Excess pressure and waste heat utilization equipment based on screw expander and heat storage device

Abstract

The utility model relates to the field of differential pressure power generation of a gas turbine pressure regulating station, and discloses excess pressure and waste heat utilization equipment based on a screw expander and a heat storage device, which comprises an upstream main pipe incoming gas, and a switch unit is arranged at the output end of the upstream main pipe incoming gas. One output end of the switch unit is connected with a screw expander through a first connecting assembly, a first heat exchanger is arranged at the output end of the screw expander, and the other output end of the switch unit is connected to one input end of the first heat exchanger through a second connecting assembly. A circulating water system is arranged at the other input end of the first heat exchanger and used for increasing the enthalpy value and the temperature of natural gas, and a second heat exchanger is arranged at one output end of the first heat exchanger. According to the utility model, the power generation system is used for generating power by utilizing the residual pressure and residual heat of the natural gas differential pressure, so that the residual energy in the natural gas conveying process is recovered, and the auxiliary power of a power plant can be supplemented.

Description

Technical Field

[0001] The utility model relates to the field of pressure difference power generation of a gas turbine pressure regulating station, in particular to a waste pressure and waste heat utilization device based on a screw expander and a heat storage device. Background Art

[0002] A gas turbine pressure regulating station refers to a station where natural gas passes through a filtering unit, a metering unit, and a heating unit, and then is adjusted and output through a pressure reducing valve, a throttle valve, etc. to adjust the pressure and flow of the natural gas so that it meets the pressure and flow range that can be used by the gas turbine, and then is output to the gas turbine front module.

[0003] However, the current gas-steam combined cycle unit has the problem of irrational use of natural gas excess pressure and waste heat: the inlet pressure of the gas turbine pressure regulating station is as high as 4-6MPa, while the pressure required to enter the gas turbine is only 2.3-2.7MPa. If only simple throttling and pressure reduction are used in the gas turbine pressure regulating station, a large amount of natural gas will be wasted. The energy dissipated is huge, resulting in a huge waste of energy, and does not conform to the principle of "pressure matching and cascade utilization". In response to this technical problem, this application proposes a waste pressure and waste heat utilization device based on a screw expander and a heat storage device. Utility Model Content

[0004] The purpose of this utility model is to solve the shortcomings of the existing technology and propose a waste pressure and waste heat utilization device based on a screw expander and a heat storage device. By utilizing the waste pressure and waste heat of the natural gas differential pressure to generate electricity through the power generation system, it not only recovers the excess energy in the natural gas transportation process, but also can supplement the power consumption of the power plant.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A waste pressure and waste heat utilization device based on a screw expander and a heat storage device, including an upstream main pipe for supplying gas, an output end of the upstream main pipe for supplying gas being provided with a switch unit, one output end of the switch unit being connected to a screw expander via a connecting component 1, an output end of the screw expander being provided with a first heat exchanger, the other output end of the switch unit being connected to one input end of the first heat exchanger via a connecting component 2, the other input end of the first heat exchanger being provided with a circulating water system for increasing the enthalpy and temperature of natural gas, a second heat exchanger being provided at one output end of the first heat exchanger, a gas turbine pre-module being provided at one end of the gas turbine pre-module, a steam turbine being provided at one end of the gas turbine, one output end of the steam turbine being connected to a heat storage device, and the heat storage device being provided at the other input end of the second heat exchanger.

[0007] Furthermore, the connecting component 1 includes a second electric regulating valve provided at the other end of the screw expander, a quick-closing valve provided at the other end of the second electric regulating valve, and a second electric valve provided at the other end of the quick-closing valve.

[0008] Furthermore, the switching unit includes a first flow meter located at the other end of the second electric valve, a second manual valve is provided at the other end of the first flow meter, a first electric regulating valve is provided at the other end of the second manual valve, a first manual valve is provided at the other end of the first electric regulating valve, a first electric valve is provided at the other end of the first manual valve, and a third manual valve is provided between the first electric valve and the first flow meter.

[0009] Furthermore, the upstream main incoming gas pipe includes a heating unit located at the other end of the first electric valve, the other end of the heating unit is provided with a metering unit, and the other end of the metering unit is provided with a filtering unit.

[0010] Furthermore, the connecting component 2 includes a third electric valve located at one end of the first flowmeter and a second electric butterfly valve located at one end of the first heat exchanger, a throttle valve is provided at one end of the third electric valve, a second flowmeter is provided at one end of the throttle valve, a fourth electric valve is provided at one end of the second flowmeter, and a first electric butterfly valve is provided between the screw expander and the second electric butterfly valve.

[0011] Furthermore, the circulating water system includes a fifth electric valve and a sixth electric valve located at the other input end of the first heat exchanger, a first check valve is provided at one end of the fifth electric valve, a first water pump is provided at one end of the first check valve, and a fourth manual valve is provided at one end of the first water pump.

[0012] Furthermore, a second check valve is provided at one end of the sixth electric valve, a second water pump is provided at one end of the second check valve, a fifth manual valve is provided at one end of the second water pump, and a third electric regulating valve is provided between the fifth manual valve and the fourth manual valve.

[0013] Furthermore, a seventh electric valve is provided between the second heat exchanger and the gas turbine pre-module, a fifth electric regulating valve is provided between the second heat exchanger and the heat storage device, a fourth electric regulating valve is provided between the heat storage device and the steam turbine, and a sixth electric regulating valve is provided between the second heat exchanger and the steam turbine.

[0014] The utility model has the following beneficial effects:

[0015] In the utility model, the gas turbine pressure regulating station waste heat utilization power generation system utilizes the waste heat of the natural gas differential pressure through the screw expander and the heat storage device to generate electricity, which not only recovers the excess energy in the natural gas transportation process, but also can supplement the power consumption of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a plan view of a waste pressure and waste heat utilization device based on a screw expander and a heat storage device proposed in the utility model.

[0017] Legend:

[0018] 1. Gas from upstream main; 2. First electric valve; 3. First manual valve; 4. First electric regulating valve; 5. Second manual valve; 6. Third manual valve; 7. First flow meter; 8. Second electric valve; 9. Quick-closing valve; 10. Second electric regulating valve; 11. Screw expander; 12. Third electric valve; 13. Throttle valve; 14. Second flow meter; 15. Fourth electric valve; 16. First electric butterfly valve; 17. Second electric butterfly valve; 18. First heat exchanger; 19. Second heat exchanger; 20. Seventh electric valve ; 21. Heat storage device; 22. Third electric control valve; 23. Fourth manual valve; 24. First water pump; 25. First check valve; 26. Fifth electric valve; 27. Fifth manual valve; 28. Second water pump; 29. ​​Second check valve; 30. Sixth electric valve; 31. Fourth electric control valve; 32. Fifth electric control valve; 33. Sixth electric control valve; 34. Gas turbine pre-module; 35. Gas turbine; 36. Steam turbine; 37. Filter unit; 38. Metering unit; 39. Heating unit. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] Reference Figure 1, the utility model provides an embodiment: a waste pressure and waste heat utilization device based on a screw expander and a heat storage device, comprising an upstream main gas supply 1, the upstream main gas supply 1 includes a heating unit 39 located at the other end of a first electric valve 2, a metering unit 38 is provided at the other end of the heating unit 39, a filter unit 37 is provided at the other end of the metering unit 38, a first flow meter 7 is located at the other end of a second electric valve 8, a second manual valve 5 is provided at the other end of the first flow meter 7, a first electric regulating valve 4 is provided at the other end of the second manual valve 5, a first manual valve 3 is provided at the other end of the first electric regulating valve 4, a first electric valve 2 is provided at the other end of the first manual valve 3, the first electric valve 2 and the first electric valve 2 are provided. A third manual valve 6 is provided between the flow meters 7, a second electric regulating valve 10 is provided at the other end of the screw expander 11, a quick-closing valve 9 is provided at the other end of the second electric regulating valve 10, and a second electric valve 8 is provided at the other end of the quick-closing valve 9. A first heat exchanger 18 is provided at the output end of the screw expander 11, a third electric valve 12 is provided at one end of the first flow meter 7, and a second electric butterfly valve 17 is provided at one end of the first heat exchanger 18. A throttle valve 13 is provided at one end of the third electric valve 12, a second flow meter 14 is provided at one end of the throttle valve 13, a fourth electric valve 15 is provided at one end of the second flow meter 14, and a first electric butterfly valve is provided between the screw expander 11 and the second electric butterfly valve 17. 16, a fifth electric valve 26 and a sixth electric valve 30 are located at the other input end of the first heat exchanger 18. One end of the fifth electric valve 26 is provided with a first check valve 25, one end of the first check valve 25 is provided with a first water pump 24, and one end of the first water pump 24 is provided with a fourth manual valve 23 for increasing the enthalpy and temperature of the natural gas. One output end of the first heat exchanger 18 is provided with a second heat exchanger 19, one output end of the second heat exchanger 19 is provided with a gas turbine pre-module 34, one end of the gas turbine pre-module 34 is provided with a gas turbine 35, one end of the gas turbine 35 is provided with a steam turbine 36, and one output end of the steam turbine 36 is connected to a heat storage device 21. The heat storage device 21 is arranged at the other input end of the second heat exchanger 19, a second check valve 29 is provided at one end of the sixth electric valve 30, a second water pump 28 is provided at one end of the second check valve 29, a fifth manual valve 27 is provided at one end of the second water pump 28, a third electric regulating valve 22 is provided between the fifth manual valve 27 and the fourth manual valve 23, a seventh electric valve 20 is provided between the second heat exchanger 19 and the gas turbine pre-module 34, a fifth electric regulating valve 32 is provided between the second heat exchanger 19 and the heat storage device 21, a fourth electric regulating valve 31 is provided between the heat storage device 21 and the steam turbine 36, and a sixth electric regulating valve 33 is provided between the second heat exchanger 19 and the steam turbine 36.

[0021] Specifically, the output end of the upstream main gas 1 is connected to the first electric valve 2 and enters the input end of the switch unit. The first output end of the switch unit is connected to the input end of the screw expander 11. The second output end of the switch unit is connected to the third electric valve 12 and then connected in parallel with the branch of the screw expander 11. Then, the screw expander 11 and the fourth electric valve 15 are combined and the output end is connected to the first input end of the first heat exchanger 18. The first output end of the first heat exchanger 18 is connected to the first input end of the second heat exchanger 19. The first output end of the second heat exchanger 19 is connected to the input end of the gas turbine pre-module 34. The output end of the fifth electric valve 26 of the water pump section is connected to the second input end of the first heat exchanger 18. The output end of the sixth electric valve 30 of the water pump section is connected to the second input end of the first heat exchanger 18. The input end, the second output end of the first heat exchanger 18 is connected to the vent, the first output end of the steam turbine 36 is connected to the input end of the heat storage device 21, the output end of the heat storage device 21 is connected to the second input end of the second heat exchanger 19, the second output end of the second heat exchanger 19 is connected to the second input end of the steam turbine 36, and the second output end of the steam turbine 36 is connected to the vent. After the gas from the main line of the gas turbine pressure regulating station is sent to the first electric valve 2 of the switch unit through the output end, the opening and closing state of the switch unit controller can adjust the natural gas flow entering the equipment during the equipment operation and maintenance period; the natural gas is transported to the input end of the screw expander 11 through the first output end of the second manual valve 5 of the switch unit. After the natural gas enters the screw expander 11, it expands through the screw expander 11 to change its enthalpy. value, pressure and temperature, and simultaneously generates power by pressure difference; the second output end of the second manual valve 5 of the switch unit is connected to the first input end of the first heat exchanger 18, so that the normal transportation of natural gas can be affected during the operation and maintenance of the branch line of the screw expander 11; the output end of the screw expander 11 and the second output end of the switch unit are connected to the first input end of the first heat exchanger 18, so that the natural gas enters the first heat exchanger 18, and the first output end and the second output end of the circulating water system are connected to the second input end of the first heat exchanger 18, so that the circulating water enters the first heat exchanger 18, and the natural gas whose enthalpy and temperature are reduced by the screw expander 11 and the throttle valve 13 exchanges heat with the circulating water in the first heat exchanger 18, thereby increasing the enthalpy and temperature of the natural gas so that it meets the requirements of entering the gas turbine pre-module 34. Allowable parameters; the first output end of the steam extraction from the intermediate pressure cylinder of the steam turbine 36 is connected to the first input end of the heat storage device 21, so that the steam extracted from the intermediate pressure cylinder is stored in the heat storage device 21. When the natural gas parameters at the first output end of the first heat exchanger 18 do not meet the allowable parameters of the gas turbine pre-module 34, the steam in the heat storage device 21 enters the second input end of the second heat exchanger 19 through the output end of the heat storage device 21 and exchanges heat with the natural gas entering the first input end of the second heat exchanger 19 from the first output end of the first heat exchanger 18, thereby further increasing the enthalpy and temperature of the natural gas; after the natural gas in the second heat exchanger 19 meets the demand, the natural gas enters the input end of the gas turbine pre-module 34 through the first output end of the second heat exchanger 19, and then enters the gas turbine 35 for subsequent power generation;The steam in the second heat exchanger 19 is connected to the second input end of the steam turbine 36 from the second output end of the second heat exchanger 19 and re-enters the intermediate pressure cylinder of the steam turbine 36.

[0022] Working principle: After the gas from the main line of the gas turbine pressure regulating station is sent to the first electric valve 2 of the switch unit through the output end, the natural gas is sent to the input end of the screw expander 11 through the first output end of the second manual valve 5 of the switch unit. After the natural gas enters the screw expander 11, it expands through the screw expander 11 to change its enthalpy, pressure and temperature, and at the same time, pressure difference power generation is performed; the natural gas enters the first heat exchanger 18, and the circulating water enters the first heat exchanger 18. The natural gas with its enthalpy and temperature reduced by the screw expander 11 and the throttle valve 13 exchanges heat with the circulating water in the first heat exchanger 18, so that it meets the allowable parameters entering the gas turbine front module 34, so that the steam extracted from the intermediate pressure cylinder is stored in the heat storage device 21. When the first heat exchanger When the natural gas parameters at the first output end of 18 do not meet the allowable parameters of the gas turbine pre-module 34, the steam in the heat storage device 21 enters the second input end of the second heat exchanger 19 through the output end of the heat storage device 21 to exchange heat with the natural gas entering the first input end of the second heat exchanger 19 from the first output end of the first heat exchanger 18, thereby further increasing the enthalpy and temperature of the natural gas; after the natural gas in the second heat exchanger 19 meets the demand, the natural gas enters the input end of the gas turbine pre-module 34 through the first output end of the second heat exchanger 19, and then enters the gas turbine 35 for subsequent power generation; the steam in the second heat exchanger 19 re-enters the intermediate pressure cylinder of the steam turbine 36 from the second output end of the second heat exchanger 19 and the second input end of the steam turbine 36.

[0023] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A waste pressure and waste heat utilization device based on a screw expander and a heat storage device, characterized in that: The invention comprises an upstream main pipe for incoming gas (1), wherein the output end of the upstream main pipe for incoming gas (1) is provided with a switch unit, one output end of the switch unit is connected to a screw expander (11) through a connecting component 1, the output end of the screw expander (11) is provided with a first heat exchanger (18), the other output end of the switch unit is connected to one input end of the first heat exchanger (18) through a connecting component 2, and the other input end of the first heat exchanger (18) is provided with a circulating water system for increasing the enthalpy and temperature of the natural gas A second heat exchanger (19) is provided at one output end of the first heat exchanger (18), a gas turbine pre-module (34) is provided at one output end of the second heat exchanger (19), a gas turbine (35) is provided at one end of the gas turbine pre-module (34), a steam turbine (36) is provided at one end of the gas turbine (35), a heat storage device (21) is connected to one output end of the steam turbine (36), and the heat storage device (21) is provided at the other input end of the second heat exchanger (19).

2. The waste pressure and waste heat utilization device based on a screw expander and a heat storage device according to claim 1, characterized in that: The connecting assembly 1 includes a second electric regulating valve (10) provided at the other end of the screw expander (11), a quick-closing valve (9) provided at the other end of the second electric regulating valve (10), and a second electric valve (8) provided at the other end of the quick-closing valve (9).

3. The waste pressure and waste heat utilization device based on a screw expander and a heat storage device according to claim 2, characterized in that: The switch unit comprises a first flow meter (7) located at the other end of the second electric valve (8), a second manual valve (5) is provided at the other end of the first flow meter (7), a first electric regulating valve (4) is provided at the other end of the second manual valve (5), a first manual valve (3) is provided at the other end of the first electric regulating valve (4), a first electric valve (2) is provided at the other end of the first manual valve (3), and a third manual valve (6) is provided between the first electric valve (2) and the first flow meter (7).

4. The waste pressure and waste heat utilization device based on a screw expander and a heat storage device according to claim 3, characterized in that: The upstream main incoming gas (1) includes a heating unit (39) located at the other end of the first electric valve (2), a metering unit (38) is provided at the other end of the heating unit (39), and a filtering unit (37) is provided at the other end of the metering unit (38).

5. The waste pressure and waste heat utilization device based on a screw expander and a heat storage device according to claim 1, characterized in that: The second connecting component comprises a third electric valve (12) located at one end of the first flow meter (7) and a second electric butterfly valve (17) located at one end of the first heat exchanger (18), a throttle valve (13) is provided at one end of the third electric valve (12), a second flow meter (14) is provided at one end of the throttle valve (13), a fourth electric valve (15) is provided at one end of the second flow meter (14), and a first electric butterfly valve (16) is provided between the screw expander (11) and the second electric butterfly valve (17).

6. The waste pressure and waste heat utilization device based on a screw expander and a heat storage device according to claim 1, characterized in that: The circulating water system comprises a fifth electric valve (26) and a sixth electric valve (30) located at the other input end of the first heat exchanger (18), a first check valve (25) being provided at one end of the fifth electric valve (26), a first water pump (24) being provided at one end of the first check valve (25), and a fourth manual valve (23) being provided at one end of the first water pump (24).

7. The excess pressure and excess heat utilization device based on a screw expander and a heat storage device according to claim 6, characterized in that: A second check valve (29) is provided at one end of the sixth electric valve (30), a second water pump (28) is provided at one end of the second check valve (29), a fifth manual valve (27) is provided at one end of the second water pump (28), and a third electric regulating valve (22) is provided between the fifth manual valve (27) and the fourth manual valve (23).

8. The waste pressure and waste heat utilization device based on a screw expander and a heat storage device according to claim 1, characterized in that: A seventh electric valve (20) is provided between the second heat exchanger (19) and the gas turbine pre-module (34), a fifth electric regulating valve (32) is provided between the second heat exchanger (19) and the heat storage device (21), a fourth electric regulating valve (31) is provided between the heat storage device (21) and the steam turbine (36), and a sixth electric regulating valve (33) is provided between the second heat exchanger (19) and the steam turbine (36).

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