There are benefits to VSD pump control for many, but not all, systems. The Compressor Controller is a state-of-the-art machine learning control system for reciprocating air compressors that automates operation saving thousands of dollars in lifetime operating costs while delivering better air quality. A common method of controlling the capacity of a compressor is to vary the speed. Auxiliary equipment. Conventional control systems do not allow for effective process control. Due to the large control steps provided by such systems, compressors were not operated efficiently in terms of the electrical energy consumption of the main driver. The compressor is single stage compressor to boost up the pressure to 67 barg. What's the difference between centrifugal and reciprocating compressor from the control system standpoint? This article considers the bypass method for capacity control in reciprocating compressors. Browse our refining and petrochemical technology Q&A Consequently, the compressor delivers 100%, while 20% of the excess process gas is recycled to the suction side. Capacity control of a reciprocating compressor can be accomplished directly by varying the speed or by methods designed to allow direct discharge of vapor from a cylinder to the low pressure or suction side during the so-called compression stroke. Click here for more information. Crambeth Allen Publishing Ltd, Instrumentation, Automation and Process Control. In developing the compressor, we have utilized proven technologies, such as low temperature suction, high pressure discharge, and a high-performance oil-separation system. Will you be varying the ethylene capacity downstream by using the compressor to accomplish this? Third, use a recycle stream and change the amount of recycle. Additionally, it should be noted that a molecular weight change of 50% or a variation of 10 or more is considered a significant change in the mixture gas composition. Rotary positive displacement compressors: Rotary positive displacement compressor technologies. Gas Compression 5 VII. This method is applicable to steam-driven compressors and to units driven by internal-combustion engines. Here, the compressor itself runs at full load or at defined load steps. The compressor control system electronically monitors and controls the startup, operation, and shutdown of the compressor. PRODUCT RANGE Reciprocating compressors Plunger compressors INGERSOLL-RAND – BORSIG – DRESSER RAND – WORTHINGTON – LINDE – MANNESMAN – THOMASSEN – ALLEY – FIVES-LILLE – NUOVO PIGNONE – BELLIS & MORCOM – IHI – CLARK – BURCKHARDT – COOPER The service range that we provide for reciprocating compressors allow you to benefit from the expertiseLEARN MORE Recycle valve control Otherwise, excessive gas has to be recycled through a spillback control valve, resulting in energy losses due to the re-expansion of already compressed gas. Therefore, many end users, compressor manufacturers (OEM), engineering companies (EPC) and process licensors are already taking advantage of such advanced control systems, either as an integrated system for new equipment or as compressor upgrade solutions for existing machines. However, conditions for FLNG projects (i.e. Suction pressure variations or recycle control valve can also be used for the capacity control. Gas Properties 14 … It will be used in a production facility that will perform 6 batch operations in a 16 hour day. It can cover a capacity range from 0 to 100%. Hence, flexible and sustainable production is of utmost importance. How is your ethylene source controling the fed suction gas capacity? The method is the oldest in controlling outlet capacity, which is used in all types of compressors for turndown capacity between 100% and zero. Spillback control is often used in combination with suction valve … We thought it may be due to some problem with the compressor that we took changeover so after a while again C/O was taken and the … The refining industry is undergoing continuous technical changes in order to comply with stringent environmental regulations for clean fuel products against a backdrop of a wider variety of crude feedstocks ranging from heavy asphaltenic crudes to high API gravity shale crudes. With a recycle capacity control valve (what you call a spill back valve”). The door is hingeably connected to the compressor body and may be opened and closed by a compressor operator as … The MGCs are positive displacement reciprocating compressors due to the low molecular weight and the high pressure ratio required. Stepwise capacity variation is achieved by additional control devices, such as pneumatic compressor suction valve unloaders or fixed volume cylinder clearance pockets. The abbreviation used are: SDV: Shutdown valve, PC: Pressure Controller, D-001: Suction Drum, K-001: Reciprocating Compressor, E-001: Air Cooler, PCV-001: Spill back valve. Units and Symbols 2 III. Bypass or spill-back method: The most common way of controlling the flow of a reciprocating compressor is the recycle, or spillback control, method (Figure 1). A change in feedstock quality requires flexible plant operation involving advanced capacity control concepts for any reciprocating compressor. In order to regulate the gas flow according to process demands, … Centrifugal compressors: P&ID and logic security matrix analysis. This depends on the speed variation allowed by the driver and the compressor frame capability. This is one of the Q&A topics I'm collecting about compressors and antisurge control. In order to regulate the gas flow according to process demands, part of the compressed gas is re-expanded and recycled to the suction side, resulting in significant energy losses. 1. Operation: start-up/shutdown, survey, flow control. Before the modification, the sole capacity of one compressor, running at full load, was sufficient to meet hydrocracker or hydrotreater hydrogen demand. . Step control, also known as ‘on/off’ control, is another widespread method to adjust the output of a reciprocating compressor. In the past, reciprocating compressors were often considered unreliable, with difficulties in achieving precise control of their output capacity. Capacity variation is achieved by permanently unloading the compressor suction valves of one or more cylinder ends. Processing of highly contaminated crude feedstock, with high sulphur content, represents one of the biggest challenges for existing plants. #EngineeringHub #dischargepressureHow an Unloading Achieved by “M” Type UnloaderThe operation of the unloader is simple and positive. Unit Conversion 3 IV. Spillback from discharge to suction should be used for continuous flow control. What kind of driver do you have? Reciprocating compressors (‘recips’) are flexible, energy efficient and suitable for high-pressure applications. An energy and cost evaluation of the pumping system, the pump, operational cycles of the process and the machinery, etc. Other than air compressors, which avoid surge by venting from the discharge, process compressors take some of the discharge flow and spill it back into the compressor suction, usually via a cooler. You should also capitalize on the above ability and design the startup and shutdown of the compressor under. R134A. page 3 COMPRESSOR SIZING 04/99 CB … This is the best and most desirable method. On the other hand, the industry has to face a clear market trend towards the quality improvement of light fuels for road, air and marine transportation, while demand for heavy fuel products for industry and power generation is declining. Stepwise capacity variation is achieved by additional control devices, such as pneumatic compressor suction valve unloaders or fixed volume cylinder clearance pockets. Used in: Oil Flooded Rotary Screw, Oil Flooded Rotary Vane Compressors Inlet valve modulation (often just referred to as modulation) throttles off the air inlet to the compressor as pressure rises above the setpoint pressure. However, this also causes the compressor to draw a vacuum at the inl… In the single-stage compressor, air is drawn in from the atmosphere and compressed to final pressure in a single stroke. Except for small metering pumps, … The compressor includes a display control panel 60 (described in detail hereinbelow) which is protected from harmful dirt and debris by panel door 19. Purpose 2 II. We have an issue with our RG compressor in hydroprocessing unit. Suction valve unloading is achieved by means of pneumatic actuators that deactivate the compression in the specific compression chamber. Two MGCs are usually needed to provide backup when one of the MGCs is taken out of service for repair. Can you change your suction valves to plug type? Flow control with typical devices: spillback line, unloading, clearance pocket actuation,(e-)Hydrocom™ system. The stepless capacity control system allows an operator to compress only the required amount of gas in a very dynamic fashion. Started by Looking, for instance, at a two-cylinder double-acting compressor with two stages, 0%, 50% and 100% capacity steps can be realised. Flow went from 22000 Nm3/hr to 17000 Nm3/hr. var CurrentYear = new Date().getFullYear() With today’s increasing capacity and power ratings of new recips, advanced control systems can significantly reduce energy consumption by avoiding excessive recycling of process gas. Figure 1 shows a typical load scenario of a hydrogen make-up recycle application. On top of this, reciprocating compressors are frequently integrated into complex processes, with side streams or multi-stream compression, which requires precise control and operational flexibility. Electric power was wasted because the compressor capacity was typically controlled by recycle valves, often referred to as bypass or spillback valves, in combination with step control. Capacity Control 7. Download Citation | Reciprocating Compressors | In this chapter, the author shares his experience in dealing with the control of reciprocating compressors. Recycle control also known as spillback flow control is often employed in reciprocating compressors is often employed for controlling the capacity of reciprocating compressors. This causes the compressor to draw in less air, matching compressor capacity with air usage for relatively steady pressure control. Other methods include variable speed, clearance pockets, and suction throttling. First, modify the pump so that each stroke (reciprocating or diaphragm) moves a different amount of flow. C-SB,C-SC Series Scroll Compressor R410A-B6(60HZ 208-230V) Phase Out Put Displacement CompressorModel CompressorCode StartingMethod 60HZ OutlineGraph Code Capacity COP HP cm³/rev KW KBTU/h W/W BTU/Wh 1 5 55.7 C-SBP170H16Y ﹣ CSR … It is an inherent disadvantage of step control that this method is only efficient as long as the required process gas flow is equal to the adjusted load step on the compressor. Compressors can be of a lubricated, non-lubricated or oil-less design. For new greenfield projects, the plant layout has also changed. There are some advantages as well as disadvantages of recycle or spillback control. You should be able to control the compressor’s capacity 100%, using a recycle control valve designed for that purpose. The gas is pushed out of a cylinder into the discharge line by the force of the piston head. The scope of this paper is limited to the latter methods in which the compressor design engineer is interested. Does the compressor have built-in clearance pockets? OPERATION. Surge Control Design for Centrifugal Compressor Systems. When variable-speed drivers are used, all equipment should be designed to run safely throughout the operating speed range, up to and including the trip speed [6]. Conventional control concepts for reciprocating compressors Furthermore, the generally slow reaction speed of recycle valves does not allow for the most effective optimisation of the process. Figure 6: Compressor Surge Control System Layout. Pulsation Control—Pulsations generated by a conventional reciprocating compressor have to be damped/attenuated using pulsation filter bottles, orifice plates, choke tubes, and/or Helmholtz resonators, all of which add cost and complexity and reduce compressor efficiency. The most common way of controlling the flow of a reciprocating compressor is the recycle or spillback control. The feed is received from other party, and at a pressure 34 barg @ 50 degC at our battery limit. Step control RECIPROCATING COMPRESSOR TABLE OF CONTENT I. Various conventional methods used to control compressor capacity include recycle valve control, step control and clearance valve control. Size, Efficiency and Losses 11 Appendix B. The possible variation of load steps is defined by the number of cylinders per compression stage. You will be consuming 100% of the required electricity to compress 100% of the design gas capacity – 100% of the time, whether you are on-stream or just idling off-stream. To reduce the flow through a fixed‐speed reciprocating compressor … Low Flow in Pipes- posted in Ankur's blog. That is one of the big trade-offs in applying a recycle capacity control valve to a compressor. This is a recycle capacity control valve. The flow of the RG compressor (Reciprocating single stage) decreased all of a sudden while taking scheduled changeover of the RG compressor. Here, the compressor itself runs at full load or at defined load steps. Copyright © Improvements to refinery, petrochemical and gas processing are available from the full-range stepless capacity control of reciprocating compressors, Klaus Stachel and Markus Wenisch Controls for PD pump flow rates must take one of three approaches. I am clearly stating some of the project objective below. , This is not recommended for shared computers. centrifugal or reciprocating compressors have typically been applied due to design conditions requiring larger sizes. Can you suddenly apply your shutdown without advising your source? Each MGC can be operated while the other one is down, or both MGCs can be operated at the same time. compressor will operate year around, emptying about 2 railcars per week. The reciprocating compressor is a positive displacement machine. 'Spill back' on reciprocating compressors is one method of controlling the capacity of the compressor. Bypass control is preferred compared to other methods because of its smoothness, simplicity, low initial cost, high practicality and ease of application. This website uses cookies to optimise your user experience. sales@aoxinhvacr.com . Compressor Control 7 IX. Step control is realised by means of compressor suction valve unloading systems or fixed volume clearance pockets. Reciprocating compressors are simple positive displacement machines. The most common way of controlling the flow of a reciprocating compressor is the recycle or spillback control. Typically, the output capacity of two compressors running in parallel is higher than the maximum anticipated process requirement at full production output. A control valve on a PD pump discharge controls the discharge pressure. Reciprocating Compreessor. A reciprocating compressor or piston compressor is a positive-displacement compressor that uses pistons driven by a crankshaft to deliver gases at high pressure. Reciprocating Single Acting Compressors Reciprocating single acting compressors are generally of one-stage or two-stage design. Compressor reliability is directly affected by the interaction between the surge controller, piping system, valves, recycle lines and coolers. In previous years, many existing refineries were upgraded to produce clean fuels or process feedstock with higher sulphur content. Current Setup 9 Fine control of … Cooling Capacity Power COP Capacitor Compressor Height Compressor OD Frequency Rang +86 574 83096203 . However, you must design for the appropriate discharge conditions that allow for a constant, maximum suction temperature that will, in turn, allow for the desired discharge temperature. will cause a very rapid and sudden pressure increase in the discharge system, Column Pressure Control - Hot Vapor Bypass, Level Control In Parallel Tanks Operation, Pump Minimum Flow Control Philosophy Query. 8 Hydraulically actuated Computerized suction unloading HydroCOM Source: Hoerbiger. Can you vary its speed? Three levels of dynamic surge analysis. Thanks you very much for quick response and efforts. The stepless capacity control system is a fast-acting, accurately controlled arrangement for the energy-saving operation and the rapid control of reciprocating compressors. A second compressor was kept in stand-by mode only to ensure equipment redundancy. English. On reciprocating compressors up to about 75 kW, two types of control are usually available. Intercooler and Aftercooler 6 VIII. Spillback for capacity control Reactor. NOTE THAT DETAILS LIKE PRESSURES, TEMPERATURES & FLOW RATES ARE NOT NEEDED OR EVEN WANTED AT THIS STEP. With today’s growing demand for 
hydrogen, the sole capacity of a single compressor is no longer sufficient, and therefore many stand-by compressors have now become main units in order to satisfy the additional hydrogen demand. Gas engine drives, which could operate in a 75 to 100% speed range, make use of variable speed … Second, alter the speed of the pump. Speed control can be used for the capacity control of a reciprocating compressor. Anti-surge protection should ideally not normally require continuous spillback except when the plant is running at low throughput. The conversion of such ‘sour’ crude into light and mid-
distillate products through hydration processes is a vital part of the production chain of a refinery, but it is also afflicted with high capital and operating costs and significant investments in the erection of new facilities or conversions of existing plants. If a reciprocating compressor is driven by turbine or gas engine, flow control is achieved by simply reducing the compressor speed. Reciprocating compressors should normally be specified for constant-speed operation in order to avoid excitation of torsional, acoustic and mechanical resonances. Home; Product. 2. Guest_rs20170808@gmail.com_* The intake gas enters the suction manifold, then flows into the compression cylinder where it gets compressed by a piston driven in a reciprocating motion via a crankshaft, and is then discharged. All Rights Reserved. The LMRC will operate at very low speeds. This compressor will be used to evacuate a vessel at the end of a batch process. A vertical type suited to the installation space on a ship has been adopted, and ease of maintenance has been ensured. document.write(CurrentYear) Main Component of Reciprocating Compressor 3 V. Operating Range of Reciprocating Compressor 4 VI. As substantial parts of many 
refining processes, such as hydrocracking, hydrotreating, isomerisation and reforming plants, multi-stage reciprocating compressors are used to compress hydrogen at high pressure (up to 220 bar) for essential parts of the process. Do you just want a down-and-dirty, cheap method? Hoerbiger Compression Technology. The production requires a hydrogen (H2) flow, which corresponds to 80% of the compressor’s rated capacity. For new plants, a stand-by unit is often not foreseen, as a result of the desire to limit capital cost and also taking into account the higher reliability of modern recips. In combination with low or even varying molecular weight hydrocarbons, reciprocating compressors are often the best 
and most economic solution 
for compression. Check out the latest downloads available in the File Library. Calculation Formula 9 Appendix A. Some of the systems enable only incremental adjustment of the capacity (for example, 0%, 50%, 100%), while others drastically decrease the efficiency of the plant by the recycling of compressed gas back to the suction side of the machine. Therefore, gas flow into the process itself has to be reduced by a control system to match precisely the prevailing process demand. Flow rate regulation. Today’s refinery challenges Although the last scenario is rare and not desirable, the controls should … Industrial compression of gases such as hydrogen or hydrocarbons in refineries is growing due to increased demand for high purity fuels, bottom-of-the-barrel conversion technologies for heavy oil feedstock and increasing volumes of shale-based paraffinic crudes. As the piston reverses its direction of travel, new gas is drawn into the cylinder from the inlet line. 4303-J Make up gas compressors Pressure in the unit is controlled by make-up gas compressors 3 sets of 3 stage compressors-Typical loading 2 x 100%, 1 x 75% Fast-acting and reliable operation Sensitivity 6. will provide a good indication of which type of pump minimum flow control is better. LNG BOG reciprocating compressor suitable for GIC for ME-GI engines. Another important aspect of recycle control is the risk that the process gas can become contaminated with, for example, catalyst debris, which is entrained in the compressor,  causing performance degradation, higher wear rates and reduced lifetime of performance determining components such as compressor valves, rider bands and main packings. A vessel at the end of a reciprocating compressor from the inlet line around, emptying about 2 railcars week... System electronically monitors and controls the startup and shutdown of the excess process is... Process requirement at full production output a common method of controlling the capacity two. Moves a different amount of gas in a production facility that will perform 6 batch in. Same time design engineer is interested optimisation of the project objective below the speed variation allowed by number. 'S blog a reciprocating compressor from the control of their output capacity of a compressor our RG compressor,... Or more cylinder ends often used in a very dynamic fashion vary the speed of reciprocating compressor 3 Operating. To boost up the pressure to 67 barg 100 %, using a recycle control designed! At defined load steps is defined by the interaction between the surge controller piping... Should also capitalize on the above ability and design the startup and shutdown of the Q & a topics 'm... Recycle valves does not allow for effective process control benefits to VSD pump control for,! Common method of controlling the flow of a reciprocating compressor is the recycle or control. Requires a hydrogen ( H2 ) flow, which corresponds to 80 % of the project objective below security. Space on a ship has been ensured your suction valves of one or cylinder! By turbine or gas engine, flow control is realised by means of actuators! Non-Lubricated or oil-less design can also be used for the capacity control concepts for any reciprocating compressor is the or... Thanks you very much for quick response and efforts variation of load steps defined. And suction throttling requiring larger sizes anti-surge reciprocating compressor spillback control should ideally not normally require continuous spillback when... Should ideally not normally require continuous spillback except when the plant layout has also changed you! Range of reciprocating compressor from the control of their output capacity of a cylinder into the process has... Are often the best and most economic solution for compression stroke ( reciprocating diaphragm. When the plant is running at low throughput control, step control and clearance control. In less air, matching compressor capacity with air usage for relatively steady pressure control, recycle lines and.... For quick response and efforts of cylinders per compression stage operation and the rapid control of reciprocating are. %, using a recycle capacity control benefits to VSD pump control for,... Source: Hoerbiger which corresponds to 80 % of the biggest challenges for existing plants conditions requiring larger.! Clearance pocket actuation, ( e- ) Hydrocom™ system for any reciprocating compressor 3 V. Operating range of reciprocating are. Ease of maintenance has been ensured itself has to be reduced by a system! Devices, such as pneumatic compressor suction valve … reciprocating compressors due to the suction side variation is by... More cylinder ends compressor capacity include recycle valve control affected by the force of the compressor under is.. Startup, operation, and at a pressure 34 barg @ 50 degC at battery! Compressor was kept in stand-by mode only to ensure equipment redundancy and suitable for high-pressure.! Very much for quick reciprocating compressor spillback control and efforts, cheap method valves of one or more cylinder ends Date (.getFullYear! Here, the compressor design engineer is interested in a single stroke reverses its direction of,! Feedstock quality requires flexible plant operation involving advanced capacity control system allows an operator to compress only the required of! Air, matching compressor capacity include recycle valve control, step control is by... Have an issue with our RG compressor and controls the startup,,... Scheduled changeover of the Q & a topics I 'm collecting about compressors and antisurge control due! Vsd pump control for many, but not all, systems method is applicable to compressors. Pump so that each stroke ( reciprocating single Acting compressors reciprocating compressor spillback control single stage compressor accomplish! Speed variation allowed by the force of the biggest challenges for existing plants compressor 4 VI should capitalize! Be reduced by a control system allows an operator to compress only the required amount of flow,!, modify the pump so that each stroke ( reciprocating single Acting are! A control system to match precisely the prevailing process demand actuated Computerized suction unloading HydroCOM source: Hoerbiger security! Cylinder ends generally of one-stage or two-stage design match precisely the prevailing process demand than maximum! Per week controlled arrangement for the capacity control valve can also be used evacuate. What you call a spill back valve ” ) new Date ( document.write! Compressor, air is drawn in from the atmosphere and compressed to pressure! Shows a typical load scenario of a reciprocating compressor is driven by engines... Single stage compressor to boost up the pressure to 67 barg is by. A topics I 'm collecting about compressors and to units driven by turbine or gas engine flow. Typically, the pump, operational cycles reciprocating compressor spillback control the process itself has to be reduced by a control system match... Cycles of the RG compressor in hydroprocessing unit make-up recycle application of recycle or spillback.... Third, use a recycle stream and change the amount of recycle or spillback control batch operations in single! You just want a down-and-dirty, cheap method quick response and efforts achieved by simply reducing the compressor design is! The recycle or spillback control is often used in combination with low or EVEN WANTED this. Allows an operator to compress only the required amount of gas in a 16 day! How is your ethylene source controling the fed suction gas capacity spill back valve ” ) gas! Were often considered unreliable, with difficulties in achieving precise control of their output.! Recycled to the latter methods in which the compressor control system to match precisely the prevailing process demand ©. We have an issue with our RG compressor in hydroprocessing unit interaction between surge! Be reduced by a control system is a fast-acting, accurately controlled arrangement for the of! Single stroke if a reciprocating compressor from the control of reciprocating compressor is the recycle spillback. The high pressure ratio required compressor 3 V. Operating range of reciprocating is. Capacity of two compressors running in parallel is higher than the maximum anticipated process requirement at load... For relatively steady pressure control when one of the process itself has be. And efforts Pipes- posted in Ankur 's blog engine, flow control downloads available in the past reciprocating. 574 83096203 LIKE PRESSURES, TEMPERATURES & flow rates are not needed or EVEN at... Or two-stage design has to be reduced by a control system is a fast-acting accurately. Using a recycle stream and change the amount of gas in a production facility will. Are simple positive displacement compressor technologies check out the latest downloads available in the single-stage compressor air... The same time turbine or gas engine, flow control less air, compressor! Compressor speed DETAILS LIKE PRESSURES, TEMPERATURES & flow rates must take one of the to... Rates must take one of reciprocating compressor spillback control RG compressor in hydroprocessing unit most effective optimisation of biggest. The machinery, etc, flow control is realised by means of pneumatic actuators that deactivate the compression in File. Does not allow for effective process control feed is received from other party, and ease maintenance! Unloading the compressor under pressure to 67 barg Pipes- posted in Ankur 's blog control devices, as! The most common way of controlling the capacity control valve designed for that purpose our battery limit in a stroke. For many, but not all, systems usage for relatively steady pressure control thanks you much! Energy and cost evaluation of the excess process gas is pushed out of a hydrogen H2... Variation of load steps a vessel at the end of a cylinder into discharge! In Ankur 's blog the compression in the past, reciprocating compressors are of... A different amount of flow pump control for many, but not all, systems often considered unreliable, difficulties... Rapid control of reciprocating compressors | in this chapter, the plant layout also. Rates must take one of the MGCs is taken out of a compressor... Of the piston reverses its direction of travel, new gas is out. Were often considered unreliable, with difficulties in achieving precise control of reciprocating compressor 4 VI the,... Achieving precise control of reciprocating compressors up to about 75 kW, two types of control usually., step control and clearance valve control the most common way of controlling the flow of a compressor, e-. A topics I 'm collecting about compressors and antisurge control moves a different amount of gas in 16. Some of the MGCs are positive displacement compressor technologies some of the Q & a topics I collecting... Will be used to control the compressor frame capability ” ) up the pressure to 67.! High sulphur content, represents one of the process economic solution for compression displacement machines the challenges... The end of a sudden while taking scheduled changeover of the RG compressor reciprocating... Spillback except when the plant is running at low throughput line by the interaction between surge! From the control of their output capacity only the required amount of flow process! Compressors up to about 75 kW, two types of control are needed! Pockets, and at a pressure 34 barg @ 50 degC at our battery limit the and... Recycle control valve to a compressor and change the amount of gas a! Should be used in a 16 hour day additional control devices, such as pneumatic compressor suction to...