Dimethyl ether machine and lithium battery hybrid power system and ship

Abstract

The utility model belongs to the technical field of ship processing and production, and discloses a dimethyl ether machine and lithium battery hybrid power system and a ship. The screen connection switches are arranged between the adjacent direct-current busbars and used for controlling the on-off of the two adjacent groups of direct-current busbars; the hybrid power system comprises an electric system and a maneuvering system which are connected in parallel, and each group of direct current busbars is provided with one hybrid power system; the maneuvering system is a dimethyl ether generator set; the propulsion units are connected with the direct-current busbars, and one group of direct-current busbars is provided with one group of propulsion units; and the daily load combination distributes the voltage required by the power system through a daily distribution board. The dimethyl ether generator set is used for replacing a traditional diesel generator set, then the lithium battery pack is used for hybrid power supply, and the hybrid power system not only can guarantee continuous power output of the ship, but also can guarantee the requirement for reducing emission.

Description

Technical Field

[0001] The utility model belongs to the technical field of ship processing and production, and relates to a dimethyl ether engine and lithium battery hybrid power system and a ship. Background Art

[0002] As a maritime navigation tool, a ship needs to have good endurance to travel longer routes. Existing pure electric ships cannot meet the demand for endurance. If diesel ships are used, there are relatively strict requirements for ship emissions during the navigation in some special sea areas and when entering and leaving ports. The emissions of diesel are highly polluting and do not meet the low-emission requirements. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a dimethyl ether engine and lithium battery hybrid power system.

[0004] To achieve the above object, the technical solution of the utility model is to provide a dimethyl ether engine and lithium battery hybrid power system, which includes:

[0005] At least two groups of DC busbars;

[0006] A parallel screen switch is arranged between adjacent DC busbars to control the on-off of adjacent two groups of DC busbars; the hybrid power system includes a parallel electric system and a motor system, and one hybrid power system is arranged for each group of DC busbars; the motor system is a dimethyl ether generator set;

[0007] A propulsion unit is connected to the DC busbar, and one propulsion unit is arranged for each group of DC busbars; the daily load combination distributes the required voltage of the power system through a daily power distribution board.

[0008] According to the utility model, further, each group of hybrid power systems includes a dimethyl ether generator set and two lithium battery packs connected in parallel thereto; the lithium battery port operates in a constant voltage mode and serves as a voltage source; voltage outer loop and current inner loop control are adopted. The dimethyl ether generator set operates in a power mode and adopts power outer loop and current inner loop control.

[0009] According to the utility model, further, a circuit breaker is arranged between the propulsion motor unit and its corresponding DC busbar, and the on-off of the circuit breaker selects whether the corresponding propulsion motor works.

[0010] According to the utility model, further, a circuit breaker is arranged between each group of lithium battery packs and the DC busbar, and the on-off of the circuit breaker selects whether the corresponding lithium battery pack works.

[0011] According to the present utility model, further, a circuit breaker is provided between the dimethyl ether generating set and its corresponding DC busbar, and the circuit breaker selects whether the corresponding dimethyl ether generating set operates by turning on and off.

[0012] According to the present utility model, further, an inverter is provided between the lithium battery pack and the DC busbar.

[0013] According to the present utility model, further, the daily load combination includes a plurality of 400V daily loads and a plurality of 230V daily loads connected in parallel; a transformer is provided between the daily load and the daily switchboard; a transformer is also provided between the daily switchboard and its corresponding DC busbar; the transformer is used to provide 440V and 230V voltages to the daily loads respectively.

[0014] According to the present utility model, further, among them,

[0015] When the load power < 0.9Pn1 and SOC > 30%, switch to the pure electric mode;

[0016] Pure electric mode, pure dimethyl ether mode and hybrid mode.

[0017] When the load power < 0.9Pn2, switch to the pure dimethyl ether mode I, that is, one of the dimethyl ether generating sets is put into operation, where Pn2 refers to the rated power of the dimethyl ether generating set;

[0018] When 0.9Pn2 < load power < 2Pn2, switch to the pure dimethyl ether mode II, that is, two dimethyl ether generating sets are put into operation, where Pn2 refers to the rated power of the dimethyl ether generating set;

[0019] When 0.3Pn1 < load power < 0.9Pn2, switch to mode IV: one dimethyl ether generator and two groups of lithium battery packs operate together;

[0020] When 0.9Pn2 < load power < 0.3Pn1 + 0.9Pn2, switch to mode VIII: two dimethyl ether generators and two groups of lithium battery packs operate together;

[0021] When 0.9Pn1 < load power < 0.9Pn2 and SOC > 20%, switch to mode VI: one dimethyl ether generator and four groups of lithium battery packs operate together;

[0022] When 0.9Pn2 < load power < 2Pn2 + Pn1 and SOC > 20%, switch to mode VII: two dimethyl ether generators and four groups of lithium batteries operate together.

[0023] According to the present utility model, further, it further includes a standby dimethyl ether generator set.

[0024] Another object of the present utility model is to provide a ship, which includes the above-mentioned dimethyl ether engine and lithium battery hybrid power system, reducing pollutant emissions while meeting the ship's endurance.

[0025] The beneficial effects of the present utility model are as follows: using a dimethyl ether generator set to replace the traditional diesel generator set and then using a lithium battery pack for hybrid power supply. This hybrid power system can not only ensure the continuous power output of the ship but also meet the requirements of emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the connection of electronic components of the dimethyl ether engine and lithium battery hybrid power system of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present utility model will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present utility model and not to limit the scope of the present utility model. In addition, it should be understood that after reading the content taught by the present utility model, those skilled in the art can make various changes or modifications to the present utility model, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0028] Please refer to Figure 1 , which is a schematic diagram of the connection of electronic components of a dimethyl ether engine and lithium battery hybrid power system; a dimethyl ether engine and lithium battery hybrid power system disclosed in an embodiment of the present application has a long endurance and is especially suitable for use on routes with a relatively long distance. It includes a DC busbar 23, 24 whose on-off is controlled by a combined screen switch 25, and the DC busbars 23, 24 are respectively connected to a group of hybrid power systems and a group of propulsion motors 7, 8; one of the hybrid systems includes a dimethyl ether generator set 1, 2 and a lithium battery pack 3, 4 or 5, 6 connected in parallel thereto. In order to avoid temporary failures of the two dimethyl ether generator sets, a standby dimethyl ether generator set is equipped. When the two dimethyl ether generator sets fail, the standby dimethyl ether generator set is started.

[0029] Specifically, circuit breakers 19, 22 are provided between the propulsion motors 7, 8 and their corresponding DC busbars 23, 24, and the circuit breakers are used to control the selection of the corresponding propulsion motors; circuit breakers 14, 15, 17, 18 are provided between each lithium battery pack 3, 4, 5, 6 and the DC busbars 23, 24, and the circuit breakers are used to control the selection of the corresponding lithium battery packs; circuit breakers 13, 16 are provided between the dimethyl ether generator set 1 or 2 and their corresponding DC busbars 23, 34, and the circuit breakers are used to control the selection of the corresponding dimethyl ether generator sets.

[0030] The lithium battery packs 3, 4, 5, 6 are respectively connected to the corresponding DC busbars 23, 24 through inverters DC / AC 26, 27, 28, 29.

[0031] Each group of DC busbars 23 and 24 is connected to a load voltage through a daily power distribution board. Circuit breakers 20 and 21 are provided between the DC busbars 23 and 24 and the daily power distribution board to adjust the selection of voltage. Transformers 30 and 31 are also provided between the daily power distribution board and the corresponding DC busbars 23 and 24. Among them, the load voltage includes a number of parallel 400V daily loads 9 and a number of 230v daily loads 10. A transformer 32 is provided between the 230v daily load 10 and the daily power distribution board. Three transformers 30, 31, and 32 are used to provide 440v and 230v voltages to the daily loads respectively. To improve the heat dissipation effect of the system, cooling fans 11 and 12 are configured on the side of the daily power distribution board.

[0032] 1) Pure electric mode

[0033] When the load power < 0.9Pn1, the four groups of lithium batteries 3, 4, 5, and 6 are simultaneously online, that is, the parallel switch 25 is connected, and SOC > 30%, and it can be switched to the pure electric mode. Among them, Pn1 refers to the total rated power of the lithium battery pack. Under normal circumstances, the four groups of lithium batteries are all put into operation. Among them, the ports of two groups of lithium batteries operate in the constant voltage mode and serve as voltage sources; voltage outer loop current inner loop control is adopted. The ports of the other two groups of lithium batteries operate in the constant current mode and serve as current sources; single current loop control is adopted.

[0034] 2) Pure dimethyl ether mode:

[0035] When the load power < 0.9Pn2 and the lithium battery pack is unavailable or in the off-grid state, it can be switched to the pure dimethyl ether mode I, that is, one of the dimethyl ether units is put into operation. Pn2 refers to the rated power of the dimethyl ether unit.

[0036] When 0.9Pn2 < load power < 2Pn2 and the lithium battery pack is unavailable or in the off-grid state, it can be switched to the pure dimethyl ether mode II, that is, two dimethyl ether units are put into operation. Pn2 refers to the rated power of the dimethyl ether unit.

[0037] When it is necessary for the dimethyl ether machine to intervene, but both dimethyl ether units fail, it can be switched to the pure dimethyl ether mode III, that is, the standby dimethyl ether unit is put into operation. Pn2 refers to the rated power of the dimethyl ether unit.

[0038] 2) Hybrid mode:

[0039] Under normal circumstances, the four groups of lithium batteries are all put into use, that is, the system works in mode VII or mode IX; but the situation where a single group of lithium batteries works abnormally cannot be excluded. At this time, the system works in mode VI or mode VIII.

[0040] 0.3Pn1 < Load power < 0.9Pn2. When a single lithium battery pack becomes unavailable or the system is in an off-grid state, it can be switched to Mode IV: one dimethyl ether generator and two lithium battery packs operate together; that is, the circuit breakers of the corresponding operating components are closed, and the circuit breakers controlling other components are opened.

[0041] 0.9Pn2 < Load power < 0.3Pn1 + 0.9Pn2. When a single lithium battery pack becomes unavailable or the system is in an off-grid state, it can be switched to Mode VIII: two dimethyl ether generators and two lithium battery packs operate together.

[0042] The lithium battery port operates in a constant voltage mode as a voltage source; voltage outer loop and current inner loop control are adopted. The dimethyl ether generator set operates in a power mode, adopting power outer loop and current inner loop control.

[0043] 0.9Pn1 < Load power < 0.9Pn2. When two lithium battery packs are both on the grid and SOC > 20%, it can be switched to Mode VI: one dimethyl ether generator and four lithium battery packs operate together.

[0044] 0.9Pn2 < Load power < 2Pn2 + Pn1. When two lithium battery packs are both on the grid and SOC > 20%, it can be switched to Mode VII: two dimethyl ether generators and four lithium batteries operate together.

[0045] During system operation, on-site control personnel can select a suitable mode according to the actual situation of the ship. Generally speaking, the system can operate in three operating states: "automatic", "semi-automatic" and "manual", and can be selected on-site and at the remote workstation.

[0046] During system operation, operators can switch the operating mode of the hybrid power system according to the current ship conditions and actual needs. Generally speaking, the system can operate in three operating states: "automatic", "semi-automatic" and "manual", and can be freely selected on-site and at the remote workstation.

[0047] 1) Automatic operation

[0048] Automatic operation means that the start-stop control of the dimethyl ether generator set, load distribution, and charge-discharge management of the lithium battery pack are all controlled by the control system. At this time, the system operates in a set mode according to the operator's pre-selection: pure electric mode, hybrid mode, and pure dimethyl ether mode, and automatically switches as needed.

[0049] When the pure electric mode is selected, the system automatically detects whether the conditions for pure electric operation are met. When the conditions permit, it can be switched to the pure electric mode. Otherwise, the pure electric mode button is displayed as unavailable, and the pure electric operation mode cannot be switched.

[0050] After switching to the pure electric mode, the generator set will stop, and the lithium battery pack will supply the electrical load demand of the entire ship.

[0051] When the pure electric mode runs until the lithium battery has a low power level (i.e., SOC is less than 20%) or when the total ship load is greater than the pure electric operation limit, the system will automatically switch to the hybrid mode, start the dimethyl ether generator set, and prompt the operator of the change in the operation mode. Even when the system meets the pure electric operation conditions again, such as when the dimethyl ether unit charges the lithium battery during navigation, the system will not automatically switch back to the pure electric mode.

[0052] Generally, the pure electric mode is adopted when entering and leaving the port, and the hybrid mode is used under navigation conditions. The core of the control logic of the system in the hybrid mode aims to make the generator set operate in the most reasonable load range to achieve its economic and high energy efficiency characteristics.

[0053] When the system is in the navigation process and the power supply from only the pure lithium battery cannot meet the total ship load demand, the single dimethyl ether generator set needs to be automatically started for power supply. At this time, the four groups of lithium batteries bear the load demand other than the dimethyl ether unit, that is, they operate in the mode. When the SOC of the lithium battery pack is consumed to 20%, another generator set is automatically started. The two generator sets share the total ship load, that is, the system automatically enters the pure dimethyl ether mode.

[0054] Generally, when the four groups of lithium batteries are depleted or the lithium batteries are off-grid due to the operating state, the pure dimethyl ether mode is selected. After switching to the pure dimethyl ether mode, there will be no situation of switching to the hybrid mode or the pure electric mode, and the dimethyl ether unit supplies the total ship's electric load demand during the entire operation process.

[0055] Considering the energy conversion efficiency and operation economy, during the system operation, the lithium battery will not be charged through the dimethyl ether unit. When shore power is connected, shore power is used to charge the lithium battery pack.

[0056] 2) Semi-automatic operation

[0057] Semi-automatic operation means that the operator needs to manually start and stop the dimethyl ether generator set and the lithium battery pack at the remote workstation. There is an interlock relationship between the generator set and the battery pack. The battery pack is started first, and in case of emergency or special conditions, the dimethyl ether generator set is started and the battery pack is shut down, that is, the system can only select the pure electric mode or the pure dimethyl ether mode. If the operator manually issues a start command at the remote control station, the generator set starts, and the rectifier AC / DC detects the voltage difference and automatically connects to the grid, and the generator set operates at a fixed power given by the operator. If the lithium battery is started, charging or discharging can be further selected through the remote control station. Similarly, the shutdown of the dimethyl ether unit and the discharge command of the lithium battery pack also need to be issued by the operator through the remote workstation. Shutdown means unloading, while charging of the lithium battery pack means loading.

[0058] The "semi-automatic operation" mode is usually used when the control system fails and automatic control cannot be performed, or when the operator selects the working conditions according to the needs of the specific application.

[0059] 3) Manual operation

[0060] Manual operation means the DME generator and lithium battery are started and stopped by the operator through local control. In this case, the DME generator set is operated at the generator site, with power set manually. The operator can start and stop each lithium battery individually and, when charging the lithium battery pack, select "Start Charging" and "Stop Charging." Manual operation is typically used during commissioning or when the control system is not functioning properly.

[0061] This hybrid system, powered by dimethyl ether fuel and lithium batteries, features electric propulsion and demonstrates and verifies key technologies, including overall system design, modeling, matching optimization, and energy management system design. Its operational model comprehensively considers actual ship operating conditions and the characteristics of various energy sources, significantly improving the ship's operational economy. The system's design and application are scalable, providing technical support for other new energy-related research and optimized ship operations.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be considered as the scope of protection of the present invention. Any technician familiar with this profession can make some changes, modifications and equivalent changes made by using the technical content disclosed above without departing from the spirit and scope of the present invention, which are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A dimethyl ether engine and lithium battery hybrid power system, wherein, Including, At least two sets of DC busbars; Parallel connection switches, which are arranged between adjacent DC busbars to control the on / off of adjacent two sets of DC busbars; A hybrid power system, including a parallel electric system and a motor system, and one hybrid power system is arranged for each set of DC busbars; The motor system is a dimethyl ether generator set; Propulsion units, which are connected to the DC busbars, and one set of propulsion units is arranged for one set of DC busbars; Daily load combination, which distributes the required voltage of the power system through a daily distribution board.

2. The dimethyl ether engine and lithium battery hybrid power system according to claim 1, wherein, Each set of hybrid power systems includes a dimethyl ether generator set and two lithium battery packs connected in parallel with it; The lithium battery ports operate in a constant voltage mode and serve as voltage sources; Voltage outer loop and current inner loop control is adopted; The dimethyl ether generator set operates in a power mode and adopts power outer loop and current inner loop control.

3. The dimethyl ether engine and lithium battery hybrid power system according to claim 1, wherein, A circuit breaker is arranged between the propulsion unit and its corresponding DC busbar, and the on / off of the circuit breaker selects whether the propulsion motor of the corresponding propulsion unit works.

4. The dimethyl ether engine and lithium battery hybrid power system according to claim 2, wherein, A circuit breaker is arranged between each set of lithium battery packs and the DC busbar, and the on / off of the circuit breaker selects whether the corresponding lithium battery pack works.

5. The dimethyl ether engine and lithium battery hybrid system according to claim 1 or 2, wherein, A circuit breaker is arranged between the dimethyl ether generator set and its corresponding DC busbar, and the on / off of the circuit breaker selects whether the corresponding dimethyl ether generator set works.

6. The dimethyl ether engine and lithium battery hybrid power system according to claim 2, wherein, An inverter is arranged between the lithium battery pack and the DC busbar.

7. The dimethyl ether engine and lithium battery hybrid power system according to claim 1, wherein, The daily load combination includes a number of 400V daily loads and a number of 230V daily loads arranged in parallel; A transformer is arranged between the daily load and the daily distribution board; A transformer is also arranged between the daily distribution board and the corresponding DC busbar; Transformers are used to provide 440V and 230V voltages to the daily loads respectively.

8. The dimethyl ether engine and lithium battery hybrid power system according to claim 1, wherein When the load power < 0.9Pn1 and SOC > 30%, switch to the pure electric mode; Pure electric mode, pure dimethyl ether mode and hybrid mode; When the load power < 0.9Pn2, switch to the pure dimethyl ether mode I, that is, one of the dimethyl ether generator sets is put into operation, and Pn2 refers to the rated power of the dimethyl ether generator set; When 0.9Pn2 < load power < 2Pn2, switch to the pure dimethyl ether mode II, that is, two dimethyl ether generator sets are put into operation, and Pn2 refers to the rated power of the dimethyl ether generator set; When 0.3Pn1 < load power < 0.9Pn2, switch to mode IV: One dimethyl ether generator and two sets of lithium battery packs operate together; When 0.9Pn2 < load power < 0.3Pn1 + 0.9Pn2, switch to mode VIII: Two dimethyl ether generators and two sets of lithium battery packs operate together; When 0.9Pn1 < load power < 0.9Pn2 and SOC > 20%, switch to mode VI: One dimethyl ether generator and four sets of lithium battery packs operate together; When 0.9Pn2 < load power < 2Pn2 + Pn1 and SOC > 20%, switch to mode VII: Two dimethyl ether generators and four sets of lithium batteries operate together.

9. The dimethyl ether engine and lithium battery hybrid power system according to claim 1 or 8, wherein, It also includes a standby dimethyl ether generator set.

10. A ship, wherein, Including using the dimethyl ether engine and lithium battery hybrid power system according to any one of claims 1 - 9.

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