Performance testing device and method for flue gas heat exchanger

Abstract

The application discloses a performance testing device and method of a flue gas heat exchanger, and relates to the field of flue gas heat exchangers.The device comprises a heat source part, a carbon smoke particle and hydrocarbon generation part, a cooling part, a device state parameter collection part and a carbon smoke particle and hydrocarbon parameter measurement part.The application has the advantages that the heat exchange performance and pressure drop performance of the heat exchanger can be comprehensively evaluated, and the influence of exhaust particle and hydrocarbon deposition on the performance of the heat exchanger can be evaluated, which is of great significance for developing a high-performance waste heat recovery heat exchanger and further promoting the energy saving and emission reduction of internal combustion engines.

Description

Technical Field

[0001] This invention relates to the field of flue gas heat exchangers, and more particularly to a performance testing device and method for flue gas heat exchangers. Background Technology

[0002] Waste heat recovery technology for internal combustion engines is considered a promising energy-saving technology. Due to its high temperature and large amount of heat, internal combustion engine exhaust is considered a high-quality waste heat source, and waste heat recovery is typically achieved using flue gas heat exchangers. As a core component of the internal combustion engine waste heat recovery system, the performance of the flue gas heat exchanger significantly impacts the efficiency of waste heat recovery. Performance evaluation and testing of the flue gas heat exchanger are crucial for its maintenance, design optimization, and consequently, for its efficient and reliable operation, as well as the stable and efficient operation of the waste heat recovery system.

[0003] In a flue gas heat exchanger, high-temperature exhaust gas transfers its heat energy to the cold-side working fluid via forced convection. The heat exchange performance of the flue gas heat exchanger directly affects the efficiency of heat recovery by the cold-side working fluid. The exhaust gas within the flue gas heat exchanger is driven by the exhaust gas from the internal combustion engine. Excessive pressure drop in the flue gas heat exchanger increases the back pressure of the internal combustion engine exhaust, leading to deterioration of in-cylinder combustion and reduced fuel efficiency. Therefore, the pressure drop performance of the flue gas heat exchanger indirectly affects fuel combustion efficiency. Furthermore, the exhaust gas from the internal combustion engine contains a large amount of particulate matter and hydrocarbons, which often adhere to the heat exchange surface of the flue gas heat exchanger, forming a layer of soot. This severely deteriorates the heat exchange performance, increases flow resistance, and may even block flow channels, further increasing the pressure drop of the heat exchanger and worsening its performance.

[0004] Patent document CN204514629U discloses a performance simulation test device for a power plant flue gas waste heat utilization system, which can test the heat exchange and resistance characteristics of heat exchange tube bundles. Existing heat exchanger test devices only focus on evaluating the heat exchange and pressure drop performance of heat exchangers, without paying attention to the performance degradation caused by exhaust particulate matter and hydrocarbon deposition. Summary of the Invention

[0005] The technical problem to be solved by this invention is to comprehensively evaluate the heat exchange performance, pressure drop performance, and the impact of exhaust particulate matter and hydrocarbon deposition on the heat exchanger performance.

[0006] The present invention solves the above-mentioned technical problems through the following technical means: a performance testing device for a flue gas heat exchanger, comprising a heat source part, a particulate matter and hydrocarbon generation part, a cooling part, a device status parameter acquisition part, and a particulate matter and hydrocarbon parameter measurement part;

[0007] The heat source section is used to provide heated air to the flue gas heat exchanger;

[0008] The particulate matter and hydrocarbon generation section is used to mix particulate matter and hydrocarbons into the high-temperature air before it enters the flue gas heat exchanger.

[0009] The cooling section is used to provide a cooling medium for the flue gas heat exchanger;

[0010] The device status parameter acquisition section is used to collect ambient air flow rate, cooling medium flow rate, flue gas inlet and outlet temperatures of the flue gas heat exchanger, flue gas inlet and outlet pressures of the flue gas heat exchanger, and cooling medium inlet and outlet temperatures of the flue gas heat exchanger.

[0011] The particulate matter and hydrocarbon parameter measurement section is used to measure the particulate matter and hydrocarbon parameters at the flue gas inlet and outlet of the flue gas heat exchanger.

[0012] As an optimized technical solution, the heat source includes a fan, a first regulating valve, an air heater, and a second regulating valve. The fan, the first regulating valve, the air heater, and the second regulating valve are connected in sequence through pipes to form a flue gas passage. The outlet end of the flue gas passage is connected to the flue gas inlet of the flue gas heat exchanger.

[0013] As an optimized technical solution, the particulate matter and hydrocarbon generation section includes a propane compressed gas cylinder, a nitrogen compressed gas cylinder, an air compressed gas cylinder, and a particulate matter and hydrocarbon generator. The propane compressed gas cylinder, nitrogen compressed gas cylinder, and air compressed gas cylinder are respectively connected to the inlet of the particulate matter and hydrocarbon generator through pipelines and are respectively equipped with pressure reducing valves. The outlet of the particulate matter and hydrocarbon generator is connected to an interface on the flue gas passage through a stainless steel pipeline. The interface is located between the second regulating valve and the flue gas heat exchanger.

[0014] As an optimized technical solution, the device status parameter acquisition section includes a gas flow meter, a flue gas inlet pressure sensor, a flue gas inlet temperature sensor, a flue gas outlet pressure sensor, and a flue gas outlet temperature sensor. The gas flow meter is installed on the flue gas passage and located between the first regulating valve and the air heater. The flue gas inlet pressure sensor and the flue gas inlet temperature sensor are installed at the flue gas inlet of the flue gas heat exchanger, and the flue gas outlet pressure sensor and the flue gas outlet temperature sensor are installed at the flue gas outlet of the flue gas heat exchanger. The gas flow meter, the flue gas inlet pressure sensor, the flue gas inlet temperature sensor, the flue gas outlet pressure sensor, and the flue gas outlet temperature sensor are connected to a data acquisition module and a central processing unit.

[0015] As an optimized technical solution, the performance testing device for the flue gas heat exchanger also includes a thermal insulation layer. The air heater shell, the pipe between the air heater and the flue gas heat exchanger, the second regulating valve, and the flue gas heat exchanger shell are all wrapped with a thermal insulation layer.

[0016] As an optimized technical solution, the cooling section includes a water pump, a cooling tower, and a third regulating valve. The water pump, cooling tower, and third regulating valve are connected by pipes to form a cooling circulation path. The outlet end of the cooling circulation path is connected to the cooling medium inlet of the flue gas heat exchanger, and the inlet end of the cooling circulation path is connected to the cooling medium outlet of the flue gas heat exchanger.

[0017] As an optimized technical solution, the device status parameter acquisition section includes a cooling medium flow meter, a cooling medium outlet temperature sensor, and a cooling medium inlet temperature sensor. The cooling medium flow meter is installed on the cooling circulation path. The cooling medium outlet temperature sensor and the cooling medium inlet temperature sensor are respectively installed at the cooling medium outlet and cooling medium inlet of the flue gas heat exchanger. The cooling medium flow meter, the cooling medium outlet temperature sensor, and the cooling medium inlet temperature sensor are connected to the data acquisition module and the central processing unit.

[0018] As an optimized technical solution, the particulate matter and hydrocarbon parameter measurement section includes a rapid exhaust gas analyzer. The two sampling heads of the rapid exhaust gas analyzer are respectively installed at a distance of 10cm to 20cm from the flue gas inlet and flue gas outlet of the flue gas heat exchanger. The rapid exhaust gas analyzer is connected to a data acquisition module and a central processing unit.

[0019] As an optimized technical solution, the performance testing device for the flue gas heat exchanger also includes a tail gas purification treatment section, which is connected to the flue gas outlet of the flue gas heat exchanger via a pipeline.

[0020] A performance testing method for a flue gas heat exchanger, using the performance testing device for the flue gas heat exchanger, includes the following steps:

[0021] Step 1: Install the flue gas heat exchanger to be tested with the performance testing device for the flue gas heat exchanger;

[0022] Step two, turn on the cooling system;

[0023] Step 3: Turn on the heat source.

[0024] Step 4: Start the device status parameter acquisition section to collect real-time data on ambient air flow rate, cooling medium flow rate, flue gas inlet and outlet temperatures of the flue gas heat exchanger, flue gas inlet and outlet pressures of the flue gas heat exchanger, and cooling medium inlet and outlet temperatures of the flue gas heat exchanger.

[0025] Step 5: Based on the parameters collected in Step 4, adjust the heat source section to achieve the target air flow rate and air temperature, and adjust the cooling section to achieve the target cooling medium flow rate and cooling medium temperature.

[0026] Step 6: After the performance testing device for the flue gas heat exchanger has stabilized, record the airflow rate (m) under the initial clean state. h Cooling medium flow rate (m) c Flue gas inlet temperature T of flue gas heat exchanger hi Flue gas outlet temperature T of flue gas heat exchanger ho Flue gas heat exchanger flue gas inlet pressure P hi Flue gas heat exchanger flue gas outlet pressure P ho Flue gas heat exchanger cooling medium inlet temperature T ci and the outlet temperature T of the cooling medium in the flue gas heat exchanger co ;

[0027] Step 7: Based on the parameters recorded in Step 6, obtain the flue gas inlet enthalpy H under the initial clean state. hi and flue gas outlet enthalpy H ho ;

[0028] Step 8: Calculate the heat exchange capacity of the flue gas heat exchanger under the initial clean state: Q clean =m h ×(H hi -H ho );

[0029] Heat exchange efficiency of flue gas heat exchanger under initial clean conditions: η = (T hi -T ho ) / (T hi -T ci );

[0030] Pressure drop at the inlet and outlet of the flue gas heat exchanger under initial clean conditions: ΔP = P hi -P ho ;

[0031] Step 9: Activate the particulate matter and hydrocarbon generation section and the particulate matter and hydrocarbon parameter measurement section to obtain real-time particulate matter and hydrocarbon parameters at the flue gas inlet and outlet; adjust the particulate matter and hydrocarbon generation section to fix the inlet particulate matter and hydrocarbon parameters; simultaneously, record the airflow rate (m) at time t in real time. h(t) Cooling medium flow rate (m) c(t) Flue gas inlet temperature T of flue gas heat exchanger hi(t) Flue gas outlet temperature T of flue gas heat exchanger ho(t) Flue gas heat exchanger flue gas inlet pressure P hi(t) Flue gas heat exchanger flue gas outlet pressure P ho(t) Flue gas heat exchanger cooling medium inlet temperature T ci(t) and the outlet temperature T of the cooling medium in the flue gas heat exchanger co(t) ;

[0032] Step 10: Based on the parameters recorded in Step 9, obtain the flue gas inlet enthalpy H at time t. hi(t) and flue gas outlet enthalpy H ho(t) ;

[0033] Step 11: Calculate the heat exchanger heat transfer of the flue gas at time t in real time: Q (t) =m h(t) ×(H hi(t) -H ho(t) );

[0034] The heat exchange efficiency of the flue gas heat exchanger at time t: η (t) =(T hi(t) -T ho(t) ) / (T hi(t) -T ci(t) );

[0035] Pressure drop at the inlet and outlet of the flue gas heat exchanger at time t: ΔP (t) =P hi(t) -P ho(t) ;

[0036] This allows for real-time testing of the heat exchange performance and pressure drop performance of the flue gas heat exchanger, as well as an assessment of the deterioration in heat exchange performance and pressure drop performance caused by the adhesion of carbon particulate matter and hydrocarbons to the heat exchange surface.

[0037] The advantages of this invention are:

[0038] 1. This invention can comprehensively evaluate the heat exchange performance, pressure drop performance, and the impact of exhaust particulate matter and hydrocarbon deposition on the heat exchanger performance. It is of great significance for developing high-performance waste heat recovery heat exchangers and thus promoting energy conservation and emission reduction in internal combustion engines.

[0039] 2. This invention can be used for performance testing of flue gas heat exchangers of various forms and structures, greatly expanding its scope of application. By replacing flue gas heat exchangers with different structural forms or different structural parameters, the anti-fouling performance of flue gas heat exchangers can be compared and analyzed, thereby achieving optimized design of flue gas heat exchangers.

[0040] 3. Based on the combination of a fan, air heater, and particulate matter and hydrocarbon generator, the problem of large fluctuations in temperature and flow rate under actual internal combustion engine exhaust conditions is solved. It achieves decoupling of different exhaust parameters under internal combustion engine exhaust conditions, avoids mutual interference between different exhaust parameters of real internal combustion engines when studying flue gas heat exchanger parameters, and enables quantitative testing of flue gas heat exchangers under fixed exhaust conditions under strict control. It can also compare and analyze the performance of heat exchangers before and after particulate matter and hydrocarbon pollution under a series of specific engine exhaust conditions. Attached Figure Description

[0041] Figure 1This is a schematic diagram of the performance testing device for the flue gas heat exchanger according to an embodiment of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0043] like Figure 1 As shown, this embodiment of the invention discloses a performance testing device for a flue gas heat exchanger, including a heat source section, a particulate matter and hydrocarbon generation section, a cooling section, a device status parameter acquisition section, a particulate matter and hydrocarbon parameter measurement section, a tail gas purification treatment section, and a heat insulation layer. The flue gas heat exchanger 8 to be tested can be any structural form such as shell-and-tube, tube-fin, or plate-fin.

[0044] The heat source section is used to provide heated air to the flue gas heat exchanger 8.

[0045] The particulate matter and hydrocarbon generation section is used to mix particulate matter and hydrocarbons into the high-temperature air before it enters the flue gas heat exchanger 8.

[0046] The cooling section is used to provide a cooling medium for the flue gas heat exchanger 8.

[0047] The device status parameter acquisition section is used to collect ambient air flow rate, cooling medium flow rate, flue gas inlet and outlet temperatures of the flue gas heat exchanger, flue gas inlet and outlet pressures of the flue gas heat exchanger, and cooling medium inlet and outlet temperatures of the flue gas heat exchanger.

[0048] The particulate matter and hydrocarbon parameter measurement section is used to measure the particulate matter and hydrocarbon parameters at the flue gas inlet and outlet of the flue gas heat exchanger.

[0049] The exhaust gas purification section is used to purify the exhaust gas discharged from the flue gas heat exchanger 8.

[0050] The heat source includes a fan 1, a first regulating valve 2, an air heater 4, and a second regulating valve 5. The fan 1 is a vortex fan, and both the first regulating valve 2 and the second regulating valve 5 are electric regulating valves. The fan 1, the first regulating valve 2, the air heater 4, and the second regulating valve 5 are connected sequentially by stainless steel pipes to form a flue gas passage. The outlet end of the flue gas passage is connected to the flue gas inlet of the flue gas heat exchanger 8. The stainless steel pipes between the fan 1, the first regulating valve 2, the air heater 4, and the second regulating valve 5 are connected by welding or flange connection. The flue gas heat exchanger 8 is connected to the flue gas passage by a threaded joint or flange for easy replacement. The fan 1 provides a fixed flow rate of room temperature air. The air flow rate is adjusted by the first regulating valve 2 and the second regulating valve 5 in conjunction with the room temperature air flow rate collected by the parameter acquisition section. The air heater 4 heats the room temperature air to a specified temperature in conjunction with the flue gas temperature at the inlet and outlet of the flue gas heat exchanger collected by the parameter acquisition section. This can simulate the high-temperature exhaust of an engine and achieve stable and accurate control of the high-temperature exhaust flow rate and temperature.

[0051] The particulate matter and hydrocarbon generation section includes a propane compressed gas cylinder 19, a nitrogen compressed gas cylinder 20, an air compressed gas cylinder 21, and a particulate matter and hydrocarbon generator 22. The propane compressed gas cylinder 19, nitrogen compressed gas cylinder 20, and air compressed gas cylinder 21 are each connected to the inlet of the particulate matter and hydrocarbon generator 22 via stainless steel pipes and are each equipped with a pressure reducing valve. The outlet of the particulate matter and hydrocarbon generator 22 is connected to an interface on the flue gas passage via a stainless steel pipe, the interface being located between the second regulating valve 5 and the flue gas heat exchanger 8. The propane compressed gas cylinder 19, nitrogen compressed gas cylinder 20, and air compressed gas cylinder 21 respectively supply propane, nitrogen, and air to the particulate matter and hydrocarbon generator. 22. Propane undergoes incomplete combustion within the soot and hydrocarbon generator 22, generating soot particles and hydrocarbons. These particles and hydrocarbons enter the flue gas passage through an interface and mix with high-temperature air to dilute them, simulating the composition of soot particles and hydrocarbons in high-temperature engine exhaust. By using a pressure reducing valve and the hydrocarbon generator 22, combined with the soot and hydrocarbon parameter measurement section to obtain the soot particle and hydrocarbon parameters at the inlet and outlet of the flue gas heat exchanger, the flow ratio and pressure of propane, nitrogen, and air are controlled to generate soot particles with specific flow rates, concentrations, particle sizes, and modes, as well as hydrocarbons with specific concentrations. This achieves the goal of adjustable soot particle flow rate, concentration, particle size, and mode, as well as adjustable hydrocarbon concentration.

[0052] The cooling system includes a water pump 15, a cooling tower 16, and a third regulating valve 17. The third regulating valve 17 is a butterfly valve, and water is used as the cooling medium. The water pump 15, cooling tower 16, and third regulating valve 17 are connected by stainless steel pipes to form a cooling circulation path. The outlet end of the cooling circulation path is connected to the cooling medium inlet of the flue gas heat exchanger 8, and the inlet end of the cooling circulation path is connected to the cooling medium outlet of the flue gas heat exchanger 8. The stainless steel pipes between the water pump 15, cooling tower 16, and third regulating valve 17 are connected by welding or flanges. The flue gas heat exchanger 8 is connected to the cooling circulation path by threaded joints or flanges for easy replacement of the flue gas heat exchanger 8. The cooling circulation path is powered by the water pump 15. After the cooling water completes heat exchange in the flue gas heat exchanger 8, it enters the cooling tower 16 to dissipate heat and maintain a constant water temperature. The flow rate is regulated by the third regulating valve 17 in conjunction with the cooling water flow rate collected by the parameter acquisition section.

[0053] The device's status parameter acquisition section includes a gas flow meter 3, a flue gas inlet pressure sensor 6, a flue gas inlet temperature sensor 7, a flue gas outlet pressure sensor 9, a flue gas outlet temperature sensor 10, a cooling medium flow meter 11, a cooling medium outlet temperature sensor 14, and a cooling medium inlet temperature sensor 18. The gas flow meter 3 is a Coriolis mass flow meter. The gas flow meter 3 is installed in the flue gas passage and located between the first regulating valve 2 and the air heater 4. The flue gas inlet pressure sensor 6 and the flue gas inlet temperature sensor 7 are installed at the flue gas inlet of the flue gas heat exchanger 8. The flue gas outlet pressure sensor 9 and the flue gas outlet temperature sensor 10 are also installed at the flue gas outlet of the air heater 8. Sensor 10 is installed at the flue gas outlet of flue gas heat exchanger 8, cooling medium flow meter 11 is installed on the cooling circulation path, cooling medium outlet temperature sensor 14 and cooling medium inlet temperature sensor 18 are installed at the cooling medium outlet and cooling medium inlet of flue gas heat exchanger 8, respectively; each flow meter and sensor is installed on the corresponding pipeline by welding or flange connection, and the flow, temperature and pressure signals measured by each flow meter and sensor are transmitted to the data acquisition module and central processing unit 12 by signal transmission line. The data acquisition module and the central processing unit are integrated together, which can realize data transmission between them, and the data is centrally processed by the central processing unit.

[0054] The particulate matter and hydrocarbon parameter measurement section includes a rapid exhaust gas analyzer 13. The two sampling heads of the rapid exhaust gas analyzer 13 are respectively installed at a distance of 10cm to 20cm from the flue gas inlet and flue gas outlet of the flue gas heat exchanger 8. The particulate matter and hydrocarbon parameters measured by the rapid exhaust gas analyzer 13 are transmitted to the data acquisition module and the central processing unit 12 via a signal transmission line, and the data is centrally processed by the central processing unit.

[0055] The exhaust gas purification treatment section (not shown in the figure) is connected to the flue gas outlet of the flue gas heat exchanger 8 through a stainless steel pipe. The flue gas that has completed heat exchange is discharged into the exhaust gas purification treatment section to reduce environmental pollution.

[0056] The outer shell of the air heater 4, the pipe between the air heater 4 and the flue gas heat exchanger 8, the second regulating valve 5, and the outer shell of the flue gas heat exchanger 8 are all wrapped with a silica aerogel felt insulation layer with a thickness of 5cm to 20cm (not shown in the figure) to prevent the high-temperature components from causing burns to the experimental personnel, and to prevent heat from being lost to the environment.

[0057] This invention also discloses a performance testing method for a flue gas heat exchanger, using the performance testing device for the flue gas heat exchanger, including the following steps:

[0058] Step 1: Install the flue gas heat exchanger 8 to be tested on the performance testing device of the flue gas heat exchanger, connect its flue gas inlet to the outlet end of the flue gas passage, connect the flue gas outlet to the tail gas purification treatment section, and connect the cooling medium inlet and cooling medium outlet to the outlet end and inlet end of the cooling circulation passage, respectively.

[0059] Step 2: Turn on the third regulating valve 17, water pump 15 and cooling tower 16 of the cooling section in sequence.

[0060] Step 3: Turn on all regulating valves, fan 1, and air heater 4 in the heat source section.

[0061] Step 4: Start the device status parameter acquisition section to collect real-time data on ambient air flow rate, cooling medium flow rate, flue gas inlet and outlet temperatures of the flue gas heat exchanger, flue gas inlet and outlet pressures of the flue gas heat exchanger, and cooling medium inlet and outlet temperatures of the flue gas heat exchanger.

[0062] Step 5: Based on the parameters collected in Step 4, adjust the opening of the first regulating valve 2 and the second regulating valve 5 to achieve the target air flow rate, adjust the heating power of the air heater 4 to achieve the target air temperature, adjust the speed of the water pump 15 to achieve the target cooling medium flow rate, and adjust the parameters of the cooling tower 16 to achieve the target cooling medium temperature.

[0063] Step 6: After the performance testing device for the flue gas heat exchanger has stabilized, record the airflow rate (m) under the initial clean state. h Cooling medium flow rate (m) c Flue gas inlet temperature T of flue gas heat exchanger hi Flue gas outlet temperature T of flue gas heat exchanger ho Flue gas heat exchanger flue gas inlet pressure P hi Flue gas heat exchanger flue gas outlet pressure P ho Flue gas heat exchanger cooling medium inlet temperature T ciand the outlet temperature T of the cooling medium in the flue gas heat exchanger co .

[0064] Step 7: Based on the parameters recorded in Step 6, retrieve the flue gas inlet enthalpy H under the initial clean state from the Refmprop property database. hi and flue gas outlet enthalpy H ho .

[0065] Step 8: Calculate the heat exchange capacity of the flue gas heat exchanger under the initial clean state: Q clean =m h ×(H hi -H ho );

[0066] Heat exchange efficiency of flue gas heat exchanger under initial clean conditions: η = (T hi -T ho ) / (T hi -T ci );

[0067] Pressure drop at the inlet and outlet of the flue gas heat exchanger under initial clean conditions: ΔP = P hi -P ho .

[0068] Step nine: Activate the particulate matter and hydrocarbon generator. First, open the cylinder valves and corresponding pressure reducing valves of each gas cylinder. Then, adjust the flow ratio and pressure of propane, nitrogen, and air entering the particulate matter and hydrocarbon generator 22 through the pressure reducing valves. Next, activate the particulate matter and hydrocarbon generator 22 and ignite it to generate particulate matter and hydrocarbons. Simultaneously, activate the rapid exhaust gas analyzer 13 to obtain real-time parameters of particulate matter and hydrocarbons at the flue gas inlet and outlet. Adjust the flow ratio and pressure of propane, nitrogen, and air to bring the particulate matter and hydrocarbon parameters at the flue gas inlet to a fixed value. Simultaneously, record the air flow rate m at time t in real-time. h(t) Cooling medium flow rate (m) c(t) Flue gas inlet temperature T of flue gas heat exchanger hi(t) Flue gas outlet temperature T of flue gas heat exchanger ho(t) Flue gas heat exchanger flue gas inlet pressure P hi(t) Flue gas heat exchanger flue gas outlet pressure P ho(t) Flue gas heat exchanger cooling medium inlet temperature T ci(t) and the outlet temperature T of the cooling medium in the flue gas heat exchanger co(t) .

[0069] Step 10: Based on the parameters recorded in Step 9, retrieve the flue gas inlet enthalpy H at time t from the Refmprop property database. hi(t) and flue gas outlet enthalpy H ho(t) .

[0070] Step 11: Calculate the heat exchanger heat transfer of the flue gas at time t in real time: Q (t) =m h(t) ×(H hi(t) -H ho(t) );

[0071] The heat exchange efficiency of the flue gas heat exchanger at time t: η (t) =(T hi(t) -T ho(t) ) / (T hi(t) -T ci(t) );

[0072] Pressure drop at the inlet and outlet of the flue gas heat exchanger at time t: ΔP (t) =P hi(t) -P ho(t) ;

[0073] This allows for real-time testing of the heat exchange performance and pressure drop performance of the flue gas heat exchanger, as well as an assessment of the deterioration in heat exchange performance and pressure drop performance caused by the adhesion of carbon particulate matter and hydrocarbons to the heat exchange surface.

[0074] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test method for a performance testing device of a flue gas heat exchanger, characterized in that: The performance testing device for a flue gas heat exchanger includes a heat source section, a particulate matter and hydrocarbon generation section, a cooling section, a device status parameter acquisition section, and a particulate matter and hydrocarbon parameter measurement section. The heat source section provides heated air to the flue gas heat exchanger. The particulate matter and hydrocarbon generation section mixes particulate matter and hydrocarbons into the high-temperature air before it enters the flue gas heat exchanger. The cooling section provides a cooling medium to the flue gas heat exchanger. The device status parameter acquisition section collects data on ambient air flow rate, cooling medium flow rate, flue gas inlet and outlet temperatures, flue gas inlet and outlet pressures, and cooling medium inlet and outlet temperatures. The particulate matter and hydrocarbon parameter measurement section measures the particulate matter and hydrocarbon parameters at the flue gas inlet and outlet of the flue gas heat exchanger. The performance testing method for flue gas heat exchangers includes the following steps: Step 1: Install the flue gas heat exchanger to be tested with the performance testing device for the flue gas heat exchanger; Step two, turn on the cooling system; Step 3: Turn on the heat source. Step 4: Start the device status parameter acquisition section to collect real-time data on ambient air flow rate, cooling medium flow rate, flue gas inlet and outlet temperatures of the flue gas heat exchanger, flue gas inlet and outlet pressures of the flue gas heat exchanger, and cooling medium inlet and outlet temperatures of the flue gas heat exchanger. Step 5: Based on the parameters collected in Step 4, adjust the heat source section to achieve the target air flow rate and air temperature, and adjust the cooling section to achieve the target cooling medium flow rate and cooling medium temperature. Step 6: After the performance testing device of the flue gas heat exchanger is running stably, record the air flow rate, cooling medium flow rate, flue gas inlet temperature, flue gas outlet temperature, flue gas inlet pressure, flue gas outlet pressure, cooling medium inlet temperature, and cooling medium outlet temperature of the flue gas heat exchanger under the initial clean state. Step 7: Based on the parameters recorded in Step 6, obtain the flue gas inlet enthalpy and flue gas outlet enthalpy under the initial clean state; Step 8: Based on the parameters obtained in Step 6 and Step 7, calculate the heat exchange capacity of the flue gas heat exchanger under the initial clean state, the heat exchange efficiency of the flue gas heat exchanger under the initial clean state, and the inlet and outlet pressure drop of the flue gas heat exchanger under the initial clean state. Step 9: Activate the particulate matter and hydrocarbon generation section and the particulate matter and hydrocarbon parameter measurement section to obtain real-time particulate matter and hydrocarbon parameters at the flue gas inlet and outlet. Adjust the particulate matter and hydrocarbon generation section to set the flue gas inlet particulate matter and hydrocarbon parameters to fixed values. Simultaneously, record in real-time the air flow rate, cooling medium flow rate, flue gas inlet temperature of the flue gas heat exchanger, flue gas outlet temperature of the flue gas heat exchanger, flue gas inlet pressure of the flue gas heat exchanger, flue gas outlet pressure of the flue gas heat exchanger, cooling medium inlet temperature of the flue gas heat exchanger, and cooling medium outlet temperature of the flue gas heat exchanger at time t. Step 10: Based on the parameters recorded in Step 9, obtain the flue gas inlet enthalpy and flue gas outlet enthalpy at time t. Step 11: Based on the parameters obtained in Steps 9 and 10, calculate in real time the heat transfer capacity of the flue gas heat exchanger at time t, the heat transfer efficiency of the flue gas heat exchanger at time t, and the inlet and outlet pressure drop of the flue gas heat exchanger at time t; then test the heat transfer performance and pressure drop performance of the flue gas heat exchanger in real time, and evaluate the deterioration of heat transfer performance and pressure drop performance caused by the adhesion of carbon particulate matter and hydrocarbons on the heat exchange surface.

2. The test method of the performance testing device for a flue gas heat exchanger according to claim 1, characterized in that: The heat source includes a fan, a first regulating valve, an air heater, and a second regulating valve. The fan, the first regulating valve, the air heater, and the second regulating valve are connected in sequence through pipes to form a flue gas passage. The outlet end of the flue gas passage is connected to the flue gas inlet of the flue gas heat exchanger.

3. The test method of the performance testing device for a flue gas heat exchanger according to claim 2, characterized in that: The particulate matter and hydrocarbon generation section includes a propane compressed gas cylinder, a nitrogen compressed gas cylinder, an air compressed gas cylinder, and a particulate matter and hydrocarbon generator. The propane compressed gas cylinder, nitrogen compressed gas cylinder, and air compressed gas cylinder are respectively connected to the inlet of the particulate matter and hydrocarbon generator through pipelines and are respectively equipped with pressure reducing valves. The outlet of the particulate matter and hydrocarbon generator is connected to an interface on the flue gas passage through a stainless steel pipeline. The interface is located between the second regulating valve and the flue gas heat exchanger.

4. The test method of the performance testing device for a flue gas heat exchanger according to claim 2, characterized in that: The device status parameter acquisition section includes a gas flow meter, a flue gas inlet pressure sensor, a flue gas inlet temperature sensor, a flue gas outlet pressure sensor, and a flue gas outlet temperature sensor. The gas flow meter is installed on the flue gas passage and located between the first regulating valve and the air heater. The flue gas inlet pressure sensor and the flue gas inlet temperature sensor are installed at the flue gas inlet of the flue gas heat exchanger, and the flue gas outlet pressure sensor and the flue gas outlet temperature sensor are installed at the flue gas outlet of the flue gas heat exchanger. The gas flow meter, the flue gas inlet pressure sensor, the flue gas inlet temperature sensor, the flue gas outlet pressure sensor, and the flue gas outlet temperature sensor are connected to a data acquisition module and a central processing unit.

5. The test method of the performance testing device for a flue gas heat exchanger according to claim 2, characterized in that: The performance testing device for the flue gas heat exchanger also includes an insulation layer. The air heater shell, the pipe between the air heater and the flue gas heat exchanger, the second regulating valve, and the flue gas heat exchanger shell are all wrapped with an insulation layer.

6. The test method of the performance testing device for a flue gas heat exchanger according to claim 1, characterized in that: The cooling section includes a water pump, a cooling tower, and a third regulating valve. The water pump, cooling tower, and third regulating valve are connected by pipes to form a cooling circulation path. The outlet end of the cooling circulation path is connected to the cooling medium inlet of the flue gas heat exchanger, and the inlet end of the cooling circulation path is connected to the cooling medium outlet of the flue gas heat exchanger.

7. The test method of the performance testing device for a flue gas heat exchanger according to claim 6, characterized in that: The device status parameter acquisition section includes a cooling medium flow meter, a cooling medium outlet temperature sensor, and a cooling medium inlet temperature sensor. The cooling medium flow meter is installed on the cooling circulation path. The cooling medium outlet temperature sensor and the cooling medium inlet temperature sensor are respectively installed at the cooling medium outlet and cooling medium inlet of the flue gas heat exchanger. The cooling medium flow meter, the cooling medium outlet temperature sensor, and the cooling medium inlet temperature sensor are connected to the data acquisition module and the central processing unit.

8. The test method of the performance testing device for a flue gas heat exchanger according to claim 1, characterized in that: The particulate matter and hydrocarbon parameter measurement section includes a rapid exhaust gas analyzer. The two sampling heads of the rapid exhaust gas analyzer are respectively installed 10cm to 20cm away from the flue gas inlet and flue gas outlet of the flue gas heat exchanger. The rapid exhaust gas analyzer is connected to a data acquisition module and a central processing unit.

9. The test method of the performance testing device for a flue gas heat exchanger according to claim 1, characterized in that: The performance testing device for the flue gas heat exchanger also includes an exhaust gas purification treatment section, which is connected to the flue gas outlet of the flue gas heat exchanger via a pipeline.

10. The test method of the performance testing device for a flue gas heat exchanger according to claim 1, characterized in that: In step six, after the performance testing device for the flue gas heat exchanger has stabilized, record the airflow rate (m) under the initial clean state. h Cooling medium flow rate (m) c Flue gas inlet temperature T of flue gas heat exchanger hi Flue gas outlet temperature T of flue gas heat exchanger ho Flue gas heat exchanger flue gas inlet pressure P hi Flue gas heat exchanger flue gas outlet pressure P ho Flue gas heat exchanger cooling medium inlet temperature T ci and the outlet temperature T of the cooling medium in the flue gas heat exchanger co ; In step seven, the flue gas inlet enthalpy H under the initial clean state is obtained based on the parameters recorded in step six. hi and flue gas outlet enthalpy H ho ; In step eight, calculate the heat exchange capacity of the flue gas heat exchanger under the initial clean state: Q clean =m h ×(H hi -H ho ); Heat exchange efficiency of flue gas heat exchanger under initial clean conditions: η = (T hi -T ho ) / (T hi -T ci ); Pressure drop at the inlet and outlet of the flue gas heat exchanger under initial clean conditions: ΔP = P hi -P ho ; In step nine, the air flow rate m at time t is recorded in real time. h(t) Cooling medium flow rate (m) c(t) Flue gas inlet temperature T of flue gas heat exchanger hi(t) Flue gas outlet temperature T of flue gas heat exchanger ho(t) Flue gas heat exchanger flue gas inlet pressure P hi(t) Flue gas heat exchanger flue gas outlet pressure P ho(t) Flue gas heat exchanger cooling medium inlet temperature T ci(t) and the outlet temperature T of the cooling medium in the flue gas heat exchanger co(t) ; In step ten, based on the parameters recorded in step nine, the flue gas inlet enthalpy H at time t is obtained. hi(t) and flue gas outlet enthalpy H ho(t) ; In step eleven, the heat exchanger capacity of the flue gas at time t is calculated in real time: Q (t) =m h(t) ×(H hi(t) -H ho(t) ); The heat exchange efficiency of the flue gas heat exchanger at time t: η (t) =(T hi(t) -T ho(t) ) / (T hi(t) -T ci(t) ); Pressure drop at the inlet and outlet of the flue gas heat exchanger at time t: ΔP (t) =P hi(t) -P ho(t) .

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