Electrolytic Energy Recovery

Abstract

The energy supply system includes an electrolysis system that performs electrolysis on a first water source to split water into hydrogen and oxygen components. The hydrogen and oxygen components are supplied to a power generation system. The power generation system includes a combustor that receives the hydrogen and oxygen components and is operable to combust the hydrogen and oxygen components. The combustor also receives a steam source. Combustion products downstream from the combustor pass over the top turbine rotor, driving it to rotate. A first generator generates electrical power from the rotation of the top turbine rotor.

Description

[Technical Field]

[0001] This application relates to an energy supply system that uses electrolysis to produce hydrogen and oxygen for use in combustion. [Background technology]

[0002] Electrical power systems are necessary to provide electrical power to all locations, for example homes, businesses, structures and buildings, which receive energy from the energy system.

[0003] Several types of power plants may supply power to a power grid. For example, nuclear energy, solar and wind energy, and fossil fuels are all utilized to generate the electricity that is supplied to the power grid.

[0004] In some cases, the power supply to the power grid may fail or generate insufficient power. This is undesirable, and it is desirable to develop reliable backup energy sources to supply power to the power grid in such cases.

[0005] In other cases, especially when electricity is generated by the sun and wind, the size of the energy conversion equipment must be increased to account for wind fluctuations or periods when the sun is not shining. However, these oversized systems may convert excess energy beyond what the power grid can utilize, but may not be able to be economically turned off. The power grid would benefit from having a mechanism to store this excess energy for times when energy conversion is low.

[0006] In at least one proposed system, water is electrolyzed and split into its hydrogen and oxygen components, which are then sent to the engine's combustor, where they are mixed and ignited.

[0007] The products of combustion pass downstream over the turbine rotor, driving it to rotate, generating electricity that can be separated and recovered by a generator. Downstream from the combustor, the separated hydrogen and oxygen are returned to their water state.

[0008] The separated and recovered water can be sent to a combustor, or the separated and recovered water can be returned to the water source for electrolysis.

[0009] Although such systems have potential advantages in reducing emissions, the proposed designs have drawbacks. Summary of the Invention [Means for solving the problem]

[0010] In a featured embodiment, the energy supply system includes an electrolysis system performing electrolysis on a first water source to split water into hydrogen and oxygen components. The hydrogen and oxygen components are supplied to a power generation system. The power generation system includes a combustor operable to receive the hydrogen and oxygen components and combust the components. The combustor also receives a steam source. Combustion products downstream of the combustor pass over a top turbine rotor, driving the top turbine rotor to rotate. A first generator generates electrical power from the rotation of the top turbine rotor.

[0011] In another embodiment according to the previous embodiment, an evaporator is positioned downstream of the turbine to receive the products of combustion, and a second water source also passes through the evaporator, and the products of combustion boil water passing through the evaporator, which is supplied to the combustor as steam.

[0012] In another embodiment according to any of the previous embodiments, a condenser is positioned downstream of the evaporator to receive the combustion products. The combustion products are condensed into liquid water by cooling the combustion products with a cooling fluid. The liquid water provided by the condenser is sent to a pump for pressurization. The pressurized water is provided to the evaporator as a second water source.

[0013] In another embodiment according to any of the previous embodiments, the working fluid in the condenser is used to preheat the oxygen and hydrogen components sent to the combustor.

[0014] In another embodiment according to any of the previous embodiments, liquid water recovered from the combustion products in a condenser is also sent to the first water source.

[0015] In another embodiment according to any of the previous embodiments, liquid water recovered from the combustion products in a condenser is also sent to the first water source.

[0016] In another embodiment according to any of the previous embodiments, steam from a second water source is also selectively injected into the turbine.

[0017] In another embodiment according to any of the previous embodiments, steam from a second water source upstream of the evaporator is also selectively delivered to the combustion product intermediate the combustor and the turbine.

[0018] In another embodiment according to any of the previous embodiments, the controller is programmed to control the electrolysis system and the power generation system, and is programmed to determine power generation by the other power generation systems, and to determine a demand for power in the power grid, and to at least one of: operate the electrolysis system and disengage the power generation systems based on a determination that the power generation exceeds the demand for power in the power grid, or stop operation of the electrolysis system and engage the power generation systems based on a determination that the power generation falls below the determined demand for power in the power grid.

[0019] In another embodiment according to any of the previous embodiments, the hydrogen and oxygen components are cooled to a liquid state and stored before being fed to the combustor.

[0020] In another embodiment according to any of the previous embodiments, the hydrogen and oxygen components are preheated before being delivered to the combustor.

[0021] In another embodiment according to any of the previous embodiments, the hydrogen and oxygen components are preheated before being delivered to the combustor.

[0022] In another embodiment according to any of the previous embodiments, the combustion products are used to preheat the hydrogen and oxygen components.

[0023] In another embodiment according to any of the previous embodiments, preheating of the oxygen and hydrogen components occurs in an evaporator.

[0024] In another embodiment according to any of the previous embodiments, the steam turboexpander extracts work from the steam before delivering the steam to the combustor, and the steam turboexpander drives a second generator.

[0025] In another embodiment according to any of the previous embodiments, the electrical power generated by the first and second generators is selectively fed into an electrical grid.

[0026] In another embodiment according to any of the previous embodiments, a bottoming cycle includes passing a heated bottoming fluid through an evaporator, the bottoming fluid downstream of the evaporator passing over a bottoming turbine, the bottoming fluid downstream of the bottoming turbine passing through a condenser to be cooled, the bottoming fluid downstream of the condenser returning to the evaporator, and the bottoming turbine driving a third generator.

[0027] In another embodiment according to any of the previous embodiments, power to drive the electrolysis system is supplied from a power source from a location external to the energy supply system.

[0028] In another embodiment according to any of the previous embodiments, water is separated from the combustion products and the separated water is returned to the second water source.

[0029] In another embodiment according to any of the previous embodiments, the steam turboexpander extracts work from the steam before delivering the steam to the combustor, the steam turboexpander drives a second generator, and the power generated by the first generator and the second generator is supplied to an electric power grid.

[0030] The present disclosure may include any one or more of the individual features disclosed above and / or below, taken alone or in any combination thereof.

[0031] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. [Brief explanation of the drawings]

[0032] [Figure 1A] FIG. 1 illustrates a power supply system. [Figure 1B] 10A-10C show different embodiments of heat exchangers for preheating both water and oxygen. [Figure 2] FIG. 2 shows an electrolysis system used in combination with the system of FIG. 1. [Figure 3] 3 is a control flowchart. DETAILED DESCRIPTION OF THE INVENTION

[0033] Power supply system 20 is shown in Figure 1A. Combustor 22 receives a hydrogen source 51 via line 49 and an oxygen source 46 via line 50. The hydrogen and oxygen may be maintained at cryogenic temperatures so that they are in a liquid state. Alternatively, the hydrogen and oxygen may be in a gaseous state. The hydrogen and oxygen are mixed within combustor 22 and ignited.

[0034] From combustor 22, the products of combustion pass downstream over turbine rotor 24, driving and rotating shaft 25. Generator 26 is shown schematically, and the rotation of shaft 25 generates electrical power that can be supplied to an application 116, such as an electric power grid.

[0035] The combustion products also pass through an evaporator 28 and an optional condenser 42. Downstream of the condenser 42, the combustion products 43 exit the system. Desirably, there should be essentially no combustion products at point 43, although in practice small amounts of liquid water or steam may be present.

[0036] The evaporator 28 heats water from a water source 54 through a line 58. A pump 56 may drive the water. The heated water becomes steam and is delivered to the combustor 22 through a line 60.

[0037] Heated water is also sent to turbine 24 in line 62. Valve 59 controls this flow rate. Steam and / or water is sent to turbine 24 for buffer flow or cooling. Valve 59 controls the steam flow between the turbine and combustor, which may control flammability limitations such as firing temperature, turbine cooling needs, and flame extinguishing concerns if too much steam is added.

[0038] A branch line 64 branches off from the water supply line upstream of the evaporator 28 to supply unheated water to a location intermediate the combustor 22 and the turbine 24. A valve 57 controls this flow rate. The valve 57 controls the ratio of steam to water. The water may be useful for specific cooling purposes within the turbine. Second, it allows some water to bypass the evaporator. The control can ensure that lines 60 and 62 contain only steam. If too much water is sent to the evaporator and some does not boil, liquid water could end up in unintended locations, such as in the turboexpander 202.

[0039] The optional bottoming main cycle 30 includes a bottoming turbine 32 and a water source 34. A pump 36 drives water through the evaporator 28 in line 38. The water is heated to steam, which drives the turbine 32. As shown, a generator 40 generates electricity from the rotation of the turbine 32. Downstream of the turbine 32, the water returns to the water source 34 through line 43.

[0040] The control of valves, power supply to the grid, flow and operation of the entire system 20 may be integrated into an overall grid power control as illustrated in FIG.

[0041] Steam turboexpander 202 is shown on line 60 and expands steam that is delivered to combustor 22. Turboexpander 202 drives generator 203, which may also provide power to application 116 (e.g., an electric power grid).

[0042] Generators 26, 40 and 203 may be utilized to generate power when needed, such as by a power grid 116, shown diagrammatically.

[0043] The water source 54 may be received in part in line 52 from water separated from the combustion products in the condenser 42. An alternative steam source 299 may be routed to the combustor 22 rather than from the evaporator 28. By way of example, a separate boiler 301 may be used.

[0044] An additional cooling fluid source 55 may be passed through the condenser 42. This additional source may be air or may be ambient water, such as river water, which further serves to cool the combustion products, remove more water, and reduce the residual combustion products that reach point 43.

[0045] Line 44 from oxygen source 46 passes through condenser 42 and is heated by the combustion products. Pump 53 is a pressure source for driving the heated oxygen into combustor 22. Similarly, hydrogen from hydrogen source 51 passes through condenser 42 in line 48. Pump 47 is a pressure source for driving the heated hydrogen into combustor 22.

[0046] 1B shows another embodiment 210 for exchanging heat between fluids. In embodiment 210, steam generated from a water source 216 in line 160 toward combustor 22 passes through heat exchanger 214. Heat exchanger 214 may be generally located at the position of evaporator 28. The combustion products at 212 spread across heat exchanger 214, heating water from water source 216 and creating steam in line 160. Additionally, line 144 passes oxygen from oxygen source 46 through this same heat exchanger 214 for preheating by the combustion products. Similarly, line 148 connects to hydrogen source 51, which is preheated in heat exchanger 214.

[0047] That is, while in the embodiment of Figure 1A two heat exchangers perform steam generation and preheating functions, both functions can be performed in a single heat exchanger. Embodiment 210 may otherwise operate similarly to the system of Figure 1A. In other words, if water is available without a condenser, for example, preheating of the fuel and oxidizer can alternatively be performed in the evaporator.

[0048] The overall system 20 provides very efficient power generation. Using liquid hydrogen and liquid oxygen provides more efficient power generation than gaseous oxygen and hydrogen. However, the energy costs of bringing gaseous oxygen and hydrogen to a liquid state may dictate the need to utilize gaseous oxygen and hydrogen.

[0049] There is a need for more reliable power generation. The disclosed system generally relies on established and known technology, yet is assembled in a unique configuration.

[0050] Large-scale battery systems are often considered as an alternative source for generating large amounts of electricity. However, such technology still needs to be developed. Furthermore, the system 20 of the present disclosure relies on materials that are more commonly available compared to the materials required for such proposed battery systems. In electric vehicles and other proposed electric systems, battery materials such as lithium are competitively pursued for other applications and therefore more difficult to obtain in sufficient quantities for widespread use in grid-scale energy storage.

[0051] Furthermore, net water usage is zero or near zero. The small amount of water emitted from the system may be in liquid form. Water vapor, a greenhouse gas in the atmosphere, is not substantially emitted from this system. Therefore, greenhouse gas emissions are zero.

[0052] Additionally, greenhouse gas emissions are zero. The proposed system generates electricity from hydrogen with an overall efficiency of over 70%, which is much higher than fuel cells, industrial gas turbines, etc. Furthermore, the disclosed system 20 can be quickly powered up and powered down as needed to supply power generated intermittently from renewable sources.

[0053] As shown in Figure 2, an electrical power grid 116 is illustrated. System 20 is shown at 114 supplying electrical power to electrical power grid 116.

[0054] Other conventional power generation sources, such as wind turbines 102, also provide power to the power grid 116. While wind turbines are shown, it should be understood that all power generation sources, including standard power plants, are considered part of the power generation system 102. Shown here is a water source 105 that provides water to an electrolysis system 107. Energy for 104 can be provided by the conventional power generation system 102 to power the electrolysis system 107, which splits the water 105 into hydrogen components 108 and oxygen components 109.

[0055] The electrolysis system 107 may be as known. The components are fed at 110 and 112 to respective storage sources 51 and 46. Components 108 and 109 may be liquefied by a refrigerant system 200 and stored in the liquid phase at 51 and 46. Waste heat from the refrigerant system 200 may be reused in various parts of the process, such as in preheating water for electrolysis. The refrigerant system 200 and waste heat reuse may be as known.

[0056] As shown in this figure, the water supply 105 may be supplied from a return line 106 from the system 20. In that sense, the water circuit here may be a closed loop, although open loop systems are also within the scope of this disclosure.

[0057] As noted above, the controller 400 of the system shown in Figure 2 controls the power generation system 20, the electrolysis process 107, and all operations disclosed throughout the system shown in Figure 2. A proposed method of operation is disclosed below, with the understanding that the controller 400 is programmed to affect the operation and control of Figure 3.

[0058] A flowchart for operating the system shown in Figure 2 is disclosed in Figure 3. In general, the electrolysis system 107 and the power generation by the system 20 cannot occur simultaneously. As an example, when the energy generated by the energy source 102 is less than the demand on the grid 116, the system 20 operates to provide additional power at 114. However, when the energy generation by the energy source 102 exceeds the demand on the grid 116, the excess energy is utilized to power the electrolysis system 107 at 104. Thus, the operating system of Figure 3 is configured to ensure stable grid operation.

[0059] In that sense, the produced oxygen 109 and hydrogen 108 may be stored, such as in a liquid state, for a period of time until needed to generate electricity, after which the oxygen and hydrogen are sent to the combustor 22.

[0060] 3 shows a flowchart. In step 300, the controller 400 monitors the amount of power generated by the system 102. In step 302, the controller 400 monitors the power demand on the grid 116. In step 304, the controller 400 determines whether the monitored generated power is equal to the grid demand. If the answer is "yes," in step 306, the system returns to step 300.

[0061] If the controller 400 determines in step 304 that the monitored generated power does not equal the grid demand, then in step 308 the controller 400 determines whether the monitored generated power exceeds the grid 116 demand.

[0062] Based on the determination that an excess amount of power will occur, in step 312, the controller 400 powers the electrolysis system 107 by providing power to the electrolysis system 104. As noted above, during this step, the power supply system 20 is preferably not operational.

[0063] If the determination in step 308 is that the generated power does not exceed the grid demand, the controller 400 determines that the generated power is below demand. Based on such determination, in step 316, the controller 400 generates power from the system 20 and the electrolysis system 107 is shut off.

[0064] The disclosed hydrogen / oxygen engine has higher thermal efficiency than existing power generation systems such as combined-cycle gas turbines or fuel cells. One reason is the lack of gaseous nitrogen compression, which does not provide corresponding power in such systems. However, the combustion temperatures of pure H2 and O2 are high. Therefore, steam injection reduces the temperature and helps maintain the combustor at more manageable temperatures.

[0065] The proposed system improves upon the prior art in several ways: First, injecting steam into the combustor allows it to withstand the very high temperatures expected.

[0066] Additionally, the proposed system increases its efficiency by generating the heat of such steam from an evaporator heated by waste heat from the turbine 24. Additionally, the optional use of liquid hydrogen and liquid oxygen to condense water further increases the efficiency of the system 20 by recovering the heat of condensation in the combustor 22.

[0067] Additionally, preheating the liquid oxygen and hydrogen going to the combustor provides advantages over the prior art.

[0068] As an added benefit, the system reduces greenhouse gas emissions compared to conventional power generation systems.

[0069] Under the present disclosure, an energy supply system can be said to include an electrolysis system for electrolyzing a first water source to split the water into hydrogen and oxygen components. The hydrogen and oxygen components are provided to a power generation system. The power generation system includes a combustor operable to receive the hydrogen and oxygen components and combust the hydrogen and oxygen components. The combustor also receives a steam source. Combustion products downstream from the combustor pass over a top turbine rotor, driving the top turbine rotor to rotate. A first generator generates electrical power from the rotation of the top turbine rotor.

[0070] While embodiments of the present disclosure have been shown, those of ordinary skill in the art will recognize that modifications would fall within the scope of the present disclosure. For that reason, the following claims should be studied to determine the true scope and content of the present disclosure.

Claims

1. 1. An electrolysis system for performing electrolysis on a first water source to split the water into hydrogen and oxygen components, comprising: the hydrogen and oxygen components are supplied to a power generation system; the power generation system includes a combustor, the combustor operable to receive the hydrogen and oxygen components and combust the hydrogen and oxygen components; The combustor also receives steam. the electrolysis system; combustion products downstream of the combustor passing over a top turbine rotor and driving the top turbine rotor to rotate; a first generator for generating electrical power from the rotation of the top turbine rotor; energy supply system, including

2. 2. The energy supply system of claim 1, wherein an evaporator is positioned to receive the combustion products downstream of the turbine, and a second water source also passes through the evaporator such that the combustion products boil the water passing through the evaporator, and the water passing through the evaporator is supplied to the combustor as the steam.

3. a condenser positioned to receive the combustion products downstream of the evaporator; the combustion products are condensed into liquid water by cooling the combustion products with a cooling fluid; The liquid water supplied from the condenser is sent to a pump for pressurization, 3. The energy supply system of claim 2, wherein pressurized water is supplied to the evaporator as a second water source.

4. The energy supply system of claim 3 , wherein the working fluid in the condenser is used to preheat the hydrogen and oxygen components that are sent to the combustor.

5. The energy supply system of claim 4 , wherein the liquid water recovered from the combustion products in the condenser is also sent to the first water source.

6. The energy supply system of claim 3 , wherein the liquid water recovered from the combustion products in the condenser is also sent to the first water source.

7. The energy supply system of claim 2 , wherein steam from a second water source is also selectively injected into the turbine.

8. The energy supply system of claim 2 , wherein water from a second water source upstream of the evaporator is also selectively delivered into the combustion products intermediate the combustor and the turbine.

9. a controller for controlling the electrolysis system and the power generation system; programmed to determine the amount of electricity generated by other power generation systems; determining a demand for the power on the power grid; operating the electrolysis system and disengaging the power generation system based on a determination that the amount of power generation exceeds the demand for the power on the grid; or based on a determination that the amount of power generated will be less than the determined power demand of the grid, shutting down operation of the electrolysis system and shutting down the power generation system; The energy supply system of claim 1 , programmed to perform at least one of the following:

10. 10. The energy supply system of claim 1, wherein the hydrogen and oxygen components are cooled to a liquid state and stored before being supplied to the combustor.

11. The energy supply system of claim 10 , wherein the hydrogen and oxygen components are preheated before being delivered to the combustor.

12. The energy supply system of claim 2 , wherein the hydrogen and oxygen components are preheated before being delivered to the combustor.

13. 13. The energy supply system of claim 12, wherein the combustion products are used to preheat the hydrogen and oxygen components.

14. 13. The energy supply system of claim 12, wherein the preheating of the oxygen and hydrogen components occurs in the evaporator.

15. The energy supply system of claim 1 , wherein a steam turboexpander extracts work from the steam before delivering the steam to the combustor, and the steam turboexpander drives a second generator.

16. 16. The energy supply system of claim 15, wherein the electric power generated by the first generator and the second generator is selectively supplied to an electric power grid.

17. 3. The energy supply system of claim 2, wherein the bottoming cycle includes a bottoming fluid that is heated by passing through the evaporator, the bottoming fluid downstream of the evaporator passing over a bottoming turbine, the bottoming fluid downstream of the bottoming turbine passing through the condenser to be cooled, the bottoming fluid downstream of the condenser returning to the evaporator, and the bottoming turbine driving a third generator.

18. 10. The energy supply system of claim 1, wherein power for driving the electrolysis system is provided from a power source from a location external to the energy supply system.

19. 10. The energy supply system of claim 1, wherein water is separated from the combustion products and the separated water is returned to the second water source.

20. 20. The energy supply system of claim 19, wherein a steam turboexpander extracts work from the steam before delivering the steam to the combustor, the steam turboexpander drives a second generator, and electrical power generated by the first generator and the second generator is supplied to an electrical power grid.

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