Dimethyl ether machine and lithium battery hybrid power system and ship

Abstract

The invention 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 invention belongs to the technical field of ship processing and production, and relates to a dimethyl ether machine and lithium battery hybrid power system and a ship. Background Art

[0002] As a means of navigation at sea, ships need to have good endurance in order to travel long distances. Existing pure electric ships cannot meet the endurance requirements. If diesel ships are used, there are stricter requirements for ship emissions in some special navigation areas and during navigation in and out of ports. Diesel emissions are more polluting and do not meet low emission requirements. Summary of the invention

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

[0004] In order to achieve the above object, the technical solution of the present invention is to provide a dimethyl ether engine and lithium battery hybrid power system, which includes:

[0005] DC busbars, at least two sets;

[0006] A cross-screen switch is arranged between adjacent DC busbars to control the on / off of two adjacent groups of DC busbars; a hybrid power system comprises an electric system and a motor system connected in parallel, and each group of DC busbars is provided with a hybrid power system; the motor system is a dimethyl ether generator set;

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

[0008] According to the present invention, each hybrid power system further comprises a dimethyl ether generator set and two lithium battery sets connected in parallel therewith; the lithium battery port operates in a constant voltage mode as a voltage source; and a voltage outer loop and a current inner loop control are adopted. The dimethyl ether generator set operates in a power mode, and a power outer loop and a current inner loop control are adopted.

[0009] According to the present invention, further, a circuit breaker is provided between the propulsion motor group and the corresponding DC busbar, and the circuit breaker is turned on and off to select whether the corresponding propulsion motor is working.

[0010] According to the present invention, further, a circuit breaker is provided between each lithium battery group and the DC busbar, and the circuit breaker is turned on and off to select whether the corresponding lithium battery group is working.

[0011] According to the present invention, further, a circuit breaker is provided between the dimethyl ether generator set and the corresponding DC busbar, and the circuit breaker is turned on and off to select whether the corresponding dimethyl ether generator set is working.

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

[0013] According to the present invention, further, 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; and the transformer is used to provide 440V and 230V voltages to the daily loads respectively.

[0014] According to the present invention, further, when the load power is less than 0.9Pn1 and the SOC is greater than 30%, the mode is switched to the pure electric mode;

[0015] Pure electric mode, pure dimethyl ether mode and hybrid mode.

[0016] Load power < 0.9Pn2, switch to pure DME mode I, that is, one of the DME units is put into operation, Pn2 refers to the rated power of the DME unit;

[0017] 0.9Pn2<load power<2Pn2, switch to pure DME mode II, that is, two DME units are put into operation, Pn2 refers to the rated power of the DME units;

[0018] 0.3Pn1<load power<0.9Pn2, switch to mode IV: one DME generator and two lithium battery groups operate together;

[0019] 0.9Pn2<load power<0.3Pn1+0.9Pn2, switch to mode VIII: two DME generators and two lithium battery groups operate together;

[0020] 0.9Pn1<load power<0.9Pn2, and SOC>20%, switch to mode VI: one DME generator and four lithium battery groups operate together;

[0021] 0.9Pn2<load power<2Pn2+Pn1, and SOC>20%, switch to mode VII: two DME generators and four lithium batteries operate together.

[0022] According to the present invention, further, a backup dimethyl ether generator set is also included.

[0023] Another object of the present invention is to provide a ship, which comprises the above-mentioned dimethyl ether engine and lithium battery hybrid power system, so as to meet the ship's endurance and reduce pollutant emissions.

[0024] The beneficial effect of the present invention is that a dimethyl ether generator set is used to replace a traditional diesel generator set, and then a lithium battery pack is used for hybrid power supply. The hybrid power system can not only ensure the continuous power output of the ship, but also meet the requirements of reducing emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a schematic diagram of the connection of electronic components of a dimethyl ether engine and lithium battery hybrid power system of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0027] See also Figure 1 , is a schematic diagram of the connection of electronic components of a dimethyl ether engine and a lithium battery hybrid power system; a dimethyl ether engine and a lithium battery hybrid power system disclosed in an embodiment of the present application has a long endurance and is particularly suitable for use on routes with long route distances. It includes DC busbars 23 and 24 controlled by a joint screen switch 25, and the DC busbars 23 and 24 are respectively connected to a group of hybrid power systems and a group of propulsion motors 7 and 8; one of the hybrid systems includes a dimethyl ether generator set 1, 2 and a lithium battery set 3, 4 or 5, 6 connected in parallel therewith. In order to avoid temporary failure of the two dimethyl ether generator sets, a backup dimethyl ether generator set is equipped. When the two dimethyl ether generator sets fail, the backup dimethyl ether generator set is started.

[0028] Specifically, circuit breakers 19 and 22 are arranged between the propulsion motors 7 and 8 and their corresponding DC busbars 23 and 24, and the setting of the circuit breakers controls the selection of the corresponding propulsion motors; circuit breakers 14, 15, 17 and 18 are arranged between each group of lithium battery groups 3, 4, 5 and 6 and the DC busbars 23 and 24, and the setting of the circuit breakers controls the selection of the corresponding lithium battery groups; circuit breakers 13 and 16 are arranged between the dimethyl ether generator group 1 or 2 and its corresponding DC busbars 23 and 34, and the setting of the circuit breakers controls the selection of the corresponding dimethyl ether generator group.

[0029] The lithium battery packs 3, 4, 5, 6 are connected to the corresponding DC busbars 23, 24 via inverters DC / AC 26, 27, 28, 29 respectively.

[0030] Each set of DC busbars 23, 24 is connected to the load voltage through the daily distribution board. Circuit breakers 20, 21 are arranged between the DC busbars 23, 24 and the daily distribution board. The setting of the circuit breakers adjusts the voltage selection; transformers 30, 31 are also arranged between the daily distribution board and the corresponding DC busbars 23, 24. Among them, the load voltage includes a number of 400V daily loads 9 and a number of 230v daily loads 10 arranged in parallel. A transformer 32 is arranged between the 230v daily load 10 and the daily distribution board. Three transformers 30, 31, 32 are used to provide 440v and 230v voltages to the daily loads respectively; in order to improve the heat dissipation effect of the system, heat dissipation fans 11, 12 are arranged on the daily distribution board side.

[0031] 1) Pure electric mode

[0032] When the load power is less than 0.9Pn1, the four groups of lithium batteries 3, 4, 5, and 6 are connected to the grid at the same time, that is, the inter-screen switch 25 is connected, and the SOC is greater than 30%, and the mode can be switched to pure electric mode, where Pn1 refers to the total rated power of the lithium battery group. Under normal circumstances, all four groups of lithium batteries are put into operation. Among them, two groups of lithium battery ports operate in constant voltage mode as voltage sources; voltage outer loop and current inner loop control are adopted. The other two groups of lithium battery ports operate in constant current mode as current sources; single current loop control is adopted.

[0033] 2) Pure dimethyl ether mode:

[0034] When the load power is less than 0.9Pn2 and the lithium battery pack is unavailable or off-grid, the system can be switched to pure DME mode I, that is, one of the DME units is put into operation, and Pn2 refers to the rated power of the DME unit.

[0035] 0.9Pn2<load power<2Pn2, when the lithium battery pack is unavailable or off-grid, it can be switched to pure DME mode II, that is, two DME units are put into operation, and Pn2 refers to the rated power of the DME unit.

[0036] When the DME unit needs to intervene, but both DME units fail, the system can be switched to pure DME mode III, that is, the standby DME unit is put into operation, and Pn2 refers to the rated power of the DME unit.

[0037] 2) Hybrid mode:

[0038] Under normal circumstances, all four groups of lithium batteries are put into use, that is, the system works in mode VII or mode IX; but it does not rule out the possibility that a single group of lithium batteries works abnormally, in which case the system works in mode VI or mode VIII.

[0039] 0.3Pn1<load power<0.9Pn2, when a single lithium battery is unavailable or off-grid, it can be switched to mode IV: one DME generator and two lithium battery groups operate together; that is, the circuit breaker of the corresponding operating component is closed, and the circuit breakers of other components are controlled to be disconnected;

[0040] 0.9Pn2<load power<0.3Pn1+0.9Pn2, when a single lithium battery is unavailable or off-grid, it can be switched to mode VIII: two DME generators and two lithium battery groups operate together;

[0041] The lithium battery port operates in constant voltage mode as a voltage source, using voltage outer loop and current inner loop control. The dimethyl ether generator set operates in power mode, using power outer loop and current inner loop control.

[0042] 0.9Pn1<load power<0.9Pn2, two lithium battery groups are connected to the grid at the same time, and SOC>20%, it can be switched to mode VI: one DME generator and four lithium battery groups operate together;

[0043] 0.9Pn2<load power<2Pn2+Pn1, two sets of lithium batteries are on the grid at the same time, and SOC>20%, it can be switched to mode VII: two DME generators and four sets of lithium batteries operate together.

[0044] When the system is running, the on-site control personnel can select the appropriate mode according to the actual situation of the ship. Generally speaking, the system can work in three operating states: "automatic", "semi-automatic" and "manual", which can be selected on local and remote workstations.

[0045] When the system is running, the operator can switch the operating mode of the hybrid power system according to the current ship operating conditions and actual needs. Generally speaking, the system can operate in three operating states: "automatic", "semi-automatic" and "manual", which can be selected at will on-site and remote workstations.

[0046] 1) Automatic operation

[0047] Automatic operation means that the start and stop control of the DME generator set, load distribution, and charge and discharge management of the lithium battery pack are all controlled by the control system. At this time, the system runs in the set mode according to the operator's pre-selection: pure electric mode, hybrid mode, and pure DME mode, and automatically switches as needed.

[0048] When the pure electric mode is selected, the system automatically detects whether the pure electric operation conditions are met and switches to the pure electric mode when conditions permit. Otherwise, the pure electric mode button is displayed as unavailable and the pure electric operation mode cannot be switched;

[0049] After switching to pure electric mode, the generator set will stop and the lithium battery pack will supply the power load demand of the entire ship;

[0050] When the pure electric operation reaches the low power level of the lithium battery (SOC is less than 20%) or when the full ship load exceeds the pure electric operation limit, the system will automatically switch to hybrid mode, start the dimethyl ether generator set, and prompt the operator to change the operation mode. Even when the system meets the pure electric operation conditions again, such as the dimethyl ether unit charging the lithium battery during navigation, the system will not automatically switch back to pure electric mode.

[0051] Generally, pure electric mode is used when entering and leaving the port, and hybrid mode is used under navigation conditions. The control logic core of the system in hybrid mode is designed to allow the generator set to operate in the most reasonable load range to achieve its economical and high energy efficiency characteristics.

[0052] When the system is sailing, if the pure lithium battery alone cannot meet the total load demand of the entire ship, the single dimethyl ether generator set needs to be automatically started for power supply. At this time, the four lithium batteries bear the load demand outside the dimethyl ether unit, that is, it operates in the mode. When the SOC of the lithium battery group is consumed to 20%, another generator set is automatically started. The two generator sets share the load of the entire ship, that is, the system automatically enters the pure dimethyl ether mode.

[0053] Generally, when the four lithium batteries are exhausted or the lithium batteries are off-grid due to operation, the pure DME mode is selected. After switching to the pure DME mode, there is no switching to the hybrid mode or the pure electric mode. The DME unit supplies the power load demand of the entire ship during the entire operation process.

[0054] Considering the energy conversion efficiency and operation economy, when the system is running, the lithium battery will not be charged through the dimethyl ether unit. When the shore power is connected, the shore power will be used to charge the lithium battery pack.

[0055] 2) Semi-automatic operation

[0056] Semi-automatic operation means that the operator needs to manually start and stop the dimethyl ether generator set and lithium battery pack at the remote workstation. There is an interlocking relationship between the generator set and the battery pack. The battery pack is started first. In emergency or special conditions, the dimethyl ether generator set is started and the battery pack is turned off. That is, the system can only choose pure electric mode or 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. The generator set operates at a fixed power given by humans. If the lithium battery is started, charging or discharging can be further selected through the remote control station. Similarly, the shutdown instructions of the dimethyl ether unit and the discharge instructions of the lithium battery pack also need to be issued by the operator through the remote workstation. Shutdown means unloading, and charging the lithium battery pack means loading.

[0057] 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.

[0058] 3) Manual operation

[0059] Manual operation means that the start and stop of the DME generator and lithium battery are controlled by the operator on site. At this time, the operation of the DME generator set is operated beside the machine, and the power is given manually. The operator can control the start and stop of any lithium battery on site. When the lithium battery pack is charged, the operator can select "charge start" and "charge end". Manual operation is usually carried out under the condition of debugging and control system failure.

[0060] The dimethyl ether fuel and lithium battery hybrid power system is equipped with electric propulsion and has the ability to demonstrate and verify key technologies such as overall system design technology, modeling technology, matching optimization technology, and energy management system design technology. Its operating mode takes into account the actual ship working conditions while taking into account the characteristics of various energy forms to greatly improve the economy of the ship during actual operation. The system design and application are both scalable and can provide technical support for other new energy-related research and the optimized operation of actual ships.

[0061] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. 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 regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and equivalent changes made by using the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes 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 hybrid power system of a dimethyl ether engine and a lithium battery, wherein: include, DC busbars, at least two sets; A cross-screen switch is arranged between adjacent DC busbars to control the on / off of two adjacent groups of DC busbars; a hybrid power system comprises an electric system and a motor system connected in parallel, and each group of DC busbars is provided with a hybrid power system; the motor system is a dimethyl ether generator set; A propulsion unit is connected to the DC busbar, and a group of the DC busbars is provided with a group of the propulsion units; The daily load combination distributes the voltage required by the power system through the daily distribution board.

2. A dimethyl ether engine and lithium battery hybrid power system as claimed in claim 1, wherein: Each group of hybrid power systems includes a dimethyl ether generator set and two lithium battery sets connected in parallel; the lithium battery port operates in constant voltage mode as a voltage source; voltage outer loop and current inner loop control are adopted. The dimethyl ether generator set operates in power mode, and power outer loop and current inner loop control are adopted.

3. A dimethyl ether engine and lithium battery hybrid power system as claimed in claim 1, wherein: A circuit breaker is provided between the propulsion motor group and the corresponding DC busbar, and the circuit breaker is turned on and off to select whether the corresponding propulsion motor is working.

4. A dimethyl ether engine and lithium battery hybrid power system as claimed in claim 2, wherein: A circuit breaker is provided between each lithium battery group and the DC busbar, and the circuit breaker is turned on and off to select whether the corresponding lithium battery group is working.

5. A dimethyl ether engine and lithium battery hybrid power system as claimed in claim 1 or 2, wherein: A circuit breaker is provided between the dimethyl ether generator set and the corresponding DC busbar, and the circuit breaker is turned on and off to select whether the corresponding dimethyl ether generator set is working.

6. A hybrid power system of dimethyl ether engine and lithium battery as claimed in claim 2, wherein: An inverter is arranged between the lithium battery pack and the DC busbar.

7. A hybrid power system of dimethyl ether engine and lithium battery as claimed in claim 1, wherein: The daily load combination includes a plurality of 400V daily loads and a plurality 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; and the transformer is used to provide 440V and 230V voltages to the daily loads respectively.

8. A dimethyl ether engine and lithium battery hybrid power system as claimed in claim 1, wherein: When the load power is less than 0.9Pn1 and the SOC is greater than 30%, the system switches to pure electric mode. Pure electric mode, pure dimethyl ether mode and hybrid mode. Load power < 0.9Pn2, switch to pure DME mode I, that is, one of the DME units is put into operation, Pn2 refers to the rated power of the DME unit; 0.9Pn2<load power<2Pn2, switch to pure DME mode II, that is, two DME units are put into operation, Pn2 refers to the rated power of the DME units; 0.3Pn1<load power<0.9Pn2, switch to mode IV: one DME generator and two lithium battery groups operate together; 0.9Pn2<load power<0.3Pn1+0.9Pn2, switch to mode VIII: two DME generators and two lithium battery groups operate together; 0.9Pn1<load power<0.9Pn2, and SOC>20%, switch to mode VI: one DME generator and four lithium battery groups operate together; 0.9Pn2<load power<2Pn2+Pn1, and SOC>20%, switch to mode VII: two DME generators and four lithium batteries operate together.

9. A dimethyl ether engine and lithium battery hybrid power system as claimed in claim 1 or 8, wherein: It also includes a backup dimethyl ether generator set.

10. A vessel, wherein: The invention comprises a hybrid power system using the dimethyl ether engine and a lithium battery as described in any one of claims 1 to 9.

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