JP2007198200A - Energy supply system using gas turbine, energy supply method, and energy supply system remodeling method - Google Patents

Abstract

An energy supply system, an energy supply method, and an energy supply system remodeling method capable of improving energy efficiency and energy supply efficiency are provided.
A combustor that burns fuel to generate combustion gas, a gas turbine that obtains rotational power from the combustion gas, and a heat recovery steam generator that heats a heat medium by the exhaust gas of the gas turbine. A heat exchanger 54 that further heats the heat medium heated by the exhaust heat recovery boiler 30, a multistage compressor 53 that compresses the heat medium heated by the heat exchanger 54, and the heat recovery steam generator 30 that is heated The steam turbine 51 that drives the compressors 53a and 53b with a part of the heat medium, the heat exchanger 45 that heats the fuel with the heat medium that flows through the pipe 60 that connects the compressors 53a and 53b, and the steam turbine 51 A steam supply system 70 that supplies the driven steam and the steam compressed by the multistage compressor 53 to the heat utilization facility 1.
[Selection] Figure 1

Description

  The present invention relates to an energy supply system for supplying thermal energy to a heat utilization facility using a gas turbine, an energy supply method, and a method for remodeling an energy supply system using existing equipment.

  One of the systems aimed at improving the energy efficiency of the system is to use a heat pump in the cogeneration system. A heat pump efficiently pumps atmospheric heat, exhaust heat, etc. using a compressor or the like. As this type of technology, for example, there is a technology that uses a heat medium in a liquid state such as hot water or cold water generated by a heat pump as cleaning water, cooling water, or the like in the system (see Patent Document 1).

Japanese Patent Publication No. 7-4212

  However, when supplying heat energy to a heat utilization facility, it is difficult to secure a sufficient amount of energy that can be transported per medium weight even when hot water or cold water is used as a heat medium. For this reason, even when the above-described technology is applied and a configuration in which a liquid heat medium obtained using a heat pump is supplied to a heat utilization facility, the installation location of the energy supply system is close to the heat utilization facility. Limited to the range.

  An object of this invention is to provide the energy supply system which can improve energy efficiency and energy supply efficiency, the energy supply method, and the modification method of an energy supply system.

  (1) In order to achieve the above object, the present invention provides a combustor that burns fuel to generate combustion gas, a gas turbine that obtains rotational power from the combustion gas from the combustor, and an exhaust of the gas turbine. An exhaust heat recovery boiler that heats the heat medium with gas, a first heat exchanger that heats the heat medium heated by the exhaust heat recovery boiler with waste heat or heat obtained from the surrounding environment, and the first heat exchanger A plurality of compression means for compressing the heat medium heated by the steam, and a steam turbine for driving the plurality of compression means by changing expansion work obtained from a part of the heat medium heated by the exhaust heat recovery boiler to rotational power A second heat exchanger that heats the fuel supplied to the combustor by a heat medium that flows through a heat medium flow path that communicates between the plurality of compression means, a heat medium that drives the steam turbine, and The heat medium compressed by serial plurality of compression means intended to comprise a steam supply system for supplying a heat source to the heat utilization facility in the form of gas.

  (2) In order to achieve the above object, the present invention provides a combustor that burns fuel to generate combustion gas, a gas turbine that obtains rotational power from the combustion gas from the combustor, and the gas turbine. An exhaust heat recovery boiler that heats the heat medium with the exhaust gas, a first heat exchanger that heats the heat medium heated by the exhaust heat recovery boiler with waste heat or heat obtained from the surrounding environment, and the first heat A plurality of compression means for compressing the heat medium heated by the exchanger, and the plurality of compression means are driven by changing the expansion work obtained from a part of the heat medium heated by the exhaust heat recovery boiler to rotational power. A second heat exchanger that heats fuel supplied to the combustor by a heat medium that flows through a heat medium flow path communicating between the steam turbine and the plurality of compression means; and a heat medium that drives the steam turbine And a steam supply system for supplying the heat medium compressed by the plurality of compression means as a heat source to the heat utilization facility in a gas state, and a heat medium condensed by heat utilization in the heat utilization facility to the exhaust heat recovery boiler A circulation pump for circulation is provided.

  (3) Preferably, in the above (1) or (2), preferably, the heat medium flow path is formed by directly spraying the heat medium heated by the exhaust heat recovery boiler in at least one place of the heat medium flow path. A heat medium spraying section for reducing the temperature of the circulating heat medium is provided.

  (4) Any of the above (1) to (3) is preferably further provided on the upstream side of the combustor in the fuel flow direction, and a heat medium in the middle of compression flowing through the plurality of compression means is introduced into the fuel. A heat medium injection unit for directly injecting and heating the fuel is provided.

  (5) In the above (4), preferably, the heat medium injection section is provided on the upstream side in the fuel flow direction of the combustor and on the downstream side in the fuel flow direction of the second heat exchanger.

  (6) In order to achieve the above object, the present invention drives a gas turbine with combustion gas obtained by burning fuel in a combustor, and heats a heat medium with an exhaust heat recovery boiler with the exhaust gas of the gas turbine. The heat medium heated by the exhaust heat recovery boiler is heated by the first heat exchanger with waste heat or heat obtained from the surrounding environment, and the heat medium heated by the first heat exchanger is compressed into a plurality of compression means. The expansion work obtained from a part of the heat medium heated by the exhaust heat recovery boiler is changed to rotational power to drive a steam turbine that drives the plurality of compression means, and between the plurality of compression means The fuel supplied to the combustor by the heat medium flowing through the heat medium flow path communicating with the heat medium is heated by the second heat exchanger, and the heat medium driving the steam turbine and the heat medium compressed by the plurality of compression means The gaseous state In shall be supplied as a heat source to the heat utilization facility.

  (7) In order to achieve the above object, the present invention heats the heat medium by the exhaust gas of the gas turbine to an existing gas turbine that obtains rotational power from the combustion gas obtained by burning the fuel in the combustor. An exhaust heat recovery boiler, a first heat exchanger that heats the heat medium heated by the exhaust heat recovery boiler with waste heat or heat obtained from the surrounding environment, and a heat medium heated by the first heat exchanger A plurality of compression means for compressing, a steam turbine for driving the plurality of compression means by replacing expansion work obtained from a part of the heat medium heated by the exhaust heat recovery boiler with rotational power, and the plurality of compression means Compressed by the second heat exchanger that heats the fuel supplied to the combustor by the heat medium that flows through the heat medium flow path that communicates between the heat medium, the heat medium that drives the steam turbine, and the plurality of compression means Medium shall additionally provided a steam supply system for supplying a heat source to the heat utilization facility in the form of gas.

  According to the present invention, energy efficiency and energy supply efficiency can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a system flow diagram showing the overall configuration of the energy supply system according to the first embodiment of the present invention.

  As shown in FIG. 1, the energy supply system includes a gas turbine 10 that is a prime mover that converts combustion energy into driving force, and exhaust heat recovery that uses combustion gas (exhaust gas) discharged from the gas turbine 10 as a heat source. It is used as a heat source in the boiler 30, the heat pump 50 driven by steam supplied from the exhaust heat recovery boiler 30, the steam supply system 70 that supplies the steam generated by the heat pump 50 to the heat utilization facility 1, and the heat utilization facility 1. A pipe 44 through which the condensed heat medium flows and a circulation pump 35 that circulates and supplies the heat medium in the pipe 44 to the exhaust heat recovery boiler 30 are provided.

  The gas turbine 10 is provided in the compressor 11 that sucks and compresses the atmosphere A, the fuel pipe 15 that circulates the fuel B, and the fuel pipe 15, and heats the fuel B with heat (described later) from the heat pump 50. Rotated by the combustor 45, the combustor 12 that burns the fuel B heated by the heat exchanger 45 together with the compressed air from the compressor 11 to generate high-temperature and high-pressure combustion gas, and the combustion gas from the combustor 12 And a turbine 13 for obtaining power. As the fuel to be combusted in the combustor 12, in addition to natural gas, city gas mainly composed of natural gas, synthetic gas such as dimethyl ether, kerosene, light oil, A heavy oil, or the like can be used. Moreover, in this Embodiment, the generator 14 is connected with the rotating shaft coaxially with the turbine 13, and the structure in the case of converting the rotational power of the turbine 13 into an electrical energy with this generator 14 is illustrated. However, the gas turbine 10 may be connected to another load device such as a pump instead of the generator 14.

  The exhaust heat recovery boiler 30 is a low-pressure side that heats the heat medium supplied from the heat utilization facility 1 in order from the downstream side to the upstream side in the flow direction of the combustion gas (exhaust gas) from the gas turbine 10 that is a heat source. The heat exchanger 31, the branch part 36 where a part of the heated heat medium branches to the heat pump 50, the pipe 37 through which the heat medium branched by the branch part 36 flows, and the heat medium flowing through the pipe 37 are pumped And a high-pressure heat exchanger 34 that further heats the heat medium heated by the heat exchanger 31 to steam. Further, on the downstream side of the exhaust heat recovery boiler 30 in the exhaust gas distribution direction, a chimney 43 that discharges the exhaust gas that has finished heat exchange in the exhaust heat recovery boiler 30 to the atmosphere is provided.

  The piping 44 through which the heat medium condensed as a heat source in the heat utilization facility 1 flows is connected to the heat exchanger 31 in the exhaust heat recovery boiler 30 on the downstream side in the heat medium flow direction. The heat exchanger 31 is connected to the branch portion 36 on the downstream side in the heat medium flow direction. The branch portion 36 is connected to a pipe 38 connected to the heat pump 50 and a pipe 37 connected to the heat exchanger 34 in the exhaust heat recovery boiler 30 on the downstream side in the heat medium flow direction. The pipe 37 is connected to the heat exchanger 34 via the high-pressure pump 39, and supplies the heat medium heated by the heat exchanger 31 to the heat exchanger 34. The heat exchanger 34 is provided on the upstream side in the exhaust gas distribution direction in the exhaust heat recovery boiler 30, and is connected to the pipe 42 connected to the heat pump 50 on the downstream side in the heat medium distribution direction.

  The heat pump 50 includes a steam turbine 51 driven by a heat medium (steam) supplied from the exhaust heat recovery boiler 30 via a pipe 42, and a heat medium (high temperature) supplied from the exhaust heat recovery boiler 30 via a pipe 38. The two-phase flow expansion turbine 52 driven by water) and the heat medium (high-temperature water and steam) circulated through the two-phase flow expansion turbine 52 are used as external heat (for example, heat from the waste water of the heat utilization facility 1 or the atmosphere). There are provided a heat exchanger (evaporator) 54 that makes a gas state (steam) by heating using it, and a multistage compressor 53 that compresses the heat medium (steam) heated by the heat exchanger 54. .

  In the present embodiment, the multi-stage compressor 53 is composed of a two-stage compressor, and includes a low-pressure side compressor first stage 53a and a high-pressure side compressor second stage 53b (hereinafter referred to as appropriate). , Also simply referred to as a compressor 53a and a compressor 53b). On the downstream side of the compressor first stage 53a in the heat medium flow direction, a pipe 60 that connects the compressors 53a and 53b is provided so that the heat medium can flow between the compressors 53a and 53b. The aforementioned heat exchanger 45 is provided in the path of the pipe 60 to the compressor second stage 53b, and the pipe 60 is arranged so as to pass through the inside of the heat exchanger 45. In this way, the fuel of the gas turbine 10 is heated in the heat exchanger 45 using the heat medium flowing through the pipe 60 as a heat source. The compression means for compressing the heat medium (steam) that has been changed to a gas state by the heat exchanger 54 is not limited to the multi-stage compressor 53 including the two-stage compressor as shown in the figure, and is at least two stages. Any compression means may be used. This is because it is only necessary to install at least one heat exchanger capable of exchanging heat with the fuel B of the gas turbine 10 between the two-stage compression means so that the heat medium being compressed can be used as a heat source for heating the fuel. is there. Therefore, for example, two or more single-stage compressors are provided and the heat exchanger 45 is provided between the single-stage compressors, or the heat exchanger 45 is interposed between the compression stages of a multi-stage compressor having two or more compression stages. Of course, a plurality of multistage compressors may be provided, and a heat exchanger 45 may be provided between the multistage compressors.

  The steam turbine 51, the multistage compressor 53, and the two-phase flow expansion turbine 52 are provided coaxially, and the multistage compressor 53 is driven by the rotational power of the steam turbine 51 and the two-phase flow expansion turbine 52. The two-phase flow expansion turbine 52 is connected to the exhaust heat recovery boiler 30 via the pipe 38 on the upstream side in the heat medium flow direction, and is connected to the heat exchanger 54 on the opposite downstream side.

  The heat exchanger 54 has, for example, a pipe 83 through which drainage, air, or the like of the heat utilization facility 1 is passed, and the heat medium is heated by a heat source that circulates in the pipe 83. Further, it is connected to the compressor first stage 53 a of the multistage compressor 53 on the downstream side in the heat medium flow direction. The compressor first stage 53 a is connected to the compressor second stage 53 b through a pipe 60, and a heat exchanger 45 is provided in the pipe 60. The steam turbine 51 is connected to the exhaust heat recovery boiler 30 via a pipe 42 on the upstream side in the heat medium flow direction.

  The steam supply system 70 is connected to a pipe 71 connected to the outlet of the steam turbine 51, a pipe 72 connected to the outlet of the compressor second stage 53b, and downstream of these pipes 71 and 72. A merger 73 and a pipe 74 connecting the merger 73 and the heat utilization facility 1 are provided. In the present embodiment, the steam that has driven the steam turbine 51 and the multi-stage compressor 53 (the compressor first stage 53a and the compressor second stage 53b) after being generated by the two-phase flow expansion turbine 52 and the heat exchanger 54 are used. The steam compressed by) is circulated through the pipes 71 and 72 and then merged by the merger 73, and is circulated through the pipe 74 and supplied to the heat utilization facility 1.

  When constructing this system, of course, the entire system may be newly constructed. However, if there is an existing gas turbine, exhaust heat recovery boiler, etc., this system can be modified even if the existing equipment is appropriately modified. Can be constructed.

  For example, when the gas turbine 10 already exists, the exhaust heat recovery boiler 30 is attached to the gas turbine 10, and the heat medium is heated by the exhaust gas of the gas turbine 10 to generate steam. Then, a heat pump 50 is additionally installed and connected to the exhaust heat recovery boiler 30, the steam turbine 51 is driven by the steam from the exhaust heat recovery boiler 30, and the heat medium heated by the exhaust heat recovery boiler 30 is transferred by the heat exchanger 54. It is heated to produce steam. Further, a heat exchanger 45 is additionally provided so that the fuel of the gas turbine 10 can be heated by the heat medium flowing through the multistage compressor 53. Next, the heat pump 50 and the heat utilization facility 1 are connected by the steam supply system 70 so that the steam that has been expanded by the steam turbine 51 and the steam generated by the heat exchanger 54 are supplied to the heat utilization facility 1. The heat medium which is configured and used by the heat utilization facility 1 and condensed is circulated to the exhaust heat recovery boiler 30 by the circulation pump 35.

  If the exhaust heat recovery boiler 30 (or another exhaust heat recovery boiler) already exists, the heat medium is circulated through the existing exhaust heat recovery boiler, and the heat pump 50 and the heat exchange are performed in the same manner as described above. A vessel 45, a steam supply system 70, a circulation pump 35, etc. may be provided.

  Next, operation | movement of the energy supply system of this Embodiment is demonstrated.

  When the atmosphere A is sucked into the compressor 11, the sucked air is compressed by the compressor 11 and pressurized to a set pressure (for example, about 0.8 [MPa]) and set temperature (for example, about 260 [° C]). ) Until heated. On the other hand, when the fuel B is circulated into the heat exchanger 45 through the fuel pipe 15, the fuel B is heated through the pipe 60 by the heat medium compressed and heated by the compressor first stage 53 a in the heat pump 50. Is done. The heat exchanger 45 can increase the amount of heat input to the combustor 12 by heating the fuel B in this way, as compared with the case where the same amount of fuel at normal temperature is used.

  The heated atmosphere A and fuel B are both supplied to the combustor 12 and then combusted, and are supplied to the turbine 13 as high-temperature and high-pressure combustion gas. Rotational power is given to the turbine 13 by the expansion work of the combustion gas, and the generator 14 to which the rotational power is transmitted generates electric energy. The combustion gas (exhaust gas) after rotating the turbine 13 is subsequently guided to the exhaust heat recovery boiler 30 as a heat source for heating the heat medium supplied from the heat utilization facility 1. The temperature of the combustion gas (exhaust gas) is high in the vicinity of the outlet of the turbine 13 (for example, about 640 [° C.]), but the circulation pump 35 passes through the heat exchangers 34 and 31 in the exhaust heat recovery boiler 30 sequentially. In order to exchange heat with the heat medium supplied by, the temperature is reduced before being discharged from the chimney 43.

  A pipe 44 is connected to the exhaust heat recovery boiler 30 on the downstream side in the combustion gas flow direction, and is used as a heat source in the heat utilization facility 1 via the pipe 44 to be condensed at a predetermined temperature (for example, 60 [° C.]). About) heat medium. The heat medium is pressurized to a set pressure (for example, about 0.6 [MPa]) by the circulation pump 35 before reaching the exhaust heat recovery boiler 30. The heat medium supplied into the exhaust heat recovery boiler 30 is supplied to the low-pressure heat exchanger 31 and is heated to a set temperature (for example, about 120 [° C.]) by the combustion gas (exhaust gas) of the gas turbine 13. While it becomes high-temperature water, it is supplied to the branch section 36 in a state where it is depressurized to a predetermined pressure (for example, about 0.5 [MPa]) in response to the pressure loss by the heat exchanger 31. Then, the heat medium is divided into a pipe 37 and a pipe 38 at the branch portion 36.

The heat medium guided to the pipe 37 is boosted to a set pressure (for example, about 7.4 [MPa]) by the high-pressure pump 39 and guided to the high-pressure side heat exchanger 34. The heat medium guided to the high-pressure side heat exchanger 34 is heated to a set temperature and pressure (for example, about 500 [° C.], about 7.0 [MPa]), and becomes superheated steam. It is supplied to a steam turbine 51 that is a power source of the heat pump 50.

  A heat medium (superheated steam) having a set pressure (for example, about 7.0 [MPa]) exiting the high pressure side heat exchanger 34 performs expansion work in the steam turbine 51. At this time, the heat medium is depressurized to a set pressure (for example, about 0.4 [MPa]) when used as a heat source in the heat utilization facility 1. The rotational power obtained by the steam turbine 51 is transmitted to the two-layer flow expansion turbine 52 and the multistage compressor 53 to drive them.

  On the other hand, the heat medium guided to the pipe 38 is supplied to the two-phase flow expansion turbine 52 in the heat pump 50. This heat medium is high-temperature water (for example, about 120 [° C.] and about 0.5 [MPa]) close to saturated steam when it leaves the low-pressure side heat exchanger 31. The heat medium in the two-phase flow expansion turbine 52 evaporates at a predetermined rate during the expansion process to form a two-phase flow, and drives the turbine 52 to reduce the temperature and reduce the pressure (for example, 60 [° C.], 0.02 [MPa]). Degree). Here, the liquid phase separated from the vapor phase is heated and evaporated by the exhaust heat (for example, about 60 to 80 [° C.]) of the heat utilization facility 1 that leaves the turbine 52 and flows through the pipe 83 in the heat exchanger 54. Together with the vapor phase, it is supplied to the compressor first stage 53 a in the multistage compressor 53. The heat source flowing through the pipe 83 may of course use heat obtained from the surrounding environment such as exhaust heat of the heat utilization facility 1 or atmospheric heat.

  The heat medium (steam) supplied to the first-stage compressor 53 a on the low-pressure side is heated by being pressurized by the compressor 53 a and guided to the pipe 60. When the heated heat medium passes through the heat exchanger 45 provided downstream, the heat medium is heat-exchanged with the fuel B before being supplied to the combustor 12 and the temperature is reduced. As described above, when the temperature of the heat medium increased by the compressor 53a is decreased, the gas density increases. Generally, the higher the gas density, the smaller the compression power required for pressurization. Therefore, when the temperature of the heat medium is reduced in this way, the compression of the heat medium is reduced when the heat medium is compressed by the high pressure side compressor second stage 53b. It is possible to pressurize to a predetermined pressure with power. As described above, in the present embodiment, the heat medium is cooled using the heat exchanger 45 between the compressors 53a and 53b to increase the gas density, thereby reducing the compression power required for compression and improving the efficiency. The decline is suppressed.

  The steam pressurized to the set pressure (for example, about 0.4 [MPa]) by the compressor second stage 53b is circulated to the merger 73 via the pipe 72 in order to be supplied to the heat utilization facility as a heat source. In the merger 73, the steam that has driven the steam turbine 51 is also supplied by the pipe 71, and the heat medium that has been divided at the branch portion 36 in the exhaust heat recovery boiler 30 is merged again here. The combined heat medium is supplied to the heat utilization facility 1 as a heating source (about 140 [° C.]) via the pipe 74.

  The heat medium (for example, about 60 [° C.]) that releases heat and condenses in the heat utilization facility 1 is discharged from the heat utilization facility 1, is appropriately purified, returns to the pipe 44, and is again recovered by the circulation pump 35. Circulated and supplied to the boiler 30.

  Next, the function and effect of this embodiment will be described.

  In the present embodiment, by supplying a heat medium in the state of vapor (gas) to the heat utilization facility 1, the amount of energy that can be transported per medium weight is greatly increased compared to the case where the heat medium is supplied in a liquid state. Can be improved. Therefore, since the power for transporting heat can be reduced, the energy supply efficiency is improved, and it is not necessary to install the present system in a place close to the heat utilization facility 1, and it can be installed in a remote place. Further, by using the heat pump 50 to generate steam to be supplied to the heat utilization facility 1, in addition to the heat energy of the exhaust heat recovery boiler 50, in other words, the fuel energy input to the gas turbine 10, the heat utilization facility 1. Since the exhaust heat from the etc. and the thermal energy of the surrounding environment can also be taken into the system, the energy efficiency can be dramatically improved.

  Here, the energy consumption efficiency (COP) indicating the performance of the heat pump 50 is defined by the ratio between the power used to drive the multistage compressor 53 and the amount of heat given to the heat medium by the heat exchanger 54. Then, using this COP value as a parameter, using the energy of the fuel B input to the combustor 12 as a denominator, the amount of power generated by the generator 14 and the amount of heat of the heat medium supplied to the heat utilization facility 1 via the pipe 74. Is defined as the total efficiency.

  At this time, for example, if the pressure and temperature of the heat medium and exhaust gas in various parts of the system show values as shown in parentheses in the above operation explanation, the overall efficiency of the system is as follows. If it exceeds 100% and the COP value is improved to 5, it becomes 128%. This is because the heat pump 54 takes in heat energy (exhaust heat, atmospheric heat, etc.) from the outside by the heat exchanger 54 in addition to the energy of the fuel B input to the combustor 12. In addition, the circulation pump 35 that circulates the heat medium in the system and the power used by the high-pressure pump 39 that boosts the heat medium by the exhaust heat recovery boiler 30 also contribute to heating of the heat medium.

In addition, the overall efficiency of a general cogeneration system is about 80%, but compared with this, the overall efficiency of the system of this embodiment is extremely high as described above, and the COP value is improved to about 4, Efficiency can be increased to 125%. Moreover, in comparison with a general cogeneration system with an overall efficiency of about 80%, this system can reduce the amount of CO ₂ generated that affects global warming by about 36%. The thermal loss in this system is the amount of heat of the temperature difference between the exhaust gas C released from the exhaust heat recovery boiler 30 by the chimney 43 and the atmosphere A sucked into the compressor 11. Therefore, if a heat quantity larger than this heat loss is taken in from the outside by the heat exchanger 54, the total efficiency of this system exceeds 100%.

  Further, as described above, the present embodiment includes the heat exchanger 45 that heats the fuel B supplied to the combustor 12 by the heat medium that flows through the pipe 60 that connects the compressors 53a and 53b. . By heating the fuel B of the gas turbine 10 with the heat exchanger 45, the amount of heat input to the combustor 12 can be increased as compared with the case where the same amount of fuel at normal temperature is used. As a result, even if the amount of fuel is reduced, combustion under the same conditions can be achieved, so that energy efficiency can be improved.

  In addition, as described above, various fuels can be used as the fuel used in the present system. However, dimethyl ether or the like that liquefies when pressurized is required to improve atomization characteristics by heating in a pipe. In addition, it is necessary to reduce the viscosity of liquid fuel such as heavy oil to improve the atomization characteristics by heating. The system of the present embodiment can use the extra heat generated by the multistage compressor 53 in the heat pump 50 for fuel heating by the heat exchanger 45 even when using fuel that requires such heating. Yes, it is possible to build an energy efficient system.

  In addition, when heating the fuel, it is generally necessary to consider the risk of ignition, etc., but the heating medium in the present embodiment is steam, and in the unlikely event that the pipe is damaged, steam will be generated in the fuel. Even if it leaks, the risk of fire is low and a safe system can be provided.

  By the way, in the present invention, while the fuel B is heated by the heat exchanger 45 as described above and the above effects are obtained, heat exchange with the fuel B is performed and the heat medium is cooled in the middle of the multistage compressor 53. By this, the effect that the compression power of the compressor second stage 53b can be reduced can be further obtained. Hereinafter, this effect will be described.

  For example, consider a case where 0.01 [MPa] steam is compressed to 0.4 [MPa] by the compressor 53a and the compressor 53b. In this case, if intermediate cooling of the heat medium is not performed between the compressors 53a and 53b, the medium temperature (steam temperature) reaches about 490 [° C.] even if the compression efficiency of the compressor is assumed to be 100%. End up. When the compression efficiency is about 85%, the steam temperature reaches about 550 [° C.]. Here, considering the latter example, the power of the compressors 53a and 53b required when pressurizing a saturated steam (heat medium) of 0.01 [MPa] to a predetermined pressure of 0.4 [MPa] Energy corresponding to the temperature difference between the saturation temperature (46 [° C.]) and the temperature when the predetermined pressure is reached after pressurization (about 550 [° C.]) is required, and the energy efficiency becomes very poor. .

  On the other hand, if the heat exchanger 45 is provided between the compressions 53a and 53b to perform intermediate cooling of the heat medium, the density of the heat medium can be increased by cooling with the fuel B. In general, the higher the gas density, the smaller the compression power of the compressor at the time of pressurization. Therefore, when compressing this heat medium with the compressor second stage 53b on the high-pressure side, pressurize to a predetermined pressure with less compression power. Is possible. As described above, in the present embodiment, the heat medium is cooled using the heat exchanger 45 between the compressors 53a and 53b to increase the gas density, thereby reducing the compression power required during compression and reducing the energy efficiency. Can be suppressed.

  Moreover, in this Embodiment, since it uses for the driving force of the multistage compressor 53 of the heat pump 50, or the two-phase flow expansion turbine 52, without converting the motive power obtained with the steam turbine 51 into electric power, the energy accompanying electric power conversion There is no loss. In addition, the steam after the expansion work by the steam turbine 51 and the steam generated by the heat pump 50 are mixed and transported to the heat utilization facility 1 by the common pipe 74, so that more heat medium can be utilized by heat without waste. It can be supplied to the facility 1. These points are also significant advantages of this system.

  Furthermore, if there is a prime mover facility such as a gas turbine that discharges exhaust heat that is not used to the atmosphere, or an exhaust heat recovery boiler facility, etc., the system can be easily modified by modifying such existing facility. The ability to build is also a great advantage of this system.

Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a system flow diagram showing the overall configuration of the energy supply system according to the second embodiment of the present invention. In the figure, the same parts as those in FIG.

  As shown in FIG. 2, this embodiment is different from the first embodiment in that the mixer 82 is provided between the outlet of the heat exchanger 45 and the inlet of the compressor second stage 53b in the pipe 60A. In addition, a branch portion 80 is provided in a pipe 38A connecting the outlet of the low-pressure side heat exchanger 31 of the exhaust heat recovery boiler 30 to the inlet of the two-phase flow expansion turbine 52, and the heat medium branched from the branch portion 80 is supplied to the pipe 81. The temperature of the heat medium in the pipe 60A can be reduced by spraying into the mixer 82 via the. Others are the same as those in the first embodiment described above, and the same effects as those in the first embodiment can be obtained.

  In addition to the configuration of the heat pump 50 of the first embodiment, the heat pump 50A further includes a branching unit 80 that divides the heat medium (high-temperature water) flowing through the pipe 38A, and a part of the heat medium from the branching unit 80. And a mixer 82 for directly spraying a heat medium (high temperature water) supplied from the pipe 81 to reduce the temperature of the heat medium (steam) flowing through the multistage compressor 53. Yes.

  The branch portion 80 is provided in a pipe 38A that connects the branch portion 36 of the exhaust heat recovery boiler 30 and the inlet of the two-phase flow expansion turbine 52 of the heat pump 50A, and is connected to the pipe 81. The pipe 81 is connected to the branch portion 80 on the upstream side in the heat medium flow direction and to the mixer 82 on the downstream side in the heat medium flow direction. A part of high-temperature water (heat medium) flowing through the pipe 38 </ b> A flows through the branch portion 80 inside the pipe 81. The mixer 82 is provided in the part from the outlet of the heat exchanger 45 to the inlet of the compressor second stage 53b in the pipe 60A connecting the compressor first stage 53a and the compressor second stage 53b. In this mixer 82, the high temperature water which distribute | circulates the piping 81 with respect to the vapor | steam (heat medium) which distribute | circulates the piping 60A is sprayed, and the temperature of the vapor | steam which distribute | circulates the piping 60A is reduced.

  In the present embodiment, the heat medium fed by the circulation pump 35 is heated by the low-pressure side heat exchanger 31 in the exhaust heat recovery boiler 30 to become high-temperature water, and is divided into the branch portion 36 and then distributed to the pipe 38A. To do. The high-temperature water guided to the pipe 38 </ b> A is further sprayed directly to the mixer 82 through the pipe 81 via the branch portion 80. On the other hand, the steam compressed by the compressor first stage 53a is guided to the heat exchanger 45 via the pipe 60A and exchanges heat with the fuel B. The steam that has exchanged heat with fuel B (ie, cooled) is then introduced into the mixer 82 before being fed to the compressor 53 and mixed with the hot water sprayed through the piping 81. And further cooled.

  Thus, by providing the mixer 82 that sprays high-temperature water directly in the steam flowing through the pipe 60A on the downstream side of the outlet of the heat exchanger 45, the temperature of the steam after being reduced by the heat exchanger 45 is reduced. Further reduction can be achieved. As a result, the temperature of the steam can be easily reduced to the saturation temperature, and the density of the heat medium can be increased. Therefore, the compression power of the compressor second stage 53b can be further reduced, and the energy efficiency can be further improved as compared with the first embodiment. Further, the amount of spraying the high temperature water onto the steam (spray amount) is not limited to the extent that the steam reaches the saturation temperature as described above, but to the extent that the entire amount becomes steam after being compressed in the compressor second stage 53b ( Spray until slightly wet steam). Furthermore, the temperature at which the water vapor temperature is used in the heat utilization facility 1 at the outlet of the compressor second stage 53b (the pressure and temperature as in the first embodiment are also set in each place in the system of the present embodiment). For example, when the amount of high-temperature water sprayed in the mixer 82 is adjusted so as to be, for example, about 140 [° C.], energy efficiency is improved.

  In addition, when it is desired to mix the high-temperature water more uniformly in the steam, the problem can be solved by arranging the mixer 82 closer to the upstream side in the heat medium flow direction to ensure a sufficient mixing distance. Further, the number of mixers installed is not limited to one as shown in FIG. 2, but at least one mixer is sufficient. That is, it is of course possible to install a plurality of pipes 60A and adjust the spray amount of high-temperature water as appropriate.

  In the above description, the mixer 82 has been described as spraying high-temperature water into steam. However, for example, an injection port that sprays high-temperature water directly onto the pipe 60A without using the above-described mixer. Etc., steam and high temperature water may be mixed. Furthermore, in the above description, the high temperature water has been described as an example of the heat medium to be sprayed. However, if the heat medium is relatively cooler than the temperature of the steam flowing through the pipe 60A, the same as above. An effect can be obtained.

  Next, a third embodiment of the present invention will be described with reference to the drawings.

  FIG. 3 is a system flow diagram showing the overall configuration of the energy supply system according to the third embodiment of the present invention. In the figure, the same reference numerals are given to the same parts as those in the previous figures, and the description thereof is omitted.

  As shown in FIG. 3, this embodiment is different from the first embodiment in that a branch portion 90 is provided in a pipe 60B that connects the outlet of the compressor first stage 53a and the inlet of the heat exchanger 45. Thus, the fuel B can be further heated by directly injecting the steam diverted from the branch part 90 into the fuel B from the steam injection part 92 through the pipe 91. Others are the same as those in the first embodiment described above, and the same effects as those in the first embodiment can be obtained.

  In addition to the configuration of the heat pump 50 of the first embodiment, the heat pump 50B is further provided in a pipe 60B that connects the outlet of the compressor first stage 53a and the inlet of the compressor second stage 53b. A branching portion 90 that divides a heat medium (steam) flowing through the inside, a pipe 91 through which a part of the heat medium flows from the branching portion 90, and a fuel medium that is provided in the fuel pipe 15B and supplied from the pipe 91 And a steam injection portion 92 that directly injects the fuel into the fuel pipe 15B and heats the fuel B.

  The branch portion 90 is provided between the outlet of the compressor first stage 53 a and the inlet of the heat exchanger 45, and is connected to the pipe 91. The pipe 91 communicates the branch part 90 and the steam injection part 92. The steam injection part 92 is provided in the fuel pipe 15B and between the outlet of the heat exchanger 45 and the inlet of the combustor 12, and injects steam directly into the fuel B to flow through the fuel pipe 15B. The temperature of the fuel B is increased.

  In the present embodiment, the heat medium (steam) pressurized by the compressor first stage 53a flows through the pipe 60B and is guided to the branching section 90. The steam is guided from the branch part 90 to the steam injection part 92 via the pipe 91 and then directly jetted into the fuel B flowing through the fuel pipe 15B via the steam injection part 92. Thereby, the fuel B heated by the heat exchanger 45 is mixed with the steam ejected through the steam injection section 92 and further heated.

  In this way, the steam injection portion 92 that directly jets steam into the fuel B that has flowed through the heat exchanger 45 is provided in the fuel pipe 15B between the outlet of the heat exchanger 45 and the inlet of the combustor 12. By providing, the fuel B after the steam and the fuel B are mixed and heated by the heat exchanger 45 can be further heated. Thereby, the amount of heat input to the combustor 12 can be further increased. Accordingly, the amount of heat input to the combustor 12 can be further increased as compared with the case where the same amount of fuel as heated in the first embodiment is used, so that the input is performed in order to achieve the same combustion condition. It is possible to further reduce the amount of fuel to be used. Thereby, energy efficiency can further be improved.

  Further, when steam is added to the fuel B, steam particles enter into the combustion gas generated when the fuel B is burned in the combustor 12, and the sensible heat of these steam particles is generated locally in the flame. To take away high heat. Thereby, local temperature unevenness of the combustion gas, particularly temperature unevenness on the high temperature side can be suppressed, and generation of NOx can be suppressed. In general, NOx tends to increase if the fuel is heated. However, since the generation of NOx can be suppressed by applying this embodiment, the amount of heat given to the fuel by the heat exchanger 45, steam, etc. can be further increased. Can do. Further, by optimizing the conditions such as the fuel heating amount and the steam mixing amount, the NOx concentration in the exhaust gas discharged from the gas turbine 10 can be lowered (for example, 10 [ppm] or less). As a result, it is possible to omit the denitration device provided in the exhaust heat recovery boiler and the like, and the environmental load can be reduced.

  In each of the above embodiments, the case where water is used as the heat medium supplied to the heat utilization facility has been described. However, there is a risk that the heat supply medium may flow out to the outside by configuring a closed system of the energy supply system. If not, another medium such as carbon dioxide, ammonia, trifluoroethanol or the like may be used as the heat medium. Further, such other medium may be used alone as a heat medium, but depending on the case, a plurality of types may be mixed, or may be used by mixing with water. Similarly to the mixer 82 of the second embodiment, the steam injection section 92 of the present embodiment is also installed closer to the upstream side in the fuel flow direction if the mixing state of the steam and the fuel B is to be made more uniform. Needless to say, the mixing distance is sufficient, and the number of installations is not limited to one as shown in FIG.

It is a system flow figure showing the whole energy supply system composition concerning a 1st embodiment of the present invention. It is a system flow figure showing the whole structure of the energy supply system which concerns on the 2nd Embodiment of this invention. It is a system flow figure showing the whole structure of the energy supply system which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat utilization facility 10 Gas turbine 12 Combustor 13 Turbine 15 Fuel piping 30 Waste heat recovery boiler 35 Circulation pump 45 Heat exchanger 50 Heat pump 51 Steam turbine 52 Two-phase flow expansion turbine 53 Multistage compressor 53a Compressor first stage 53b Compression Second stage 54 Heat exchanger 60 Pipe 70 Steam supply system 82 Mixer 92 Steam injection section

Claims (7)

A combustor that burns fuel to produce combustion gases;
A gas turbine that obtains rotational power from combustion gas from the combustor;
An exhaust heat recovery boiler that heats the heat medium by the exhaust gas of the gas turbine;
A first heat exchanger for heating the heat medium heated by the exhaust heat recovery boiler with waste heat or heat obtained from the surrounding environment;
A plurality of compression means for compressing the heat medium heated by the first heat exchanger;
A steam turbine that drives the plurality of compressing means by replacing expansion work obtained from a part of the heat medium heated by the exhaust heat recovery boiler with rotational power;
A second heat exchanger that heats fuel supplied to the combustor by a heat medium that flows through a heat medium flow path communicating between the plurality of compression means;
An energy supply system comprising: a heat supply system that supplies the heat medium that has driven the steam turbine and the heat medium that has been compressed by the plurality of compression means in a gas state to a heat utilization facility as a heat source. A combustor that burns fuel to produce combustion gases;
A gas turbine that obtains rotational power from combustion gas from the combustor;
An exhaust heat recovery boiler that heats the heat medium by the exhaust gas of the gas turbine;
A first heat exchanger for heating the heat medium heated by the exhaust heat recovery boiler with waste heat or heat obtained from the surrounding environment;
A plurality of compression means for compressing the heat medium heated by the first heat exchanger;
A steam turbine that drives the plurality of compressing means by replacing expansion work obtained from a part of the heat medium heated by the exhaust heat recovery boiler with rotational power;
A second heat exchanger that heats fuel supplied to the combustor by a heat medium that flows through a heat medium flow path communicating between the plurality of compression means;
A steam supply system that supplies the heat medium that has driven the steam turbine and the heat medium compressed by the plurality of compression means as a heat source in a gas state to a heat utilization facility;
An energy supply system comprising: a circulation pump that circulates the heat medium condensed by heat utilization in the heat utilization facility to the exhaust heat recovery boiler. The energy supply system according to claim 1 or 2,
Furthermore, a heat medium spraying unit for directly spraying the heat medium heated by the exhaust heat recovery boiler and reducing the temperature of the heat medium flowing through the heat medium flow path is provided at at least one location of the heat medium flow path. An energy supply system characterized by that. The energy supply system according to any one of claims 1 to 3,
And a heat medium injection part provided on the upstream side of the combustor in the fuel flow direction, and directly injecting the heat medium in the middle of compression flowing through the plurality of compression means into the fuel to heat the fuel. Energy supply system. The energy supply system according to claim 4, wherein
The energy supply system according to claim 1, wherein the heat medium injecting section is provided upstream of the combustor in the fuel flow direction and downstream of the second heat exchanger in the fuel flow direction. The gas turbine is driven by the combustion gas obtained by burning the fuel in the combustor,
The heat medium is heated by the exhaust heat recovery boiler with the exhaust gas of this gas turbine,
The heat medium heated by the exhaust heat recovery boiler is heated by the first heat exchanger with waste heat or heat obtained from the surrounding environment,
The heat medium heated by the first heat exchanger is compressed by a plurality of compression means,
Driving a steam turbine that drives the plurality of compression means by changing expansion work obtained from a part of the heat medium heated by the exhaust heat recovery boiler to rotational power;
The fuel supplied to the combustor is heated by a second heat exchanger with a heat medium flowing through a heat medium flow path communicating between the plurality of compression means,
An energy supply method comprising: supplying a heat medium that has driven the steam turbine and a heat medium compressed by the plurality of compression means to a heat utilization facility in a gas state as a heat source. In an existing gas turbine that obtains rotational power from combustion gas obtained by burning fuel with a combustor,
An exhaust heat recovery boiler that heats the heat medium by the exhaust gas of the gas turbine;
A first heat exchanger for heating the heat medium heated by the exhaust heat recovery boiler with waste heat or heat obtained from the surrounding environment;
A plurality of compression means for compressing the heat medium heated by the first heat exchanger;
A steam turbine that drives the plurality of compressing means by replacing expansion work obtained from a part of the heat medium heated by the exhaust heat recovery boiler with rotational power;
A second heat exchanger that heats fuel supplied to the combustor by a heat medium that flows through a heat medium flow path communicating between the plurality of compression means;
A modification of the energy supply system, wherein a heat supply system that supplies the heat medium that drives the steam turbine and the heat medium compressed by the plurality of compression means as a heat source to the heat utilization facility in a gaseous state is additionally provided. Method.

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