Marine frequency converter waste heat recovery and reuse system

Abstract

The application discloses a kind of marine frequency converter waste heat recovery and recycling system, it includes frequency converter, air extractor, temperature difference sensor, power generation power loop;Frequency converter and air extractor are equipped with air extractor air pipe between;Air extractor air pipe is equipped with check valve;Power generation power loop has working medium in pipeline;Power generation power loop includes evaporator, organic rankine cycle power generation device, condenser, working medium pump;Evaporator, organic rankine cycle power generation device, condenser, working medium pump are sequentially connected;Working medium pump is connected to evaporator.The application can recover and recycle waste heat generated by frequency converter, achieve the purpose of ship energy saving and emission reduction, it is both economical, and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of marine technology, and in particular to a waste heat recovery and reuse system for marine frequency converters. Background Technology

[0002] In recent years, with the increasing importance and urgency of energy conservation and emission reduction in ships, more energy-saving electrical equipment has been applied on board. For example, variable frequency drives are used for shaft generators, cooling water pumps, and engine room and cargo hold fans, thus optimizing power consumption through variable frequency technology.

[0003] The operating efficiency of a frequency converter determines the heat energy it generates. The formula for operating efficiency is n = (PO / PI) × 100%, where PO is the output power of the frequency converter, PI is the input power, and n is the operating efficiency. Most existing marine frequency converters have an efficiency of around 80-90%, meaning there is a 10-20% energy loss, most of which ultimately generates heat. Since the main components of frequency converters are high-precision electronic components such as insulated-gate bipolar transistors (IBGTs), which are not heat-resistant, the ideal operating temperature for frequency converters is recommended to be 0-40℃. However, when high-power frequency converters are used for extended periods, the internal temperature may reach 100-120℃, requiring water / air cooling to lower the temperature. Therefore, a large amount of cooling water / air is needed to cool the 10-20% waste heat.

[0004] Shipboard frequency converters typically use water cooling or air cooling for temperature control. Water cooling requires connecting cooling water pipes (fresh water or seawater) to the frequency converter; air cooling necessitates adding air conditioning within the frequency converter room. Regardless of the method used, external equipment is needed to cool the heat generated by the frequency converter. This wastes heat and consumes additional cooling water / air, making it unreasonable from both an energy-saving and economic perspective. Summary of the Invention

[0005] In order to overcome the above-mentioned defects in the existing technology, the present invention provides a waste heat recovery and reuse system for marine frequency converters.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] A marine frequency converter waste heat recovery and reuse system includes a frequency converter; it also includes an exhaust fan for extracting high-temperature air from the frequency converter, and a temperature difference sensor that can send a signal to the exhaust fan when the frequency converter heats up; an exhaust air pipe is provided between the frequency converter and the exhaust fan; a check valve is provided on the exhaust air pipe; the marine frequency converter waste heat recovery and reuse system also includes a power generation circuit; the power generation circuit contains a working fluid; the power generation circuit includes an evaporator that can heat the working fluid to a gaseous state by the high-temperature air delivered by the exhaust fan, an organic Rankine cycle power generation device that can generate electricity using the gaseous working fluid, a condenser for cooling the working fluid to a liquid state, and a working fluid pump for driving the working fluid to circulate in the circuit; the evaporator, the organic Rankine cycle power generation device, the condenser, and the working fluid pump are connected in sequence; the working fluid pump is connected to the evaporator.

[0008] Furthermore, the exhaust fan's outlet is connected to the evaporator.

[0009] Furthermore, the temperature difference sensor is located on the frequency converter, and there is an electrical connection between the temperature difference sensor and the exhaust fan.

[0010] Furthermore, there are multiple frequency converters, and each frequency converter is equipped with a temperature difference sensor.

[0011] Furthermore, a check valve is installed on the exhaust air pipe connected to each frequency converter.

[0012] Furthermore, there is one exhaust fan, and the exhaust air pipes of each frequency converter are connected to the exhaust fan.

[0013] Furthermore, the exhaust air ducts of the frequency converters in the same compartment are connected in series to the exhaust fan.

[0014] Furthermore, the exhaust air ducts of the frequency converters in different compartments are connected to the exhaust fan in parallel.

[0015] Furthermore, the exhaust fan is equipped with a bypass port.

[0016] Furthermore, the organic Rankine cycle power generation unit is connected to the main distribution board.

[0017] The beneficial effects of this invention are as follows: This invention can recover and reuse the waste heat generated by the frequency converter. Through this system, the waste heat generated by the frequency converter can be effectively recovered in a centralized manner, and then the heat energy can be converted into electrical energy, which is then used to supply power to the entire ship via the main switchboard, achieving the purpose of energy conservation and emission reduction for ships, which is both economical and environmentally friendly. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention. Detailed Implementation

[0019] The present invention will be described more clearly and completely below with reference to a preferred embodiment and the accompanying drawings.

[0020] like Figure 1 As shown, a marine frequency converter waste heat recovery and reuse system includes a frequency converter 10; it also includes an exhaust fan 11 for extracting high-temperature air from the frequency converter, a temperature difference sensor 12 that can send a signal to the exhaust fan when the frequency converter heats up; and an exhaust air pipe 13 is provided between the frequency converter 10 and the exhaust fan 11.

[0021] A check valve 14 is installed on the exhaust air duct 13. A temperature difference sensor 12 is installed on the frequency converter 10, and there is an electrical connection between the temperature difference sensor 12 and the exhaust fan 11.

[0022] The marine inverter waste heat recovery and reuse system also includes a power generation circuit 20; the power generation circuit contains a working fluid; the power generation circuit 20 includes an evaporator 21 that can heat the working fluid to a gaseous state by high-temperature air delivered by a fan, an organic Rankine cycle power generation device 22 that can generate electricity using the gaseous working fluid, a condenser 23 for cooling the working fluid to a liquid state, and a working fluid pump 24 for driving the working fluid to circulate within the circuit; the evaporator 21, the organic Rankine cycle power generation device 22, the condenser 23, and the working fluid pump 24 are connected in sequence; the working fluid pump 24 is connected to the evaporator 21.

[0023] The exhaust port of the exhaust fan 11 is connected to the evaporator 21.

[0024] There are multiple frequency converters (10), and each frequency converter is equipped with a temperature difference sensor.

[0025] Each frequency converter's exhaust air duct is equipped with a check valve. The check valve prevents air from flowing back.

[0026] There is one exhaust fan 11, and the exhaust air pipes of each frequency converter are connected to the exhaust fan.

[0027] The air ducts of the frequency converters in the same compartment are connected to the exhaust fan in series.

[0028] The exhaust air ducts of the frequency converters in different compartments are connected to the exhaust fan in parallel.

[0029] The exhaust fan 11 is equipped with a bypass port 15.

[0030] The condenser in the power generation circuit has a condensation source. The condenser uses cooling water as the condensation source.

[0031] The organic Rankine cycle power generation unit is connected to the main distribution board 25.

[0032] Figure 1 A dashed line indicates a signal line, and a dotted line indicates an air line.

[0033] The working principle of the marine frequency converter waste heat recovery and reuse system is as follows:

[0034] When the frequency converter is operating, the temperature difference sensor detects a temperature rise and sends a signal to the exhaust fan, which then runs and extracts the high-temperature air from the frequency converter. The extracted high-temperature air is sent to the evaporator, where it exchanges heat with a low-temperature liquid working fluid, producing a high-pressure, high-temperature gaseous working fluid. This high-pressure, high-temperature gaseous working fluid enters the organic Rankine cycle power generation unit, where the generator produces electricity to power the main switchboard. The low-pressure gaseous working fluid discharged from the organic Rankine cycle power generation unit enters the condenser, where it exchanges heat with external cooling water, forming a low-pressure liquid working fluid. After being pressurized by the working fluid pump, the low-pressure liquid working fluid becomes a high-pressure, low-temperature liquid working fluid and returns to the evaporator, thus completing the heat exchange cycle.

[0035] When a fault occurs in the power generation circuit, the exhaust fan can discharge the centrally recovered waste heat through the bypass port.

[0036] When all frequency converters are located in the same compartment, waste heat recovery can be carried out by simply using a series connection.

[0037] At that time, the frequency converters were located in different compartments, such as the central control room and the frequency converter room. Figure 1 As shown, the waste heat from frequency converters distributed in different locations can be collected and centrally sent to the evaporator in parallel.

[0038] This invention enables the recovery and reuse of waste heat generated by frequency converters. This system effectively and centrally recovers the waste heat generated by the frequency converters, converts the heat energy into electrical energy, and supplies power to the entire ship via the main switchboard, achieving the goal of energy conservation and emission reduction for ships—both economical and environmentally friendly.

[0039] Furthermore, given the large size and high heat dissipation of modern marine frequency converters, it is even more meaningful to use this system for waste heat recovery and reuse.

[0040] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A waste heat recovery and reuse system for marine frequency converters, comprising a frequency converter; characterized in that, It also includes an exhaust fan for drawing out high-temperature air from the inverter, a temperature difference sensor that sends a signal to the exhaust fan when the inverter heats up, an exhaust air pipe between the inverter and the exhaust fan, and a check valve on the exhaust air pipe. The marine inverter waste heat recovery and reuse system also includes a power generation circuit. The power generation circuit contains a working fluid. The power generation circuit includes an evaporator that heats the working fluid to a gaseous state using the high-temperature air supplied by the exhaust fan, and an organic Rankine cycle power generation device that uses the gaseous working fluid to generate electricity. A condenser for cooling the working fluid to a liquid state and a working fluid pump for driving the working fluid to circulate within the loop; an evaporator, an organic Rankine cycle power generation unit, a condenser, and a working fluid pump are connected in sequence; the working fluid pump is connected to the evaporator; the exhaust fan outlet is connected to the evaporator; a temperature difference sensor is installed on the frequency converter, and the temperature difference sensor and the exhaust fan are electrically connected; the exhaust air pipes of the frequency converters in the same compartment are connected to the exhaust fan in series; the exhaust air pipes of the frequency converters in different compartments are connected to the exhaust fan in parallel; the exhaust fan is equipped with a bypass port.

2. The marine frequency converter waste heat recovery and reuse system as described in claim 1, characterized in that, There are multiple frequency converters, and each frequency converter is equipped with a temperature difference sensor.

3. The marine frequency converter waste heat recovery and reuse system as described in claim 2, characterized in that, Each frequency converter's exhaust air pipe is equipped with a check valve.

4. The marine frequency converter waste heat recovery and reuse system as described in claim 3, characterized in that, There is one exhaust fan, and the exhaust air pipes of each frequency converter are connected to the exhaust fan.

5. The marine frequency converter waste heat recovery and reuse system as described in claim 1, characterized in that, The organic Rankine cycle power generation unit is connected to the main distribution board.

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