System and method for testing fuel consumption of dual-fuel engine

Abstract

The invention relates to a dual-fuel engine fuel consumption test system and test method. Wherein the testing system comprises a traditional fuel supply flow path, the traditional fuel supply flow path comprises a first traditional fuel supply branch and a second traditional fuel supply branch which are connected in parallel, and the first traditional fuel supply branch comprises a first branch valve and a first measuring range flowmeter; the second traditional fuel supply branch comprises a second branch valve and a second measuring range flowmeter; the alternative fuel supply flow path comprises a first alternative fuel supply branch and a second alternative fuel supply branch which are connected in parallel, and the first alternative fuel supply branch comprises a third branch valve and a third measuring range flowmeter; the second alternative fuel supply branch comprises a fourth branch valve and a fourth measuring range flowmeter; wherein the traditional fuel supply flow path and the alternative fuel supply flow path are arranged in parallel.

Description

Technical Field

[0001] The present application relates to the field of dual-fuel engine testing, and in particular to a dual-fuel engine fuel consumption testing system and testing method. Background Art

[0002] Dual-fuel engines generally run on traditional fuel (such as diesel) and alternative fuel (such as methanol, ammonia) to reduce carbon emissions and pollution.

[0003] Taking methanol-diesel dual-fuel engine as an example, in the development test, fuel consumption is an important parameter for calculating unit fuel consumption rate and methanol fuel substitution rate. Therefore, the method of accurately measuring fuel consumption in the test of methanol-diesel dual-fuel engine is more important.

[0004] However, the inventors have found in practice that the accuracy of the test results of the fuel consumption and substitution rate of a dual-fuel engine, such as a methanol-diesel dual-fuel engine, needs to be further improved.

[0005] After in-depth research, the inventor found that the reason is probably that the methanol-diesel dual-fuel engine has very small methanol and diesel consumption in the traditional fuel mode (diesel mode) and the alternative fuel mode (methanol mode), respectively, accounting for 1% to 5% of the maximum consumption. For conventional flow meters (mass flow meters, vortex flow meters, etc.), the effective measurement range is generally 10% to 100% of the maximum range. When the consumption is lower than 10% of the maximum range of the flow meter, the measurement deviation and fluctuation will be large, and the fuel consumption cannot be accurately reflected. At present, facing this situation, it is more common to still use a large-range flow meter and ignore the deviation when measuring small flows, which leads to inaccurate calculation of the fuel substitution rate.

[0006] Therefore, there is a need in the art for a dual-fuel engine fuel consumption test system and test method to obtain more accurate test results of fuel substitution rate and fuel consumption. Summary of the invention

[0007] An object of the present application is to provide a dual-fuel engine fuel consumption test system.

[0008] An object of the present application is to provide a fuel consumption test method for a dual-fuel engine.

[0009] According to the first aspect of the present application, a dual-fuel engine fuel consumption test system includes: a traditional fuel supply flow path, including a first traditional fuel supply branch and a second traditional fuel supply branch connected in parallel, the first traditional fuel supply branch including a first branch valve and a first range flowmeter; the second traditional fuel supply branch including a second branch valve and a second range flowmeter; an alternative fuel supply flow path, including a first alternative fuel supply branch and a second alternative fuel supply branch connected in parallel, the first alternative fuel supply branch including a third branch valve and a third range flowmeter; the second alternative fuel supply branch including a fourth branch valve and a fourth range flowmeter; wherein the traditional fuel supply flow path and the alternative fuel supply flow path are arranged in parallel; the range of the first range flowmeter is smaller than that of the second range flowmeter, and the range of the third range flowmeter is smaller than that of the fourth range flowmeter.

[0010] In one or more embodiments of the test system, the conventional fuel supply flow path further includes a pressure stabilizing tank disposed downstream of the first conventional fuel supply branch and the second conventional fuel supply branch, and a fuel replenishing valve disposed on the pressure stabilizing tank.

[0011] In one or more embodiments of the test system, the first branch valve includes a first valve and a second valve; the second branch valve includes a third valve and a fourth valve; the third branch valve includes a fifth valve and a sixth valve; and the fourth branch valve includes a seventh valve and an eighth valve.

[0012] In one or more embodiments of the test system, the conventional fuel supply flow path further comprises a first flow switch electrically connected to the second valve and the fourth valve, wherein the normally open terminal of the first flow switch is connected to the fourth valve, and the normally closed terminal is connected to the second valve.

[0013] In one or more embodiments of the testing system, the alternative fuel supply flow path also includes a purge valve arranged upstream of the first alternative fuel supply branch and the second alternative fuel supply branch, and a second flow switch electrically connected to the sixth valve and the eighth valve, and the purge valve is arranged in parallel with the second flow switch.

[0014] In one or more embodiments of the test system, the purge valve can enable the second flow switch to simultaneously open the first alternative fuel supply branch and the second alternative fuel supply branch for inert gas purge.

[0015] In one or more embodiments of the test system, the first valve, the third valve, the fifth valve, and the seventh valve are all manual valves, and the second valve, the fourth valve, the sixth valve, and the eighth valve are all electric valves.

[0016] In one or more embodiments of the test system, the alternative fuel supply flow path further includes an alternative fuel concentration detector disposed downstream of the first alternative fuel supply branch and the second alternative fuel supply branch.

[0017] In one or more embodiments of the test system, the first range flow meter and the fourth range flow meter respectively correspond to the consumption rates of traditional fuel and alternative fuel that meet the requirements of the dual-fuel engine in alternative fuel mode; the second range flow meter and the third range flow meter respectively correspond to the consumption rates of traditional fuel and alternative fuel that meet the requirements of the dual-fuel engine in traditional fuel mode.

[0018] A dual-fuel engine fuel consumption test method according to the second aspect of the present application is applicable to the test system as described in the first aspect, and the test method includes: setting a first trigger flow corresponding to the traditional fuel supply flow path and a second trigger flow corresponding to the alternative fuel supply flow path; when the consumption of the traditional fuel is less than the first trigger flow, the first traditional fuel supply branch is opened and the second traditional fuel supply branch is closed, and when the consumption of the traditional fuel is above the first trigger flow, the first traditional fuel supply branch is closed and the second traditional fuel supply branch is opened; when the consumption of the alternative fuel is less than the second trigger flow, the first alternative fuel supply branch is opened and the second alternative fuel supply branch is closed, and when the consumption of the alternative fuel is above the second trigger flow, the first alternative fuel supply branch is closed and the second alternative fuel supply branch is opened.

[0019] In one or more embodiments of the testing method, the alternative fuel supply flow path also includes a purge valve arranged upstream of the first alternative fuel supply branch and the second alternative fuel supply branch; when the purge valve is opened, the first alternative fuel supply branch and the second alternative fuel supply branch are opened at the same time.

[0020] The beneficial effects of the above-described embodiments include but are not limited to one or a combination of the following:

[0021] 1. By setting the first branch and the second branch in the alternative fuel and traditional fuel flow paths respectively, two flow meters with different ranges are installed in parallel to cover the accurate measurement of fuel consumption in the range of 1% to 100%;

[0022] 2. Through the setting of flow switch, the automatic switching of flow meters with different ranges is realized, and this function is completely realized by hardware without the assistance of measurement and control computer;

[0023] 3. By setting up a pressure stabilizing box in the traditional fuel flow path, the problem of sudden increase in fuel demand during the engine sudden loading test, untimely system switching, and insufficient fuel supply can be overcome. At the same time, the problem of bubbles in the return oil affecting fuel consumption measurement can be optimized;

[0024] 4. By setting a purge valve in the alternative fuel flow path, a purge function that meets security requirements in the supply of alternative fuels is achieved based on the automatic switching flow meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features, properties and advantages of the present application will become more apparent through the following description in conjunction with the accompanying drawings and embodiments. It should be noted that the drawings are only examples and are not drawn in proportion. They should not be used to limit the actual scope of protection claimed by the present application, including:

[0026] Figure 1 It is a schematic block diagram of a dual-fuel engine fuel consumption test system according to an embodiment.

[0027] Figure 2 The invention is a flow switch control schematic diagram of a dual-fuel engine fuel consumption test system according to an embodiment.

[0028] Figure 3 The invention is a schematic diagram of the control of the electric valve of the methanol system of the dual-fuel engine fuel consumption test system according to one embodiment.

[0029] Figure 4 It is a flow chart of a dual-fuel engine fuel consumption test method according to an embodiment. DETAILED DESCRIPTION

[0030] Reference will now be made in detail to various embodiments of the present invention, examples of which are shown in the accompanying drawings and described below. Although the present invention will be described in conjunction with the exemplary embodiments, it should be appreciated that this specification is not intended to limit the present invention to those exemplary embodiments. On the contrary, the present invention is intended to cover not only these exemplary embodiments, but also various alternative forms, modifications, equivalent forms and other embodiments that may be included within the spirit and scope of the present invention as defined by the appended claims.

[0031] In the following description, the orientation or positional relationship indicated by "inside", "outside", "upper", "lower", "top", "bottom" or other orientation terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0032] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "some embodiments" means a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "some embodiments" mentioned twice or multiple times in different locations in this specification do not necessarily refer to the same embodiment. In addition, some features, structures or characteristics of some embodiments of the present application can be appropriately combined.

[0033] As described above, the inventors have found in practice that the accuracy of the test results of the fuel consumption and substitution rate of the dual-fuel engine, taking the methanol-diesel dual-fuel engine as an example, needs to be further improved. After in-depth research, the inventors found that the reason is probably that the methanol-diesel dual-fuel engine has very small methanol and diesel consumption in the traditional fuel mode (diesel mode) and the alternative fuel mode (methanol mode), respectively, accounting for 1% to 5% of the maximum consumption. For conventional flow meters (mass flow meters, vortex flow meters, etc.), the effective measurement range is generally 10% to 100% of the maximum range. When the consumption is lower than 10% of the maximum range of the flow meter, the measurement deviation and fluctuation will be large, and the fuel consumption cannot be accurately reflected. At present, in the face of this situation, it is more common to still use a large-range flow meter and ignore the deviation when measuring small flows, which leads to inaccurate calculation of the fuel substitution rate.

[0034] Based on the above considerations, the inventors, after in-depth research, invented a dual-fuel engine fuel consumption test system and test method. By setting a first branch and a second branch in the alternative fuel and traditional fuel flow paths respectively, and installing two flow meters with different ranges in parallel, accurate measurement of fuel consumption in the range of 1% to 100% can be covered.

[0035] In the following description, diesel is used as an example for "traditional fuel" and methanol is used as an example for "alternative fuel". The engine is described by taking a methanol-diesel dual-fuel engine for ships as an example, but the invention is not limited thereto. For example, the alternative fuel may also be ammonia fuel, etc. It is not limited to dual-fuel engines for ships, and may be applicable to other applications, such as heavy vehicles, railway trains, ground dual-fuel generators for power generation, etc. As long as the engine needs to adopt a dual-fuel injection scheme, the test system and test method disclosed in this application may be applied.

[0036] refer to Figures 1 to 3 As shown, the dual-fuel engine fuel consumption test system 100 includes a conventional fuel supply path 101 and an alternative fuel supply path 102 .

[0037] The traditional fuel supply flow path 101 includes a first traditional fuel supply branch 1011 and a second traditional fuel supply branch 1012 in parallel. The first traditional fuel supply branch 1011 includes a first branch valve and a first range flowmeter 2; the second traditional fuel supply branch 1012 includes a second branch valve and a second range flowmeter 3.

[0038] The alternative fuel supply flow path 102 includes a first alternative fuel supply branch 1021 and a second alternative fuel supply branch 1022 connected in parallel. The first alternative fuel supply branch 1021 includes a third branch valve and a third range flowmeter 13; the second alternative fuel supply branch 1022 includes a fourth branch valve and a fourth range flowmeter 14.

[0039] Among them, the traditional fuel supply flow path 101 and the alternative fuel supply flow path 102 are arranged in parallel; the range of the first range flowmeter 2 is smaller than the second range flowmeter 3 , and the range of the third range flowmeter 13 is smaller than the fourth range flowmeter 14 .

[0040] like Figure 1 As shown, the flow path of the conventional fuel illustrated as "fuel oil" or "oil" in the figure may be output from the conventional fuel tank, output through the first alternative fuel supply branch 1021 or the second alternative fuel supply branch 1022, and then output to the engine 10 after pressure buildup through the conventional fuel supply module 9. The flow path of the alternative fuel illustrated as "methanol" or "alcohol" in the figure may be output from the alternative fuel tank, output through the first conventional fuel supply branch 1011 or the second conventional fuel supply branch 1012, and then output to the engine 10 after pressure buildup through the methanol supply pump 18.

[0041] like Figure 1 As shown, in some embodiments, the specific structure of each branch valve can be that the first branch valve includes a first valve 1 and a second valve 4; the second branch valve includes a third valve 21 and a fourth valve 5; the third branch valve includes a fifth valve 12 and a sixth valve 15; and the fourth branch valve includes a seventh valve 22 and an eighth valve 16.

[0042] In some embodiments, the first valve 1, the third valve 21, the fifth valve 12, and the seventh valve 22 are all manual valves, and the second valve 4, the fourth valve 5, the sixth valve 15, and the eighth valve 16 are all electric valves. In addition, the first valve 1 and the second valve 4 are respectively located upstream and downstream of the first range flowmeter 2, the third valve 21 and the fourth valve 5 are respectively located upstream and downstream of the first range flowmeter 3, the fifth valve 12 and the sixth valve 15 are respectively located upstream and downstream of the third range flowmeter 13, and the seventh valve 22 and the eighth valve 16 are respectively located upstream and downstream of the fourth range flowmeter 14. In this way, it is easy to disassemble, inspect, and maintain the valves.

[0043] The traditional fuel supply flow path 101 and the alternative fuel supply flow path 102 are arranged in parallel; the range of the first range flowmeter 2 is smaller than that of the second range flowmeter 3, and the range of the third range flowmeter 13 is smaller than that of the fourth range flowmeter 14, so that the fuel consumption rate of the methanol-diesel dual-fuel engine in the high working condition of the pure diesel mode and the fuel consumption rate of the methanol-diesel dual-fuel engine in the methanol mode can be covered. During the test, only one of the first traditional fuel supply branch 1011 and the second traditional fuel supply branch 1012 is opened and worked. Similarly, during the test, only one of the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022 is opened and worked. That is, for example, when the fuel consumption rate of the methanol-diesel dual-fuel engine is in the high operating condition of the pure diesel mode, the second traditional fuel supply branch 1012 and the first alternative fuel supply branch 1021 are opened, while when the fuel consumption rate of the methanol-diesel dual-fuel engine is in the methanol mode, the first traditional fuel supply branch 1011 and the second alternative fuel branch 1022 are opened.

[0044] Continue to refer Figure 1 As shown, in some embodiments, the conventional fuel supply flow path 101 further includes a pressure stabilizing tank 7 disposed downstream of the first conventional fuel supply branch 1011 and the second conventional fuel supply branch 1012, and an oil replenishing valve 6 disposed in the pressure stabilizing tank 7. The specific structure of the oil replenishing valve may be a float oil replenishing valve, but is not limited thereto. In this way, the engine fuel supply and reflux functions can be realized, and the oil replenishing valve 6 ensures the stability of the liquid level in the pressure stabilizing tank 7, and enables the flowmeter located on the oil replenishing main pipe to measure accurately. The pressure stabilizing tank 7 avoids abnormal fuel supply when the engine operating conditions suddenly change. Since the return oil returns to the pressure stabilizing tank, the diesel is defoamed in the pressure stabilizing tank, thereby avoiding the influence of the return oil foaming on the accurate measurement of fuel consumption.

[0045] Continue to refer Figure 1 As shown, in some embodiments, the conventional fuel supply flow path 101 further includes a first flow switch 8 electrically connected to the second valve 4 and the fourth valve 5, the normally open terminal of the first flow switch 8 being connected to the fourth valve 5, and the normally closed terminal being connected to the second valve 4. The outlet of the pressure stabilizing tank 7 is provided with a first flow switch 8, which can monitor the fuel supply amount of the engine, and the second valve 4 and the fourth valve 5 are both controlled by the flow switch 8. Figure 2 As shown, the control strategies that can be implemented are as follows:

[0046] (A) Set the first trigger flow T corresponding to the traditional fuel supply flow path 101, and the value is determined by the numerical range of the intersection of the two flow meter scales. When the machine is in a stopped or standby state, the flow on the oil supply pipeline of the pressure regulating box is not enough to trigger the flow switch, and the flow switch does not work. The second valve 4 is connected to the normally closed terminal of the flow switch, and the fourth valve 5 is connected to the normally open terminal of the flow switch. The second valve 4 remains open in this scenario, and the fourth valve 5 remains closed. Therefore, in the stopped or standby scenario, the small flow fuel consumption measurement flow path is opened, and the large flow fuel consumption measurement flow path is closed, that is, the first traditional fuel supply branch 1011 is opened, and the second traditional fuel supply branch 1012 is closed.

[0047] (B) When the fuel consumption increases as the engine operating condition increases and is less than the first trigger flow rate T, the flow switch 8 does not operate because the flow rate is lower than the first trigger flow rate T. This state is consistent with the stop and standby state.

[0048] (C) When the engine operating condition continues to rise and the fuel consumption ≥ the trigger flow rate T, the flow rate on the fuel inlet pipeline increases and is greater than the trigger flow rate of the first flow switch 8, and the first flow switch 8 is activated. The fourth valve 5 is controlled to open, and the second valve 4 is controlled to close synchronously, and the flow meter switches to the large-range branch, that is, the first traditional fuel supply branch 1011 is closed, and the second traditional fuel supply branch 1012 is opened.

[0049] (D) When the engine operating condition is maintained or further improved and the fuel consumption is maintained ≥ T, the fourth valve 5 is continuously opened, that is, the first conventional fuel supply branch 1011 is closed and the second conventional fuel supply branch 1012 is opened.

[0050] (E) When the engine operating condition is adjusted and the fuel consumption is less than T, the flow switch 8 is reset. The flow switch controls the second valve 4 to open and synchronously controls the fourth valve 5 to close, and the fuel consumption is measured by the flow meter 2. The system returns to the state corresponding to the scenarios (A) and (B).

[0051] It can be understood that, in the methanol mode, the control strategies of the first replacement fuel supply branch 1021 and the second replacement fuel supply branch 1022 are similar to the control strategies (A), (B), (C), (D), and (E) of the above-mentioned traditional fuels, that is, when the consumption of the alternative fuel is less than the second trigger flow rate, the first replacement fuel supply branch 1021 is opened and the second replacement fuel supply branch 1022 is closed; when the consumption of the alternative fuel is above the second trigger flow rate, the first replacement fuel supply branch 1021 is closed and the second replacement fuel supply branch 1022 is opened, which will not be repeated here.

[0052] Continue to refer Figure 1As shown, in some embodiments, the alternative fuel supply flow path 102 further includes a purge valve 19 disposed upstream of the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022, and a second flow switch 17 electrically connected to the sixth valve 15 and the eighth valve 16, and the purge valve 19 is disposed in parallel with the second flow switch 17. Preferably, the purge valve 19 can enable the second flow switch 17 to simultaneously open the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022 for inert gas purge.

[0053] This allows for a purge mode that meets the safety requirements for alternative fuels. Figure 1 as well as Figure 3 When the purge valve 19 is opened, the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022 are opened at the same time. Figure 1 as well as Figure 3 As shown, in the methanol system, in order to ensure the safety of the methanol supply pipeline, the methanol supply pipeline should be purged with nitrogen at the beginning and end of the test to remove the residual methanol liquid and steam in the supply pipeline. The automatic range switching test device of the methanol supply system should open the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022 at the same time during nitrogen purging to remove the methanol in each branch and ensure the pipeline inerting effect.

[0054] Therefore, the methanol supply system has a parallel structure of flow meters with different ranges and flow switches based on the principle of the fuel supply system, namely, the third range flow meter 13 and the fourth range flow meter 14 connected in parallel, the sixth valve 15 and the eighth valve 16 for controlling the on-off of the parallel flow meter branch pipe, and the second flow switch 17 located on the methanol supply pipe. The range of the third range flow meter 13 covers the high methanol consumption range of the methanol mode, the range of the fourth range flow meter 14 covers the low methanol consumption range of the diesel mode, and the sixth valve 15 and the eighth valve 16 are also controlled by the second flow switch 17. After passing through the valve box 11, the third range flow meter 13 and the fourth range flow meter 14 connected in parallel and the second flow switch 17, the methanol is supplied to the engine by the methanol supply pump 18. The purge valve 19 is opened when receiving the nitrogen purge switch signal. In addition, in some embodiments, the alternative fuel supply flow path 102 also includes an alternative fuel concentration detector 20 arranged downstream of the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022. Based on the control strategy consistent with the diesel system range switching, the control method of the purge step in the test method includes:

[0055] (1) The nitrogen purge switch signal of the purge valve 19 is connected in parallel with the control signal of the second flow switch 17, so that the mass flow meter branch pipes of the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022 are controlled by the nitrogen purge signal with the highest priority. When nitrogen purge is performed, the nitrogen purge valve receives the switch signal from the control console and opens, and the flow meters of the first traditional fuel supply branch 1011 and the second traditional fuel supply branch 1012 are opened synchronously, so that nitrogen completely purges all parts of the methanol system. The control schematic diagram is shown in FIG. Figure 3 shown.

[0056] (2) An alternative fuel concentration detector 20 (methanol concentration detector) is installed at the pipe flange connection downstream of the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022, and the alarm signal is connected to the control console. When methanol leaks, the methanol consumption measurement will be too high. Due to the volatile nature of methanol, the leaked liquid methanol quickly evaporates and turns into steam, causing the methanol concentration detector to alarm. When the tester receives the alarm signal, he organizes relevant personnel to check and repair the methanol leakage point, and then continues the test.

[0057] (3) For the traditional fuel supply flow path of methanol, the flow switch configuration and the flow switch control valve strategy are consistent with the flow switch control strategy of the alternative fuel supply flow path described above. Due to the toxic, flammable, explosive and volatile characteristics of methanol fuel, when selecting the third branch valve, third range flow meter 13, fourth branch valve, fourth range flow meter 14, and second flow switch 17 corresponding to the methanol system, explosion-proof components should generally be selected.

[0058] As above, Figure 4 As shown, the present application also provides a dual-fuel engine fuel consumption test method, using the test system 100 introduced in the above embodiment, the test method includes:

[0059] Setting a first trigger flow rate corresponding to the conventional fuel supply flow path 101 and a second trigger flow rate corresponding to the alternative fuel supply flow path 102;

[0060] When the consumption of the traditional fuel is less than the first trigger flow rate, the first traditional fuel supply branch 1011 is opened and the second traditional fuel supply branch 1012 is closed; when the consumption of the traditional fuel is above the first trigger flow rate, the first traditional fuel supply branch 1011 is closed and the second traditional fuel supply branch 1012 is opened;

[0061] When the consumption of the alternative fuel is less than the second trigger flow rate, the first alternative fuel supply branch 1021 is opened and the second alternative fuel supply branch 1022 is closed. When the consumption of the alternative fuel is above the second trigger flow rate, the first alternative fuel supply branch 1021 is closed and the second alternative fuel supply branch 1022 is opened.

[0062] In some embodiments, for the purge requirement of alternative fuels such as methanol, the alternative fuel supply flow path 101 also includes a purge valve 19 arranged upstream of the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022; when the purge valve 19 is opened, the first alternative fuel supply branch 1021 and the second alternative fuel supply branch 1022 are opened at the same time.

[0063] When conducting the test, the specific operation method can be the following steps:

[0064] The fuel consumption measurement method is as follows:

[0065] a) Open the manual valves upstream of all flow meter branches in the methanol and diesel supply flow paths, i.e. Figure 1 As shown, the first valve 1, the third valve 21, the fifth valve 12, and the seventh valve 22. When the diesel and methanol fuel supply is lower than the trigger flow of the corresponding system flow switch, that is, lower than the first trigger flow and the second trigger flow, the small-range branch of each system automatically remains open, that is, the first traditional fuel supply branch 1011 and the first alternative fuel supply branch 1021 automatically remain open.

[0066] b) Switch the operating conditions according to the test plan and record the fuel consumption data.

[0067] When switching the working condition according to the test plan, if the fuel supply flow crosses the first flow trigger value of the flow switch, the test system automatically switches the flow meter pipeline, and the flow meter switching functions of the diesel and methanol systems are independent of each other. The flow meter after switching displays the normal value, and the flow meter of the cut-off branch displays 0 or noise value, and the data of the corresponding flow meter is recorded.

[0068] c) When methanol leaks, repair the leaking point behind the methanol flow meter.

[0069] When the control center receives the alarm signal, relevant personnel are dispatched to protect the methanol liquid and steam, and repair the leakage point behind the methanol flow meter to ensure the accurate measurement of the methanol flow meter.

[0070] d) After the test, use nitrogen to purge the methanol supply pipeline.

[0071] After the test, the test participants will issue a nitrogen purge command, and the methanol flow meter branch pipes will automatically open at the same time, and automatically return to normal flow control after the purge is completed, and wait until the purge is completed.

[0072] In addition, the steps for flow meter selection can be to evaluate the actual range of methanol and diesel consumption under various test scenarios of the engine based on the various technical parameters of the methanol-diesel dual-fuel engine, and determine the required range for fuel consumption measurement. Calculate the required range of the flow meter based on the minimum and maximum values ​​of the range. Match the purchase of flow meters with similar specifications according to the required range of the flow meter. If the dual flow meters cannot cover the required range of fuel consumption measurement, the number of parallel branches of the intermediate range flow meter can be set to be consistent with the number of flow meters. Build a multi-range flow meter pipeline. When selecting methanol system equipment, the flow meter should be explosion-proof. When processing, manufacturing or modifying the fuel supply system, use Figure 1 The fuel consumption test pipeline is built according to the principle of

[0073] Regarding the steps of configuring the flow switch and the electric valve, that is, configuring the first flow switch 8, the second flow switch 17, the second valve 4, the fourth valve 5, the sixth valve 15, and the eighth valve 16, specifically, configuring the trigger flow T of the flow switch. The trigger flow should be determined according to the range between the maximum range of the small-range flow meter and the minimum range of the large-range flow meter.

[0074] If more than two flow meters need to be selected according to the selection strategy, more than two flow switches need to be configured, and the trigger flow configuration of each flow switch should be selected based on the interval range where the ranges of multiple flow meters overlap.

[0075] For the electric valves of the methanol flow path, based on the same control principle as the fuel flow path, the nitrogen purge switch signal is connected in parallel with the control lines of the electric valves of all methanol flow meter branches.

[0076] Regarding the configuration of flow meter signals, the specific steps may be to configure the specific range of each flow meter signal channel on the centralized control console to ensure that the flow meter readings displayed on the centralized control console are true and accurate, and that the values ​​displayed on the meter header are consistent with the values ​​displayed on the centralized control console.

[0077] Regarding the steps for configuring the methanol concentration detector, the methanol concentration detector can be connected to the control console to test whether the methanol concentration detection and alarm functions are normal.

[0078] Finally, after completing the above configuration steps, you can conduct an engine test and start the fuel consumption measurement test. Conduct an engine fuel consumption measurement test, record the fuel consumption readings on the corresponding flow meters in the diesel and methanol systems, and complete the test.

[0079] In summary, the beneficial effects of the low temperature durability test system and test method described in the above embodiments include but are not limited to one or a combination of the following:

[0080] 1. By setting the first branch and the second branch in the alternative fuel and traditional fuel flow paths respectively, two flow meters with different ranges are installed in parallel to cover the accurate measurement of fuel consumption in the range of 1% to 100%;

[0081] 2. Through the setting of flow switch, the automatic switching of flow meters with different ranges is realized, and this function is completely realized by hardware without the assistance of measurement and control computer;

[0082] 3. By setting up a pressure stabilizing box in the traditional fuel flow path, the problem of sudden increase in fuel demand during the engine sudden loading test, untimely system switching, and insufficient fuel supply can be overcome. At the same time, the problem of bubbles in the return oil affecting fuel consumption measurement can be optimized;

[0083] 4. By setting a purge valve in the alternative fuel flow path, a purge function that meets security requirements in the supply of alternative fuels is achieved based on the automatic switching flow meter.

[0084] Although the present application is disclosed in the above embodiments, it is not intended to limit the present application. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, any modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application shall fall within the scope of protection defined by the claims of the present application.

Claims

1. A dual-fuel engine fuel consumption test system (100), characterized in that: include: A conventional fuel supply flow path (101), comprising a first conventional fuel supply branch (1011) and a second conventional fuel supply branch (1012) connected in parallel, wherein the first conventional fuel supply branch (1011) comprises a first branch valve and a first range flow meter (2); and the second conventional fuel supply branch (1012) comprises a second branch valve and a second range flow meter (3); The alternative fuel supply flow path (102) comprises a first alternative fuel supply branch (1021) and a second alternative fuel supply branch (1022) connected in parallel, wherein the first alternative fuel supply branch (1021) comprises a third branch valve and a third range flow meter (13); and the second alternative fuel supply branch (1022) comprises a fourth branch valve and a fourth range flow meter (14); The conventional fuel supply flow path (101) and the alternative fuel supply flow path (102) are arranged in parallel; the range of the first range flow meter (2) is smaller than that of the second range flow meter (3); and the range of the third range flow meter (13) is smaller than that of the fourth range flow meter (14).

2. The test system (100) according to claim 1, characterized in that: The conventional fuel supply flow path (101) further comprises a pressure stabilizing tank (7) arranged downstream of the first conventional fuel supply branch (1011) and the second conventional fuel supply branch (1012), and an oil replenishing valve (6) arranged on the pressure stabilizing tank (7).

3. The test system (100) according to claim 1, characterized in that: The first branch valve comprises a first valve (1) and a second valve (4); the second branch valve comprises a third valve (21) and a fourth valve (5); the third branch valve comprises a fifth valve (12) and a sixth valve (15); and the fourth branch valve comprises a seventh valve (22) and an eighth valve (16).

4. The test system (100) according to claim 3, characterized in that: The conventional fuel supply flow path (101) further comprises a first flow switch (8) electrically connected to the second valve (4) and the fourth valve (5), wherein the normally open terminal of the first flow switch (8) is connected to the fourth valve (5), and the normally closed terminal is connected to the second valve (4).

5. The test system (100) according to claim 3, characterized in that: The alternative fuel supply flow path (102) also includes a purge valve (19) arranged upstream of the first alternative fuel supply branch (1021) and the second alternative fuel supply branch (1022), and a second flow switch (17) electrically connected to the sixth valve (15) and the eighth valve (16), and the purge valve (19) is arranged in parallel with the second flow switch (17).

6. The test system (100) according to claim 5, characterized in that: The purge valve (19) enables the second flow switch (17) to simultaneously open the first alternative fuel supply branch (1021) and the second alternative fuel supply branch (1022) for inert gas purge.

7. The test system (100) according to claim 3, characterized in that: The first valve (1), the third valve (21), the fifth valve (12) and the seventh valve (22) are all manual valves, and the second valve (4), the fourth valve (5), the sixth valve (15) and the eighth valve (16) are all electric valves.

8. The test system (100) according to claim 1, characterized in that: The alternative fuel supply flow path (102) further comprises an alternative fuel concentration detector (20) arranged downstream of the first alternative fuel supply branch (1021) and the second alternative fuel supply branch (1022).

9. The test system (100) according to claim 1, characterized in that: The first range flow meter (2) and the fourth range flow meter (14) respectively correspond to the consumption rates of the traditional fuel and the alternative fuel that satisfy the dual-fuel engine in the alternative fuel mode; the second range flow meter (3) and the third range flow meter (13) respectively correspond to the consumption rates of the traditional fuel and the alternative fuel that satisfy the dual-fuel engine in the traditional fuel mode.

10. A dual-fuel engine fuel consumption test method (100), characterized in that: Applicable to the test system (100) according to any one of claims 1 to 9, the test method comprising: Setting a first trigger flow rate corresponding to the conventional fuel supply flow path (101) and a second trigger flow rate corresponding to the alternative fuel supply flow path (102); When the consumption of the conventional fuel is less than the first trigger flow rate, the first conventional fuel supply branch (1011) is opened and the second conventional fuel supply branch (1012) is closed; when the consumption of the conventional fuel is above the first trigger flow rate, the first conventional fuel supply branch (1011) is closed and the second conventional fuel supply branch (1012) is opened; When the consumption of the alternative fuel is less than the second trigger flow rate, the first alternative fuel supply branch (1021) is opened and the second alternative fuel supply branch (1022) is closed; when the consumption of the alternative fuel is above the second trigger flow rate, the first alternative fuel supply branch (1021) is closed and the second alternative fuel supply branch (1022) is opened.

11. The testing method (100) according to claim 10, characterized in that: The alternative fuel supply flow path (101) further comprises a purge valve (19) arranged upstream of the first alternative fuel supply branch (1021) and the second alternative fuel supply branch (1022); when the purge valve (19) is opened, the first alternative fuel supply branch (1021) and the second alternative fuel supply branch (1022) are opened simultaneously.

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