Regenerative power generation and carbon dioxide capture system using waste heat of internal combustion engine

Abstract

A regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine of the present invention comprises: a refrigerator; a liquid carbon dioxide storage tank and a gaseous carbon dioxide storage tank capable of storing carbon dioxide (CO2); a transfer valve (V1) for transferring liquid carbon dioxide to an external liquid carbon dioxide transfer unit; a flow control valve (CV2) for regulating the amount of compressed gaseous carbon dioxide; a temperature detection unit for detecting an inlet and an outlet of the refrigerator; a flow control valve (CV3) enabling the discharging of non-condensable gas exhaust; a flow control valve (CV4) for regulating a flow enabling the transfer of liquid carbon dioxide to the gaseous carbon dioxide storage tank; a flow path forming valve (S1) for forming a flow path for making a flow path for transferring liquid carbon dioxide to the outside; a flow path forming valve (S2) for forming flow paths by dividing flow paths of the liquid carbon dioxide storage tank and the gaseous carbon dioxide storage tank; a flow path forming valve (S3) for forming a flow path enabling the suctioning of exhaust gas; and a fourth controller enabling the distribution of a power supply to a battery, the refrigerator, and a compression pump by using electricity received from a generator.

Description

Regenerative power generation and carbon dioxide capture system using waste heat from internal combustion engines

[0001] The present invention relates to a regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine, which, when an internal combustion engine reaches an operating temperature, transfers compressed gaseous carbon dioxide stored in a gaseous carbon dioxide (CO2) tank to a heat exchanger using a flow control valve, injects carbon dioxide heated by heat exchange through a nozzle, rotates a turbine, and compresses gaseous carbon dioxide to produce liquid carbon dioxide by driving a compression pump using electricity produced by a generator or electricity charged in a battery.

[0002] A carbon dioxide power generation system linked to an engine capable of increasing power generation and energy efficiency and reducing greenhouse gases is described in Korean Patent Publication No. 10-2562651 (July 28, 2023).

[0003] A carbon dioxide power generation system linked to an engine comprises an engine, a turbine that is driven by exhaust gas discharged from the engine and supplies compressed air to the engine, a first compressor, a circulation pipe through which carbon dioxide circulates, a first heater that heats carbon dioxide circulating in the circulation pipe through heat exchange with exhaust gas, and a carbon dioxide turbine that is driven by carbon dioxide that has passed through the first heater.

[0004] The carbon dioxide power generation system is equipped with a cooler that cools carbon dioxide passing through a carbon dioxide turbine, a pump or second compressor that compresses carbon dioxide passing through the cooler, and an engine cooling heat exchanger that cools the engine through heat exchange with carbon dioxide passing through the second compressor.

[0005] The carbon dioxide power generation system is equipped with a scavenging heat exchanger that cools compressed air supplied to the engine through heat exchange with carbon dioxide that has passed through an engine cooling heat exchanger, and a reheater that performs heat exchange between carbon dioxide that has passed through the scavenging heat exchanger and has been supplied to the first heater and carbon dioxide that has passed through the carbon dioxide turbine and has been supplied to the cooler.

[0006] The carbon dioxide power generation system is equipped with a heat pump that receives carbon dioxide that has passed through a pump or a second compressor and exchanges heat with a fluid for hot water or heating, and a three-way valve for branching and supplying carbon dioxide that has passed through the pump or the second compressor to an engine cooling heat exchanger and a heat pump.

[0007] A supercritical carbon dioxide power generation system using supercritical carbon dioxide, reflecting an external heat sink (outside air, water) in the cooling and pressure control of carbon dioxide, and having a two-path power generation circuit, and a method for operating a supercritical carbon dioxide power generation system according to the heat sink temperature are described in Korean Patent Publication No. 10-1752230 (July 4, 2017).

[0008] The supercritical carbon dioxide power generation system comprises a heat exchanger (101), a pump (601) for pressurizing carbon dioxide, and a first turbine (201) into which a portion of carbon dioxide that is pressurized and discharged from the pump (601) passes through the heat exchanger (101) and flows in.

[0009] A supercritical carbon dioxide power generation system is configured to include a recuperator (401) in which heat is exchanged between the remaining portion of carbon dioxide that is pressurized and discharged from a pump (601) and the carbon dioxide discharged from a first turbine (201), a second turbine (202) in which the remaining portion of carbon dioxide that is pressurized and discharged from a pump (601) passes through the recuperator (401) and flows in, a condenser (501) that cools the carbon dioxide that has passed through the recuperator (401) via the first turbine (201) and the carbon dioxide discharged from the second turbine (802), and a generator (301) connected to the first turbine (201) and the second turbine (202).

[0010] [Prior Art Literature]

[0011] [Patent Document]

[0012] (Patent Document 1) Korean Patent Publication KR 10-2562651 B1

[0013] (Patent Document 2) Korean Patent Registration No. KR 10-1752230 B1

[0014] The coolant temperature of vehicles powered by internal combustion engines is maintained at 60-120℃ and waste heat is released into the atmosphere. In the case of passenger cars, approximately 200g / km of carbon dioxide is emitted without capture.

[0015] In the case of hybrid internal combustion engines, energy can be stored using generators and batteries, but it cannot store more than a certain amount, and like internal combustion engines, waste heat is released into the atmosphere.

[0016] The purpose of the present invention is to drive a compression pump using regenerative power generation using waste heat from an internal combustion engine to compress gaseous carbon dioxide (CO2) and send the produced liquid carbon dioxide to a gaseous carbon dioxide tank for replenishment or to transport the captured carbon dioxide to the outside in order to effectively respond to the introduction of a carbon tax, etc.

[0017] The regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine of the present invention comprises a refrigerator, a liquid carbon dioxide storage tank capable of storing carbon dioxide (CO2), and a gaseous carbon dioxide storage tank.

[0018] The present invention comprises a transfer valve (V1) for transferring liquid carbon dioxide to an external liquid carbon dioxide transfer unit, a flow control valve (CV2) for controlling the amount of compressed gas carbon dioxide, a temperature sensing unit for sensing the temperature of the inlet and outlet of the refrigerator, and a flow control valve (CV3) for discharging non-condensable gas exhaust.

[0019] The present invention comprises a flow control valve (CV4) that controls the flow rate of liquid carbon dioxide to be transferred to a gaseous carbon dioxide storage tank, and a flow path forming valve (S1) that forms a flow path for transferring liquid carbon dioxide to the outside.

[0020] The present invention is a configuration comprising a flow path forming valve (S2) that divides the flow paths of a liquid carbon dioxide storage tank and a gaseous carbon dioxide storage tank to form a flow path, a flow path forming valve (S3) that forms a flow path that can suck exhaust gas, and a fourth controller that can distribute power received from a generator to a battery, a refrigerator, and a compression pump.

[0021] The present invention detects the temperature of the waste heat source emitted from an internal combustion engine by a temperature sensing unit (T2), and when the operating temperature is reached, compressed gaseous carbon dioxide (CO2) stored in a gaseous carbon dioxide (CO2) storage tank is transferred to a first heat exchanger (510) using a flow control valve (CV1) and a flow control valve (CV2).

[0022] The present invention is a configuration in which carbon dioxide (CO2) heated by a first heat exchanger is injected through a nozzle to drive a turbine and generate power as a generator.

[0023] The present invention is a configuration in which carbon dioxide (CO2), whose pressure has dropped due to turbine operation, undergoes heat exchange in a second heat exchanger and a third heat exchanger exposed to the atmosphere, and when the temperature of the heated carbon dioxide (CO2) drops, a compression pump is driven by electricity produced by a generator or electricity charged in a battery to recompress the carbon dioxide with the dropped temperature.

[0024] The present invention is a configuration in which, when the pressure of a gaseous carbon dioxide storage tank decreases due to a leak or a drop in temperature, gaseous carbon dioxide is sucked from the exhaust gas inlet of an internal combustion engine through a filter unit (90) and a flow forming valve to produce liquid carbon dioxide (CO2) using electricity produced by a generator or electricity charged in a battery.

[0025] In the present invention, gaseous carbon dioxide (CO2) can be liquefied at about 5 bar and -18°C, and the non-liquefied non-condensable gas is exhausted through the non-condensable gas exhaust section (60) by the flow control valve (CV3).

[0026] The liquid carbon dioxide (CO2) produced in the present invention is configured to be replenished into a gaseous carbon dioxide storage tank or the produced liquid carbon dioxide is transported to the outside through a liquid carbon dioxide transport unit.

[0027] The present invention is effective in introducing a carbon tax, etc. by driving a compression pump to generate regenerative power using waste heat from an internal combustion engine, compressing gaseous carbon dioxide (CO2), and sending the produced liquid carbon dioxide to a gaseous carbon dioxide tank to replenish it, or transporting the captured carbon dioxide to the outside.

[0028] Figure 1 is a schematic diagram of a regenerative power generation and carbon dioxide capture system using waste heat from an internal combustion engine according to the present invention.

[0029] The present invention relates to a regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine, which, when an internal combustion engine reaches an operating temperature, transfers compressed gaseous carbon dioxide stored in a gaseous carbon dioxide tank to a heat exchanger using a flow control valve, injects carbon dioxide heated by heat exchange through a nozzle, rotates a turbine, and compresses gaseous carbon dioxide to produce liquid carbon dioxide by driving a compression pump using electricity produced by a generator or electricity charged in a battery.

[0030] Hereinafter, with reference to the attached drawings, a regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine according to the present invention will be described in more detail.

[0031] Figure 1 is a schematic diagram of a regenerative power generation and carbon dioxide capture system using waste heat from an internal combustion engine according to the present invention.

[0032] A regenerative power generation and carbon dioxide capture system using waste heat from an internal combustion engine is configured to include a refrigerator (100), a liquid carbon dioxide storage tank (200) capable of storing carbon dioxide (CO2), and a gaseous carbon dioxide storage tank (300).

[0033] Liquid carbon dioxide can be transferred to an external liquid carbon dioxide transfer unit (70) through the transfer valve (V1).

[0034] The flow control valve (CV2) adjusts the opening inversely proportional to the temperature difference between the first temperature sensing unit (T1) and the second temperature sensing unit (T2) of the first heat exchanger (510), and when the pressure of the pressure sensing unit (P4) of the gaseous carbon dioxide storage tank (300) drops below the minimum operating pressure, the valve is closed to control the amount of compressed gaseous carbon dioxide.

[0035] The inlet and outlet temperatures of the refrigerator (100) are detected by a temperature sensing unit (T7, T8), and when the temperature difference between the temperature sensing units (T7, T8) becomes small due to non-condensable gas, the exhaust amount can be controlled by a flow control valve (CV3) that can discharge non-condensable gas.

[0036] The flow control valve (CV4) is a valve capable of controlling the flow rate that detects the pressure of the pressure sensing unit (P4) of the gaseous carbon dioxide storage tank (300) and opens the valve when the pressure drops to transfer liquid carbon dioxide to the gaseous carbon dioxide storage tank (300) to increase the pressure.

[0037] The flow path forming valve (S1) is a valve that forms a flow path to circulate gaseous carbon dioxide that has passed through the third heat exchanger (530) to the gaseous carbon dioxide storage tank (300) by forming a flow path, or to maintain pressure by supplying gaseous carbon dioxide from the gaseous carbon dioxide storage tank (300) to prevent liquid carbon dioxide from vaporizing in order to transport liquid carbon dioxide from the liquid carbon dioxide storage tank (200) to the outside.

[0038] The flow path forming valve (S2) is a valve that forms a flow path to circulate gaseous carbon dioxide that has passed through the third heat exchanger (530) to the gaseous carbon dioxide storage tank (300) by forming a flow path, or to convert gaseous carbon dioxide into liquid carbon dioxide by receiving a battery charging completion signal and a generator electric capacity signal from the fourth controller (640) and changing the flow path of the gaseous carbon dioxide storage tank (300) to the liquid carbon dioxide storage tank (200).

[0039] The Euro forming valve (S3) is a valve that forms a passage through which exhaust gas can be sucked.

[0040] The fourth controller (640) detects the electric capacity received from the generator (50) and sends a signal to the second controller (620). If the electric capacity produced by the generator (50) exceeds the electric capacity required for the operation of the device, power can be distributed to the refrigerator (100) and the compression pump (400). If the electric capacity does not reach the electric capacity required for the operation of the device, electricity is stored in the battery (30).

[0041] The first controller (610) detects the signal of the generator (50) and the temperature and pressure sensing unit (P1) of the temperature sensing unit (T1, T2, T3, T4) of the first heat exchanger, and outputs a signal to control the flow control valve (CV1) so that the turbine power generation is operated efficiently.

[0042] When the pressure of the pressure sensing unit (P4) of the gaseous carbon dioxide storage tank (300) decreases, the flow control valve (CV1) is closed.

[0043] The second controller (620) outputs a signal for controlling the first controller (610), the pay-forming valve (S1, S2), the compression pump (400), and the flow control valve (CV2).

[0044] The second controller (620) can form a flow path by controlling the payload forming valves (S1, S2, S3). It monitors the pressure of the pressure sensing unit (P4) and controls the flow control valve (CV4) to maintain an appropriate pressure in the gaseous carbon dioxide storage tank (300).

[0045] The compression pump (400) is operated by receiving signals from the first controller (610) and the third controller (630).

[0046] By receiving a signal from the pressure sensor (P3), the opening of the flow control valve (CV2) and the compression pump (400) can be controlled to transport liquid carbon dioxide, thereby maintaining the pressure of the liquid carbon dioxide storage tank (200).

[0047] The compressed carbon dioxide, which has passed through the compression pump (400) and has its temperature increased, passes through the condenser forming valve (S2) and is liquefied through heat exchange with the refrigerator (100) and stored in the liquid carbon dioxide storage tank (200).

[0048] However, since the temperature of carbon dioxide rises during the process of compressing gaseous carbon dioxide in the compression pump (400), a heat exchanger capable of exchanging heat with the compressed carbon dioxide that has passed through the compression pump (400) may be additionally provided, or a configuration may be provided for exchanging heat by connecting to any one of the first, second, and third heat exchangers.

[0049] The third controller (630) outputs a signal for controlling the operation of the refrigerator (100).

[0050] The third controller (630) receives signals from the liquid carbon dioxide level detection unit (L1) and the refrigerator circulation temperature (T7, T8) and outputs a signal for controlling the operation of the refrigerator (100).

[0051] The temperature of the waste heat source (20) emitted from the internal combustion engine is detected by the temperature sensing unit (T2), and when the operating temperature is reached, the compressed gaseous carbon dioxide stored in the gaseous carbon dioxide (CO2) storage tank (300) is transferred to the first heat exchanger (510) using the flow control valve (CV1) and the flow control valve (CV2).

[0052] Carbon dioxide (CO2) heated by the first heat exchanger (510) is injected through a nozzle to drive a turbine (40) and generate electricity using a generator (50).

[0053] Carbon dioxide (CO2), whose pressure has dropped due to the operation of the turbine (40), undergoes heat exchange in the second heat exchanger (520) and the third heat exchanger (530) exposed to the atmosphere, and the temperature of the heated carbon dioxide (CO2) drops.

[0054] The compression pump (400) is driven by electricity generated from a generator (50) or electricity charged in a battery (30) to recompress the carbon dioxide (CO2) whose temperature has dropped.

[0055] After transferring the liquid carbon dioxide or using electricity generated by a generator or electricity charged in a battery according to the user's settings, gaseous carbon dioxide (CO2) can be sucked from the exhaust gas inlet (80) of an internal combustion engine through a filter unit (90) and a flow forming valve (S3) to produce liquid carbon dioxide (CO2).

[0056] Gaseous carbon dioxide (CO2) can be liquefied at approximately 5 bar and -18°C, and non-liquefied non-condensable gas can be detected by a decrease in temperature difference in the temperature sensing unit (T7, T8), and is exhausted through the non-condensable gas exhaust unit (60) by the flow control valve (CV3).

[0057] The produced liquid carbon dioxide (CO2) can be used to replenish the gaseous carbon dioxide storage tank (300) or to cool the gaseous carbon dioxide storage tank (300) by detecting overheating of the gaseous carbon dioxide with a temperature sensor (T5).

[0058] Additionally, the cooled and produced liquid carbon dioxide can be transported to the outside through a liquid carbon dioxide transport unit (70).

[0059] The water level detection unit (L1) detects the level of liquid carbon dioxide in the liquid carbon dioxide storage tank (200).

[0060] The temperature sensing unit (T2) detects the temperature of the waste heat source (20) emitted by the internal combustion engine, and the temperature sensing unit (T1) detects the temperature of the waste heat source that has passed through the first heat exchanger (510).

[0061] The temperature sensing unit (T3, T4) senses the temperature of the gaseous carbon dioxide transferred to the gaseous carbon dioxide storage tank (300) before and after passing through the first heat exchanger (510).

[0062] The temperature sensing unit (T5) senses the temperature of gaseous carbon dioxide passing through the second heat exchanger (520).

[0063] The temperature sensing unit (T6) senses the temperature of the liquid carbon dioxide storage tank (200).

[0064] The temperature sensing unit (T7, T8) senses the refrigerant temperature of the refrigerator, and the temperature sensing unit (T9) senses the ambient temperature.

[0065] The pressure sensing unit (P1) senses the pressure of carbon dioxide heated by heat exchange in the first heat exchanger (510) flowing into the turbine (40).

[0066] The pressure sensing unit (P2) senses the pressure of the liquid carbon dioxide passing through the flow path forming valve (S1) that creates a flow path for transporting the liquid carbon dioxide to the outside.

[0067] The pressure sensing unit (P2) can protect the pump by detecting the pressure of the circulating gas carbon dioxide passing through the flow forming valve (S1).

[0068] The pressure of gaseous carbon dioxide supplied from the gaseous carbon dioxide storage tank (300) passing through the flow forming valve (S1) to transfer liquid carbon dioxide to the outside is detected and becomes a reference value for the operation setting of the pump (PP1) so that liquid carbon dioxide can be discharged.

[0069] The pressure sensing unit (P3, P4) senses the pressure of the liquid carbon dioxide storage tank (200) and the gaseous carbon dioxide storage tank (300).

[0070] As seen above, the coolant temperature of vehicles driven by internal combustion engines is maintained at 60-120℃ and waste heat is released into the atmosphere, and in the case of passenger cars, approximately 200g / km of carbon dioxide is emitted without capture.

[0071] In the case of hybrid internal combustion engines, energy can be stored using generators and batteries, but it cannot store more than a certain amount, and like internal combustion engines, waste heat is released into the atmosphere.

[0072] The present invention is effective in introducing a carbon tax, etc. by driving a compression pump to generate regenerative power using waste heat from an internal combustion engine, compressing gaseous carbon dioxide (CO2), and sending the produced liquid carbon dioxide to a gaseous carbon dioxide tank to replenish it, or transporting the captured carbon dioxide to the outside.

[0073] Although the present invention has been described in detail through representative examples above, those skilled in the art to which the present invention pertains will understand that various modifications can be made to the above-described embodiments without departing from the scope of the present invention.

[0074] Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by all changes or modifications derived from the claims and equivalent concepts as well as the claims described below.

[0075] [Explanation of symbols]

[0076] 10: Cooler

[0077] 20: Waste heat source

[0078] 30: Battery

[0079] 40: Turbine

[0080] 50: Generator

[0081] 60: Non-condensing gas exhaust

[0082] 70: Liquid carbon dioxide transfer unit

[0083] 80: (Gas carbon dioxide) exhaust gas inlet

[0084] 90: Filter section

[0085] 100: Freezer

[0086] 200: Liquid carbon dioxide storage tank

[0087] 300: Gaseous carbon dioxide storage tank

[0088] 400: Compression pump

[0089] 510: First heat exchanger

[0090] 520: Second heat exchanger

[0091] 530: Third heat exchanger

[0092] 610: First controller

[0093] 620: Second controller

[0094] 630: Third controller

[0095] 640: 4th controller

[0096] CV1, CV2, CV3, CV4: Flow control valves

[0097] P1, P2, P3, P4: Pressure sensing unit

[0098] L1: Water level detection unit

[0099] S1, S2, S3: Euro forming valves

[0100] T1, T2, T3, T4, T5, T6, T7, T8, T9: Temperature sensing unit

[0101] V1: Transfer valve

Claims

1. A regenerative power generation and carbon dioxide capture system using waste heat from an internal combustion engine includes a refrigerator (100), a liquid carbon dioxide storage tank (200) capable of storing carbon dioxide (CO2), and a gaseous carbon dioxide storage tank (300). A transfer valve (V1) that transfers liquid carbon dioxide to an external liquid carbon dioxide transfer unit (70), A flow control valve (CV2) that controls the amount of compressed gas carbon dioxide, A temperature sensing unit (T7, T8) that detects the temperature at the inlet and outlet of the refrigerator (100), A flow control valve (CV3) capable of discharging non-condensable gas exhaust; A flow control valve (CV4) that controls the flow rate of liquid carbon dioxide to be transferred to a gaseous carbon dioxide storage tank (300), A flow path forming valve (S1) that creates a flow path for transporting liquid carbon dioxide to the outside; A flow path forming valve (S2) that divides the flow path of the liquid carbon dioxide storage tank (200) and the gas carbon dioxide storage tank (300) and forms a flow path, A flow path forming valve (S3) that forms a flow path for sucking exhaust gas, and A regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine, characterized in that it has a fourth controller (630) capable of distributing power received from a generator (50) to a battery (30), a refrigerator (100), and a compression pump (400).

2. In paragraph 1, The temperature of the waste heat source (20) emitted from the internal combustion engine is detected by the temperature sensing unit (T2), and when the operating temperature is reached, the compressed gaseous carbon dioxide stored in the gaseous carbon dioxide (CO2) storage tank (300) is transferred to the first heat exchanger (510) using the flow control valve (CV1) and the flow control valve (CV2). A regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine, characterized in that carbon dioxide (CO2) heated by a first heat exchanger (510) is injected through a nozzle to drive a turbine (40) and generate power using a generator (50).

3. In paragraph 2, Carbon dioxide (CO2), whose pressure has dropped due to turbine operation, undergoes heat exchange in the second heat exchanger (520) and the third heat exchanger (530) exposed to the atmosphere, and when the temperature of the heated carbon dioxide (CO2) drops, A regenerative power generation and carbon dioxide capture system utilizing waste heat from an internal combustion engine, characterized in that it recompresses carbon dioxide (CO2) whose temperature has dropped by driving a compression pump (400) with electricity produced by a generator (50) or electricity charged in a battery (30).

4. In paragraph 3, A regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine, characterized in that when the pressure of a gaseous carbon dioxide storage tank (300) decreases due to a leak or a drop in temperature, the system sucks gaseous carbon dioxide (CO2) from the exhaust gas inlet (80) of the internal combustion engine through a filter unit (90) and a flow forming valve (S3) to produce liquid carbon dioxide (CO2) using electricity produced by a generator or electricity charged in a battery.

5. In any one of paragraphs 1 to 4, Gaseous carbon dioxide (CO2) can be liquefied at approximately 5 bar and -18°C, and non-liquefied non-condensable gas is exhausted through the non-condensable gas exhaust section (60) by the flow control valve (CV3). A regenerative power generation and carbon dioxide capture system using waste heat of an internal combustion engine, characterized in that the produced liquid carbon dioxide (CO2) is replenished in a gaseous carbon dioxide storage tank (300) or the produced liquid carbon dioxide is transported to the outside through a liquid carbon dioxide transport unit (70).

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