A condensate system with low-high differential arrangement condensate pump

Abstract

The application discloses a condensate system with low-height-arrangement condensate pump, which comprises a condenser, a condensate pump, a check valve and a deaerating device, and the condenser, the condensate pump, the check valve and the deaerating device are sequentially connected by pipelines from top to bottom, wherein the condenser and the condensate pump can be closely arranged, and the water entering the condensate pump is converted from micro-supercooled saturated water to supercooled water through pre-supercooling and post-reheating, so that the saturated steam pressure is lowered, the effective net positive suction head of the condensate pump is increased, and thus the arrangement position of the condensate pump can also be increased. The application can reduce the height difference between the condenser and the condensate pump and the height of the whole system.

Description

Technical Field

[0001] This invention belongs to the technical field of marine condensate systems, specifically a condensate system suitable for use in confined spaces on a ship. Background Technology

[0002] Traditional condensate system layout, such as Figure 1 As shown. A traditional condensate system (partial) consists of a condenser 10, a bubbling deaerator 11, a condensate pump 12, and a check valve 13.

[0003] The bubbling deaerator 11 is typically arranged inside the condenser 10. This arrangement utilizes the space in the condenser hot well to reduce condensate subcooling. Excessive condensate subcooling can lead to excessive dissolved oxygen in the condensate, causing more severe corrosion to the internal flow path of steam-using equipment.

[0004] In traditional designs, the condensate pump 12 must be positioned low, typically in a pit in engineering practice. A significant height difference must be maintained between the condensate pump inlet and the condensate outlet of the condenser. Since the condenser is under a high vacuum, the condensate pump inlet pressure is extremely low. Only by positioning the condensate pump low can the condensate level itself generate static pressure, increasing the effective inlet pressure, increasing the effective net positive suction head (NPSH), and reducing the likelihood of condensate vaporization. This prevents cavitation and protects the pump body and impeller.

[0005] This structure generally does not present significant problems in land-based systems and large-space systems, but on ships, due to the limitations of hull size, it is difficult to carry out arrangements with large elevation differences.

[0006] Among existing related patent technologies, such as patent (CN217423215U) which discloses a deaerator cooling anti-cavitation feedwater system, this patent uses a combination of "deaerator + non-contact heat exchanger" to generate subcooling in the saturated water at the deaerator outlet, thereby increasing the net positive suction head (NPSH) at the feedwater pump inlet. This aims to reduce the height requirement for the high-level placement of the deaerator, solving the problems of high installation costs and difficult maintenance caused by the large deaerator placement height in traditional solutions (high-pressure deaerators require 17-18m). While this patent reduces the deaerator placement height, it adds coolers / condensate tanks, electric regulating valves, manual valves, multiple branch pipes, and bypass pipes. In the confined engine room of a ship, the total space occupied by the equipment may actually increase rather than decrease. The recirculation loop, cooling water branch pipes, and bypass regulating branch pipes complicate the piping layout, significantly increasing the difficulty of piping laying, support, and thermal compensation design under the limited space conditions of a ship. Summary of the Invention

[0007] This invention proposes a condensate system with a low elevation difference between the condensate pump and the condensate pump. This reduces the height difference between the condenser and the condensate pump, thus reducing the overall system height.

[0008] To achieve the above objectives, the technical solution of the present invention is: a condensate system with a condensate pump that can be arranged with a low elevation difference, including a condenser, a condensate pump, a check valve, and a deaerator. The condenser, condensate pump, check valve, and deaerator are connected sequentially from top to bottom through pipelines. The condenser and the condensate pump can be arranged closely together. By using a subcooling followed by reheating method, the water entering the condensate pump is converted from slightly subcooled saturated water to subcooled water, the saturated vapor pressure decreases, the effective net positive suction head (NPSH) of the condensate pump increases, and thus the arrangement position of the condensate pump can also be raised accordingly.

[0009] Furthermore, when the saturation pressure of water at 60℃ is 0.0199MPa and the saturation pressure of water at 50℃ is 0.0124MPa, and the pressure difference is 0.0075MPa, which is equal to 0.765 meters of water column, the location of the condensate pump is raised by 0.765 meters.

[0010] Furthermore, the condensate pump and check valve adopt a redundant structure of two parallel connections.

[0011] Furthermore, the condensate enters the deaerator after passing through a check valve.

[0012] Furthermore, the deaerator consists of pipelines, flanges, superheated steam inlet pipes, bubbling deaerators, and a shell. The inlet and outlet pipelines are fixedly connected to both ends of the shell via flanges. The bubbling deaerator is connected to the shell via a superheated steam inlet pipe, and the deaerator steam inlet of the superheated steam inlet pipe is located on the outside of the shell.

[0013] Furthermore, steam is injected into the shell through the superheated steam inlet pipe, where it mixes thoroughly with the subcooled water, which then transforms into saturated water.

[0014] Compared with the prior art, the present invention has the following significant advantages:

[0015] 1. Based on the existing structure of condensate pumps with large height differences, this invention uses a process of first subcooling and then reheating to convert the water entering the condensate pump from slightly subcooled saturated water to subcooled water. This results in a decrease in saturated vapor pressure, an increase in the effective net positive suction head (NPSH) of the condensate pump, and allows the condensate pump to be positioned at a higher elevation. This is beneficial for the layout of condensate systems in confined spaces.

[0016] 2. The biggest difference between the system layout structure of this invention and the traditional structure lies in its smaller height. This allows for more flexible arrangement of the various devices in the condensate system within a limited compartment space. The internal components of the condensate pump, such as blades and casing, are effectively protected.

[0017] 3. The downstream bubbling deaerator also ensures that the subcooled water will not affect the flow structure of the steam-using equipment. Attached Figure Description

[0018] Figure 1 This is a structural diagram of a traditional steam-water separator; Figure 2 This is a schematic diagram of the condensate system of the present invention, which uses condensate pumps arranged with low elevation differences; Figure 3 This is a schematic diagram of the deoxygenation device. Figure 4 This is a schematic diagram of a bubbling deoxygenation device. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the team diagram and embodiments.

[0020] like Figure 2 As shown in the figure, this embodiment of the invention provides a condensate system with condensate pumps arranged at low elevation differences. The structure consists of a condenser 1, a condensate pump 2, a check valve 3, and a deaerator 4. The condenser 1, condensate pump 2, check valve 3, and deaerator 4 are connected in sequence from top to bottom using pipelines to complete the installation. The condenser 1 and condensate pump 2 can be arranged closely together. Furthermore, the condensate pump 2 and check valve 3 adopt a redundant structure of two parallel connections. The structure of the deaerator 4 is as follows... Figure 3 As shown.

[0021] Firstly, by enhancing heat exchange, the condensate undergoes excessive heat exchange within condenser 1, resulting in a greater degree of subcooling and a lower condensate temperature at the outlet of condenser 1.

[0022] The low inlet water temperature of the condensate pump results in a low saturated steam pressure, which increases the difficulty of vaporization of the low-pressure subcooled water in the second blade of the condensate pump. This suppresses cavitation inside the pump body and improves the pump's operating condition.

[0023] For example, the saturation pressure of water at 60℃ is 0.0199 MPa, and the saturation pressure of water at 50℃ is 0.0124 MPa. The pressure difference is 0.0075 MPa, which is approximately equal to 0.765 meters of water column. This means that the location of the condensate pump also needs to be raised by 0.765 meters.

[0024] The condensate enters the deaerator 4 after passing through one-way valve 3. For example... Figure 3 As shown, the deaerator 4 consists of a pipe 4-1, a flange 4-2, a superheated steam inlet pipe 4-3, a bubbling deaerator 4-4, and a shell 4-5. The inlet and outlet pipes 4-1 are fixedly connected to both ends of the shell 4-5 via flanges 4-2. The bubbling deaerator 4-4 is connected inside the shell 4-5 via the superheated steam inlet pipe 4-3. The deaerator steam inlet of the superheated steam inlet pipe 4-3 is located on the outside of the shell 4-5. The core equipment is the bubbling deaerator 4-4, whose external shape is shown in the figure. Figure 4 As shown. Steam is injected into the shell 4-5 through the superheated steam inlet pipe 4-3, where it mixes thoroughly with the subcooled water. The subcooled water then becomes saturated water.

[0025] The size of the deaerator is basically the same as that of the system piping, so no additional space is needed.

[0026] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the concept and scope of the present invention. Therefore, all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A condensate system with condensate pumps arranged at low elevation differences, characterized in that: It includes a condenser, a condensate pump, a check valve, and a deaerator. The condenser, condensate pump, check valve, and deaerator are connected sequentially from top to bottom through pipelines. The condenser and condensate pump are closely arranged. Through a process of subcooling followed by reheating, the water entering the condensate pump is changed from slightly subcooled saturated water to subcooled water. The saturated vapor pressure decreases, and the effective net positive suction head (NPSH) of the condensate pump increases, thereby allowing the condensate pump to be positioned higher.

2. The condensate system with condensate pumps arranged at low elevation differences according to claim 1, characterized in that: When the saturation pressure of water at 60℃ is 0.0199MPa and the saturation pressure of water at 50℃ is 0.0124MPa, and the pressure difference is 0.0075MPa, which equals 0.765 meters of water column, the location of the condensate pump will rise by 0.765 meters.

3. The condensate system with condensate pumps arranged at low elevation differences according to claim 1, characterized in that: The condensate pump and check valve adopt a redundant structure of two parallel connections.

4. The condensate system with condensate pumps arranged at low elevation differences according to claim 1, characterized in that: The condensate enters the deoxygenation device after passing through a one-way valve.

5. The condensate system with condensate pumps arranged at low elevation differences according to claim 1, characterized in that: The deaerator consists of pipelines, flanges, superheated steam inlet pipes, bubbling deaerators, and a shell. The inlet and outlet pipelines are fixedly connected to both ends of the shell via flanges. The bubbling deaerator is connected to the shell via a superheated steam inlet pipe, and the deaerator steam inlet of the superheated steam inlet pipe is located on the outside of the shell.

6. The condensate system with condensate pumps arranged at low elevation differences according to claim 5, characterized in that: Steam is injected into the shell through the superheated steam inlet pipe, where it mixes thoroughly with the subcooled water, which then transforms into saturated water.

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