High-vibration-resistance vertical barrel bag type condensate pump

Abstract

The utility model discloses a high anti-vibration type vertical barrel type condensate pump, which relates to the technical field of condensate pumps and comprises a motor seat, a support seat and a discharge seat which are sequentially arranged from top to bottom, a water outlet section and a water outlet elbow communicated with the water outlet section are arranged in the discharge seat, and a bottom plate of the discharge seat is fixedly connected with the upper end of an outer barrel. A closed annular water storage cavity is formed in the discharge seat by taking the water outlet section as the center, the annular water storage cavity is communicated with an inner cavity of the outer barrel through a window hole formed in a bottom plate of the discharge seat, and the annular water storage cavity is used for storing pumping liquid so as to increase the overall weight and stability of the pump set during operation; an exhaust pipe is fixedly connected to the top of the discharge seat, communicates with the annular water storage cavity and is used for being connected with external degassing equipment for air exhaust and water injection when the pump set is started for the first time. By arranging the annular water storage cavity, the mass of the upper structure of the pump foundation is increased, the gravity center of the upper structure is lowered, the rigidity is enhanced in cooperation with the regular conical structure, and therefore unit vibration is reduced.

Description

Technical Field

[0001] This utility model relates to condensate pumps, specifically a high vibration-resistant vertical cylindrical bag condensate pump. Background Technology

[0002] Vertical baghouse condensate pumps are key equipment in the condensate systems of large-scale power units such as thermal and nuclear power plants. Their function is to extract condensate from the condenser hot well and pressurize it before sending it to the deaerator. These pumps typically employ a bottom-suction, top-discharge vertical arrangement, with the pump body submerged in the condenser hot well and the inlet under negative pressure. Therefore, they require extremely high resistance to cavitation and operational stability.

[0003] Currently, technological development in this field mainly focuses on improving efficiency, optimizing hydraulic models, and facilitating maintenance. For example, utility model patent CN201535257 U discloses a structure combining a double-suction first-stage impeller with radial guide vanes, which effectively improves cavitation resistance and reduces axial dimensions; utility model patent CN203023135 U improves pump efficiency and reliability by optimizing bearing structure and flow channel arrangement; and a novel vertical cylindrical bag-type condensate pump CN115638138 A focuses on modular design of the pump unit, significantly improving pump maintainability by optimizing drive shaft connection structure and mechanical seal arrangement, making maintenance and replacement of vulnerable parts more convenient.

[0004] However, in practical applications, especially under the wide range of variable frequency operation conditions, a common problem that has long plagued the industry and has not been completely solved is becoming increasingly prominent: the unit is prone to structural resonance in a specific speed range, resulting in excessive vibration. The fundamental reason is that the structural layout of the part above the pump foundation (mainly including the motor, support seat, and discharge seat) has inherent defects: (1) The motor, as the heaviest component, is suspended high at the top of the entire structure, while the support seat and discharge seat below it are mostly thin-walled cylindrical structures with relatively light weight. This "top-heavy" mass distribution pattern results in a very high center of gravity of the upper subsystem of the pump foundation, poor anti-disturbance ability, and easy to induce vibration; (2) The traditional motor seat, support seat, and discharge seat are mostly connected by split flanges, and the connection point constitutes a weak link in rigidity, resulting in a low natural frequency of the entire upper structure.

[0005] When a pump unit operates at a variable frequency drive (VFD) and passes through the speed range corresponding to its system's natural frequency, the external excitation frequency coincides with the natural frequency, triggering severe resonance. This directly manifests as a sharp increase and exceedance of vibration values ​​at the motor and non-drive ends. Sustained resonance not only generates enormous noise but also causes fatigue damage to critical components such as bearings, mechanical seals, and impellers, significantly increasing the failure rate, shortening maintenance cycles, and seriously threatening the safe and stable operation of the power plant. Utility Model Content

[0006] To address the problems existing in the prior art, this utility model provides a high vibration-resistant vertical cylindrical bag condensate pump, which aims to solve the long-standing vibration problem of vertical cylindrical bag pumps.

[0007] The technical solution adopted in this utility model is as follows: A high vibration-resistant vertical cylindrical bag-type condensate pump includes a motor base, a support base, and a discharge base arranged sequentially from top to bottom. The discharge base is provided with a water outlet section and a water outlet bend communicating with the water outlet section. The bottom plate of the discharge base is fixedly connected to the upper end of the outer cylinder. A closed annular water storage cavity is provided in the discharge base with the water outlet section as the center. The annular water storage cavity is connected to the inner cavity of the outer cylinder through a window hole provided on the bottom plate of the discharge base. The annular water storage cavity is used to store the pumped liquid to increase the overall weight and stability of the pump unit during operation. An exhaust pipe is fixedly connected to the top of the discharge base. The exhaust pipe is connected to the annular water storage cavity and is used to connect an external degassing device for air extraction and water injection when the pump unit is started for the first time.

[0008] Furthermore, the window opening is a plurality of fan-shaped openings evenly distributed along the circumference.

[0009] Furthermore, the outer walls of the cylinder of the motor base, support base, and discharge base together form an integral conical structure, the lower diameter of which is larger than the upper diameter.

[0010] Furthermore, the annular water storage cavity is connected to the balance water chamber above the balance drum through a connecting structure to balance the axial force of the water pump.

[0011] Furthermore, the connecting structure includes a connecting through hole opened at the top of the annular water storage cavity, and the connecting through hole is directly connected to the balance water chamber.

[0012] Furthermore, the communication structure includes a connecting through hole opened at the top of the annular water storage cavity, and a balance pipe connecting the connecting through hole and the balance water chamber.

[0013] The beneficial effects of this utility model are as follows:

[0014] (1) By setting an annular water storage cavity and filling it with liquid in the discharge seat, this utility model is equivalent to adding a large ballast tank to the upper part of the pump set, which significantly lowers the center of gravity of the upper subsystem of the pump base and improves its unfavorable mass distribution of "top-heavy". At the same time, the motor base, support base and discharge seat are arranged in an integral positive conical structure, which enhances the overall rigidity and structural strength. Through the dual means of "increasing weight" and "increasing rigidity", the natural frequency of the entire pump set system is greatly improved, which effectively avoids the common variable frequency operation speed range, eliminates the resonance phenomenon from the root, and enables the pump set to operate smoothly under various working conditions. The vibration value is significantly better than the industry standard.

[0015] (2) By connecting the top of the annular water storage cavity directly or through a short pipe to the balance water chamber above the balance drum, this utility model eliminates the external balance water pipeline and its complex support components required by traditional pumps. This not only simplifies the external pipeline system and eliminates the risk of failure caused by vibration or breakage of the external pipeline, but also makes the pump body structure more compact and neat, and improves the inherent reliability of the system.

[0016] (3) The annular water storage cavity is connected to the outer cylinder through the bottom window to form an automatic water replenishment closed system. After being filled with air by the exhaust pipe for the first time, it can always maintain a full liquid state in the closed circulation of the pump operation, without the need for additional maintenance, thus reducing the operating cost of the equipment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the high vibration-resistant vertical cylindrical bag condensate pump of this utility model.

[0018] Figure 2 This is a partial structural schematic diagram of the high vibration-resistant vertical cylindrical bag condensate pump of this utility model.

[0019] In the diagram: 1. Motor base; 2. Support base; 3. Discharge base; 4. Outer cylinder; 5. Water outlet section; 6. Water outlet bend; 7. Annular water storage cavity; 8. Exhaust pipe; 9. Window hole; 10. Balance drum; 11. Balance water chamber; 12. Connecting through hole. Detailed Implementation

[0020] To facilitate understanding of this utility model, it will be described more comprehensively and in detail below with reference to the accompanying drawings and preferred embodiments. However, the scope of protection of this utility model is not limited to the following specific embodiments.

[0021] like Figure 1 , Figure 2As shown in the figure, this embodiment provides a high vibration-resistant vertical bag-type condensate pump, including a motor base 1, a support base 2, and a discharge base 3 arranged coaxially from top to bottom. The discharge base 3 has an outlet section 5 inside, which is connected to a horizontally extending outlet bend 6. The bottom plate of the discharge base 3 is fixedly connected to the upper end of the outer cylinder 4 via a flange connection, thereby forming the main pressure-bearing shell of the pump. The main body of the pump (including the impeller, guide vanes, intermediate section, pump shaft, and other core hydraulic components) adopts a conventional vertical bag-type pump structure in the art, which is prior art and will not be described further here.

[0022] The core improvement of this utility model lies in the fact that a closed annular water-storing cavity 7 is provided inside the dispensing seat 3, surrounding the water outlet section 5. This annular water-storing cavity 7 is formed by machining the inner wall of the dispensing seat 3 and is an independent, sealed chamber capable of storing water. Multiple windows 9 are provided at the bottom of the annular water-storing cavity 7, and these windows 9 penetrate the bottom plate of the dispensing seat 3, connecting the annular water-storing cavity 7 to the inner cavity of the outer cylinder 4. As a preferred embodiment, these windows 9 are multiple fan-shaped holes evenly distributed circumferentially to ensure that water can smoothly and evenly enter the cavity.

[0023] An exhaust pipe 8 is fixedly installed on the top of the annular water storage cavity 7. This exhaust pipe 8 communicates with the interior of the annular water storage cavity 7. Before the pump unit is started for the first time, this exhaust pipe 8 is connected to an external vacuum pump to completely expel the air trapped inside the annular water storage cavity 7. Since the bottom of the cavity is connected to the inner cavity of the outer cylinder 4 through the window 9, after a negative pressure is formed inside the cavity, the liquid in the outer cylinder 4 will automatically flow in through the window 9 under the action of the pressure difference, eventually completely filling the entire annular water storage cavity 7. This increases the weight of the upper structure of the pump base, effectively lowers its overall center of gravity, and improves the operational stability of the pump unit.

[0024] Furthermore, the outer walls of the cylinders of the motor base 1, support base 2, and discharge base 3 together form an integral conical structure. The lower diameter of this structure is larger than the upper diameter, and the transition is balanced. This design enhances the rigidity and bending resistance of the pump base's upper structure, and works in conjunction with the weight-increasing effect of the annular water storage cavity to suppress vibration.

[0025] Regarding axial force balancing, the annular water-storing cavity 7 is also connected to the balancing water chamber 11 above the balancing drum 10 via a connecting structure. In one embodiment, this connecting structure is a connecting through-hole 12 directly formed at the top of the annular water-storing cavity 7, allowing direct communication between the low-pressure water inside the annular water-storing cavity 7 and the balancing water chamber 11. In another optional embodiment, the connecting structure may also include an interface formed at the top and a balancing pipe connecting the interface and the balancing water chamber 11. Both methods can utilize the liquid inside the annular water-storing cavity 7 to balance most of the axial force, thereby eliminating the need for a complex external balancing water piping system and making the structure simpler and more reliable.

[0026] The working principle and process of this utility model are as follows:

[0027] Before the pump is first started, the air in the annular water-storage chamber 7 is evacuated through the vent pipe 8. Liquid then flows into the outer cylinder 4 through the window 9 under pressure differential, filling it completely. Subsequently, in the closed-loop system, this chamber remains fully filled, forming a fixed ballast. During pump operation, this ballast, combined with the conical structure, significantly increases the pump's natural frequency, keeping it away from the excitation frequency within the operating speed range, thus fundamentally avoiding resonance. Simultaneously, the balancing water channel integrated at the top of the annular water-storage chamber 7 effectively balances the axial force, ensuring long-term stable operation of the bearings.

[0028] With the aid of the teachings present in the foregoing description and related drawings, those skilled in the art will conceive of many modifications and other embodiments of the present invention. Therefore, it is to be understood that the present invention is not limited to the specific embodiments disclosed, and modifications and other embodiments are considered to be included within the scope of the appended claims. Although specific terms are used herein, they are used in a general and descriptive sense only and are not intended to be limiting.

Claims

1. A high vibration-resistant vertical cylindrical bag-type condensate pump, comprising a motor base (1), a support base (2), and a discharge base (3) arranged sequentially from top to bottom, wherein the discharge base (3) is provided with a water outlet section (5) and a water outlet bend (6) communicating with the water outlet section (5), and the bottom plate of the discharge base (3) is fixedly connected to the upper end of the outer cylinder (4), characterized in that: The discharge seat (3) has a closed annular water storage cavity (7) centered on the water outlet section (5). The annular water storage cavity (7) is connected to the inner cavity of the outer cylinder (4) through a window (9) on the bottom plate of the discharge seat (3). The annular water storage cavity (7) is used to store pumped liquid to increase the overall weight and stability of the pump set during operation. The top of the discharge seat (3) is fixedly connected to an exhaust pipe (8). The exhaust pipe (8) is connected to the annular water storage cavity (7) and is used to connect an external degassing device for air extraction and water injection when the pump set is started for the first time.

2. The high vibration-resistant vertical cylindrical bag condensate pump as described in claim 1, characterized in that: The window (9) consists of multiple fan-shaped holes evenly distributed along the circumference.

3. The high vibration-resistant vertical cylindrical bag condensate pump as described in claim 1, characterized in that: The outer walls of the cylinder of the motor base (1), support base (2) and discharge base (3) together form an integral conical structure, the lower diameter of which is larger than the upper diameter.

4. A high vibration-resistant vertical cylindrical bag-type condensate pump as described in any one of claims 1-3, characterized in that: The annular water storage cavity (7) is connected to the balance water chamber (11) above the balance drum (10) through a connecting structure to balance the axial force of the water pump.

5. A high vibration-resistant vertical cylindrical bag condensate pump as described in claim 4, characterized in that: The connecting structure includes a connecting through hole (12) opened at the top of the annular water storage cavity (7), and the connecting through hole (12) is directly connected to the balance water chamber (11).

6. A high vibration-resistant vertical cylindrical bag condensate pump as described in claim 4, characterized in that: The connecting structure includes a connecting through hole (12) opened at the top of the annular water storage cavity (7), and a balancing pipe connecting the connecting through hole (12) and the balancing water chamber (11).

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