Integrated roots water ring vacuum pump set of condenser vacuum pumping system and construction method

Abstract

This invention provides an integrated Roots-water ring vacuum pump unit and its construction method for a condenser vacuum system, including a common base; a Roots vacuum pump, a water ring vacuum pump, an interstage cooler, and a steam-water separator fixedly installed on the base; a prefabricated piping system; an integrated local control cabinet; and all components are assembled, wired, and pre-tested before leaving the factory, forming an integrated skid-mounted module. This invention also provides standardized material configurations for different water sources such as seawater, circulating water, and closed-loop water, as well as a unified interface specification system and rapid construction methods. The skid-mounted integrated design shortens the installation cycle from the traditional 10-15 days to 3-5 days; the graded corrosion protection scheme solves corrosion and blockage problems at the source; and the unified interface standard facilitates direct application in projects, possessing strong scalability and replicability.

Description

Technical Field

[0001] This invention relates to the field of auxiliary equipment technology for thermal power plants, and in particular to an integrated Roots water ring vacuum pump set and its construction method for a condenser vacuum system. Background Technology

[0002] Energy-saving retrofits of existing condenser vacuum systems in thermal power plants, with the addition of Roots-water ring vacuum pump sets as the core equipment, currently employ a decentralized procurement and on-site assembly model for related equipment, resulting in numerous technical defects. The overall system integration is low, with Roots pumps, water ring pumps, coolers, separators, and other equipment from different manufacturers. This necessitates extensive on-site piping connections, instrument installation, wiring, and commissioning, leading to long construction periods and issues such as poor interface compatibility and susceptibility to leaks. Furthermore, inconsistent interface standards exist; there are no unified specifications for gas, water, electrical, and thermal interface dimensions, resulting in significant duplication of design work and non-interchangeable spare parts, severely impacting project implementation and subsequent operation and maintenance efficiency.

[0003] Furthermore, existing equipment and solutions lack specialized optimization designs for thermal power units, and are mostly general-purpose industrial vacuum units, which are not adapted to the characteristics of condenser extraction media with high humidity, trace amounts of steam, and the need for long-term continuous operation. There are also shortcomings in material selection and cooling solutions. Ordinary Roots pump impellers are made of cast iron or ductile iron, which have weak resistance to cavitation and corrosion. Heat exchanger materials are not specifically selected based on the different cooling water qualities of power plants, such as seawater, circulating water, and closed-loop water. Cooling solutions are simplistic and have poor adaptability, making them prone to blockage and corrosion in summer, resulting in low heat exchange efficiency and a high equipment failure rate. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated Roots water ring vacuum pump set and construction method for a condenser vacuum system, aiming to solve the problems of uncontrollable quality, long cycle, and poor adaptability caused by the decentralized procurement and on-site assembly of equipment in existing renovation projects.

[0005] According to one objective of the present invention, an integrated Roots water ring vacuum pump unit for a condenser vacuum system is provided, comprising: A public base; Roots vacuum pump, water ring vacuum pump, interstage cooler, and steam-water separator are fixedly installed on the common base. A prefabricated piping system is used to sequentially connect the Roots vacuum pump, water ring vacuum pump, interstage cooler, and steam-water separator to form an air extraction passage. An integrated local control cabinet is installed on the common base and is electrically connected to the motors and instruments of each device. The common base, all equipment, pipes and control cabinets are assembled, wired and pre-tested before leaving the factory to form an integrated skid-mounted module.

[0006] Furthermore, the interstage cooler is a shell-and-tube heat exchanger, located between the exhaust port of the Roots vacuum pump and the suction port of the water ring vacuum pump, used to condense condensable steam in the pumping process and reduce the suction temperature and compression load of the water ring vacuum pump.

[0007] Furthermore, it also includes a working fluid cooler, which is a plate heat exchanger installed on the working fluid circulation pipeline of the water ring vacuum pump. The cooling medium is closed-loop water, used to control the working fluid temperature of the water ring vacuum pump and prevent cavitation.

[0008] Furthermore, based on the type and corrosion level of the cooling water source, at least three standardized material configuration levels are provided: Class A corrosion protection configuration: suitable for open cooling in seawater, the heat exchange tubes of the interstage cooler are made of pure titanium, the tube sheet is made of 317 stainless steel, the bolts are made of 316 stainless steel, and the pipes and valves in contact with seawater are made of 316L stainless steel. Class B corrosion protection configuration: suitable for freshwater open cooling, the heat exchange tubes and tube sheets of the interstage cooler are made of 316L stainless steel. Class C corrosion protection configuration: suitable for closed-loop water cooling, with interstage cooler heat exchange tubes made of 316L stainless steel or carbon steel.

[0009] Furthermore, the rotor of the Roots vacuum pump is made of 304 stainless steel or higher grade stainless steel and is manufactured using an integral casting process; the impeller and distributor of the water ring vacuum pump are made of 304 stainless steel or higher grade stainless steel; the common base adopts a welded steel frame structure, and the surface is coated with a heavy-duty anti-corrosion coating after sandblasting and rust removal; the anchor bolts and base accessories are made of stainless steel; the enclosure of the integrated local control cabinet is made of 316L stainless steel with a thickness of not less than 2.0mm and a protection level of not less than IP56.

[0010] Furthermore, the prefabricated piping system includes an extraction pipe, a cooling water pipe, a water supply pipe, and a water discharge pipe. The pipes in contact with the extraction medium are made of 316L or 304 stainless steel, and the pipe connections are made using argon arc welding. The weld joints are then pickled and passivated. The integrated local control cabinet is equipped with a PLC or a remote I / O module, which is connected to the unit's DCS via a communication bus or hardwired connection.

[0011] Furthermore, the pump set's air extraction inlet flange, cooling water inlet and outlet flange, water supply flange, and exhaust flange adopt a unified standard interface specification, including the flange nominal diameter, nominal pressure, sealing surface type, and connection dimensions; the air extraction inlet flange is standardized into three specifications: DN150, DN200, and DN250 according to the unit capacity, with a nominal pressure of PN10 and a sealing surface of type RF.

[0012] According to another objective of the present invention, the present invention provides a construction method for an integrated Roots water ring vacuum pump unit for the above-mentioned condenser vacuum system, comprising the following steps: Step 1: Prefabricate the foundation on the power plant side, reserve anchor bolt holes, and complete the prefabrication of external interface pipe flanges; Step 2: Hoist the integrated pump unit into place as a whole, adjust its level, and tighten the anchor bolts; Step 3: Connect the external air extraction pipe, cooling water pipe, water supply pipe, and exhaust pipe; Step 4: Connect the external power cable and control cable; Step 5: Perform power-on checks and logic tests; Step 6: Complete commissioning and operation.

[0013] Furthermore, in step 2, the standard for adjusting the levelness is ≤0.1mm / m; in steps 3 and 4, all external interfaces use standardized flanges and gland heads for quick connection.

[0014] Furthermore, it also includes performance verification methods, including the following acceptance test items: Total power test: Under the rated load condition of the unit, measure the total operating current and total power of the pump set to confirm that they are not greater than the guaranteed value in the contract; Vacuum performance test: Under the same load and the same circulating water temperature, compare the condenser vacuum value of the original vacuum pump before the modification with the condenser vacuum value of the Roots pump set after the modification to confirm that it is not lower than the level before the modification. Vibration test: Under the rated operating conditions of the pump set, the effective value of the vibration velocity of each bearing part was measured to confirm that it meets the GB / T6075.3 standard; Noise test: Measure the noise level at a distance of 1 meter from the equipment casing and confirm that it is ≤85dB(A); Joint operation test: Simulate faults such as Roots pump tripping, inlet valve closure, and low water level to confirm that the interlocking protection action is correct.

[0015] The technical solution of this invention adopts a skid-mounted integrated design, integrating the Roots pump, water ring pump, cooler, separator, and control cabinet all onto a common base. Pre-assembly and pre-commissioning are completed before delivery, requiring only external interface connection on-site for commissioning. This significantly shortens the installation cycle from the traditional 10-15 days to 3-5 days. Simultaneously, a graded anti-corrosion configuration system is established for different water sources such as seawater, circulating water, and closed-loop water, addressing corrosion and clogging issues at the material source. The interstage cooler condenses condensable steam, reducing the power consumption of the forestage pump by more than 30%, and the closed-loop water cooler ensures no cavitation in summer. Furthermore, standardized mechanical, thermal control, and electrical interface specifications are unified, forming a standardized system that facilitates direct application in projects, significantly reducing redundant design and possessing strong scalability and replicability. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the integrated Roots water ring vacuum pump unit of the condenser vacuum system according to an embodiment of the present invention; Figure 2 This is a construction flowchart of the integrated Roots water ring vacuum pump unit for the condenser vacuum system according to an embodiment of the present invention.

[0018] In the diagram: 1. Common base; 2. Roots vacuum pump; 3. Water ring vacuum pump; 4. Interstage cooler; 5. Steam-water separator; 6. Piping; 7. Control cabinet. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] Example 1 like Figure 1 As shown, an integrated Roots water ring vacuum pump set for a condenser vacuum system includes: A common base 1; Roots vacuum pump 2, water ring vacuum pump 3, interstage cooler 4, and steam-water separator 5 are fixedly installed on the common base 1; A prefabricated piping system is used to sequentially connect the Roots vacuum pump 2, the water ring vacuum pump 3, the interstage cooler 4, and the steam-water separator 5 to form an air extraction passage. The integrated local control cabinet 7 is installed on the common base 1 and is electrically connected to the motors and instruments of the Roots vacuum pump 2, water ring vacuum pump 3, interstage cooler 4, and steam-water separator 5. The common base 1, Roots vacuum pump 2, water ring vacuum pump 3, interstage cooler 4, steam-water separator 5, piping 6, and control cabinet 7 are assembled, wired, and pre-tested before leaving the factory, forming an integrated skid-mounted module.

[0023] Specifically, the interstage cooler is a shell-and-tube heat exchanger located between the exhaust port of the Roots vacuum pump and the suction port of the water ring vacuum pump. It is used to condense condensable vapors in the pumping process and reduce the suction temperature and compression load of the water ring vacuum pump.

[0024] This embodiment also includes a working fluid cooler, which is a plate heat exchanger installed on the working fluid circulation pipeline of the water ring vacuum pump. The cooling medium is closed-loop water, which is used to control the working fluid temperature of the water ring vacuum pump and prevent cavitation.

[0025] In this embodiment, the public base adopts a welded steel frame structure, and the surface is coated with a heavy-duty anti-corrosion coating after sandblasting and rust removal. The anchor bolts and base accessories are made of stainless steel.

[0026] The integrated local control cabinet is made of 316L stainless steel with a thickness of not less than 2.0mm and a protection level of not less than IP56. The cabinet door is equipped with a guide-type sealing gasket.

[0027] In this embodiment, at least three standardized material configuration levels are provided based on the type of cooling water source and the degree of corrosion: Class A corrosion protection configuration: suitable for open cooling in seawater, the heat exchange tubes of the interstage cooler are made of pure titanium, the tube sheet is made of 317 stainless steel, the bolts are made of 316 stainless steel, and the pipes and valves in contact with seawater are made of 316L stainless steel. Class B corrosion protection configuration: suitable for freshwater open cooling, the heat exchange tubes and tube sheets of the interstage cooler are made of 316L stainless steel. Class C corrosion protection configuration: suitable for closed-loop water cooling, with interstage cooler heat exchange tubes made of 316L stainless steel or carbon steel.

[0028] In this embodiment, the rotor of the Roots vacuum pump is made of 304 stainless steel or higher grade stainless steel and is made using an integral casting process; welding of the impeller is prohibited.

[0029] The impeller and distributor of the water ring vacuum pump are made of 304 stainless steel or higher grade stainless steel.

[0030] The prefabricated piping system includes air extraction pipes, cooling water pipes, water supply pipes, and water discharge pipes. The pipes in contact with the air extraction medium are made of 316L or 304 stainless steel. The pipe connections are made using argon arc welding, and the weld joints are pickled and passivated.

[0031] The integrated local control cabinet is equipped with a PLC or remote IO module, which is connected to the unit's DCS via a communication bus or hardwired connection to realize remote start-up and shutdown, status monitoring and interlock protection.

[0032] The pump unit's air extraction inlet flange, cooling water inlet and outlet flanges, water supply flange, and exhaust flange adopt a unified standard interface specification, including the flange nominal diameter, nominal pressure, sealing surface type, and connection dimensions. The air extraction inlet flange is standardized into three specifications: DN150, DN200, and DN250, based on the unit capacity, with a nominal pressure of PN10 and a sealing surface of type RF.

[0033] like Figure 2 As shown, the construction method of the integrated Roots water ring vacuum pump unit for the condenser vacuum system includes the following steps: Step 1: Prefabricate the foundation on the power plant side, reserve anchor bolt holes, and complete the prefabrication of external interface pipe flanges; Step 2: Hoist the integrated pump unit into place as a whole, adjust its level, and tighten the anchor bolts; Step 3: Connect the external air extraction pipe, cooling water pipe, water supply pipe, and exhaust pipe; Step 4: Connect the external power cable and control cable; Step 5: Perform power-on checks and logic tests; Step 6: Complete commissioning and operation.

[0034] The performance verification method for the above-mentioned integrated Roots-water ring vacuum pump unit includes the following acceptance test items: Total power test: Under the rated load condition of the unit, measure the total operating current and total power of the pump set to confirm that they are not greater than the guaranteed value in the contract; Vacuum performance test: Under the same load and the same circulating water temperature, compare the condenser vacuum value of the original vacuum pump before the modification with the condenser vacuum value of the Roots pump set after the modification to confirm that it is not lower than the level before the modification. Vibration test: Under the rated operating conditions of the pump set, the effective value of the vibration velocity of each bearing part was measured to confirm that it meets the GB / T6075.3 standard; Noise test: Measure the noise level at a distance of 1 meter from the equipment casing and confirm that it is ≤85dB(A); Joint operation test: Simulate faults such as Roots pump tripping, inlet valve closure, and low water level to confirm that the interlocking protection action is correct.

[0035] A standardized method for complete sets of equipment for energy-saving retrofitting of vacuum systems in thermal power units includes the following steps: The Roots pump, water ring pump, cooler, separator, and control cabinet are integrated into a common base to form a standardized skid-mounted module; A standardized material selection table is provided based on the corrosivity level of the cooling water source; Based on the unit capacity level, standardized interface specifications and equipment performance parameter tables are provided; Provide standardized factory test outlines and on-site acceptance test outlines.

[0036] This invention adopts a skid-mounted integrated design, integrating all components of the vacuum pump unit onto a common base. The entire assembly and pre-composition are completed before leaving the factory, and the system can be put into operation on site simply by connecting external interfaces. This significantly shortens the installation cycle from the traditional 10-15 days to 3-5 days. At the same time, it unifies the mechanical, thermal control, and electrical interface specifications, forming a standardized interface system that is easy for projects to directly apply. This effectively reduces redundant design and the variety of spare parts in stock, making it highly scalable and replicable.

[0037] This invention employs a tiered corrosion protection and cooling scheme, providing standardized corrosion protection configurations for different water sources such as seawater, circulating water, and closed-loop water systems. This addresses equipment corrosion and clogging issues at the material source, improving operational reliability. The interstage cooler condenses condensable steam, reducing the load on the water ring pump and lowering the power of the forestage pump by more than 30% compared to traditional solutions. The working fluid cooler uses closed-loop water to prevent cavitation under high water temperatures in summer. Furthermore, this invention clearly defines performance indicators and testing methods for power, vacuum, vibration, and noise, making performance verifiable and assessable, facilitating acceptance and quality assurance assessments by the purchasing party.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated Roots water ring vacuum pump set for a condenser vacuum system, characterized in that, include: A public base; Roots vacuum pump, water ring vacuum pump, interstage cooler, and steam-water separator are fixedly installed on the common base. A prefabricated piping system is used to sequentially connect the Roots vacuum pump, water ring vacuum pump, interstage cooler, and steam-water separator to form an air extraction passage. An integrated local control cabinet is installed on the common base and is electrically connected to the motors and instruments of each device. The common base, all equipment, pipes and control cabinets are assembled, wired and pre-tested before leaving the factory to form an integrated skid-mounted module.

2. The integrated Roots water ring vacuum pump unit for the condenser vacuum system according to claim 1, characterized in that, The interstage cooler is a shell-and-tube heat exchanger located between the exhaust port of the Roots vacuum pump and the intake port of the water ring vacuum pump. It is used to condense condensable vapors during pumping, reduce the intake temperature of the water ring vacuum pump, and decrease the compression load.

3. The integrated Roots water ring vacuum pump unit for the condenser vacuum system according to claim 1, characterized in that, It also includes a working fluid cooler, which is a plate heat exchanger installed on the working fluid circulation pipeline of the water ring vacuum pump. The cooling medium is closed-loop water, which is used to control the working fluid temperature of the water ring vacuum pump and prevent cavitation.

4. The integrated Roots water ring vacuum pump unit for the condenser vacuum system according to claim 1, characterized in that, Based on the type of cooling water source and the degree of corrosion, at least three standardized material configuration levels are available: Class A corrosion protection configuration: suitable for open cooling in seawater, the heat exchange tubes of the interstage cooler are made of pure titanium, the tube sheet is made of 317 stainless steel, the bolts are made of 316 stainless steel, and the pipes and valves in contact with seawater are made of 316L stainless steel. Class B corrosion protection configuration: suitable for freshwater open cooling, the heat exchange tubes and tube sheets of the interstage cooler are made of 316L stainless steel. Class C corrosion protection configuration: suitable for closed-loop water cooling, with interstage cooler heat exchange tubes made of 316L stainless steel or carbon steel.

5. The integrated Roots water ring vacuum pump set for the condenser vacuum system according to claim 1, characterized in that, The rotor of the Roots vacuum pump is made of 304 stainless steel or higher grade stainless steel and is manufactured using an integral casting process; the impeller and distributor of the water ring vacuum pump are made of 304 stainless steel or higher grade stainless steel; the common base adopts a welded steel frame structure, and the surface is coated with a heavy-duty anti-corrosion coating after sandblasting and rust removal; the anchor bolts and base accessories are made of stainless steel; the enclosure of the integrated local control cabinet is made of 316L stainless steel with a thickness of not less than 2.0mm and a protection level of not less than IP56.

6. The integrated Roots water ring vacuum pump unit for the condenser vacuum system according to claim 1, characterized in that, The prefabricated piping system includes an extraction pipe, a cooling water pipe, a water supply pipe, and a water discharge pipe. The pipes in contact with the extraction medium are made of 316L or 304 stainless steel. The pipe connections are made using argon arc welding, and the weld joints are pickled and passivated. The integrated local control cabinet is equipped with a PLC or a remote I / O module, which is connected to the unit's DCS via a communication bus or hardwired connection.

7. The integrated Roots water ring vacuum pump set for the condenser vacuum system according to claim 1, characterized in that, The pump set's air extraction inlet flange, cooling water inlet and outlet flange, water supply flange, and exhaust flange adopt a unified standard interface specification, including the flange nominal diameter, nominal pressure, sealing surface type, and connection dimensions; the air extraction inlet flange is standardized into three specifications: DN150, DN200, and DN250 according to the unit capacity, with a nominal pressure of PN10 and a sealing surface of type RF.

8. A construction method for an integrated Roots water ring vacuum pump unit for a condenser vacuum system as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Prefabricate the foundation on the power plant side, reserve anchor bolt holes, and complete the prefabrication of external interface pipe flanges; Step 2: Hoist the integrated pump unit into place as a whole, adjust its level, and tighten the anchor bolts; Step 3: Connect the external air extraction pipe, cooling water pipe, water supply pipe, and exhaust pipe; Step 4: Connect the external power cable and control cable; Step 5: Perform power-on checks and logic tests; Step 6: Complete commissioning and operation.

9. The construction method of the integrated Roots water ring vacuum pump set for the condenser vacuum system according to claim 8, characterized in that, In step 2, the standard for adjusting the level is ≤0.1mm / m; in steps 3 and 4, all external interfaces use standardized flanges and gland heads for quick connection.

10. The construction method of the integrated Roots water ring vacuum pump set for the condenser vacuum system according to claim 8, characterized in that, It also includes performance verification methods, including the following acceptance test items: Total power test: Under the rated load condition of the unit, measure the total operating current and total power of the pump set to confirm that they are not greater than the guaranteed value in the contract; Vacuum performance test: Under the same load and the same circulating water temperature, compare the condenser vacuum value of the original vacuum pump before the modification with the condenser vacuum value of the Roots pump set after the modification to confirm that it is not lower than the level before the modification. Vibration test: Under the rated operating conditions of the pump set, the effective value of the vibration velocity of each bearing part was measured to confirm that it meets the GB / T6075.3 standard; Noise test: Measure the noise level at a distance of 1 meter from the equipment casing and confirm that it is ≤85dB(A); Joint operation test: Simulate faults such as Roots pump tripping, inlet valve closure, and low water level to confirm that the interlocking protection action is correct.

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