Dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment

Abstract

Dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment. Existing dry gas seals maintain the sealing state by the balance between the elastic force and the medium film pressure between the moving and static rings. However, when the spring fails, the balance state will be broken, resulting in the loss of the sealing function. The composition of the present invention includes: a shaft (1), a shaft housing (2), a head (3), a static ring (6), a dynamic ring (10), an elastic device (11), and a fixing seat (12); the shaft housing is fixed to the head, and a plurality of static ring control rods are inserted on the circumferential surface of the shaft housing, and the plurality of static ring control rods are fixed to the static ring; the dynamic ring is sleeved on the shaft and sealed with the shaft through an elastic sealing ring, and a main sealing surface between the dynamic and static rings is formed between the dynamic ring and the static ring; the dynamic ring is connected to the fixing seat on the shaft through an elastic device. The present invention is used for the dry gas seal of the shaft end of a supercritical carbon dioxide turbine equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of the safety of turbine equipment in a supercritical carbon dioxide (S-CO2) Brayton cycle power generation system, and particularly relates to a dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment. Background Art

[0002] Compared with the steam Rankine cycle, the supercritical carbon dioxide (S-CO2) Brayton cycle has the advantages of being easy to reach the critical state, having a compact cycle system, high cycle efficiency, and high cycle flexibility, opening up a new field for future energy utilization. The supercritical carbon dioxide (S-CO2) cycle process is that CO2 absorbs the heat of the heat source, generates steam to drive the turbine, and then completes the thermal work conversion through regeneration, cooling, and compression.

[0003] Among them, as an important power equipment in the cycle system, in a high-parameter cycle system, it is inevitable that the turbine equipment is designed as a large axial flow type. Therefore, the sealing performance of its shaft end has a great impact on the pneumatic efficiency of the system. The end seal of the axial flow turbine equipment is a dynamic seal. At present, the most advanced dynamic seal device is the dry gas seal. The dry gas seal is a non-contact end face seal and has been widely used in the fields of petroleum, chemical industry, etc. due to its advantages such as long life and low power consumption.

[0004] The existing dry gas seals all rely on the balance of the elastic force and the medium film pressure between the dynamic and static rings to maintain the sealing state. However, when the spring fails, the balance state will be broken, resulting in the loss of the sealing function, and only shutdown can be used for treatment. In addition, due to the physical properties of the supercritical carbon dioxide (S-CO2) working medium with high density and low viscosity, when the pressure balance state of the sealing end face becomes unstable and leakage occurs, it cannot be guaranteed whether the elastic device of the dry gas seal itself can quickly generate a new pressure balance. Summary of the Invention

[0005] The purpose of the present invention is to provide a dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment.

[0006] The above purpose is achieved by the following technical solutions:

[0007] A dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment, which comprises: a shaft, a shaft housing, a head, a stationary ring, a rotating ring, an elastic device, and a fixing seat;

[0008] The shaft housing is fixed to the head, and a plurality of stationary ring control rods are inserted on the circumferential surface of the shaft housing, and the plurality of stationary ring control rods are fixed on the stationary ring;

[0009] The rotating ring is sleeved on the shaft and sealed with the shaft through an elastic sealing ring, and a main sealing surface between the rotating ring and the stationary ring is formed;

[0010] The moving ring is connected to the fixed seat on the shaft through an elastic device.

[0011] For the dry gas seal device at the shaft end of a supercritical carbon dioxide turbine equipment, the stationary ring and the head are sealed through an elastic sealing ring.

[0012] For the dry gas seal device at the shaft end of a supercritical carbon dioxide turbine equipment, the shaft housing and the head are sealed through an elastic sealing ring.

[0013] For the dry gas seal device at the shaft end of a supercritical carbon dioxide turbine equipment, there are four stationary ring control rods.

[0014] Beneficial effects:

[0015] 1. In the present invention, the moving ring rotates with the shaft, the stationary ring is fixed by the stationary ring control rod, and both ends of the elastic device are respectively connected to the fixed seat and the moving ring. When the spring force of the elastic device and the medium pressure between the end faces of the stationary and moving rings reach a stable equilibrium state, a rigid medium film is formed between the stationary and moving rings to produce a sealing effect. The elastic device can control the axial displacement of the moving ring to ensure the stable state of the medium film between the end faces of the stationary and moving rings when the pressure inside the turbine changes.

[0016] 2. In the present invention, when the elastic device inside the dry gas seal fails due to a fault, or when the pressure inside the turbine far exceeds the normal operating pressure, the axial movement of the moving ring can no longer ensure the tightness of the main sealing surface. At this time, the emergency system of this dry gas seal needs to be activated, that is, manually operate the stationary ring control rod outside the turbine to make the stationary ring move axially, control the thickness of the medium film between the main sealing surfaces, and prevent leakage from occurring. Description of the drawings

[0017] Appendix Figure 1 is a schematic structural diagram of the present invention;

[0018] Appendix Figure 2 is a side view of the present invention;

[0019] In the figure: 1, shaft; 2, shaft housing; 3, head; 4, 7, 9, elastic sealing rings; 5, stationary ring control rod; 6, stationary ring; 8, main sealing surface between the stationary and moving rings; 10, moving ring; 11, elastic device; 12, fixed seat. Specific embodiments

[0020] Embodiment 1:

[0021] A dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment, which comprises: a shaft, a shaft housing, a head, a stationary ring, a moving ring, an elastic device and a fixed seat;

[0022] The shaft housing is fixed to the head, and a plurality of stationary ring control rods are inserted on the circumferential surface of the shaft housing, and the plurality of stationary ring control rods are fixed to the stationary ring;

[0023] The rotating ring is sleeved on the shaft and sealed with the shaft through an elastic sealing ring, and a main sealing surface between the rotating ring and the stationary ring is formed;

[0024] The rotating ring is connected to the fixed seat on the shaft through an elastic device.

[0025] Embodiment 2:

[0026] For the dry gas seal device at the shaft end of the supercritical carbon dioxide turbine equipment according to Embodiment 1, the stationary ring is sealed with the head through an elastic sealing ring.

[0027] Embodiment 3:

[0028] For the dry gas seal device at the shaft end of the supercritical carbon dioxide turbine equipment according to Embodiment 1 or 2, the shaft housing is sealed with the head through an elastic sealing ring.

[0029] Embodiment 4:

[0030] For the dry gas seal device at the shaft end of the supercritical carbon dioxide turbine equipment according to Embodiment 1 or 2 or 3, there are four stationary ring control rods.

[0031] This device has a total of 4 seals: the dynamic seal (8) between the rotating ring and the stationary ring end face; the static seal (4) between the head and the shaft housing; the static seal (7) between the stationary ring and the head; the static seal (9) between the rotating ring and the shaft. Among them, the dynamic seal (8) between the rotating ring and the stationary ring end face is the main seal, and the other 3 are secondary seals.

[0032] When this dry gas seal device is in the normal working state, the rotating ring (10) rotates with the shaft (1), the stationary ring (6) is fixed by the stationary ring control rod (5), and both ends of the elastic device (11) are connected to the fixed seat (12) and the rotating ring (10) respectively. When the spring force of the elastic device and the medium pressure between the rotating ring and the stationary ring end face reach a stable equilibrium state, a rigid medium film is formed between the rotating ring and the stationary ring to produce a sealing effect. The elastic device (11) can control the axial displacement of the rotating ring (10) to ensure the stable state of the medium film between the rotating ring and the stationary ring end face when the pressure inside the turbine changes.

[0033] When the elastic device inside the dry gas seal fails due to a malfunction, or when the pressure inside the turbine far exceeds the normal operating pressure, the axial movement of the rotating ring (10) can no longer ensure the tightness of the main sealing surface (8). At this time, the emergency system of this dry gas seal needs to be activated, that is, manually operate the stationary ring control rod (5) outside the turbine to move the stationary ring (6) axially, control the thickness of the medium film between the main sealing surfaces (8), and prevent leakage from occurring.

Claims

1. A dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment, characterized in that: It consists of: a shaft, a shaft housing, a head, a stationary ring, a rotating ring, an elastic device and a fixing seat; The shaft housing is fixed to the head, and a plurality of stationary ring control rods are inserted on the circumferential surface of the shaft housing, and the plurality of stationary ring control rods are fixed to the stationary ring; The rotating ring is sleeved on the shaft and sealed with the shaft through an elastic sealing ring, and a main sealing surface between the rotating ring and the stationary ring is formed; The rotating ring is connected to the fixing seat on the shaft through an elastic device.

2. The dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment according to claim 1, characterized in that: The stationary ring is sealed with the head through an elastic sealing ring.

3. The dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment according to claim 2, characterized in that: The shaft housing is sealed with the head through an elastic sealing ring.

4. The dry gas seal device for the shaft end of a supercritical carbon dioxide turbine equipment according to claim 3, characterized in that: There are four stationary ring control rods.

Images