阅读说明：本技术 具有天然气再气化的发电厂设施 (Power plant facility with natural gas regasification ) 是由 卡斯滕·格雷贝尔 乌韦·朱雷策克 于 2019-05-17 设计创作，主要内容包括：本发明涉及一种发电厂设施(1),其具有：燃气轮机(2),所述燃气轮机包括压缩机(3)、燃烧室(4)和涡轮机(5)；还有用于运输液态的和气态的天然气的天然气管路(6)；接入天然气管路(6)中的用于提高液态天然气压力的天然气压缩机(7)；和同样接入天然气管路(6)中的膨胀机(8),所述发电厂设施还包括和在天然气压缩机(7)和膨胀机(8)之间接入有用于蒸发液态天然气的第一热交换器(9)和用于继续加热再气化的天然气的第二热交换器(10),其中发电厂设施包括废热蒸汽发生器(14)并且第二热交换器(10)与废热蒸汽发生器(14)中的冷凝物预热器(15)耦联。本发明还涉及一种用于运行这种发电厂设施(1)的方法。(The invention relates to a power plant facility (1) comprising: a gas turbine (2) comprising a compressor (3), a combustion chamber (4) and a turbine (5); a natural gas line (6) for transporting liquid and gaseous natural gas; a natural gas compressor (7) connected to the natural gas line (6) for increasing the pressure of the liquefied natural gas; and an expander (8) which is likewise connected into the natural gas line (6), wherein a first heat exchanger (9) for evaporating the liquefied natural gas and a second heat exchanger (10) for further heating the regasified natural gas are connected between the natural gas compressor (7) and the expander (8), wherein the power plant comprises a waste heat steam generator (14) and the second heat exchanger (10) is coupled to a condensate preheater (15) in the waste heat steam generator (14). The invention also relates to a method for operating such a power plant facility (1).)

1. A power plant facility (1) having: a gas turbine (2) comprising a compressor (3), a combustion chamber (4) and a turbine (5); a natural gas line (6) for transporting liquid and gaseous natural gas to the gas turbine (2); a natural gas compressor (7) connected to the natural gas line (6) for increasing the pressure of the liquefied natural gas; and an expander (8) likewise incorporated into the natural gas line (6), the power plant facility further comprising and between the natural gas compressor (7) and the expander (8) a first heat exchanger (9) for evaporating liquid natural gas and a second heat exchanger (10) for further heating the regasified natural gas, characterized in that the power plant facility comprises a waste heat steam generator (14) and in that the second heat exchanger (10) is coupled to a condensate preheater (15) in the waste heat steam generator (14).

2. A power plant facility according to claim 1, further comprising a third heat exchanger (11) connected downstream of the expander (8) in the natural gas pipeline (6).

3. The power plant facility (1) according to claim 1 or 2,

wherein the first heat exchanger (9) is connected to a suction line (13) of the gas turbine (2) via a heat transfer medium circuit (12).

4. The power plant facility (1) according to any of the preceding claims,

wherein the first heat exchanger (9) is connected into a cooling system of the power plant facility (1) via a heat transfer medium circuit (12).

5. Power plant facility (1) according to claim 3 or 4,

wherein the heat transfer medium circulation loop (12) is a water-ethanol circulation loop.

6. The power plant facility (1) according to any of the preceding claims,

wherein a hot condensate extraction point (16) for the second heat exchanger (10) is located downstream of the high-pressure feed water pump (17) in the feed water flow direction.

7. The power plant facility (1) according to any of the preceding claims,

wherein a hot condensate extraction point (16) for the second heat exchanger (10) is located downstream of a condensate recirculation pump (18) in the condensate flow direction, and the second heat exchanger (10) is a double-walled safety heat exchanger.

8. The power plant facility (1) according to any of the preceding claims,

wherein the third heat exchanger (11) is coupled to a water supply (19) of the waste heat steam generator (14).

9. A method for operating a power plant facility (1) with evaporation of liquefied natural gas, wherein liquefied natural gas is brought to at least 150bar and heat from the gas turbine intake air and/or from the cooling system of the power plant facility (1) is used for gasifying the liquefied natural gas, characterized in that in a further step the natural gas is heated further in heat exchange with hot condensate from a condensate preheater (15) of a waste heat steam generator (14).

10. The method of claim 9, wherein the first and second light sources are selected from the group consisting of,

wherein the further heated natural gas is expanded via an expander (8) to a gas pressure level required for the operation of the gas turbine for power output.

11. The method of claim 10, wherein the first and second light sources are selected from the group consisting of,

wherein the expanded natural gas is continuously heated in heat exchange relationship with the feed water.

Technical Field

The invention relates to a power plant facility and a method for operating the same. In particular, it relates to the energy and economic optimization of the evaporation of liquefied natural gas when directly coupled to a gas and steam turbine installation or a gas power plant.

Background

Typically, natural gas Liquids (LNG) are vaporized by ambient heat (air/sea water) or chemical heat. Alternatively, concepts have been developed that aim to harness cold at low temperatures in energy via a cascaded organic rankine cycle.

Disclosure of Invention

The object of the present invention is to provide a power plant facility which enables improved power or improved efficiency and which at the same time can be produced as simply and cost-effectively as possible. A further object of the invention is to provide a corresponding method for operating such a power plant facility.

The object is achieved according to the invention for a power plant facility by the fact that the invention proposes a power plant facility having: a gas turbine comprising a compressor, a combustor, and a turbine; a natural gas pipeline for transporting liquid and gaseous natural gas to the gas turbine; a compressor connected to the natural gas pipeline for increasing the pressure of the liquid natural gas; and an expander also connected into the natural gas line, wherein a first heat exchanger for evaporating the gaseous natural gas and a second heat exchanger for further heating the regasified natural gas are arranged between the compressor and the expander, wherein the power plant comprises a waste heat steam generator, and wherein the second heat exchanger is coupled to a condensate preheater in the waste heat steam generator.

By coupling the lng vaporization to the downstream connected vaporizer, it is possible to maximize the use of cryogenic refrigeration for the generation of electric current with the highest efficiency. The already vaporized natural gas is further heated to approximately 130 to 170 c by coupling a second heat exchanger to a condensate preheater, i.e. to the last heating surface in the waste heat steam generator.

It is particularly advantageous for the efficiency of the power plant facility if a third heat exchanger is connected downstream of the expansion machine in the natural gas line. In principle, although the following possibilities also exist: the natural gas is heated by means of the second heat exchanger until it can be fed to the combustion with corresponding preheating even after expansion, so that the use of a third heat exchanger can be dispensed with for cost reasons. A technically better variant is, however, one with continued heating by a third heat exchanger connected downstream of the expansion.

In an advantageous embodiment of the invention, the first heat exchanger is connected via a heat transfer medium circuit to the intake line of the gas turbine.

In a further advantageous embodiment, the first heat exchanger is connected via a heat transfer medium circuit to the cooling system of the power plant. In this case, the heat from the gas turbine intake air or from the cooling system can be used in series or in parallel.

In this case, with regard to freezing and thermal conductivity of the heat transfer medium, it is expedient if the heat transfer medium circuit is a water-ethanol circuit.

It is expedient for the hot condensate extraction point for the second heat exchanger to be located downstream of the high-pressure feed water pump in the flow direction of the feed water at a correspondingly high pressure in order to prevent, in the event of a leak, the natural gas from undesirably escaping into the water-steam circuit for safety reasons.

It is alternatively advantageous if the hot condensate extraction point for the second heat exchanger is located downstream of the condensate recirculation pump in the flow direction of the condensate and the second heat exchanger is a double-walled safety heat exchanger as a measure for preventing undesirable escape of natural gas. The alternative arrangement of the hot condensate extraction point has efficiency advantages.

It is advantageous in respect of the third heat exchanger that it is coupled to the water supply of the waste heat steam generator. After the preheated natural gas is expanded via an expander to other pressure levels required for gas turbine operation to output power, a gas temperature of about 40 ℃ to 70 ℃ is produced. In order to achieve the maximum permissible gas turbine fuel temperature for performance reasons, a third heat exchanger is arranged in the natural gas line between the expander and the gas turbine. The third heat exchanger takes its heat from the medium or high pressure feed water of the waste heat steam generator.

The approach can also be used in gas turbine power plants even when no waste heat steam generator is provided in such power plant configurations. The heat exchanger surfaces required for concentrating the exhaust gas heat into the second and third heat exchangers can be arranged, for example, in a chimney bypass in the interior of the gas turbine, wherein the hot exhaust gas is conducted and cooled via separate channels with heating surfaces and is mixed again into the hot exhaust gas mass flow.

The object is achieved by a method for operating a power plant with evaporation of liquefied natural gas, wherein the liquefied natural gas is subjected to at least 150bar, wherein heat from the gas turbine intake air and/or from the cooling system of the power plant is used in order to gasify the liquefied natural gas, and wherein in a further step the natural gas is heated further in heat exchange with hot condensate from the condensate preheater of the waste heat steam generator.

In this case, the natural gas, which is heated further, is expediently expanded via an expander to the gas pressure level required for the operation of the gas turbine in order to output power.

It is also advantageous to continue heating the expanded natural gas in heat exchange relationship with the feed water.

In a power plant facility with a gas turbine, but without a water-steam circuit, the hot exhaust gas can be conducted via a channel with heating surfaces for evaporating and heating the liquefied natural gas and mixed again cool into the main exhaust gas mass flow.

By re-evaporating the expander coupled downstream and the associated optimal cold/heat concentration of the GuD process via a plurality of heat exchangers, significantly improved GuD performance with respect to GuD power (up to approximately ± 10%) and with respect to GuD efficiency (approximately +0.3 to + 0.5% -Pkt.) can be achieved. The idea is that the LNG tank and the subsequent pressure rise to about 150 bar. In the downstream connected heat exchangers, LNG is vaporized under high pressure up to a temperature of about 5 ℃ (temperatures slightly below 0 ℃ are also permissible, as long as sufficient hot water is provided in the second heat exchanger).

The advantage of this concept lies in particular in the relatively cost-effective realization of the performance improvement in addition to the disclosed improvement in performance, since all components except the expander (including the generator and the auxiliary system) and the second heat exchanger have to be used in a corresponding natural gas fired power plant (first heat exchanger and liquid gas pump) or should be used in a corresponding natural gas fired power plant (third heat exchanger).

Drawings

The invention is explained in detail on the basis of the figures, which are exemplary. Schematically and not to scale:

FIG. 1 shows a gas and steam turbine installation according to the invention, and

fig. 2 shows a gas turbine installation.

Detailed Description

Fig. 1 shows schematically and exemplarily a power plant 1 according to the invention in the form of a gas and steam turbine plant.

The power plant facility 1 comprises a gas turbine 2 with a compressor 3, a combustion chamber 4 and a turbine 5. Fig. 1 shows a natural gas line 6 branching off from a natural gas tank 22 for transporting liquid and gaseous natural gas, into which a natural gas compressor 7 and an expander 8 for increasing the pressure of the liquid natural gas are connected.

A first heat exchanger 9 for evaporating the gaseous natural gas and a second heat exchanger 10 for further heating the regasified natural gas are connected between the natural gas compressor 7 and the expander 8. A third heat exchanger 11 is also provided in the natural gas line 6 downstream of the expander 8.

The first heat exchanger 9 is connected via a heat transfer medium circuit 12 and a fourth heat exchanger 28 to the intake line 13 of the gas turbine 2 and via a fifth heat exchanger 29 to the cooling system of the power plant facility 1. In the embodiment of fig. 1, the fourth and fifth heat exchangers 28, 29 are arranged in series. But a parallel arrangement is also conceivable.

The heat transfer medium circulation loop 12 is typically a water-ethanol circulation loop.

If the power plant facility 1 is a gas and steam turbine facility as shown in fig. 1, it also comprises a waste heat steam generator 14, wherein the second heat exchanger 10 is coupled with a condensate preheater 15 in the waste heat steam generator 14. Fig. 1 shows two options for hot condensate extraction for the second heat exchanger 10. In the first case, the hot condensate extraction point 16 is located downstream of the high-pressure feed water pump 17. In the second case, the hot condensate extraction point 16 is located downstream of the condensate recirculation pump 18. In this case, the second heat exchanger 10 is to be designed as a double-walled safety heat exchanger.

Fig. 1 finally shows that the third heat exchanger 11 is coupled to a water supply 19 of the waste heat steam generator 14.

There is the possibility of extracting a feed water from the high-pressure section 23 or the medium-pressure section 24 for heating the natural gas via the third heat exchanger 11. Fig. 1 shows two variants.

The inventive concept can also be transferred to other power plant types. Fig. 2 shows a gas turbine installation 25 with an exhaust gas stack 26 and a stack bypass 20 at the exhaust gas stack 26. The components provided for the regasification of natural gas are unchanged with respect to the installation of fig. 1. The heat for the second and third heat exchangers 10, 11 is obtained from the gas turbine exhaust gas via the respective heat exchanger surfaces 21 in the stack bypass 20 of the exhaust gas stack 26. In operation, a portion of the exhaust gas is conducted via the stack bypass 20 and, after the heat has been output to the respective heat exchanger surface 21, is mixed again into the main exhaust gas flow 27.