Lubrification system for rotating equipment and control method thereof

Abstract

A lubrification system for rotating equipment is disclosed. The lubrification system integrates oil pressure control and pumping functions. The system comprises an oil circuit, tank, filtration system, cooling system, and an integrated oil pressure control and pumping system with at least two variable speed pumps. A pressure measurement device provides feedback for pump speed control. The system offers improved efficiency, compact design, and adaptability to various operational conditions, making it particularly suitable for industrial and power plant applications.

Description

Lubnfication system for rotating equipment and control method thereofDescriptionTECHNICAL FIELD

[0001] The present disclosure concerns a lubrication system for rotating equipment, particularly in industrial and power plant applications. More particularly, the disclos- sure provides an integrated oil pressure control and pumping system for efficiently managing oil circulation and pressure in rotating machinery.BACKGROUND ART

[0002] Rotating equipment, such as turbines, compressors, and pumps, are critical components in many industrial processes. These machines require efficient and reliable lubrication systems to ensure optimal performance and longevity. Conventional lubrication systems for rotating equipment often employ separate components for oil circulation, pressure control, filtration, and cooling. These systems typically use fixed- speed pumps with pressure control valves, which can be inefficient and less responsive to varying operational demands. Additionally, traditional systems may require larger footprints and more complex piping arrangements, increasing installation and maintenance costs.

[0003] Accordingly, an improved lubrication system for rotating equipment to address the issues of the current art would be beneficial and would be welcomed in the technology. More in general, it would be desirable to provide improved lubrication systems that address these issues while providing enhanced control and reliability.SUMMARY

[0004] In one aspect, the subject matter disclosed herein is directed to a lubrication system for rotating equipment that integrates oil pressure control and pumping functions into a single system. This integration, along with the use of variable speed pumps, offers improved efficiency, responsiveness, and compact design compared to conven-tional systems. In particular, the subject matter disclosed herein is directed to a lubn- fication system for rotating equipment, the lubrification system comprising an oil circuit, an oil tank, an oil filtration system, an oil cooling system, an oil pressure control system and an oil circulation pumping system, wherein the oil pressure control system and the oil circulation pumping system are combined together into an integrated oil pressure control and pumping system, the oil circuit is configured to connect the integrated oil pressure control and pumping system with a lubrification oil inlet of at least one rotating equipment and to connect a lubrification oil outlet of the at least one rotating equipment with the oil tank and the oil circuit is also configured to connect the oil tank with the oil filtration system, the oil cooling system and the integrated oil pressure control and pumping system, wherein the integrated oil pressure control and pumping system comprises at least two variable speed pumps and at least a pressure measurement device configured to measure the pressure of the oil in the oil circuit and the integrated oil pressure control and pumping system is configured to control the pressure of the oil in the oil circuit by operating the variable speed pumps according to the measured value of pressure. In particular, the at least two variable speed pumps are arranged downstream of the oil cooling system and upstream of the lubrification oil inlet of the at least one rotating equipment. The pressure measurement device is arranged along the oil circuit downstream of the variable speed pumps and upstream of the lubrification oil inlet of the at least one rotating equipment.

[0005] Further features and embodiments are described herein below and set out in the appended claims.

[0006] In particular, in one aspect, the at least two variable speed pumps comprise at least one main variable speed pump and at least one auxiliary variable speed pump, driven by respective variable frequency drive motors. In particular, at least the variable frequency drive motor of the auxiliary variable speed pump is connected to auxiliary energy sources, such as batteries or one or more engine generators.

[0007] In one aspect, the oil filtration system the oil cooling system, together with the oil pressure control system and the oil circulation pumping system forming the integrated oil pressure control and pumping system, are arranged on a shared baseplate and the oil tank is arranged external to the baseplate. The oil tank can be arranged inline with the baseplate. Also, the oil tank can be cylindrical and can be arranged horizontally, and preferably is supported by two or more saddles.

[0008] In another aspect, the subject matter disclosed herein is directed to a method of operating the lubrification system above, wherein the operation of the main variable speed pump and the auxiliary variable speed pump is controlled to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range.

[0009] In still another aspect, the subject matter disclosed herein is directed to a method of operating the lubrification system above, wherein, in case the main variable speed pump is failing to operate, the operation of the auxiliary variable speed pump is controlled to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range or to coast down the rotating machine and subsequently stop the auxiliary variable speed pump.

[0010] In still another aspect, the subject matter disclosed herein is directed to a method of operating the lubrification system above, wherein, in case the main power supply is off, then the rotating machine is tripped and an auxiliary power generator connected to the auxiliary variable speed pump is switched to maintain a coast down preset speed until the rotating machine speed is zeroed, and subsequently the auxiliary variable speed pump is stopped.

[0011] The system and method of the disclosure aim to reduce costs, improve reliability, and enhance the overall performance of lubrication systems in industrial applications.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] A more complete appreciation of the disclosed embodiments of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:Fig. l illustrates a schematic of a lubrification system for rotating equipment according to an embodiment.DETAILED DESCRIPTION OF EMBODIMENTS

[0013] Reference now will be made in detail to embodiments of the disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the disclosure, not limitation of the disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. Reference throughout the specification to “one embodiment” or “an embodiment” or “some embodiments” means that the particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrase “in one embodiment” or “in an embodiment” or “in some embodiments” in various places throughout the specification is not necessarily referring to the same embodiment s). Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0014] When introducing elements of various embodiments the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0015] A schematic of an exemplary lubrification system for rotating equipment is shown in Fig.l. The lubrification system for rotating equipment comprises an oil circuit 10, an oil tank 20, an oil filtration system 30, an oil cooling system 40, an oil pressure control system 50, an oil circulation pumping system 60, which are integrated in an integrated oil pressure control and pumping system 70.

[0016] A significant aspect of the disclosure is the integration of the oil pressure control system 50 with the oil circulation pumping system 60 into an integrated oil pressure control and pumping system 70. The integrated oil pressure control and pumping system 70 comprises a pressure measurement device located downstream of the pumps and upstream of the lubrication oil inlet of the rotating equipment. The integrated oil pressure control and pumping system 70 eliminates the need for a separate pressure control valve, instead utilizing at least two variable speed pump. In more advanced configurations, such as the configuration shown in Fig. 1, the system may include a main variable speed pump 61 and an auxiliary variable speed pump 62. Thevariable speed pumps 61, 62 are driven by respective variable frequency drive motors 63, 64. To enhance control and efficiency, each variable frequency drive motor 63, 64 is equipped with its own inverter, which is arranged directly on the motor. This arrangement allows for precise control of oil pressure and flow, adapting to the changing needs of the rotating equipment.

[0017] At least one of the variable speed pumps 61, 62, generally the auxiliary variable speed pump 62, is configured as an emergency pump. To this aim, the auxiliary variable speed pump 62 is connected to auxiliary energy sources (batteries or an engine generator). Both variable speed pumps can also be connected to the auxiliary energy sources, this option involving an increased cost.

[0018] An important feature of the disclosure is the arrangement of the oil filtration system 30, oil cooling system 40, together with the oil pressure control system 50 and the oil circulation pumping system 60 forming the integrated oil pressure control and pumping system 70, on a shared baseplate 100. The oil tank 20 is positioned external to the baseplate 100. In the embodiment of Fig. 1, the oil tank 20 is positioned external to the baseplate 100 and in line with it. This configuration allows for efficient space utilization and improved accessibility for maintenance.

[0019] The oil tank 20 of Fig. 1 is cylindrical and arranged horizontally, supported by three saddles 21. This design provides stability and facilitates easy inspection and maintenance of the tank.

[0020] In the oil circuit, the oil filtration system 30 is positioned upstream of the oil cooling system 40. The filtration system comprises a duplex oil filter, allowing for continuous operation during filter changes or maintenance. The oil cooling system 40 utilizes a plate cooler, preferably a single plate design, for efficient heat transfer. The oil cooling system 40 downstream of the oil filtration system 30 allows for less dirt to get into the oil cooling system 40, differently from the API, according to which the oil filtration system shall be positioned downstream of the oil cooling system 40, for safety reasons. Also, by using a plate heat exchanger instead of a tube bundle, there is less risk of dirt getting into the oil.

[0021] The system operates in different modes depending on the conditions:- Normal OperationAuxiliary variable speed pump Activation- Main variable speed pump Failure- Power Loss Scenario

[0022] In Normal Operation mode, the main variable speed pump 61 is used to deliver lubrication oil within a set pressure range. If the pressure falls below the lower limit, the pump speed is increased. If it exceeds the upper limit, the speed is decreased.

[0023] In particular, according to the Normal Operation mode, the main variable speed pump 61 is used to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range, with a lower limit and a higher limit, whereas the auxiliary variable speed pump 62 is in stand-by, and the method comprises the following steps: measuring the pressure of the lubrification oil downstream of the main variable speed pump 61 and if the pressure of the lubrification oil downstream of the main variable speed pump 61 is higher than the higher limit of the pressure range- then the speed of the main variable speed pump 61 is decreased; if the pressure of the lubrification oil downstream of the main variable speed pump 61 is higher than the lower limit and lower than the higher limit of the pressure range- then the speed of the main variable speed pump 61 is maintained; and if the pressure of the lubrification oil downstream of the main variable speed pump 61 is lower than the lower limit of the pressure range,- then the speed of the main variable speed pump 61 is increased.

[0024] According to the Auxiliary variable speed pump Activation mode, if the main variable speed pump reaches maximum speed and pressure is still low, the auxiliary variable speed pump 62 is activated. The speeds of both pumps are then adjusted to maintain the desired pressure range.

[0025] In particular, according to the Auxiliary variable speed pump Activation mode, the main variable speed pump 61 is used to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range, with a lower limit and a higher limit, whereas the auxiliary variable speed pump 62 isin stand-by, and the method comprises the following steps: measuring the pressure of the lubrification oil downstream of the main variable speed pump 61 and if the pressure of the lubrification oil downstream of the main variable speed pump 61 is higher than the higher limit of the pressure range- then the speed of the main variable speed pump 61 is decreased; if the pressure of the lubrification oil downstream of the main variable speed pump 61 is higher than the lower limit and lower than the higher limit of the pressure range- then the speed of the main variable speed pump 61 is maintained; and if the pressure of the lubrification oil downstream of the main variable speed pump 61 is lower than the lower limit of the pressure range,- then the speed of the main variable speed pump 61 is increased; and if the speed of the main variable speed pump 61 is equal to the maximum operating speed of the main variable speed pump 61 and the pressure of the lubrification oil downstream of the main variable speed pump 61 is lower than the lower limit of the pressure range- then the auxiliary variable speed pump 62 is switched on and if the pressure of the lubrification oil downstream of the main variable speed pump 61 and the auxiliary variable speed pump 62 is higher than the higher limit of the pressure range,- then the speed of the auxiliary variable speed pump 62 is decreased or the auxiliary variable speed pump 62 is switched off; if the pressure of the lubrification oil downstream of the main variable speed pump 61 and the auxiliary variable speed pump 62 is higher than the lower limit and lower than the higher limit of the pressure range,- then the speed of the auxiliary variable speed pump 62 is maintained; and if the pressure of the lubrification oil downstream of the main variable speed pump 61 and the auxiliary variable speed pump 62 is lower than the lower limit of the pressure range,- then the speed of the auxiliary variable speed pump 62 is increased; and if both the speed of the main variable speed pump 61 is equal to the maximum operating speed of the main variable speed pump 61 and the speedof the auxiliary variable speed pump 62 is equal to the maximum operating speed of the auxiliary variable speed pump 61 and the pressure of the lubri- fication oil downstream of the main variable speed pump 51 and the auxiliary variable speed pump 52 is lower than the lower limit of the pressure range,- then the rotating machine is coasted down,- the main variable speed pump 61 is stopped, and subsequently- the speed of the auxiliary variable speed pump 62 is decreased down to a coast down preset speed and is maintained until the machine speed is zeroed, and subsequently- the speed of the auxiliary variable speed pump 62 is decreased down to a cool down preset speed and is maintained until the cool down sequence is completed, and subsequently- the auxiliary variable speed pump 62 is stopped.

[0026] According to the Main variable speed pump Failure mode, in case of main variable speed pump failure, the auxiliary variable speed pump is switched on and operated to maintain the required pressure.

[0027] In particular, according to the Main variable speed pump Failure mode, the main variable speed pump 61 is used to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range, with a lower limit and a higher limit, whereas the auxiliary variable speed pump 62 is in stand-by, and in case the main variable speed pump 61 is failing to operate, the method comprises the following steps: switching the auxiliary variable speed pump 62 on and measuring the pressure of the lubrification oil downstream of the auxiliary variable speed pump 62 and if the pressure of the lubrification oil downstream of the auxiliary variable speed pump 62 is higher than the higher limit of the pressure range- then the speed of the main variable speed pump 62 is decreased; if the pressure of the lubrification oil downstream of the auxiliary variable speed pump 62 is higher than the lower limit and lower than the higher limit of the pressure range- then the speed of the auxiliary variable speed pump 62 is maintained; andif the pressure of the lubnfication oil downstream of the auxiliary variable speed pump 62 is lower than the lower limit of the pressure range,- then the speed of the auxiliary variable speed pump 62 is increased; and if the speed of the auxiliary variable speed pump 62 is equal to the maximum operating speed of the auxiliary variable speed pump 62 and the pressure of the lubrification oil downstream of the auxiliary variable speed pump 62 is lower than the lower limit of the pressure range- then the rotating machine is coasted down, and subsequently- the speed of the auxiliary variable speed pump 62 is decreased down to a coast down preset speed and is maintained until the rotating machine speed is zeroed, and subsequently- the speed of the auxiliary variable speed pump 62 is decreased down to a cool down preset speed and is maintained until the cool down sequence is completed, and subsequently- the auxiliary variable speed pump 62 is stopped.

[0028] Finally, according to the Power Loss Scenario mode, if main power supply is lost, the rotating machine is tripped, and the auxiliary variable speed pump, connected to auxiliary power sources (e.g., batteries or an engine generator), is used to provide lubrication during coast-down and cool-down sequences.

[0029] In particular, according to the Power Loss Scenario mode, the main variable speed pump 61 is used to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range, with a lower limit and a higher limit, whereas the auxiliary variable speed pump 62 is in stand-by, and, in case main power supply is off, the method comprises the following steps:- the rotating machine is tripped and an auxiliary power generator connected to the auxiliary variable speed pump 62 is switched on and- the auxiliary variable speed pump 62 is switched on and- the speed of the auxiliary variable speed pump 62 is increased up to a coast down preset speed and is maintained until the rotating machine speed is zeroed, and subsequently- the auxiliary variable speed pump 62 is stopped.

[0030] The lubnfication system for rotating equipment implies many advantages, such as: cost reduction, because use of off-the-shelf components and simplified design reduces overall system cost; compact design, due to the fact that integration of components on a common baseplate and external tank arrangement minimizes the system footprint;- improved efficiency, since variable speed pumps allow for precise pressure control without the need for pressure control valves or oil accumulators. enhanced reliability, because redundant pump configuration and auxiliary power options ensure lubrication under various operational scenarios. simplified maintenance, for the reason that use of easily replaceable components like the single plate cooler reduces maintenance complexity.

[0031] The lubrication system is particularly suitable for use in industrial plants and power plants where reliable lubrication of rotating equipment is critical, providing a cost-effective and efficient solution for lubricating various types of rotating equipment, including steam turbines, gas turbines, and supercritical oxy combustion expanders.

[0032] While the disclosure has been described in terms of various specific embodiments, it will be apparent to those of ordinary skill in the art that many modifications, changes, and omissions are possible without departing form the spirt and scope of the claims. In addition, unless specified otherwise herein, the order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments.

Claims

Lubnfication system for rotating equipment and control method thereofCLAIMS1. A method of operating a lubrification system, wherein said lubrifi- cation system comprises at least two variable speed pumps (61, 62) comprising at least one main variable speed pump (61) and at least one auxiliary variable speed pump (62) and wherein the main variable speed pump (61) is used to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range, with a lower limit and a higher limit, whereas the auxiliary variable speed pump (62) is in stand-by, the method comprising the following steps: measuring the pressure of the lubrification oil downstream of the main variable speed pump (61) and if the pressure of the lubrification oil downstream of the main variable speed pump (61) is higher than the higher limit of the pressure range- then the speed of the main variable speed pump (61) is decreased; if the pressure of the lubrification oil downstream of the main variable speed pump (61) is higher than the lower limit and lower than the higher limit of the pressure range- then the speed of the main variable speed pump (61) is maintained; and if the pressure of the lubrification oil downstream of the main variable speed pump (61) is lower than the lower limit of the pressure range,- then the speed of the main variable speed pump (61) is increased.

2. A method of operating a lubrification system, wherein the lubrification system comprises at least two variable speed pumps (61, 62) comprising at least one main variable speed pump (61) and at least one auxiliary variable speed pump (62) and wherein the main variable speed pump (61) is used to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range, with a lower limit and a higher limit, whereas the auxiliary variable speed pump (62) is in stand-by, the method comprising the following steps: measuring the pressure of the lubrification oil downstream of the main variable speed pump (61) and if the pressure of the lubrification oil downstream of the main variable speed pump(61) is higher than the higher limit of the pressure range- then the speed of the main variable speed pump (61) is decreased; if the pressure of the lubrification oil downstream of the main variable speed pump (61) is higher than the lower limit and lower than the higher limit of the pressure range- then the speed of the main variable speed pump (61) is maintained; and if the pressure of the lubrification oil downstream of the main variable speed pump (61) is lower than the lower limit of the pressure range,- then the speed of the main variable speed pump (61) is increased; and if the speed of the main variable speed pump (61) is equal to the maximum operating speed of the main variable speed pump (61) and the pressure of the lubrification oil downstream of the main variable speed pump (61) is lower than the lower limit of the pressure range- then the auxiliary variable speed pump (62) is switched on and if the pressure of the lubrification oil downstream of the main variable speed pump (61) and the auxiliary variable speed pump (62) is higher than the higher limit of the pressure range,- then the speed of the auxiliary variable speed pump (62) is decreased or the auxiliary variable speed pump (62) is switched off; if the pressure of the lubrification oil downstream of the main variable speed pump (61) and the auxiliary variable speed pump (62) is higher than the lower limit and lower than the higher limit of the pressure range,- then the speed of the auxiliary variable speed pump (62) is maintained; and if the pressure of the lubrification oil downstream of the main variable speed pump (61) and the auxiliary variable speed pump (62) is lower than the lower limit of the pressure range,- then the speed of the auxiliary variable speed pump (62) is increased; and if both the speed of the main variable speed pump (61) is equal to the maximum operating speed of the main variable speed pump (61) and the speed of the auxiliary variable speed pump (62) is equal to the maximum operating speed of the auxiliary variable speed pump (61) and the pressure of the lubrification oil downstream of the main variable speed pump (51) and theauxiliary variable speed pump (52) is lower than the lower limit of the pressure range,- then the rotating machine is coasted down,- the main variable speed pump (61) is stopped, and subsequently- the speed of the auxiliary variable speed pump (62) is decreased down to a coast down preset speed and is maintained until the machine speed is zeroed, and subsequently- the speed of the auxiliary variable speed pump (62) is decreased down to a cool down preset speed and is maintained until the cool down sequence is completed, and subsequently- the auxiliary variable speed pump (62) is stopped.

3. A method of operating a lubrification system, wherein the lubrifica- tion system comprises at least two variable speed pumps (61, 62) comprising at least one main variable speed pump (61) and at least one auxiliary variable speed pump (62) and wherein the main variable speed pump (61) is used to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range, with a lower limit and a higher limit, whereas the auxiliary variable speed pump (62) is in stand-by, wherein, in case the main variable speed pump (61) is failing to operate, the method comprises the following steps: switching the auxiliary variable speed pump (62) on and measuring the pressure of the lubrification oil downstream of the auxiliary variable speed pump (62) and if the pressure of the lubrification oil downstream of the auxiliary variable speed pump (62) is higher than the higher limit of the pressure range- then the speed of the main variable speed pump (62) is decreased; if the pressure of the lubrification oil downstream of the auxiliary variable speed pump (62) is higher than the lower limit and lower than the higher limit of the pressure range- then the speed of the auxiliary variable speed pump (62) is maintained; and if the pressure of the lubrification oil downstream of the auxiliary variable speed pump (62) is lower than the lower limit of the pressure range,- then the speed of the auxiliary variable speed pump (62) is increased; and if the speed of the auxiliary variable speed pump (62) is equal to the maximumoperating speed of the auxiliary variable speed pump (62) and the pressure of the lubrification oil downstream of the auxiliary variable speed pump (62) is lower than the lower limit of the pressure range- then the rotating machine is coasted down, and subsequently- the speed of the auxiliary variable speed pump (62) is decreased down to a coast down preset speed and is maintained until the rotating machine speed is zeroed, and subsequently- the speed of the auxiliary variable speed pump (62) is decreased down to a cool down preset speed and is maintained until the cool down sequence is completed, and subsequently- the auxiliary variable speed pump (62) is stopped.

4. A method of operating a lubrification system, wherein the lubrification system comprises at least two variable speed pumps (61, 62) comprising at least one main variable speed pump (61) and at least one auxiliary variable speed pump (62) and wherein the main variable speed pump (61) is used to deliver lubrification oil to be circulated in the lubrification system at a pressure comprised within a set pressure range, with a lower limit and a higher limit, whereas the auxiliary variable speed pump (62) is in stand-by, wherein, in case main power supply is off, the method comprises the following steps:- the rotating machine is tripped and an auxiliary power generator connected to the auxiliary variable speed pump (62) is switched on and- the auxiliary variable speed pump (62) is switched on and- the speed of the auxiliary variable speed pump (62) is increased up to a coast down preset speed and is maintained until the rotating machine speed is zeroed, and subsequently the auxiliary variable speed pump (62) is stopped.

5. A lubrification system for rotating equipment configured to operate according to a method of one of claims 1-4, the lubrification system comprising: an oil circuit (10), an oil tank (20), an oil filtration system (30), an oil cooling system (40), an oil pressure control system (50) and an oil circulation pumping system (60), wherein the oil pressure control system (50) and the oil circulation pumping system (60) are combined together into an integrated oil pressure control and pumping system (70),the oil circuit (10) being configured to connect the integrated oil pressure control and pumping system (70) with a lubrification oil inlet of at least one rotating equipment, the oil circuit (10) being also configured to connect a lubrification oil outlet of the at least one rotating equipment with the oil tank (20) and the oil circuit (10) being also configured to connect the oil tank (20) with the oil filtration system (30), the oil cooling system (40) and the integrated oil pressure control and pumping system (70), such that oil from the rotating equipment flows in sequence through the oil tank (20), alternatively the oil filtration system (30) and the oil cooling system (40) or the oil cooling system (40) and the oil filtration system (30), and the integrated oil pressure control and pumping system (70), the integrated oil pressure control and pumping system comprising at least two variable speed pumps (61, 62), each variable speed pump (61, 62) comprising an oil inlet and a pressurized oil outlet, the oil inlet of the variable speed pumps (61, 62) being configured to be coupled with the oil circuit (10) downstream of the oil cooling system (40) and the pressurized oil outlet of the variable speed pumps (61, 62) being configured to be coupled to the oil circuit (10) upstream of the lubrification oil inlet of the at least one rotating equipment, the integrated oil pressure control and pumping system (70) comprising at least one pressure measurement device (51) configured to measure the pressure of the oil in the oil circuit (10) and being arranged along the oil circuit (10) downstream of the variable speed pumps (61, 62) and upstream of the lubrification oil inlet of the at least one rotating equipment, and wherein the integrated oil pressure control and pumping system (70) is configured to control the pressure of the oil In the oil circuit (10) by operating the variable speed pumps (61, 62) according to the measured value of pressure, wherein the at least two variable speed pumps (61, 62) comprise at least one main variable speed pump (61) and at least one auxiliary variable speed pump (62).

6. The lubrification system of claim 5, wherein the pressure measurement device (51) is arranged at the lubrification oil inlet of the at least one rotating equipment.

7. The lubrification system of one or more of claims 5-6, wherein the main variable speed pump (61) and the auxiliary variable speed pump (62) are driven by respective variable frequency drive motors (63, 64).

8. The lubnfication system of claim 7, wherein an inverter is provided for each variable frequency drive motors (63, 64) and the inverter is arranged on the variable frequency drive motors (63, 64).

9. The lubrification system of claim 7 or 8, wherein at least the variable frequency drive motor (64) of the auxiliary variable speed pump (62) is connected to auxiliary energy sources.

10. The lubrification system of claim 9, wherein the auxiliary energy sources comprise batteries or an engine generator.

11. The lubrification system of one or more of the claims 5-10, wherein the oil filtration system (30) is arranged upstream of the oil cooling system (40).

12. The lubrification system of claim 11, wherein the oil filtration system (30) comprises a duplex oil filter.

13. The lubrification system of claim 11 or 12, wherein the oil cooling system (30) comprises a plate cooler.

14. The lubrification system of claim 13, wherein the plate cooler is a single plate cooler.

15. The lubrification system of one or more of claims 5-14, wherein the oil filtration system (30), the oil cooling system (40) and the integrated oil pressure control and pumping system (70) are arranged on a common baseplate (100), the oil tank (20) being arranged external to the baseplate (100).

16. The lubrification system of claim 15, wherein the oil tank (20) is arranged in line with the baseplate (100).

17. The lubrification system of claim 15 or 16, wherein the oil tank (20) is cylindrical and is arranged horizontally.

18. The lubrification system of claim 17, wherein the oil tank (20) is supported by two or more saddles (21).

19. The lubrification system of one or more of claims 5-18, wherein therotating machine is chosen amongst a steam turbine, a gas turbine, a supercritical oxy combustion expander.

20. Use of the lubrification system of any of claims 5-19 in an industrial plant.

21. Use of the lubrification system of any of claims 5-19 in a power plant.

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