Renewal energy power generation system

Abstract

Provided is a renewable energy power generation system (10) having a renewable energy power generating apparatus (12) arranged to generate electric power; and a hydrogen power generation module (20) having a separation unit (22) adapted to separate water into hydrogen and oxygen, and a fuel cell unit (28) adapted to receive air or oxygen, and hydrogen from said separation unit or from a hydrogen storage; the fuel cell unit being arranged to produce electric power in the presence of hydrogen and oxygen; wherein the hydrogen power generation module being adapted to receive electric power from the at least one renewable energy power generating apparatus at least prior to production of electric power by the fuel cell unit.

Claims

1. A renewable energy power generation system supplying AC power to appliances and air conditioning to an associated space, comprising: at least one renewable energy power generating apparatus that generates electric power; a hydrogen power generation module having a separation unit that separates water into hydrogen and oxygen; a fuel cell unit that receives air or oxygen, and hydrogen from said separation unit or from a hydrogen storage; the fuel cell unit being arranged to produce electric power in the presence of hydrogen and oxygen; and a conversion means comprising an inverter that converts DC output from the renewable energy power generating apparatus and the fuel cell unit to AC power, wherein the hydrogen power generation module receives electric power from the at least one renewable energy power generating apparatus at least prior to production of electric power by the fuel cell unit, electric appliances and an air conditioner are connected to the system such that the system supplies the AC power to the appliances and the air conditioner, said fuel cell unit supplying heat to the air conditioner for exchanging heat with a working fluid of the air conditioner, the air conditioner including a heat exchanger where heat from the fuel cell unit is transferred to the working fluid of the air conditioner, and a controller controls operation of the system.

2. The renewable energy power generation system according to claim 1, wherein said fuel cell unit produces water at an elevated temperature, wherein the water from the fuel cell is conveyed to the air conditioner.

3. The renewable energy power generation system according to claim 1, having a water purification module and further having a water tank holding relatively pure water from the water purification module and water generated by the fuel cell unit, and there being a mineralizer adding appropriate minerals to water from the water tank to make potable mineralized water.

4. The renewable energy power generation system according to claim 1, wherein said fuel cell unit produces water at an elevated temperature and the water from the fuel cell unit is conveyed to the air conditioner, and the system further comprises at least two renewable energy power generating apparatuses producing different DC output voltages, a DC to DC converter, the DC to DC converter receiving the output voltages and the converter providing a stabilized DC output, the stabilized DC output supplying power to the conversion means and to the separation unit and fuel cell unit.

5. The renewable energy power generation system according to claim 1 wherein the system further comprises at least two renewable energy power generating apparatuses producing different DC output voltages, a DC to DC converter, the DC to DC converter receiving the output voltages and the converter providing a stabilized DC output, the stabilized DC output supplying power to the conversion means.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order that the present invention can be readily understood and put into practical effect the description will hereinafter refer to the accompanying drawings which illustrate non limiting embodiments of the present invention and wherein

(2) FIG. 1 is a block flow diagram showing main components of an embodiment of the renewable energy hydrogen power generation system according to the present invention;

(3) FIG. 2 is a shows a programmable logic controller for controlling the components [15] of the system shown in FIG. 1; and

(4) FIG. 3 is a schematic flow diagram showing details of operation of the fuel cell assembly.

DETAILED DESCRIPTION OF THE DRAWINGS

(5) Referring to the drawings and initially to FIG. 1, there is shown an embodiment of the renewable energy hydrogen power generation system 10 according to the present invention. The system 10 has renewal energy module 12 adapted to generate electrical power from wind turbines 14, solar collectors which in this embodiment are photovoltaic cells 16 and hydro turbines 18. The wind turbines generate electric power at about 48V DC. The photovoltaic cells produce electric power at about 12V DC and the hydro turbines at about 6 to 9V DC. The module 12 uses a DC/DC converter 20 to regulate its output at about 48V DC.

(6) The system 10 also has a hydrogen power generation module 21 having an electrolysis separation unit 22 for separating water (H.sub.2O) into hydrogen and oxygen components, a compressor 24 for compressing the hydrogen and feeding it into a metal hydride storage 26, and a hydrogen fuel cell assembly 28 adapted to receive hydrogen from the storage 26. The fuel cell assembly 28 is formed of a stack of fuel cells which facilitate an electrochemical reaction between oxygen and hydrogen to produce electric power and water at an elevated temperature of about 80°. The oxygen is extracted from air that is introduced into the fuel cells.

(7) The DC electric powers from the renewable energy module 12 and the hydrogen power module 21 are controllably supplied to an AC power utility module 30 which uses an inverter 32 to convert the DC power into AC power for operating electric consuming devices 34 such as lighting equipment, winches, pumps, and devices generally available at a hotel. Excess power is fed to a DC power storage module 40 for charging batteries 42 and/or super capacitors 44.

(8) The warm water from the fuel cell assembly 28 is fed into a heating ventilation and air conditioning module (HVAC) 50 having an air conditioning system 52 for conditioning air temperature in a building. A part of the warm water may be diverted into a potable water module 60 for providing potable water. The module 60 has a distilled water tank 62 to which the warm water is delivered and a mineralization tank 64 for adding desired minerals to the water from the tank 62.

(9) The system 10 also has a water purification module 70 for producing desalinated water from sea water. In this embodiment, the module 70 use a reverse osmosis unit 72 for separating saline from sea water. The purified water is fed into the distilled water tank 62 and the saline waste is discarded as a by-product. Low pressure pump 74 is used to draw water from sea and a high pressure pump 76 is used to supply water at a relatively high pressure at the reverse osmosis unit 72.

(10) A low pressure pump 23 in the hydrogen power generation module 20 draws distilled water from the tank 62 and fed it into the separating unit 22 for producing hydrogen gas. A de-ionization unit may be provided for de-ionising the distilled water prior to entering the separating unit 22.

(11) As shown in FIG. 2, the system 10 has a programmable logic controller 80 adapted to control operation of controllable components of the system.

(12) FIG. 3 shows a sixty cell stack fuel cell assembly 28 which receives hydrogen from a hydrogen storage tank 26. A pressure reducer 27 reduces the pressure of the hydrogen from the tank 26 before reaching the assembly 28. Hydrogen passing through the assembly 28 may be returned by a recycle pump 27A or purged through a valve 27B.

(13) An air blower 29A draws air through a filter 29B into the assembly 28. Water formed during the electrochemical reaction between hydrogen and oxygen in the assembly 28 is passed through a condenser 52A of the HVAC 52 as described above and a part of the water is fed into a humidifier 90 comprising a spray tower 91, a pump 92, a heat exchanger 93 and radiator 94. The water is fed to the spray tower 91 where it humidifies return air from the assembly 28. The pump 92 forces the humidified air to give up certain heat at the heat exchanger 93 before returning to the assembly 28. A flowable heat transfer medium receives heat at the exchanger 93 and releases the heat via the radiator 94.

(14) For safe operating environment, the fuel cell assembly 28 must operate within safe operation parameters. The controller 80 or a dedicated controller (not shown) is adapted to configure and control operation of the assembly 28. Typically, the procedure for operating the assembly involves:

(15) Start Up 1. Start cooling circuit; 2. Start heater in cooling circuit; 3. Start flushing cathode with air; 4. Start flushing anode with nitrogen;

(16) Control coolant flow rate <200 kg/h—increase flow rate; coolant heating rate >20 k/min—slow heating rate; N.sub.2 flow rate in anode <32 Nl/min—increase flow rate; air flow rate in cathode <65 Ml/min—decrease flow rate; stack temp >65° c.—switch off coolant heater; stack temp <60° c.—switch on coolant heater,

(17) When stack temp >60° c. and) N.sub.2 flush time >20 min and) initiate operating mode air flush time >10 min)

(18) Operating Mode 1. Switch to OCV (i.e. idle operation on H.sub.2); 2. Set load point; 3. Start H.sub.2 and air flow; 4. Set load to stack;

(19) Control in coolant temp <62.5° c.—slow cooling down; out coolant temp >67.5° c.—increase cooling rate; pressure difference. over mea >300 m Bar—Initiate shut-down; H.sub.2 and air stoichometric ratios out of balance—adjust; cell voltage >9.8V—decrease H.sub.2 and air stoic mix; cell voltage <0.55V—increase H.sub.2 and air@stoic. mix; cell voltage <0.3V over 5 sec—alarm; cell voltage <specified minimum—initiate shut down;

(20) Shut Down 1. switch to OCV; 2. close H.sub.2 supply valve; 3. switch off air flow; 4. purge anode with H.sub.2 for 10 min; 5. shut down cooling circuit.

(21) Whilst the above has been given by way of illustrative example of the present invention many variations and modifications thereto will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as herein set forth in the following claims.