell combined heat and power system and a fuel cell combined heat and power system.

[0006] The first aspect of the application provides a control method of a fuel cell combined heat and power system, the fuel cell combined heat and power system comprising a fuel cell, a first heat exchange assembly and a second heat exchange assembly; the first heat exchange assembly comprising a first heat exchanger, a hot side of the first heat exchanger being connected with the fuel cell to form a first heat exchange loop, the second heat exchange assembly comprising a second heat exchanger, a hot side of the second heat exchanger being connected with a cold side of the first heat exchanger to form a second heat exchange loop, the cold side of the second heat exchanger being configured to be connected with a heat-using device; the method comprising:

[0007] determining a target adjustment amount that does not meet a corresponding outlet temperature threshold from the outlet temperature of the hot side of the first heat exchanger and the outlet temperature of the cold side of the first heat exchanger, and determining the corresponding outlet temperature threshold as a target outlet temperature threshold;

[0008] determining a feedback flow value of the cold side of the first heat exchanger based on the target adjustment amount and the target outlet temperature threshold;

[0009] determining a feedforward flow value of the cold side of the first heat exchanger based on a thermodynamic model of the first heat exchanger; wherein the thermodynamic model is capable of characterizing heat exchange characteristics of the first heat exchanger;

[0010] correcting the feedforward flow value based on the feedback flow value to obtain a target flow value of the cold side of the first heat exchanger;

[0011] controlling the flow of the cold side of the first heat exchanger based on the target flow value, so that the target adjustment amount meets the target outlet temperature threshold.

[0012] In some embodiments, the determining of the feedforward flow value of the cold side of the first heat exchanger based on the thermodynamic model of the first heat exchanger comprises:

[0013] determining the feedforward flow value of the cold side of the first heat exchanger based on the inlet temperature of the hot side of the first heat exchanger, the inlet temperature of the cold side of the first heat exchanger and the target outlet temperature threshold using the thermodynamic model.

[0014] In some embodiments, the first heat exchange assembly further comprises a radiator connected between an inlet of the fuel cell and an outlet of the hot side of the first heat exchanger; the control method further comprises:

[0015] determining a target heat dissipation power of the radiator based on the outlet temperature of the hot side of the first heat exchanger;

[0016] controlling the radiator to dissipate heat of the heat exchange medium output by the hot side of the first heat exchanger based on the target heat dissipation power.

[0017] In some embodiments, the determining, from the outlet liquid temperature of the first heat exchanger hot side and the outlet liquid temperature of the first heat exchanger cold side, a target adjustment amount that does not meet a corresponding outlet liquid temperature threshold, and determining the corresponding outlet liquid temperature threshold as a target outlet liquid temperature threshold, comprises:

[0018] In a case where the outlet liquid temperature of the first heat exchanger cold side does not meet the corresponding outlet liquid temperature threshold, determining the outlet liquid temperature of the first heat exchanger cold side as the target adjustment amount, and determining the corresponding outlet liquid temperature threshold as the target outlet liquid temperature threshold.

[0019] In a case where the outlet liquid temperature of the first heat exchanger cold side meets the corresponding outlet liquid temperature threshold, and the outlet liquid temperature of the first heat exchanger hot side does not meet the corresponding outlet liquid temperature threshold, determining the outlet liquid temperature of the first heat exchanger hot side as the target adjustment amount, and determining the outlet liquid temperature threshold of the first heat exchanger hot side as the target outlet liquid temperature threshold.

[0020] In some embodiments, the determining, based on the thermodynamic model of the first heat exchanger, a feedforward flow value of the first heat exchanger cold side, comprises:

[0021] In a case where the target adjustment amount is the outlet liquid temperature of the first heat exchanger cold side, determining, by the thermodynamic model, the feedforward flow value of the first heat exchanger cold side based on the inlet liquid temperature of the first heat exchanger hot side, the inlet liquid temperature of the first heat exchanger cold side, and the outlet liquid temperature threshold of the first heat exchanger cold side.

[0022] In some embodiments, the determining, based on the thermodynamic model of the first heat exchanger, a feedforward flow value of the first heat exchanger cold side, comprises:

[0023] In a case where the target adjustment amount is the outlet liquid temperature of the first heat exchanger hot side, determining, by the thermodynamic model, a predicted outlet liquid temperature of the first heat exchanger cold side and a first predicted flow value based on the inlet liquid temperature of the first heat exchanger hot side, the inlet liquid temperature of the first heat exchanger cold side, and the outlet liquid temperature threshold of the first heat exchanger hot side.

[0024] In a case where the predicted outlet liquid temperature of the first heat exchanger cold side meets the outlet liquid temperature threshold of the first heat exchanger cold side, taking the first predicted flow value as the feedforward flow value.

[0025] In some embodiments, the determining, based on the thermodynamic model of the first heat exchanger, a feedforward flow value of the first heat exchanger cold side, further comprises:

[0026] In a case where the predicted outlet temperature of the cold side of the first heat exchanger does not meet the outlet temperature threshold of the cold side of the first heat exchanger, the thermal model determines a second predicted flow value of the cold side of the first heat exchanger based on the inlet temperature of the hot side of the first heat exchanger, the inlet temperature of the cold side of the first heat exchanger, and the outlet temperature threshold of the cold side of the first heat exchanger, and takes the second predicted flow value as the feedforward flow value.

[0027] In some embodiments, the thermal model is constructed by the following formula:

[0028]

[0029] wherein W h represents the flow value of the hot side of the first heat exchanger; W c represents the flow value of the cold side of the first heat exchanger; C p,h represents the specific heat capacity of the heat exchange medium of the hot side of the first heat exchanger; C p,c represents the specific heat capacity of the heat exchange medium of the cold side of the first heat exchanger; T h,in represents the inlet temperature of the hot side of the first heat exchanger; T h,out represents the outlet temperature of the hot side of the first heat exchanger; T c,out represents the outlet temperature of the cold side of the first heat exchanger; T c,in represents the inlet temperature of the cold side of the first heat exchanger; q represents the heat exchange heat; h represents the heat exchange coefficient of the first heat exchanger; A represents the heat exchange area of the first heat exchanger; ΔT m represents the logarithmic temperature difference, ΔT m = (T h,in -T c,out -T h,out +T c,in ) / ln((T h,in -T c,out ) / (T h,out -T c,in ).

[0030] The second embodiment of the present application provides a fuel cell combined heat and power system, comprising:

[0031] a fuel cell;

[0032] a first heat exchange assembly comprising a first heat exchanger and a first liquid pump; the hot side of the first heat exchanger is connected with the fuel cell to form a first heat exchange circuit; the first liquid pump is arranged in the first heat exchange circuit to provide power for the flow of heat exchange medium in the first heat exchange circuit;

[0033] a second heat exchange assembly, comprising a second heat exchanger and a second liquid pump; the second heat exchanger is connected with the first heat exchanger to form a second heat exchange loop, and the cold side of the second heat exchanger is used to be connected with a heat using device; the second liquid pump is arranged in the second heat exchange loop and can at least provide power for the flow of the heat exchange medium in the cold side of the first heat exchanger;

[0034] a controller connected with the first liquid pump and the second liquid pump respectively, and the controller is configured to:

[0035] determining a target adjustment amount that does not meet a corresponding outlet temperature threshold value from the outlet temperature of the first heat exchanger and the outlet temperature of the cold side of the first heat exchanger, and determining the corresponding outlet temperature threshold value as a target outlet temperature threshold value;

[0036] determining a feedback flow value of the cold side of the first heat exchanger based on the target adjustment amount and the target outlet temperature threshold value;

[0037] determining a feedforward flow value of the cold side of the first heat exchanger based on a thermal model of the first heat exchanger, wherein the thermal model can represent the heat exchange characteristics of the first heat exchanger;

[0038] correcting the feedforward flow value based on the feedback flow value to obtain a target flow value of the cold side of the first heat exchanger;

[0039] controlling the liquid flow of the second liquid pump based on the target flow value, so that the target adjustment amount meets the target outlet temperature threshold value.

[0040] In some embodiments, the first heat exchange assembly further comprises a radiator connected between the liquid inlet of the fuel cell and the liquid outlet of the hot side of the first heat exchanger; and the controller is further configured to:

[0041] determining a target heat dissipation power of the radiator based on the outlet temperature of the hot side of the first heat exchanger;

[0042] controlling the radiator to dissipate heat from the heat exchange medium output by the hot side of the first heat exchanger based on the target heat dissipation power.

[0043] The control method of the fuel cell combined heat and power system can maintain the outlet temperature of the cold side of the first heat exchanger and the outlet temperature of the hot side of the first heat exchanger around the corresponding outlet temperature threshold value, keep the inlet temperature of the heat exchange medium of the fuel cell stable, and thus benefit the stability of the power generation of the fuel cell, prolong the service life of the fuel cell, meet the demand of the heat using device for the heat using temperature, and achieve the purpose of meeting the power supply demand and the heat supply demand to a certain extent. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 Flow chart of a control method for a fuel cell cogeneration system according to a first embodiment of the present application;

[0045] Figure 2 Flow chart of another part of a control method for a fuel cell cogeneration system according to a first embodiment of the present application;

[0046] Figure 3a Flow chart of a part of a control method for a fuel cell cogeneration system according to a second embodiment of the present application;

[0047] Figure 3b Flow chart of another part of a control method for a fuel cell cogeneration system according to a second embodiment of the present application;

[0048] Figure 4 Schematic diagram of a fuel cell cogeneration system according to a third embodiment of the present application. DETAILED DESCRIPTION

[0049] Various aspects and features of the present application are described herein with reference to the accompanying drawings.

[0050] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the foregoing description should not be construed to limit the application, but merely to exemplify the embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the application.

[0051] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments of the present application and, together with the general description of the application given above, and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0052] These and other characteristics, features and advantages of the present application will become apparent from the following description, taken with the accompanying drawings, wherein:

[0053] It should also be understood that, although the terms "first" and "second" can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element being described could be termed a second element, and, similarly, a second element can be termed a first element, without changing the meaning of the description.

[0054] The above and other aspects, features and advantages of the present application will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings, when understood in conjunction with the following detailed description.

[0055] Specific embodiments of the application are described herein with reference to the accompanying drawings. However, it will be understood that the application is not limited to these embodiments, but can be practiced with modification and alteration within the scope of the appended claims. Similarly, where specific details of structures and / or functions are set forth in the foregoing description, it will be appreciated that the application can be practiced without such specific details. Accordingly, the application is not limited to the embodiments described herein, but is to be practiced with the

[0056] The specification can use phrases such as "in one embodiment", "in another embodiment", "in yet another embodiment", or "in other embodiments", which can refer to one or more of the same or different embodiments of the application.

[0057] A first embodiment of the application provides a control method of a fuel cell combined heat and power system. Referring to FIG. 1, Figure 4 As shown, the fuel cell combined heat and power system can include a fuel cell 319, a first heat exchange assembly, and a second heat exchange assembly.

[0058] The first heat exchange assembly includes a first heat exchanger 317, and a hot side of the first heat exchanger 317 is connected to the fuel cell 319 to form a first heat exchange loop. Specifically, the fuel cell 319 can have an outlet and an inlet of a heat exchange medium. An inlet of the hot side of the first heat exchanger 317 can be connected to the outlet of the fuel cell 319, and an outlet of the hot side of the first heat exchanger 317 can be connected to the inlet of the fuel cell 319, so that the heat exchange medium can circulate between the fuel cell 319 and the first heat exchanger 317.

[0059] The second heat exchange assembly includes a second heat exchanger 323, and a hot side of the second heat exchanger 323 is connected to a cold side of the first heat exchanger 317 to form a second heat exchange loop, and a cold side of the second heat exchanger 323 is used to be connected to a heat-using device 331. Specifically, an inlet of the hot side of the second heat exchanger 323 can be connected to an outlet of the cold side of the first heat exchanger 317, and an outlet of the hot side of the second heat exchanger 323 can be connected to an inlet of the cold side of the first heat exchanger 317, so that the heat exchange medium can circulate between the first heat exchanger 317 and the second heat exchanger 323. It can be understood that the heat exchange medium in the first heat exchange loop and the second heat exchange loop can be the same or different.

[0060] The fuel cell 319 generates electric energy through reaction, and supplies heat energy to the heat-using device 331 through the first heat exchange assembly and the second heat exchange assembly. The types of the fuel cell 319 and the heat-using device 331 are not limited herein, and various types of fuel cells 319 and various types of heat-using devices 331 can be used in specific implementation. For example, the fuel cell 319 can supply electric energy to a living environment, an office environment or a power grid, and at the same time, the first heat exchange assembly and the second heat exchange assembly can heat living water such as kitchen water or bathroom water.

[0061] Figure 1 The flow chart of the control method of the fuel cell combined heat and power system is shown in FIG. 10, and the control method of the fuel cell combined heat and power system can specifically include the following steps. Figure 1

[0062] S110, determining a target adjustment amount that does not meet a corresponding outlet temperature threshold value from the outlet temperature of the hot side of the first heat exchanger and the outlet temperature of the cold side of the first heat exchanger, and determining the corresponding outlet temperature threshold value as a target outlet temperature threshold value.

[0063] Optionally, temperature sensors T3, T4, T5 and T6 can be arranged at the inlet of the hot side of the first heat exchanger, the outlet of the hot side of the first heat exchanger, the inlet of the cold side of the first heat exchanger and the outlet of the cold side of the first heat exchanger respectively, as shown in FIG. 2. Figure 1 The outlet temperature T h,out of the hot side of the first heat exchanger is detected by the temperature sensor T4, the outlet temperature T c,out of the cold side of the first heat exchanger is detected by the temperature sensor T6, and the outlet temperature T h,out of the hot side of the first heat exchanger and the outlet temperature T c,out of the cold side of the first heat exchanger are compared with corresponding temperature threshold values respectively to determine whether T h,out and T c,out meet the corresponding outlet temperature threshold values.

[0064] Optionally, the outlet temperature threshold value of the hot side of the first heat exchanger can include a lower limit temperature value T hmin of the hot side, an upper limit temperature value T hmax of the hot side and a target temperature value T hmin of the hot side between the lower limit temperature value T hmin and the upper limit temperature value T hmax of the hot side. When T hmax ∈ [T hmin , T hmax ], T hmin is the target temperature value of the hot side. ht h,out hmin hmaxIf the temperature meets the corresponding outlet temperature threshold, it can be determined that the outlet temperature of the hot side of the first heat exchanger meets the corresponding outlet temperature threshold; otherwise, it can be determined that the outlet temperature of the hot side of the first heat exchanger does not meet the corresponding outlet temperature threshold.

[0065] Optionally, the outlet liquid temperature threshold of the cold side of the first heat exchanger may include the target cold side temperature value T. ct When T c,out >T ct If the outlet temperature is within the specified range, it can be determined that the outlet temperature on the cold side of the first heat exchanger meets the corresponding outlet temperature threshold; otherwise, it can be determined that the outlet temperature on the cold side of the first heat exchanger does not meet the corresponding outlet temperature threshold. It is understood that the outlet temperature thresholds for the hot and cold sides of the first heat exchanger can be set according to actual needs. When the outlet temperature thresholds are different, the method for determining whether the outlet temperature meets the corresponding outlet temperature threshold may not be suitable.

[0066] Optionally, when the outlet liquid temperature T on the hot side of the first heat exchanger h,out The outlet liquid temperature T of the cold side of the first heat exchanger c,out If all values ​​meet the corresponding outlet temperature threshold, the current control logic can be maintained, and T can continue to be monitored. h,out and T c,out .

[0067] When the outlet liquid temperature T on the hot side of the first heat exchanger h,out The outlet liquid temperature T of the cold side of the first heat exchanger c,out If one of the two conditions meets the corresponding outlet temperature threshold, and the other does not, then T can be used. h,out and T c,out One of the values ​​that does not meet the corresponding outlet temperature threshold is determined as the target adjustment value, and the outlet temperature threshold corresponding to the target adjustment value is determined as the target outlet temperature threshold.

[0068] For example, when the outlet liquid temperature T on the hot side of the first heat exchanger h,out The liquid outlet temperature meets the threshold value of the hot side of the first heat exchanger, and the liquid outlet temperature T of the cold side of the first heat exchanger... c,out If the outlet liquid temperature does not meet the threshold value of the cold side of the first heat exchanger, T can be... c,out It is determined as the target adjustment amount.

[0069] When the outlet liquid temperature T on the hot side of the first heat exchanger h,out The outlet liquid temperature T of the cold side of the first heat exchanger c,out If none of the above conditions meet the corresponding outlet temperature threshold, it can be determined from T. h,out and T c,out Choose one from the options as the target adjustment variable. For example, T can be selected as the target adjustment variable. h,out and T c,outone of the temperature thresholds corresponding to the larger one of the target adjustment amount and the target outlet liquid temperature threshold as a target adjustment amount, or can be based on priority from T h,out and T c,out one of the temperature thresholds corresponding to the larger one of the target adjustment amount and the target outlet liquid temperature threshold as a target adjustment amount, or can be based on priority from T

[0070] It can be understood that in actual application, the target adjustment amount and the target outlet liquid temperature threshold can be re-determined in each or multiple adjustment periods.

[0071] S120, determining a feedback flow value of the cold side of the first heat exchanger based on the target adjustment amount and the target outlet liquid temperature threshold.

[0072] Optionally, a difference ΔTα between the target adjustment amount and the target outlet liquid temperature threshold can be determined, and the difference ΔTα can be taken as input data of a proportional-integral (PI) controller. The feedback flow value Wcb of the cold side of the first heat exchanger can be determined by the PI controller based on a proportional coefficient Kp, an integral coefficient Ki and the difference ΔTα. It can be understood that the feedback flow value Wcb can also be determined by other methods.

[0073] S130, determining a feedforward flow value of the cold side of the first heat exchanger based on a thermodynamic model of the first heat exchanger. The thermodynamic model can represent the heat exchange characteristics of the first heat exchanger.

[0074] Optionally, the thermodynamic model can be constructed in advance based on the heat exchange characteristics of the first heat exchanger, and the thermodynamic model can be a mathematical model. The inlet liquid temperature of the hot side of the first heat exchanger, the flow of the hot side of the first heat exchanger, the inlet liquid temperature of the cold side of the first heat exchanger and other parameters can be taken as input data of the thermodynamic model, and the feedforward flow value Wcf of the cold side of the first heat exchanger can be determined by the thermodynamic model.

[0075] S140, correcting the feedforward flow value based on the feedback flow value to obtain a target flow value of the cold side of the first heat exchanger.

[0076] Optionally, the feedforward flow value can be taken as a basic amount of the cold side of the first heat exchanger, and the feedback flow value can be taken as an adjustment amount of the cold side of the first heat exchanger. Based on the determination of the feedback flow value and the feedforward flow value, the feedback flow value can be used to correct the feedforward flow value to generate the target flow value of the cold side of the first heat exchanger.

[0077] Optionally, the target flow value of the cold side of the first heat exchanger can be determined based on the following formula:

[0078] Wc=Wcf+Wcb(1).

[0079] Wherein, Wc represents the target flow rate value on the cold side of the first heat exchanger; Wcf represents the feedforward flow rate value; and Wcb represents the feedback flow rate value.

[0080] S150, based on the target flow rate value, control the flow rate on the cold side of the first heat exchanger so that the target adjustment amount meets the target outlet temperature threshold.

[0081] Optionally, a first infusion pump may be provided on the first heat exchange circuit, which can be used to provide power for the flow rate of the heat exchange medium in the first heat exchange circuit. A second infusion pump may be provided on the second heat exchange circuit, which is at least used to provide power for the flow of the heat exchange medium in the cold side of the first heat exchanger. Based on the determined target flow rate value, the power of the second infusion pump can be controlled based on the target flow rate value to regulate the flow rate on the cold side of the first heat exchanger, so as to achieve the purpose of regulating the outlet temperature of the cold side or the outlet temperature of the hot side of the first heat exchanger. Within the current regulation cycle, the target regulation amount can be made to tend to meet the target outlet temperature threshold. Through periodic cyclic regulation, the outlet temperature of both the cold side and the hot side of the first heat exchanger can be made to tend to meet the corresponding outlet temperature threshold.

[0082] The control method of the fuel cell cogeneration system in this application embodiment, through periodic cyclic adjustment, can maintain the outlet liquid temperature of the cold side and the outlet liquid temperature of the hot side of the first heat exchanger near the corresponding outlet liquid temperature threshold. This can keep the inlet liquid temperature of the heat exchange medium of the fuel cell stable, which is beneficial to maintaining the stable power generation of the fuel cell, extending the service life of the fuel cell, and meeting the heat-using equipment's heat-using temperature requirements. To a certain extent, it can achieve the goal of balancing power supply and heat supply requirements.

[0083] In some embodiments, the thermal model is constructed based on the following formula:

[0084]

[0085] Among them, W h This represents the flow rate on the hot side of the first heat exchanger; W c This indicates the flow rate on the cold side of the first heat exchanger; C p,h C represents the specific heat capacity of the heat exchange medium on the hot side of the first heat exchanger. p,c T represents the specific heat capacity of the heat exchange medium on the cold side of the first heat exchanger. h,in T represents the inlet liquid temperature on the hot side of the first heat exchanger. h,out T represents the outlet liquid temperature on the hot side of the first heat exchanger; c,out T represents the outlet liquid temperature on the cold side of the first heat exchanger. c,inThe inlet temperature of the cold side of the first heat exchanger is represented by q; the heat exchange volume is represented by h; the heat transfer coefficient of the first heat exchanger is represented by A; and the heat transfer area of ​​the first heat exchanger is represented by ΔT. m Represents the logarithmic temperature difference, ΔT m =(T h,in -T c,out -T h,out +T c,in ) / ln((T h,in -T c,out ) / (T h,out -T c,in ).

[0086] Optionally, the flow rate W on the hot side of the first heat exchanger h The flow rate W of the first heat exchanger can be detected by a flow sensor or determined based on the operating parameters of the first infusion pump. For example, the flow rate W on the hot side of the first heat exchanger can be determined based on the power or speed of the first infusion pump. h The inlet liquid temperature T on the hot side of the first heat exchanger can be detected by temperature sensor T3. h,in The inlet liquid temperature T on the cold side of the first heat exchanger can be detected by temperature sensor T5. c,in The target temperature T on the hot side of the first heat exchanger can be determined. ht The predicted flow rate and predicted outlet temperature of the cold side of the first heat exchanger are determined using a thermodynamic model, serving as the outlet temperature on the hot side. Alternatively, the target temperature T on the cold side of the first heat exchanger can be used. ct As the outlet liquid temperature on the cold side of the first heat exchanger, the predicted outlet liquid temperature on the hot side of the first heat exchanger and the predicted flow rate on the cold side of the first heat exchanger are determined by a thermodynamic model.

[0087] In some embodiments, step S130, determining the feedforward flow rate value on the cold side of the first heat exchanger based on the thermodynamic model of the first heat exchanger, may include the following steps.

[0088] The feedforward flow rate value of the cold side of the first heat exchanger is determined using the thermodynamic model based on the inlet liquid temperature on the hot side of the first heat exchanger, the inlet liquid temperature on the cold side of the first heat exchanger, and the target outlet liquid temperature threshold.

[0089] Based on the determination of the inlet liquid temperature on the hot side and the inlet liquid temperature on the cold side of the first heat exchanger, assuming that the outlet liquid temperature on the hot side of the first heat exchanger meets the corresponding temperature threshold, or assuming that the outlet liquid temperature on the cold side of the first heat exchanger meets the corresponding temperature threshold, the feedforward flow rate value on the hot side of the first heat exchanger is determined, and then the target flow rate value is determined. The determined target flow rate value is conducive to achieving the goal of the target adjustment amount meeting the target outlet liquid temperature threshold.

[0090] For example, if the target adjustment is the outlet liquid temperature on the cold side of the first heat exchanger, the target temperature value T on the cold side of the first heat exchanger can be... ct The outlet liquid temperature T of the first heat exchanger on the cold side in formula (2) c,out The predicted flow rate on the cold side of the first heat exchanger and the predicted outlet temperature on the hot side of the first heat exchanger are determined by a thermodynamic model.

[0091] For example, if the target adjustment is the outlet liquid temperature on the hot side of the first heat exchanger, the target temperature value T on the hot side of the first heat exchanger can be... ht The outlet liquid temperature T of the first heat exchanger on the hot side in formula (2) h,out The predicted flow rate and predicted outlet temperature of the cold side of the first heat exchanger are determined by a thermodynamic model.

[0092] Cooperate Figure 4 As shown, in some embodiments, the first heat exchange component further includes a radiator connected between the liquid inlet of the fuel cell and the liquid outlet on the hot side of the first heat exchanger. The radiator is used to dissipate heat and cool the heat exchange medium output by the first heat exchanger.

[0093] Based on this, in coordination Figure 2 As shown, the control method further includes the following steps.

[0094] S160, based on the outlet liquid temperature on the hot side of the first heat exchanger, determine the target heat dissipation power of the radiator.

[0095] S170, based on the target heat dissipation power, control the radiator to dissipate heat from the heat exchange medium output from the hot side of the first heat exchanger.

[0096] Optionally, the target hot-side temperature T of the first heat exchanger can be determined based on the target inlet temperature of the fuel cell and the heat loss characteristics of the pipeline. ht That is, the target temperature value T on the hot side. ht Pipeline losses have been taken into account. Based on this, the outlet liquid temperature on the hot side of the first heat exchanger and the target hot side temperature value T can be used as a basis. ht The target heat dissipation power of the radiator is determined.

[0097] For example, a temperature sensor T4 can be installed near the liquid outlet on the hot side of the first heat exchanger, and the detection result of the temperature sensor T4 can be used as the liquid outlet temperature on the hot side of the first heat exchanger. Then, based on T4 and T... ht The difference between the values ​​is used to determine the target heat dissipation power of the radiator.

[0098] Setting a radiator between the first heat exchanger and the fuel cell can improve the temperature regulation capability of the first heat exchange component. When the outlet liquid temperature on the hot side of the first heat exchanger is higher than the target inlet liquid temperature of the fuel cell, the heat exchange medium can be cooled by the radiator to maintain the stability of the inlet liquid temperature of the heat exchange medium of the fuel cell, thereby maintaining the stability of the power generation of the fuel cell.

[0099] A second embodiment of this application provides a control method for a fuel cell combined heat and power system. See also... Figure 4 As shown, the fuel cell combined heat and power system includes a fuel cell 319, a first heat exchange component, and a second heat exchange component.

[0100] The first heat exchange assembly may include a first heat exchanger 317, a first infusion pump 311, a radiator 318, a heater 313, a first three-way valve 312, a second three-way valve 314, a first valve 316, and a second valve 315. The fuel cell 319, the first infusion pump 311, the first three-way valve 312, the first valve 316, the hot side of the first heat exchanger 317, the radiator 318, and the second three-way valve 314 can be sequentially connected to form a first heat exchange circuit. The heater 313 can be connected between the first three-way valve 312 and the second three-way valve 314 to form a heating branch. The second valve 315 can be connected in parallel with the first heat exchanger 317 to form a bypass branch. Temperature sensors T1 and T2 can be respectively installed at the inlet and outlet of the fuel cell 319; temperature sensors T3 and T4 can be respectively installed at the inlet and outlet of the hot side of the first heat exchanger 317; temperature sensors T5 and T6 can be respectively installed at the inlet and outlet of the cold side of the first heat exchanger 317; and temperature sensors T7 and T8 can be respectively installed at the inlet and outlet of the radiator 318.

[0101] The second heat exchange assembly may include a second heat exchanger 323, a second infusion pump 321, and a buffer container 322. The cold side of the first heat exchanger 317, the second infusion pump 321, the hot side of the second heat exchanger 323, and the buffer container 322 may be connected in sequence to form a second heat exchange circuit. The cold side of the second heat exchanger 323 may be connected to the heat-using device 331. The buffer container 322 is used to temporarily store the heat exchange medium in the second heat exchange circuit.

[0102] See Figure 3a and Figure 3b As shown, the control method of the fuel cell cogeneration system in the second embodiment of this application may specifically include the following steps.

[0103] S201, Start the fuel cell cogeneration system.

[0104] Optionally, the target power output of the fuel cell can be preset. During the fuel cell start-up and heating process, the heating branch can be opened via the first and second three-way valves, the bypass branch can be opened by opening the second valve, and the hot side of the first heat exchanger can be disconnected by closing the first valve. The heat exchange medium does not flow through the first heat exchanger. The flow rate of the heat exchange medium through the bypass branch and the heating branch can be adjusted by regulating the first three-way valve. The heat exchange medium is heated by the heater, thereby increasing the reaction temperature inside the fuel cell. When the outlet temperature of the fuel cell reaches the corresponding outlet temperature threshold, the heater can be turned off.

[0105] The infusion flow rate of the first infusion pump can be determined based on the target power generation of the fuel cell. For example, a relationship curve between infusion flow rate and power generation can be constructed based on experience and / or experimental test results, and the target infusion flow rate of the first infusion pump can be determined based on the relationship curve and the target power generation.

[0106] S202, regulates the status of the radiator.

[0107] Optionally, the decision to turn on the radiator can be based on the detection results of temperature sensor T7 or temperature sensor T4. Optionally, if the first heat exchanger is not turned on, the decision to turn on the radiator can be based on the detection results of temperature sensor T7. If the first heat exchanger is turned on, the decision to turn on the radiator can be based on the detection results of temperature sensor T4.

[0108] Optionally, the radiator can be controlled based on the principle of hysteresis control. Specifically, the target hot-side temperature T of the first heat exchanger can be set based on the target inlet temperature of the fuel cell and the heat loss in the pipeline. ht T ht The temperature can be slightly higher than the target inlet temperature of the fuel cell, so that when the heat exchange medium is transported to the inlet of the fuel cell through the pipeline, it exactly matches the target inlet temperature of the fuel cell. The detection result of temperature sensor T7 can be recorded as T7, and the detection result of temperature sensor T4 can be recorded as T4. Based on this, T7 > T hmax Or T4 > T hmax When T7 < T, turn on the heat sink. ht Or T4 < T ht When the heat sink is turned off, the radiator will be shut off. At T ht ≤T7≤T hmax Or T ht ≤T4≤T hmax At this time, the current state of the heat sink can be maintained.

[0109] Optional, can be based on T4 and T ht The difference between them, or based on T7 and T htThe difference between T7 and T1 determines the heat dissipation power of the radiator. For example, during the startup phase of a fuel cell cogeneration system, the heat dissipation power can be determined based on T7 and T1. ht The difference between T4 and T1 determines the heat dissipation power of the radiator. During the stable operation phase of the fuel cell cogeneration system, the heat dissipation power can be determined based on T4 and T1. ht The difference between the values ​​determines the heat dissipation power of the radiator.

[0110] S203, regulate the state of the hot side of the first heat exchanger.

[0111] Optionally, the state of the hot side of the first heat exchanger can be controlled based on the hysteresis control principle. For example, the detection result of temperature sensor T1 can be recorded as T1, the detection result of temperature sensor T3 can be recorded as T3, and the detection result of temperature sensor T5 can be recorded as T5. A temperature difference ΔTβ can be preset. For example, if the inlet temperature of the hot side of the first heat exchanger is required to be 10°C higher than the inlet temperature of the cold side of the first heat exchanger, then ΔTβ = 10°C. When the hot side of the first heat exchanger is not open, it can be determined whether T1 is greater than T5 + ΔTβ. If T1 > T5 + ΔTβ, then the first valve is opened to connect the hot side of the first heat exchanger, and the second valve is closed to close the bypass branch. When the hot side of the first heat exchanger is open, it can be determined whether T3 is less than T5. If T3 < T5, then the second valve is opened to open the bypass branch, and the first valve is closed to disconnect the hot side of the first heat exchanger.

[0112] S204, determine whether the hot side of the first heat exchanger is connected. If not, proceed to step S203. If yes, proceed to S205.

[0113] S205, determine whether the outlet liquid temperature on the cold side of the first heat exchanger meets the corresponding outlet liquid temperature threshold.

[0114] Optionally, the detection result of temperature sensor T6 can be recorded as T6. Based on this, it can be determined whether T6 is greater than T. ct If T6≤T ct Then proceed with steps S206 to S209. If T6 > T ct Then proceed to step S210.

[0115] S206, the outlet liquid temperature on the cold side of the first heat exchanger is determined as the target adjustment amount, and the corresponding outlet liquid temperature threshold is determined as the target outlet liquid temperature threshold.

[0116] S207, Based on the target adjustment amount and the target outlet liquid temperature threshold, determine the feedback flow rate value Wcb on the cold side of the first heat exchanger.

[0117] Optionally, the outlet liquid temperature T on the cold side of the first heat exchanger can be determined. c,out and the target temperature T on the cold side of the first heat exchangerct The difference between them is ΔTα. Specifically, T6 can be taken as the outlet liquid temperature T on the cold side of the first heat exchanger. c,out Therefore, ΔTα=T ct -T6. The difference ΔTα is used as input data for the proportional-integral (PI) controller. The PI controller determines the feedback flow rate value Wcb on the cold side of the first heat exchanger based on the proportional coefficient Kp, the integral coefficient Ki, and the difference ΔTα.

[0118] S208, based on the thermal model, the inlet liquid temperature T on the hot side of the first heat exchanger is used. h,in The inlet liquid temperature T on the cold side of the first heat exchanger c,in The target cold side temperature T of the first heat exchanger ct The predicted outlet temperature of the hot side of the first heat exchanger and the predicted flow rate of the cold side of the first heat exchanger are determined, and the predicted flow rate of the cold side of the first heat exchanger is used as the feedforward flow rate Wcf of the cold side of the first heat exchanger.

[0119] S209, determine whether the outlet liquid temperature on the hot side of the first heat exchanger meets the corresponding outlet liquid temperature threshold.

[0120] Optionally, it can be determined whether T4 is located in [T hmin T hmax Within ] . If T4∈[T hmin T hmax If T4 < T, then proceed to step S205. hmin Or T4 > T hmax Then proceed with steps S210 to S213.

[0121] S210, the outlet liquid temperature on the hot side of the first heat exchanger is determined as the target adjustment amount, and the corresponding outlet liquid temperature threshold is determined as the target outlet liquid temperature threshold.

[0122] S211, Based on the target adjustment amount and the target outlet temperature threshold, determine the feedback flow rate value on the cold side of the first heat exchanger.

[0123] Optionally, the outlet liquid temperature T on the hot side of the first heat exchanger can be determined. h,out and the target temperature T on the hot side of the first heat exchanger ht The difference ΔTα between the two values ​​is used as input data for the proportional-integral (PI) controller. The PI controller determines the feedback flow rate Wcb on the cold side of the first heat exchanger based on the proportional coefficient Kp, the integral coefficient Ki, and the difference ΔTα.

[0124] S212, based on the thermal model, the inlet liquid temperature T on the hot side of the first heat exchanger is used. h,inThe inlet liquid temperature T on the cold side of the first heat exchanger c,in The target temperature T on the hot side of the first heat exchanger ht Determine the predicted outlet liquid temperature T on the cold side of the first heat exchanger. c,out ′ and the first predicted flow rate value Wc1 on the cold side of the first heat exchanger.

[0125] S213, determine the predicted outlet liquid temperature T on the cold side of the first heat exchanger. c,out Does it meet the outlet liquid temperature threshold of the cold side of the first heat exchanger? If yes, proceed to step S214; otherwise, proceed to step S215.

[0126] Optional, T can be determined c,out Is it greater than the target cold-side temperature value T? ct If T c,out ′>T ct If T c,out ′≤T ct Then proceed to step S215.

[0127] S214, the first predicted flow rate value Wc1 on the cold side of the first heat exchanger is used as the feedforward flow rate value Wcf on the cold side of the first heat exchanger.

[0128] S215, based on the thermal model, the inlet liquid temperature T on the hot side of the first heat exchanger is used. h,in The inlet liquid temperature T on the cold side of the first heat exchanger c,in and the target temperature T on the cold side of the first heat exchanger ct The second predicted flow rate value on the cold side of the first heat exchanger is determined, and the second predicted flow rate value is used as the feedforward flow rate value Wcf.

[0129] S216, Based on the feedback flow value, correct the feedforward flow value to obtain the target flow value on the cold side of the first heat exchanger.

[0130] Optionally, the target flow rate value on the cold side of the first heat exchanger can be determined based on the following formula:

[0131] Wc = Wcf + Wcb

[0132] Wherein, Wc represents the target flow rate value on the cold side of the first heat exchanger; Wcf represents the feedforward flow rate value; and Wcb represents the feedback flow rate value.

[0133] S217, based on the target flow rate value Wc, control the rotation speed of the second infusion pump to control the flow rate on the cold side of the first heat exchanger, so that the target adjustment amount meets the target outlet temperature threshold.

[0134] The third embodiment of this application provides a fuel cell combined heat and power system. Figure 4 This is a schematic diagram of a fuel cell cogeneration system according to the third embodiment of this application. See also... Figure 4 As shown, the fuel cell cogeneration system of the third embodiment of this application may include a fuel cell 319, a first heat exchange component, a second heat exchange component, and a controller.

[0135] The first heat exchange assembly includes a first heat exchanger 317 and a first infusion pump 311; the hot side of the first heat exchanger 317 is connected to the fuel cell 319 to form a first heat exchange circuit; the first infusion pump 311 is disposed in the first heat exchange circuit and is used to provide power for the flow of heat exchange medium in the first heat exchange circuit.

[0136] The second heat exchange assembly includes a second heat exchanger 323 and a second infusion pump 321; the hot side of the second heat exchanger 323 is connected to the cold side of the first heat exchanger 317 to form a second heat exchange circuit, and the cold side of the second heat exchanger 323 is used to connect to the heat-using equipment 331; the second infusion pump 321 is disposed in the second heat exchange circuit and can at least provide power for the flow of heat exchange medium in the cold side of the first heat exchanger 317.

[0137] The controller is connected to the first infusion pump 311 and the second infusion pump 321 respectively, and the controller is configured as follows:

[0138] The target adjustment amount that does not meet the corresponding outlet temperature threshold is determined from the outlet liquid temperature on the hot side of the first heat exchanger 317 and the outlet liquid temperature on the cold side of the first heat exchanger 317, and the corresponding outlet temperature threshold is determined as the target outlet temperature threshold.

[0139] Based on the target adjustment amount and the target outlet liquid temperature threshold, the feedback flow rate value of the cold side of the first heat exchanger 317 is determined;

[0140] Based on the thermodynamic model of the first heat exchanger 317, the feedforward flow rate value of the cold side of the first heat exchanger 317 is determined; wherein, the thermodynamic model can characterize the heat transfer characteristics of the first heat exchanger 317.

[0141] Based on the feedback flow value, the feedforward flow value is corrected to obtain the target flow value of the cold side of the first heat exchanger 317.

[0142] Based on the target flow rate value, the infusion flow rate of the second infusion pump 321 is controlled so that the target adjustment amount meets the target outlet temperature threshold.

[0143] In some embodiments, the controller is specifically configured as follows:

[0144] The feedforward flow rate value of the cold side of the first heat exchanger 317 is determined using the thermodynamic model based on the inlet liquid temperature of the hot side of the first heat exchanger 317, the inlet liquid temperature of the cold side of the first heat exchanger 317, and the target outlet liquid temperature threshold.

[0145] In some embodiments, the first heat exchange assembly further includes a radiator 318 connected between the liquid inlet of the fuel cell 319 and the liquid outlet on the hot side of the first heat exchanger 317; the controller is further configured to:

[0146] The target heat dissipation power of the radiator 318 is determined based on the liquid outlet temperature of the hot side of the first heat exchanger 317.

[0147] Based on the target heat dissipation power, the radiator 318 is controlled to dissipate heat from the heat exchange medium output from the hot side of the first heat exchanger 317.

[0148] Optionally, the first heat exchange assembly may further include a heater 313, a first three-way valve 312, a second three-way valve 314, a first valve 316, and a second valve 315. The fuel cell 319, the first infusion pump 311, the first three-way valve 312, the first valve 316, the hot side of the first heat exchanger 317, the radiator 318, and the second three-way valve 314 may be connected in sequence to form a first heat exchange circuit. The heater 313 may be connected between the first three-way valve 312 and the second three-way valve 314 to form a heating branch. The second valve 315 may be connected in parallel with the first heat exchanger 317 to form a bypass branch. Temperature sensors T1 and T2 can be respectively installed at the inlet and outlet of the fuel cell 319; temperature sensors T3 and T4 can be respectively installed at the inlet and outlet of the hot side of the first heat exchanger 317; temperature sensors T5 and T6 can be respectively installed at the inlet and outlet of the cold side of the first heat exchanger 317; and temperature sensors T7 and T8 can be respectively installed at the inlet and outlet of the radiator 318.

[0149] Optionally, the second heat exchange assembly may further include a buffer container 322, which may be disposed between the liquid outlet on the hot side of the second heat exchanger 323 and the liquid inlet on the cold side of the first heat exchanger 317. The buffer container 322 is used to temporarily store the heat exchange medium in the second heat exchange circuit. The second infusion pump 321 may be disposed between the liquid outlet on the cold side of the first heat exchanger 317 and the liquid inlet on the hot side of the second heat exchanger 323.

[0150] In some embodiments, the controller is specifically configured as follows:

[0151] If the outlet liquid temperature on the cold side of the first heat exchanger 317 does not meet the corresponding outlet liquid temperature threshold, the outlet liquid temperature on the cold side of the first heat exchanger 317 is determined as the target adjustment amount, and the corresponding outlet liquid temperature threshold is determined as the target outlet liquid temperature threshold.

[0152] If the outlet liquid temperature on the cold side of the first heat exchanger 317 meets the corresponding outlet liquid temperature threshold, and the outlet liquid temperature on the hot side of the first heat exchanger 317 does not meet the corresponding outlet liquid temperature threshold, the outlet liquid temperature on the hot side of the first heat exchanger 317 is determined as the target adjustment amount, and the outlet liquid temperature threshold on the hot side of the first heat exchanger 317 is determined as the target outlet liquid temperature threshold.

[0153] In some embodiments, the controller is specifically configured as follows:

[0154] When the target adjustment is the outlet liquid temperature of the cold side of the first heat exchanger 317, the feedforward flow rate value of the cold side of the first heat exchanger 317 is determined by the thermodynamic model based on the inlet liquid temperature of the hot side of the first heat exchanger 317, the inlet liquid temperature of the cold side of the first heat exchanger 317, and the outlet liquid temperature threshold of the cold side of the first heat exchanger 317.

[0155] In some embodiments, the controller is specifically configured as follows:

[0156] When the target adjustment amount is the liquid outlet temperature of the hot side of the first heat exchanger 317, the predicted liquid outlet temperature and the first predicted flow rate value of the cold side of the first heat exchanger 317 are determined by the thermodynamic model based on the liquid inlet temperature of the hot side of the first heat exchanger 317, the liquid inlet temperature of the cold side of the first heat exchanger 317, and the liquid outlet temperature threshold of the hot side of the first heat exchanger 317.

[0157] If the predicted outlet temperature of the cold side of the first heat exchanger 317 meets the outlet temperature threshold of the cold side of the first heat exchanger 317, the first predicted flow rate value is used as the feedforward flow rate value.

[0158] In some embodiments, the controller is further configured to:

[0159] If the predicted outlet temperature of the cold side of the first heat exchanger 317 does not meet the outlet temperature threshold of the cold side of the first heat exchanger 317, the second predicted flow rate value of the cold side of the first heat exchanger 317 is determined by the thermodynamic model based on the inlet temperature of the hot side of the first heat exchanger 317, the inlet temperature of the cold side of the first heat exchanger 317, and the outlet temperature threshold of the cold side of the first heat exchanger 317, and the second predicted flow rate value is used as the feedforward flow rate value.

[0160] In some embodiments, the thermal model is constructed using the following formula:

[0161]

[0162] Among them, W h This indicates the flow rate value on the hot side of the first heat exchanger 317; W c This indicates the flow rate on the cold side of the first heat exchanger 317; C p,h C represents the specific heat capacity of the heat exchange medium on the hot side of the first heat exchanger 317. p,c T represents the specific heat capacity of the heat exchange medium on the cold side of the first heat exchanger 317. h,in This indicates the inlet liquid temperature on the hot side of the first heat exchanger 317; T h,out This indicates the outlet liquid temperature on the hot side of the first heat exchanger 317; T c,out This indicates the outlet liquid temperature on the cold side of the first heat exchanger 317; T c,in ΔT represents the inlet liquid temperature on the cold side of the first heat exchanger 317; q represents the heat exchange volume; h represents the heat transfer coefficient of the first heat exchanger 317; A represents the heat transfer area of ​​the first heat exchanger 317; ΔT m Represents the logarithmic temperature difference, ΔT m =(T h,in -T c,out -T h,out +T c,in ) / ln((T h,in -T c,out ) / (T h,out -T c,in ).

[0163] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A control method for a fuel cell combined heat and power system, characterized in that, The fuel cell combined heat and power system includes a fuel cell, a first heat exchange assembly, and a second heat exchange assembly; the first heat exchange assembly includes a first heat exchanger, the hot side of which is connected to the fuel cell to form a first heat exchange loop; the second heat exchange assembly includes a second heat exchanger, the hot side of which is connected to the cold side of the first heat exchanger to form a second heat exchange loop, the cold side of which is used to connect to a heat-using device; the method includes: The target adjustment amount that does not meet the corresponding outlet temperature threshold is determined from the outlet liquid temperature on the hot side of the first heat exchanger and the outlet liquid temperature on the cold side of the first heat exchanger, and the corresponding outlet temperature threshold is determined as the target outlet temperature threshold. Based on the target adjustment amount and the target outlet liquid temperature threshold, the feedback flow rate value of the cold side of the first heat exchanger is determined; Based on the thermodynamic model of the first heat exchanger, the feedforward flow rate value on the cold side of the first heat exchanger is determined; wherein, the thermodynamic model can characterize the heat transfer characteristics of the first heat exchanger. Based on the feedback flow value, the feedforward flow value is corrected to obtain the target flow value on the cold side of the first heat exchanger; Based on the target flow rate value, the flow rate on the cold side of the first heat exchanger is controlled so that the target adjustment amount meets the target outlet liquid temperature threshold; wherein... The thermodynamic model is constructed using the following formula: in, This indicates the flow rate on the hot side of the first heat exchanger; This indicates the flow rate on the cold side of the first heat exchanger; This indicates the specific heat capacity of the heat exchange medium on the hot side of the first heat exchanger; This indicates the specific heat capacity of the heat exchange medium on the cold side of the first heat exchanger; This indicates the inlet liquid temperature on the hot side of the first heat exchanger; This indicates the outlet liquid temperature on the hot side of the first heat exchanger; This indicates the outlet liquid temperature on the cold side of the first heat exchanger; This indicates the inlet liquid temperature on the cold side of the first heat exchanger; For heat exchange; This represents the heat transfer coefficient of the first heat exchanger; This represents the heat exchange area of ​​the first heat exchanger; Represents the logarithmic temperature difference. 。 2. The method according to claim 1, characterized in that, The determination of the feedforward flow rate value on the cold side of the first heat exchanger based on the thermodynamic model of the first heat exchanger includes: The feedforward flow rate value of the cold side of the first heat exchanger is determined using the thermodynamic model based on the inlet liquid temperature on the hot side of the first heat exchanger, the inlet liquid temperature on the cold side of the first heat exchanger, and the target outlet liquid temperature threshold.

3. The method according to claim 1, characterized in that, The first heat exchange assembly further includes a radiator connected between the liquid inlet of the fuel cell and the liquid outlet on the hot side of the first heat exchanger; the control method further includes: The target heat dissipation power of the radiator is determined based on the liquid outlet temperature on the hot side of the first heat exchanger. Based on the target heat dissipation power, the radiator is controlled to dissipate heat from the heat exchange medium output from the hot side of the first heat exchanger.

4. The method according to claim 3, characterized in that, The step of determining the target adjustment amount that does not meet the corresponding outlet temperature threshold from the outlet liquid temperature on the hot side of the first heat exchanger and the outlet liquid temperature on the cold side of the first heat exchanger, and determining the corresponding outlet temperature threshold as the target outlet temperature threshold, includes: If the outlet liquid temperature on the cold side of the first heat exchanger does not meet the corresponding outlet liquid temperature threshold, the outlet liquid temperature on the cold side of the first heat exchanger is determined as the target adjustment amount, and the corresponding outlet liquid temperature threshold is determined as the target outlet liquid temperature threshold. If the outlet liquid temperature on the cold side of the first heat exchanger meets the corresponding outlet liquid temperature threshold, and the outlet liquid temperature on the hot side of the first heat exchanger does not meet the corresponding outlet liquid temperature threshold, the outlet liquid temperature on the hot side of the first heat exchanger is determined as the target adjustment amount, and the outlet liquid temperature threshold on the hot side of the first heat exchanger is determined as the target outlet liquid temperature threshold.

5. The method according to claim 4, characterized in that, The determination of the feedforward flow rate value on the cold side of the first heat exchanger based on the thermodynamic model of the first heat exchanger includes: When the target adjustment is the outlet liquid temperature of the cold side of the first heat exchanger, the feedforward flow rate value of the cold side of the first heat exchanger is determined by the thermodynamic model based on the inlet liquid temperature of the hot side of the first heat exchanger, the inlet liquid temperature of the cold side of the first heat exchanger, and the outlet liquid temperature threshold of the cold side of the first heat exchanger.

6. The method according to claim 4, characterized in that, The determination of the feedforward flow rate value on the cold side of the first heat exchanger based on the thermodynamic model of the first heat exchanger includes: When the target adjustment is the liquid outlet temperature of the hot side of the first heat exchanger, the predicted liquid outlet temperature and the first predicted flow rate value of the cold side of the first heat exchanger are determined by the thermodynamic model based on the liquid inlet temperature of the hot side of the first heat exchanger, the liquid inlet temperature of the cold side of the first heat exchanger, and the liquid outlet temperature threshold of the hot side of the first heat exchanger. If the predicted outlet temperature on the cold side of the first heat exchanger meets the outlet temperature threshold of the cold side of the first heat exchanger, the first predicted flow rate value is used as the feedforward flow rate value.

7. The method according to claim 6, characterized in that, The step of determining the feedforward flow rate value on the cold side of the first heat exchanger based on the thermodynamic model of the first heat exchanger further includes: If the predicted outlet temperature of the cold side of the first heat exchanger does not meet the outlet temperature threshold of the cold side of the first heat exchanger, the second predicted flow rate value of the cold side of the first heat exchanger is determined by the thermodynamic model based on the inlet temperature of the hot side of the first heat exchanger, the inlet temperature of the cold side of the first heat exchanger, and the outlet temperature threshold of the cold side of the first heat exchanger, and the second predicted flow rate value is used as the feedforward flow rate value.

8. A fuel cell combined heat and power system, characterized in that, include: Fuel cells; The first heat exchange component includes a first heat exchanger and a first infusion pump; the hot side of the first heat exchanger is connected to the fuel cell to form a first heat exchange circuit; the first infusion pump is disposed in the first heat exchange circuit and is used to provide power for the flow of heat exchange medium in the first heat exchange circuit. The second heat exchange assembly includes a second heat exchanger and a second infusion pump; the hot side of the second heat exchanger is connected to the cold side of the first heat exchanger to form a second heat exchange circuit, and the cold side of the second heat exchanger is used to connect to a heat-using device; the second infusion pump is disposed in the second heat exchange circuit and can at least provide power for the flow of heat exchange medium in the cold side of the first heat exchanger. The controller is connected to both the first infusion pump and the second infusion pump, and the controller is configured as follows: The target adjustment amount that does not meet the corresponding outlet temperature threshold is determined from the outlet liquid temperature on the hot side of the first heat exchanger and the outlet liquid temperature on the cold side of the first heat exchanger, and the corresponding outlet temperature threshold is determined as the target outlet temperature threshold. Based on the target adjustment amount and the target outlet liquid temperature threshold, the feedback flow rate value of the cold side of the first heat exchanger is determined; Based on the thermodynamic model of the first heat exchanger, the feedforward flow rate value on the cold side of the first heat exchanger is determined; wherein, the thermodynamic model can characterize the heat transfer characteristics of the first heat exchanger. Based on the feedback flow value, the feedforward flow value is corrected to obtain the target flow value on the cold side of the first heat exchanger; Based on the target flow rate value, the infusion flow rate of the second infusion pump is controlled to ensure that the target adjustment amount meets the target outlet temperature threshold; wherein... The thermodynamic model is constructed using the following formula: in, This indicates the flow rate on the hot side of the first heat exchanger; This indicates the flow rate on the cold side of the first heat exchanger; This indicates the specific heat capacity of the heat exchange medium on the hot side of the first heat exchanger; This indicates the specific heat capacity of the heat exchange medium on the cold side of the first heat exchanger; This indicates the inlet liquid temperature on the hot side of the first heat exchanger; This indicates the outlet liquid temperature on the hot side of the first heat exchanger; This indicates the outlet liquid temperature on the cold side of the first heat exchanger; This indicates the inlet liquid temperature on the cold side of the first heat exchanger; For heat exchange; This represents the heat transfer coefficient of the first heat exchanger; This represents the heat exchange area of ​​the first heat exchanger; Represents the logarithmic temperature difference. 。 9. The system according to claim 8, characterized in that, The first heat exchange assembly further includes a radiator connected between the liquid inlet of the fuel cell and the liquid outlet on the hot side of the first heat exchanger; the controller is further configured to: The target heat dissipation power of the radiator is determined based on the liquid outlet temperature on the hot side of the first heat exchanger. Based on the target heat dissipation power, the radiator is controlled to dissipate heat from the heat exchange medium output from the hot side of the first heat exchanger.

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