CN102900561B - Adopt the slit seal Stirling thermoelectric converter that supporting flexible leaf spring supports - Google Patents

Abstract

A gap-sealed Stirling thermoelectric converter supported by leaf springs, including a thermal cylinder, a compression cylinder and a linear alternator, the three are fixedly connected by flanges, and heat exchangers are sequentially set inside the thermal cylinder toward the center And the expansion cylinder, the expansion piston is installed in the expansion cylinder; the expansion piston is sleeved on the expansion piston rod; the inner cavity of the expansion piston is equipped with several groups of supporting flexible plate springs, and the several groups of supporting flexible plate springs are respectively sleeved on the expansion The inner wall of the piston and the limit tube on the expansion piston rod are positioned so that a gap sealing structure is formed between the expansion cylinder and the expansion piston, and between the expansion piston and the expansion piston rod in the radial direction; the present invention adopts a flexible plate spring The support system realizes the non-contact gap sealing structure, and at the same time meets the rigidity requirements of the oscillating system of the generator rotor, and realizes the structural feature that the moving parts run for a long time without wear, thus ensuring the long life and high reliability of the Stirling generator.

Description

Gap-sealed Stirling thermoelectric converter supported by a flexible leaf spring

technical field

The invention relates to a gap-type sealed Stirling thermoelectric converter supported by a supporting flexible plate spring, which belongs to the technical field of energy.

Background technique

The Stirling thermoelectric converter is a key component of the Stirling power generation system. The Stirling thermoelectric conversion technology uses heat sources such as radioactive isotope heat sources, solar energy, and nuclear energy to convert thermal energy into mechanical energy through the Stirling thermoelectric converter, and then through the Stirling thermoelectric converter. The linear alternator outputs electrical power. Stirling thermoelectric conversion technology has the highest efficiency among thermoelectric conversion technologies. Gap sealing technology is the key technology of the Stirling thermoelectric converter, which is usually realized by means of flexible leaf spring support and gas static pressure bearing, so as to realize the non-contact sealing between the moving piston and the cylinder.

Space Stirling power generation technology has reached the stage of space flight application abroad, and the feasibility of space application has also been verified. However, compared with the advanced level, there is a big gap between the research level of Stirling thermoelectric conversion technology in my country, and it is just in its infancy at present, and many research contents have just been carried out. The flexible plate spring support system is used on the Stirling thermoelectric converter to realize the non-contact gap sealing structure between the moving piston and the cylinder, and at the same time meet the rigidity requirements of the generator rotor oscillation system, and realize the structural characteristics of the long-term operation of the moving parts without wear , so as to ensure the long life and high reliability of the Stirling thermoelectric converter. This Stirling thermoelectric conversion technology, which replaces traditional mechanical seals and reduces friction loss, air leakage loss and wear, has not been studied in China, and is an innovative point of the present invention.

Contents of the invention

The purpose of the present invention is to solve the dynamic sealing problem in the Stirling thermoelectric converter, and to invent a gap sealing structure supported by a flexible plate spring to realize the non-contact between the expansion piston and the cylinder, the compression piston and the cylinder Sealing, so as to achieve the purpose of long life and high reliability operation of the Stirling thermoelectric converter.

The technical solution of the present invention is: a gap-type sealed Stirling thermoelectric converter supported by a leaf spring, including a heat cylinder, a compression cylinder and a linear alternator, the three are fixedly connected by flanges, and the inside of the heat cylinder faces The center is successively fitted with a heat exchanger and an expansion cylinder, and an expansion piston is installed in the expansion cylinder; the expansion piston is set on the expansion piston rod; several groups of supporting flexible plate springs are installed in the inner chamber of the expansion piston, and the several groups of supporting flexible plates The plate spring is positioned through the limit tubes respectively sleeved on the inner wall of the expansion piston and the expansion piston rod, and the limit tubes are pressed by the fastening ring; thus, between the expansion cylinder and the expansion piston, the expansion piston A gap seal structure is formed between the expansion piston rod and the expansion piston rod in the radial direction; the bottom end of the expansion piston rod has a base, and symmetrically arranged small holes are opened on the base, and the small holes communicate with the compression cylinder.

A compression piston is installed in the compression cylinder, the rod of the compression piston is in the center of the linear alternator, and the two ends of the rod of the compression piston are installed with supporting flexible plate springs, and the supporting flexible plate springs are installed on the Both ends of the rod portion of the compression piston and the limit tube on the inner wall of the generator housing are compressed and positioned; thus a gap sealing structure is formed between the head of the compression piston and the compression cylinder in the radial direction.

The gap of the gap sealing structure is 8 μm to 20 μm, so as to realize the non-contact sealing between the moving piston and the cylinder.

The supporting flexible plate spring adopts a linear arm plate spring or a concentric spiral plate spring or an eccentric spiral plate spring.

The hot cylinder, expansion piston and expansion cylinder are made of Inconel 718 or MarM-247 stainless steel alloy.

The heat exchanger is made of porous metal foam.

The advantage of the present invention compared with prior art is:

The flexible plate spring support system is used to realize the non-contact gap sealing structure, and at the same time meet the rigidity requirements of the generator rotor oscillation system, and realize the structural characteristics of the moving parts without wear for a long time, thus ensuring the long life and high performance of the Stirling generator. reliable. Compared with the prior art, the gap sealing structure supported by the flexible plate spring in the Stirling thermoelectric converter has no leakage loss, and the friction loss and hysteresis loss are also small, which has great advantages.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Among them, 1-heat cylinder, 2-heat exchanger, 3-expansion piston, 4-expansion cylinder, 5-fastening bolt, 6-fastening ring, 7-limiting tube, 8-supporting flexible plate spring, 9- Expansion piston rod, 10-compression cylinder, 11-compression piston, 12-linear alternator, 13-generator casing, 14-small hole.

Detailed ways

The present invention and its beneficial effects will be further described in detail with reference to the accompanying drawings.

As shown in Figure 1, the heat cylinder 1 is located at the left end, the compression cylinder 10 is located in the middle, and the generator 12 is located at the right end, and the three are fixed together through flanges. The thermal cylinder 1, the heat exchanger 2, the expansion cylinder 4, and the expansion piston 3 are long cylinders, which are sequentially fitted together inwardly; the expansion piston 3 is installed on the expansion piston rod 9 located on the central axis of the thermal cylinder 1. There are two sets of supporting flexible plate springs 8 in the expansion piston 3, which are respectively placed at the two ends of the expansion piston rod 9; the outer diameter of the supporting flexible plate springs 8 is closely matched with the inner wall of the expansion piston 3, and its central hole is sleeved on the expansion piston. On the rod 9, the two sets of supporting flexible plate springs 8 and their two outer ends are positioned by the limit tubes 7 respectively sleeved on the inner wall of the expansion piston 3 and the expansion piston rod 9, while the two sets of supporting flexible plate springs 8 The limiting tube at one of the two outer ends is limited by the boss in the expansion piston 3 and the boss on the expansion piston rod 9, and the limiting tube at the other end of the two outer ends is limited by the inner wall of the expansion piston 3 The threaded fastening ring 6 and the fastening bolt 5 at the center of the head of the expansion piston rod 9 are compressed; A gap sealing structure is formed in the radial direction, and the gap is 8 μm to 20 μm, so as to realize the non-contact sealing between the moving piston and the cylinder; the bottom end of the expansion piston rod 9 has a base, and the base has four symmetrically arranged The small hole 14 communicates with the compression cylinder 10 so that the working gas can reciprocate in the compression cylinder 10 and the expansion cylinder 4 . The seat of the expansion piston rod 9 is embedded in the end surface of the compression cylinder 10 which is in contact with the expansion cylinder 4 . The supporting flexible plate spring 8 in the expansion cylinder 4 requires a relatively large elastic coefficient, fatigue resistance and creep resistance at high temperature (≥100°C).

A compression piston 11 is installed in the compression cylinder 10, the rod of the compression piston 11 is in the center of the generator 12, and the two ends of the rod of the compression piston 11 are equipped with supporting flexible plate springs 8, and the supporting flexible plate The spring 8 is compressed and positioned through the limit tube 7 installed at both ends of the rod of the compression piston 11 and the inner wall of the generator casing 13, and the limit tube 7 at the tail end of the rod of the compression piston 11 passes through the limit tube 7 of the compression piston 11 The fastening bolt 5 in the center of the end is fixed, and all the other limit pipes are positioned by the bosses located on the inner wall of the generator casing 13 and the rod of the compression piston 11 . Therefore, a gap sealing structure is formed between the head of the compression piston 11 and the compression cylinder 10 in the radial direction, and the gap is 8 μm-20 μm, so as to realize non-contact sealing between the moving piston and the cylinder. The linear alternator 12 is located between two groups of supporting flexible plate springs 8, its moving magnet is installed in the center of the rod of the compression piston 11, and the stator and the generator case 13 are connected by keys.

The supporting flexible plate spring 8 adopts a linear arm plate spring or a concentric spiral plate spring or an eccentric spiral plate spring.

The hot cylinder 1, the expansion piston 3 and the expansion cylinder 4 are all made of Inconel 718 that can withstand a high temperature of 650°C or MarM-247 stainless steel alloy that can withstand a high temperature of 850°C.

The heat exchanger 2 is made of porous metal foam, and its porosity can reach more than 95%, which can greatly improve the heat exchange efficiency. .

The principle of the present invention is: support the flexible plate spring to support the expansion piston and the compression piston, so that there are gap seals between the expansion piston and the expansion cylinder, between the expansion piston and the expansion piston rod, and between the compression piston and the compression cylinder. The gas film between the piston and the cylinder wall acts as a sealing surface and lubricant (the performance of the gap seal depends on the gap between the piston and the cylinder wall, the stroke of the piston and the viscosity of the gas), thereby realizing a non-contact seal between the piston and the cylinder . An external heat source is used to heat the thermal cylinder 1 of the Stirling thermoelectric converter, and the working medium gas in the expansion cylinder 4 expands, pushing the supporting flexible plate spring 8 to oscillate, and the supporting flexible plate spring 8 drives the expansion piston 3 to move, and the working medium gas passes through the expansion piston 3 Push to shuttle between the hot end and the cold end of the expansion cylinder 4, when the working medium gas absorbs heat and expands at the hot end of the expansion cylinder 4, pushes the compression piston 11 to move, when the working medium gas releases heat and contracts at the cold end of the expansion cylinder 4, Push the compression piston 11 to reverse movement. The compression piston 11 drives the moving magnet of the linear alternator 12 to reciprocate, and generates alternating current output on the excitation coil.

Claims (5)

1. A gap-type sealed Stirling thermoelectric converter supported by a leaf spring, including a thermal cylinder (1), a compression cylinder (10) and a linear alternator (12), the three are fixedly connected by a flange, and its characteristics That is: the heat exchanger (2) and the expansion cylinder (4) are sequentially set inside the heat cylinder (1) toward the center, and the expansion piston (3) is installed in the expansion cylinder (4); the expansion piston (3) is installed On the expansion piston rod (9); several groups of supporting flexible plate springs (8) are installed in the cavity of the expansion piston (3), and the several groups of supporting flexible plate springs (8) are respectively sleeved on the inner wall of the expansion piston (3) and the limit tube (7) on the expansion piston rod (9), and the limit tube (7) is pressed by the fastening ring (6); so that the expansion cylinder (4) and the expansion piston ( 3), between the expansion piston (3) and the expansion piston rod (9), a gap sealing structure is formed in the radial direction; the bottom end of the expansion piston rod (9) has a base, and a symmetrical opening is formed on the base. A small hole (14) is arranged, the small hole is connected with the compression cylinder (10); a compression piston (11) is installed in the compression cylinder (10), and the rod of the compression piston (11) is in the linear In the center of the alternator (12), a supporting flexible plate spring (8) is installed at both ends of the rod of the compression piston (11), and the supporting flexible plate spring (8) passes through the The two ends of the rod and the limit tube (7) on the inner wall of the generator casing (13) are compressed and positioned; thus forming a gap in the radial direction between the head of the compression piston (11) and the compression cylinder (10). Gap sealing structure. 2. A gap-sealed Stirling thermoelectric converter supported by a leaf spring according to claim 1, characterized in that: the gap of the gap sealing structure is 8 μm to 20 μm, so as to realize the gap between the moving piston and the cylinder. non-contact seal. 3. A gap-type sealed Stirling thermoelectric converter supported by a leaf spring according to claim 1 or 2, characterized in that: the supporting flexible leaf spring (8) adopts a linear arm leaf spring or a concentric volute leaf spring. 4. A gap-sealed Stirling thermoelectric converter supported by a leaf spring according to claim 1, characterized in that, the thermal cylinder (1), expansion piston (3) and expansion cylinder (4) adopt Inconel 718 or MarM-247 stainless steel alloy. 5. A gap-type sealed Stirling thermoelectric converter supported by a leaf spring according to claim 1, characterized in that: the heat exchanger (2) is made of porous metal foam.