COMBINED HEAT AND POWER SYSTEM AND METHOD OF OPERATION

• US 20180298816A1
• Filed: 04/14/2017
• Published: 10/18/2018
• Est. Priority Date: 04/14/2017
• Status: Active Grant

• Current Assignee: Enexor Energy LLC
• Original Assignee: Enexor Energy Co.
• Inventors: Conde, Ricardo
• Granted Patent: US 10,443,495 B2
• Time in Patent Office: Days
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F01L 15/10 with main slide valve and auxiliary valve dragged thereby
• CPC Class Codes: F02C 1/04 the working fluid being heated indirectly in a fluidised-bed combustor F02C3/205
• CPC Class Codes: F02C 3/26 the fuel or oxidant being solid or pulverulent, e.g. in slurry or suspension
• CPC Class Codes: F02C 6/18 using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10
• CPC Class Codes: F02C 7/08 Heating air supply before combustion, e.g. by exhaust gases
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A combined heat and power (CHP) system. The CHP system including a combustion chamber with an air inlet and an exhaust. The combustion chamber configured to receive a hot secondary gas for combustion. A heat exchanger coupled to the particle separator receives mixed combustion gases and transfers heat to a secondary gas. The CHP system also includes a turbine configured to receive and compress a secondary gas and direct the compressed secondary gas to the heat exchanger, the turbine is also configured to receive a heated compressed secondary gas and expand it to generate work therefrom, the expanded heated secondary gas is also used for combustion and to regulate the temperature of the combustion gases entering the heat exchanger. A generator is connected to the drive shaft of the turbine and configured to generate electricity with the work generated therein.

Claims

1. A combined heat and power (CHP) system, the CHP system comprising:

a combustion system having a combustion chamber and a feed mechanism configured to feed solid fuel into the combustion chamber, the combustion chamber having an gas inlet for combustion and a combustion gas exhaust, wherein the combustion chamber is configured to receive an expanded heated secondary gas to the combustion air inlet for combustion of the solid fuel;

a proportional valve operably coupled in series with the gas inlet and operable to control the flow of the heated expanded secondary gas thereto;

a an exhaust plenum operatively connected to the combustion chamber and configured to receive high temperature combustion gases therefrom, the plenum including a secondary gas port operable to direct the expanded heated secondary gas to the exhaust plenum for mixing with the high temperature combustion gases;

a high temperature heat exchanger operably coupled to the exhaust plenum and configured to receive the mixed combustion gases therefrom, the high temperature heat exchanger operable to transfer heat from the mixed combustion gases to a compressed secondary gas;

a gas turbine having a compression section and an expansion section operably connected on a drive shaft, the gas turbine configured to receive a secondary gas at an inlet to the compression section and compress the secondary gas and to direct the compressed secondary gas to an inlet of the high temperature heat exchanger, the gas turbine configured to receive a heated compressed secondary gas at an inlet to the expansion section to expand the heated compressed secondary gas and generate work therefrom, wherein an output of the expansion section of the gas turbine is operably coupled to the secondary gas port of the particle separator and the combustion inlet of the combustion chamber; and

a generator operably connected to the drive shaft of the gas turbine and configured to generate electricity with the work generated therein.

2. The CHP system of claim 1 further including a control mechanism for controlling the feed rate of the solid fuel into the combustion chamber.

3. The CHP system of claim 1 wherein the control mechanism includes a feed mechanism and a control valve.

4. The CHP system of claim 1 further including a temperature sensor, the temperature sensor operable to sense the temperature of the combustion gases at the combustion gas exhaust.

5. The CHP system of claim 1 wherein the temperature sensor is at least one of a thermocouple, infrared detector and a semiconductor detector.

6. The CHP system of claim 1 further including a high temperature particle separator having an inlet and an exhaust, the separator operatively connected to the combustion chamber and configured to receive high temperature combustion gases therefrom, wherein the exhaust includes the exhaust plenum.

7. The CHP system of claim 1 wherein the high temperature particle separator includes at a cyclonic separator, the cyclonic separator operably coupled to a hopper for removal of particulate matter.

8. The CHP system of claim 1 wherein the cyclonic separator removes about 99% of all particulates larger than five microns.

9. The CHP system of claim 1 wherein the gas valve is a proportional valve operably connected to a controller and configured to control a flow of the heated expanded secondary gas to mix with the high temperature combustion gases.

10. The CHP system of claim 9 wherein the gas valve controls the flow of the heated expanded secondary gas to mix with the high temperature combustion gases based on a temperature of at least one of the expanded secondary gas, the high temperature combustion gas and the mixed combustion gases.

11. The CHP system of claim 1 wherein the proportional valve is operably connected to a controller and configured to control the flow of the heated expanded secondary gas into the combustion chamber.

12. The CHP system of claim 11 wherein the proportional valve controls the flow of the heated expanded secondary gas to the combustion chamber based on a temperature of at least one of the expanded secondary gas, the high temperature combustion gas, the mixed combustion gases, and a temperature of the heated compressed secondary gas.

13. The CHP system of claim 12 wherein the proportional valve controls the flow of the heated expanded secondary gas to the combustion chamber based on a temperature of the heated compressed secondary gas.

14. The CHP system of claim 1 further including a second temperature sensor, the second temperature sensor operable to sense the temperature of the mixed combustion gases.

15. The CHP system of claim 1 further including a third temperature sensor, the third temperature sensor operable to sense the temperature of the heated expanded secondary gas.

16. The CHP system of claim 1 further including a controller, the controller operably connected to at least one of a first temperature sensor, a second temperature sensor, and a third temperature sensor, the controller also operably connected to at least one of the control mechanism, a proportional valve and a gas valve, the controller configured to execute a method to control at least one of a feed rate of the solid fuel into the combustion chamber, a flow of the expanded heated secondary gas into the combustion chamber, and a temperature of the mixed combustion gas.

17. The CHP system of claim 1 further including a blower and a heater operably connected to the combustion chamber, the blower and the heater configured to operate to initiate combustion of the solid fuel in the combustion chamber.

18. The CHP system of claim 1 further including a draft inducing exhaust fan operably connected to the combustion chamber, the draft inducing exhaust fan configured to maintain the combustion chamber at a lower pressure than the expanded heated secondary gas.

19. The CHP system of claim 1 wherein the high temperature heat exchanger is configured as a single counter flow heat exchanger.

20. The CHP system of claim 1 further including a low temperature heat exchanger operably connected to the high temperature heat exchanger and configured to receive the mixed combustion gases that have been cooled therein, the low temperature heat exchanger operable to transfer heat from the cooled mixed combustion gases to a secondary low temperature working fluid for a secondary low temperature application.

21. A method of operating a combined heat and power (CHP) system, the method comprising:

initiating a combustion process in a combustion chamber and combusting a solid fuel with an expanded heated secondary gas and generating a high temperature combustion gas;

regulating a temperature of the high temperature combustion gases with an expanded heated secondary gas to yield a mixed combustion gas;

compressing a secondary gas;

transferring heat from the mixed combustion gas to a compressed secondary gas;

expanding a compressed heated secondary gas and generating work thereby; and

employing the work generated.

22. The method of operating a CHP system of claim 21 further including at least one of controlling a feed rate of the solid fuel into the combustion chamber, controlling a flow rate of the expanded heated secondary gas into the combustion chamber, and controlling the regulating based on at least one of a temperature of the expanded heated secondary gas, a temperature of the mixed combustion gas, a temperature of the high temperature combustion gases, and the work generated.

23. The method of operating a CHP system of claim 22 wherein the regulating a temperature of the high temperature combustion gases includes controlling a flow of the heated expanded secondary gas and mixing with the high temperature combustion gases after the particle separating.

24. The method of operating a CHP system of claim 21 further including measuring a temperature of the high temperature combustion gases.

25. The method of operating a CHP system of claim 21 further including measuring a temperature of the mixed combustion gas.

26. The method of operating a CHP system of claim 21 further including measuring a temperature of the expanded heated secondary gas.

27. The method of operating a CHP system of claim 21 wherein the transferring occurs in a counter flow heat exchanger.

28. The method of operating a CHP system of claim 22 wherein the expanded heated secondary gas is at a temperature of about 600°

C. and is applied directly into the combustion process.

29. The method of operating a CHP system of claim 21 wherein the combustion process achieves a temperature of at least one of 1000°

C., 1050°

C. 1100°

C., and 1150°

C.

30. The method of operating a CHP system of claim 21 further including removing particulate matter from the high temperature combustion gases with a high temperature particle separator.