JPH0454048B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a turbo compressor system applicable to various industrial plants such as aircraft jet engines and fuel cell power generation plants. be.

(b) Prior Art As shown in Fig. 1, a turbo compressor system represented by a jet engine includes a compressor a whose inlet is open to the atmosphere, and a gas passage b that connects the inlet to the outlet of the compressor a. Some gas turbines are equipped with a turbine c for driving a compressor connected to the gas passage b, and a heat adding means d interposed in the middle of the gas passage b for applying thermal energy to the inlet side of the turbine c. However, this type of system is difficult to start up and has many problems. That is, in the conventional system, at startup, a drive source f such as a motor is connected to the rotating shaft e of the compressor a and the turbine c via a transmission g. Then, the drive source f is operated to rotate the compressor a and the turbine c, and when the compressor a has a constant compression ratio, the heat adding means d is ignited to shift to self-excited operation. ing. This requires a starting drive source other than a turbo compressor, which typically requires very high rotational speeds. Therefore,
Various protection circuits are required, and even the slightest malfunction has defects that can lead to major malfunctions.
There is a problem that the entire system becomes complicated and large-scale.

In addition, as a starting method that does not use a mechanical drive source such as a motor, it is considered to blow high-pressure gas for starting into the inlet of the turbine, but in this method, the flow rate on the compressor side at the time of starting is There is a problem that the compressor tends to cause surging because there is very little amount of surging.

(c) Purpose The present invention has been made in view of the above circumstances, and it is possible to start the engine reliably with minimum energy without requiring a complicated and large-scale starting device, and moreover, it is possible to start the engine reliably with minimum energy, and moreover, An object of the present invention is to provide a turbo compressor system that can effectively prevent surging in a compressor section, which tends to occur.

(D) Structure In order to achieve the above object, the present invention supplies starting gas from the inlet side of the compressor, and also increases the supply pressure of this starting gas by the amount of thermal energy applied from the heat adding means to the inlet side of the turbine. The supply pressure is gradually decreased as the supply pressure increases, and when the supply pressure has decreased to atmospheric pressure, self-excited operation can be started.

(E) Example Hereinafter, an example in which the present invention is applied to an air compression part of a fuel cell power generation plant will be described with reference to FIG. 2.

As shown in FIG. 2, in the turbo compressor system according to the present invention, a compressor 1 is driven by a turbine 2 having a variable nozzle 2a. The inlet 1a of the compressor 1 is opened to the atmosphere through an air supply passage 4 with a supply valve 3 interposed therebetween, and the outlet 1b of the compressor 1 and the inlet 2b of the turbine 2 are connected through a gas passage 5. Connected. The gas passage 5 is formed by providing a main passage part 5a and a sub passage part 5b in parallel, and an air chamber 7 of a fuel cell 6 which functions as a heat adding means is interposed in the middle of the main passage part 5a. and the sub passage section 5.
A combustor 8, which is a second heat adding means, is interposed in the middle of b. Further, a starting gas supply means 9 is provided in a portion of the air supply passage 4 subsequent to the air supply valve 3. The starting gas supply means 9 includes a high-pressure gas source 11 such as a cylinder that discharges high-pressure starting gas, a starting gas guide path 12 that connects this high-pressure gas source 11 to the air supply passage 4, and this starting gas guide path 12. A control valve 13 is provided in the middle of the guideway 12 to open and close the guideway 12 steplessly.

Next, the operation of this embodiment will be explained. At the time of starting, the air supply valve 3 is closed, and the control valve 13 of the starting gas supply means 9 is opened.
Then, the high-pressure starting gas discharged from the high-pressure gas source 11 is supplied to the inlet 1a of the compressor 1, and the starting gas that has passed through the compressor 1 is introduced to the inlet 2b of the turbine 2. 2 and compressor 1 start rotating. In this state, the air chamber 7 of the fuel cell 6
As the amount of thermal energy applied from the combustion furnace 8 to the inlet 2b of the turbine 2 increases, the power of the turbine 2 tends to increase.
Even if the supply pressure of the starting gas is lowered, operation continues. Therefore, the opening degree of the control valve 13 of the starting gas supply means 9 is gradually reduced within a range that allows the operation of the turbine 2 to be maintained, and when the supply pressure of the starting gas has decreased to atmospheric pressure, the intake valve 13 is Open to switch to self-excited operation. This step can be explained using a formula as follows. Compressor 1
Letting the amount of work be Hc, Hc is expressed by the following formula: Hc=Cpa・Wc・1/ξc・Tcin {(Pcout/Pcin) _K-1 / _K −1} (1). Here, Cpa is the specific heat of the gas
Wc is the gas mass flow rate, ξc is the compressor efficiency,
Tcin is the inlet temperature of compressor 1, Pcin is the inlet pressure, Pcout is the outlet pressure, k is the specific heat ratio, and the work of the turbine 2 is Ht.
is expressed by the formula Ht=Cpt・Wt・ηt・Ttin{1−(Ptout/Ptin) _K ′ _-1 / _K ′ ……(2). Here, Cpt is the specific heat of the gas
Wt is gas mass flow rate, ηt is turbine efficiency, Ttin
is the inlet temperature of turbine 2, Ptin is the inlet pressure,
Ptout is the outlet pressure, and k' is the specific heat ratio. When compressor 1 and turbine 2 are operating,
The relationship Hc=Ht holds true, but if the amount of heat given to the starting gas from the air chamber 7 and combustor 8 increases and the inlet temperature Ttin of the turbine 2 rises,
The amount of work Ht of the turbine 2 shown by equation (1) increases. Therefore, as the amount of heat supplied increases, the amount of work of the compressor 1 expressed by equation (2) can also be increased, and the inlet pressure Pcin of the compressor 1 can be gradually reduced. Then, when the inlet pressure Pcin reaches atmospheric pressure, it is possible to smoothly shift to complete self-excited operation. By the way, in the self-excited operation in this embodiment, the combustion amount of the combustor 8 and the opening degree of the variable nozzle 2a of the turbine 2 are appropriately controlled to maintain a constant pressure in the air chamber 7 of the fuel cell 6, for example, 5 ata. It is designed to supply air.

In addition, in the above embodiment, the case where the present invention is applied to the air compression part of a fuel cell power generation plant has been explained, but the present invention is not necessarily limited to this, but can also be applied to other types of turbo compressor systems. The same applies.

Further, the starting gas supply means is not limited to one using a gas cylinder or the like, but may be one using a blower or a small air compressor.

Furthermore, the working gas is not limited to air.

(F) Effects Since the present invention has the above configuration, the following effects can be obtained.

First, since starting can be performed without using high-speed rotating machinery such as a motor or transmission, or various protective devices, the system can be simplified and the energy required for starting can be minimized. Can be done.

Further, since the starting gas is supplied to the inlet side of the compressor instead of directly to the inlet side of the turbine, a sufficient flow rate of the compressor can be ensured even in the starting operation mode. Therefore, surging that tends to occur during startup can be effectively prevented, and stable startup performance can be ensured.

Furthermore, if there is surplus high-pressure gas, that gas can be supplied to the inlet of the compressor using the starting gas supply means, so idling operation can be performed with the heat addition means such as the combustor stopped. There is also the convenience of being able to

[Brief explanation of the drawing]

FIG. 1 is a system explanatory diagram showing a conventional example, and FIG. 2 is a system explanatory diagram showing an embodiment of the present invention. 1...Completsa, 1a...Entrance, 1b...
Outlet, 2... Turbine, 2b... Inlet, 3... Air supply valve, 5... Gas passage, 7... Heat addition means (air chamber), 8... Heat addition means (combustor), 9...
Starting gas supply means.

Claims (1)

[Claims] a compressor whose inlet is open to the atmosphere through an air supply valve; a turbine for driving the compressor whose inlet is connected to the outlet of the compressor through a gas passage and whose outlet is open to the atmosphere; a heat adding means which is interposed and applies thermal energy to the inlet side of the turbine; and a starting gas having a pressure higher than atmospheric pressure is supplied to the inlet of the sampler at the time of startup when the air supply valve is closed to operate the turbine; and a starting gas supply means for gradually decreasing the supply pressure of the starting gas in accordance with an increase in the amount of heat supplied by the heat adding means, while satisfying the condition that the operation of the starting gas can be maintained, the supply pressure of the starting gas is A turbo compressor system characterized in that the air supply valve is opened when the air pressure drops to atmospheric pressure to shift to self-excited operation.