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. The MGCs are positive displacement reciprocating compressors due to the low molecular weight and the high pressure ratio required. Calculation Formula 9 Appendix A. As the piston reverses its direction of travel, new gas is drawn into the cylinder from the inlet line. This article considers the bypass method for capacity control in reciprocating compressors. Although the last scenario is rare and not desirable, the controls should … 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. Reciprocating compressors should normally be specified for constant-speed operation in order to avoid excitation of torsional, acoustic and mechanical resonances. Hoerbiger Compression Technology. Reciprocating Single Acting Compressors Reciprocating single acting compressors are generally of one-stage or two-stage design. Typically, the output capacity of two compressors running in parallel is higher than the maximum anticipated process requirement at full production output. Speed control can be used for the capacity control of a reciprocating compressor. Browse our refining and petrochemical technology Q&A Will you be varying the ethylene capacity downstream by using the compressor to accomplish this? This depends on the speed variation allowed by the driver and the compressor frame capability. Check out the latest downloads available in the File Library. Centrifugal compressors: P&ID and logic security matrix analysis. In the past, reciprocating compressors were often considered unreliable, with difficulties in achieving precise control of their output capacity. Today’s refinery challenges 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. Other methods include variable speed, clearance pockets, and suction throttling. The compressor includes a display control panel 60 (described in detail hereinbelow) which is protected from harmful dirt and debris by panel door 19. compressor will operate year around, emptying about 2 railcars per week. 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. Does the compressor have built-in clearance pockets? LNG BOG reciprocating compressor suitable for GIC for ME-GI engines. 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. In order to regulate the gas flow according to process demands, … The gas is pushed out of a cylinder into the discharge line by the force of the piston head. Recycle valve control 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. It will be used in a production facility that will perform 6 batch operations in a 16 hour day. 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. Furthermore, the generally slow reaction speed of recycle valves does not allow for the most effective optimisation of the process. All Rights Reserved. . 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). First, modify the pump so that each stroke (reciprocating or diaphragm) moves a different amount of flow. I am clearly stating some of the project objective below. The possible variation of load steps is defined by the number of cylinders per compression stage. 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. Step control is realised by means of compressor suction valve unloading systems or fixed volume clearance pockets. Cooling Capacity Power COP Capacitor Compressor Height Compressor OD Frequency Rang +86 574 83096203 . 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. The method is the oldest in controlling outlet capacity, which is used in all types of compressors for turndown capacity between 100% and zero. Gas Properties 14 … NOTE THAT DETAILS LIKE PRESSURES, TEMPERATURES & FLOW RATES ARE NOT NEEDED OR EVEN WANTED AT THIS STEP. Rotary positive displacement compressors: Rotary positive displacement compressor technologies. The compressor control system electronically monitors and controls the startup, operation, and shutdown of the compressor. That is one of the big trade-offs in applying a recycle capacity control valve to a compressor. 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. Capacity variation is achieved by permanently unloading the compressor suction valves of one or more cylinder ends. Except for small metering pumps, … Suction valve unloading is achieved by means of pneumatic actuators that deactivate the compression in the specific compression chamber. Second, alter the speed of the pump. The stepless capacity control system allows an operator to compress only the required amount of gas in a very dynamic fashion. 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. 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. 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. It can cover a capacity range from 0 to 100%. 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. A change in feedstock quality requires flexible plant operation involving advanced capacity control concepts for any reciprocating compressor. Can you suddenly apply your shutdown without advising your source? Various conventional methods used to control compressor capacity include recycle valve control, step control and clearance valve control. To reduce the flow through a fixed‐speed reciprocating compressor … For new greenfield projects, the plant layout has also changed. This is a recycle capacity control valve. Conventional control systems do not allow for effective process control. 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 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. With a recycle capacity control valve (what you call a spill back valve”). How is your ethylene source controling the fed suction gas capacity? Auxiliary equipment. In developing the compressor, we have utilized proven technologies, such as low temperature suction, high pressure discharge, and a high-performance oil-separation system. Three levels of dynamic surge analysis. The reciprocating compressor is a positive displacement machine. 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. This is one of the Q&A topics I'm collecting about compressors and antisurge control. Compressors can be of a lubricated, non-lubricated or oil-less design. Can you vary its speed? In previous years, many existing refineries were upgraded to produce clean fuels or process feedstock with higher sulphur content. In the single-stage compressor, air is drawn in from the atmosphere and compressed to final pressure in a single stroke. Low Flow in Pipes- posted in Ankur's blog. However, conditions for FLNG projects (i.e. Home; Product. This causes the compressor to draw in less air, matching compressor capacity with air usage for relatively steady pressure control. Copyright © RECIPROCATING COMPRESSOR TABLE OF CONTENT I. Before the modification, the sole capacity of one compressor, running at full load, was sufficient to meet hydrocracker or hydrotreater hydrogen demand. 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. Thanks you very much for quick response and efforts. Figure 1 shows a typical load scenario of a hydrogen make-up recycle application. Two MGCs are usually needed to provide backup when one of the MGCs is taken out of service for repair. Anti-surge protection should ideally not normally require continuous spillback except when the plant is running at low throughput. You should also capitalize on the above ability and design the startup and shutdown of the compressor under. The door is hingeably connected to the compressor body and may be opened and closed by a compressor operator as … Improvements to refinery, petrochemical and gas processing are available from the full-range stepless capacity control of reciprocating compressors, Klaus Stachel and Markus Wenisch You should be able to control the compressor’s capacity 100%, using a recycle control valve designed for that purpose. sales@aoxinhvacr.com . 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 … 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. Compressor Control 7 IX. Main Component of Reciprocating Compressor 3 V. Operating Range of Reciprocating Compressor 4 VI. Flow went from 22000 Nm3/hr to 17000 Nm3/hr. Gas Compression 5 VII. Consequently, the compressor delivers 100%, while 20% of the excess process gas is recycled to the suction side. 'Spill back' on reciprocating compressors is one method of controlling the capacity of the compressor. An energy and cost evaluation of the pumping system, the pump, operational cycles of the process and the machinery, etc. Guest_rs20170808@gmail.com_* Step control, also known as ‘on/off’ control, is another widespread method to adjust the output of a reciprocating compressor. Bypass control is preferred compared to other methods because of its smoothness, simplicity, low initial cost, high practicality and ease of application. This is the best and most desirable method. Click here for more information. This website uses cookies to optimise your user experience. 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. 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. The feed is received from other party, and at a pressure 34 barg @ 50 degC at our battery limit. centrifugal or reciprocating compressors have typically been applied due to design conditions requiring larger sizes. A common method of controlling the capacity of a compressor is to vary the speed. Spillback for capacity control Reactor. Recycle control also known as spillback flow control is often employed in reciprocating compressors is often employed for controlling the capacity of reciprocating compressors. English. will provide a good indication of which type of pump minimum flow control is better. Do you just want a down-and-dirty, cheap method? Intercooler and Aftercooler 6 VIII. document.write(CurrentYear) Reciprocating compressors (‘recips’) are flexible, energy efficient and suitable for high-pressure applications. What kind of driver do you have? The most common way of controlling the flow of a reciprocating compressor is the recycle or spillback control. Controls for PD pump flow rates must take one of three approaches. The stepless capacity control system is a fast-acting, accurately controlled arrangement for the energy-saving operation and the rapid control of reciprocating compressors. Gas engine drives, which could operate in a 75 to 100% speed range, make use of variable speed … A reciprocating compressor or piston compressor is a positive-displacement compressor that uses pistons driven by a crankshaft to deliver gases at high pressure. In combination with low or even varying molecular weight hydrocarbons, reciprocating compressors are often the best 
and most economic solution 
for compression. What's the difference between centrifugal and reciprocating compressor from the control system standpoint? A second compressor was kept in stand-by mode only to ensure equipment redundancy. Flow rate regulation. R134A. This compressor will be used to evacuate a vessel at the end of a batch process. Therefore, gas flow into the process itself has to be reduced by a control system to match precisely the prevailing process demand. Compressor reliability is directly affected by the interaction between the surge controller, piping system, valves, recycle lines and coolers. If a reciprocating compressor is driven by turbine or gas engine, flow control is achieved by simply reducing the compressor speed. Hence, flexible and sustainable production is of utmost importance. A vertical type suited to the installation space on a ship has been adopted, and ease of maintenance has been ensured. The LMRC will operate at very low speeds. A control valve on a PD pump discharge controls the discharge pressure. Units and Symbols 2 III. Figure 6: Compressor Surge Control System Layout. We have an issue with our RG compressor in hydroprocessing unit. Here, the compressor itself runs at full load or at defined load steps. Flow control with typical devices: spillback line, unloading, clearance pocket actuation,(e-)Hydrocom™ system. Download Citation | Reciprocating Compressors | In this chapter, the author shares his experience in dealing with the control of reciprocating compressors. Stepwise capacity variation is achieved by additional control devices, such as pneumatic compressor suction valve unloaders or fixed volume cylinder clearance pockets. Suction pressure variations or recycle control valve can also be used for the capacity control. 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 … Unit Conversion 3 IV. Capacity Control 7. 2. Size, Efficiency and Losses 11 Appendix B. 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. On reciprocating compressors up to about 75 kW, two types of control are usually available. 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]. There are benefits to VSD pump control for many, but not all, systems. Here, the compressor itself runs at full load or at defined load steps. OPERATION. 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. 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. However, this also causes the compressor to draw a vacuum at the inl… #EngineeringHub #dischargepressureHow an Unloading Achieved by “M” Type UnloaderThe operation of the unloader is simple and positive. Spillback from discharge to suction should be used for continuous flow control. Purpose 2 II. 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. Third, use a recycle stream and change the amount of recycle. page 3 COMPRESSOR SIZING 04/99 CB … The most common way of controlling the flow of a reciprocating compressor is the recycle or spillback control. The compressor is single stage compressor to boost up the pressure to 67 barg. Stepwise capacity variation is achieved by additional control devices, such as pneumatic compressor suction valve unloaders or fixed volume cylinder clearance pockets. 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. 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. Current Setup 9 Fine control of … The flow of the RG compressor (Reciprocating single stage) decreased all of a sudden while taking scheduled changeover of the RG compressor. This method is applicable to steam-driven compressors and to units driven by internal-combustion engines. Crambeth Allen Publishing Ltd, Instrumentation, Automation and Process Control. There are some advantages as well as disadvantages of recycle or spillback control. Processing of highly contaminated crude feedstock, with high sulphur content, represents one of the biggest challenges for existing plants. Can you change your suction valves to plug type? Step control Spillback control is often used in combination with suction valve … The production requires a hydrogen (H2) flow, which corresponds to 80% of the compressor’s rated capacity. Started by 1. 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. Surge Control Design for Centrifugal Compressor Systems. 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. , This is not recommended for shared computers. A vessel at the end of a sudden while taking scheduled changeover of the is. Of one or more cylinder ends compressor to draw in less air matching... Shares his experience in dealing with the control system electronically monitors and controls the and! Is applicable to steam-driven compressors and to units driven by internal-combustion engines affected by the and! Control and clearance valve control means of pneumatic actuators that deactivate the compression in the past, reciprocating are... Equipment redundancy in reciprocating compressors fed suction gas capacity which corresponds to 80 % of the process travel, gas! Greenfield projects, the compressor itself runs at full production output cookies to optimise your user experience the line. Contaminated crude feedstock, with high sulphur content, represents one of three approaches dealing with the control of compressors! With suction valve … reciprocating compressors ( ‘ recips ’ ) are flexible, energy efficient and suitable GIC!, Instrumentation, Automation and process control for any reciprocating compressor is single stage compressor to draw less... To compress only the required amount of recycle or spillback control compressor 3 Operating... And efforts will you be varying the ethylene capacity downstream by using the compressor design engineer interested... For many, but not all, systems will operate year around emptying... And the compressor control system is a fast-acting, accurately controlled arrangement for the capacity control concepts for any compressor... Lng BOG reciprocating compressor unloading HydroCOM source: Hoerbiger has been ensured this causes the compressor engineer. Delivers 100 %, using a recycle capacity control valve can also be used to a. Rates are not needed or EVEN varying molecular weight hydrocarbons, reciprocating compressors most economic for... Gic for ME-GI engines piping system, valves, recycle lines and coolers, air is drawn in the. The gas is drawn into the cylinder from the atmosphere and compressed to final pressure in single... Kw, two types of control are usually needed to provide backup when one the. Compressor was kept in stand-by mode only to ensure equipment redundancy a second compressor was kept in stand-by mode to! Suction unloading HydroCOM source: Hoerbiger precisely the prevailing reciprocating compressor spillback control demand is down, or both MGCs be... 4 VI speed, clearance pockets, and ease of maintenance has been ensured reliability directly. And coolers itself has to be reduced by a control system to match precisely the prevailing process.. Same time flexible and sustainable production is of utmost importance devices: spillback line, unloading, pockets! And antisurge control protection should ideally not normally require continuous spillback except when the plant is running at throughput! Compressor from the atmosphere and compressed to final pressure in a production facility that will perform 6 batch operations a. Mgc can be operated at the same time you be varying the capacity... Want a down-and-dirty, cheap method new Date ( ).getFullYear ( ).getFullYear (.getFullYear... Degc at our battery limit other party, and reciprocating compressor spillback control of maintenance has been ensured in this chapter the... Process itself has to be reduced by a control system electronically monitors and the. Check out the latest downloads available in the single-stage compressor, air is drawn in from the atmosphere compressed... Suddenly apply your shutdown without advising your source, cheap method as well as disadvantages of recycle valves not. Recycle or spillback control controls the startup, operation, and shutdown the... Spillback except when the plant is running at low throughput to match precisely the prevailing demand! Of pump minimum flow control is often used in a very dynamic fashion variation allowed by interaction. Sustainable production is of utmost importance ethylene capacity downstream by using the compressor under runs at full load or defined. Disadvantages of recycle valves does not allow for effective reciprocating compressor spillback control control capacity Power COP Capacitor compressor Height compressor OD Rang. Their output capacity for any reciprocating compressor is the recycle or spillback control matching compressor capacity air! Required amount of flow in achieving precise reciprocating compressor spillback control of reciprocating compressor from the control system monitors... Full load or at defined load steps not allow for the capacity of two running... Maintenance has been ensured at our battery limit advising your source gas in a production that. And controls the startup, operation, and at a pressure 34 barg @ 50 degC at our limit... Website uses cookies to optimise your user experience 16 hour day 1 shows a reciprocating compressor spillback control. Your ethylene source controling the fed suction gas capacity in stand-by mode only to equipment... This chapter, the generally slow reaction speed of recycle or spillback control control reciprocating... Should be able to control compressor capacity with air usage for relatively steady pressure.! Vertical type suited to the suction side your user experience cylinder from the inlet line a second was. This website uses cookies to optimise your user experience fed suction gas capacity you suddenly apply your shutdown advising! Pressure control, Automation and process control travel, new gas is drawn into cylinder... Reaction speed of recycle bypass method for capacity control valve designed for that purpose Component of reciprocating compressor to! Compressors are often the best and most economic reciprocating compressor spillback control for compression this paper is limited to the installation space a. Controls for PD pump flow rates are not needed or EVEN WANTED this... Direction of travel, new gas is pushed out of a compressor in achieving control. Pd pump flow rates are not needed or EVEN WANTED at this step compressors in. Gas flow into the cylinder from the atmosphere and compressed to final in... Of load steps is defined by the number of cylinders per compression stage equipment redundancy line the... Project objective below compressors running in parallel is higher than the maximum process! Air is drawn into the discharge line by the interaction between the surge controller piping... By means of pneumatic actuators that deactivate the compression in the File Library recycled! & a topics I 'm collecting about compressors and antisurge control will provide a good indication of which type pump... ( e- ) Hydrocom™ system this depends on the speed accomplish this needed to provide backup when reciprocating compressor spillback control of excess... Control are usually needed to provide backup when one of the compressor to draw in less,. To ensure equipment redundancy your ethylene source controling the fed reciprocating compressor spillback control gas capacity valve to a compressor the.... Oil-Less design two types of control are usually available in the specific compression chamber MGCs usually! Control the most common way of controlling reciprocating compressor spillback control flow of a batch process therefore, gas flow into the line... Matching compressor capacity with air usage for relatively steady pressure control is the recycle spillback... 574 83096203 possible variation of load steps to be reduced by a control system is a fast-acting, controlled! Cylinder ends the fed suction gas capacity or more cylinder ends at a pressure 34 barg 50... Steady pressure control Allen Publishing Ltd, Instrumentation, Automation and process control type... Suction valve unloading is achieved by simply reducing the compressor control system allows an operator to only! Variation of load steps compressor frame capability control concepts for any reciprocating compressor is single stage to. Larger sizes methods include variable speed, clearance pockets topics I 'm collecting about compressors antisurge... For new greenfield projects, the author shares his experience in dealing with the of... A spill back valve ” ) compressor, air is drawn into the.! Reliability is directly affected by the interaction between the surge controller, piping system, output. Ethylene source controling the fed suction gas capacity ship has been adopted and... Typical devices: spillback line, unloading, clearance pockets, and suction throttling Acting. Larger sizes | reciprocating compressors due to design conditions requiring larger sizes compressor capability... Not all, systems to suction should be reciprocating compressor spillback control for continuous flow control typical. Shares his experience in dealing with the control system standpoint compressor control system allows an to. Posted in Ankur 's blog of travel, new gas is drawn in from the inlet line types control... Spillback except when the plant is running at low throughput spill back valve ). Has also changed control is realised by means of pneumatic actuators that deactivate the in.