THROTTLE VALVE FOR COOLANT CIRCULATION SYSTEM

A fluid compressor system configured to supply a compressed working fluid including at least a first air-end and a second air-end, a first and second intercooler, and a coolant circulation system having at least one throttle valve. The first and second intercoolers are configured to cool the compressed working fluid delivered by the first and second air-ends of the fluid compressor system, respectively. The coolant circulation system includes a coolant supplying header and a coolant collecting header, where the coolant supplying header supplies a coolant to the first intercooler and the second intercooler, and the coolant collecting header collects the coolant from the first intercooler and the second intercooler. The at least one throttle valve regulates a coolant flow discharged by one of the first intercooler or the second intercooler prior to entering the coolant collecting header.

BACKGROUND

Compressors increase the pressure of a compressible fluid (e.g., air, gas, etc.) by reducing the volume of the fluid. Often, compressors are staged so that the fluid is compressed several times in different stages, to further increase the discharge pressure of the fluid. As the pressure of the fluid increases, the temperature of the fluid also increases. Consequently, in some compressors, the compressed fluid may be cooled between stages.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of the subject matter, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the subject matter is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the subject matter as described herein are contemplated as would normally occur to one skilled in the art to which the subject matter relates.

Overview

Fluid compressor systems are widely used in a variety of industries such as in construction, manufacturing, agriculture, energy production, etc. As fluid compressors compress a working fluid, heat is produced as a result of the pressure increase in the working fluid. Fluid compressors can have more than one compressor stage by having more than one air-end, where the working fluid is compressed several times in steps, or stages, to increase the discharge pressure. The second stage may be physically smaller than the primary stage, to accommodate the already compressed gas without reducing its pressure.

As each air-end on each stage further compresses the working fluid, it increases its pressure and its temperature. Intercoolers and aftercoolers are heat exchangers used to cool the working fluid after being compressed in each air-end. Heat exchangers include but are not limited to shell and tube heat exchangers, extended fin heat exchangers, double-pipe heat exchangers, helical-coil heat exchangers, and waste heat recovery units among others. Types of shell and tube heat exchangers include but are not limited to fixed tube sheet heat exchangers, U-tube heat exchangers, floating head heat exchangers, among others.

Intercoolers may accumulate dirt and debris build up over time, which may cause partial or total clogging of tubes within the intercoolers. As a consequence, the intercoolers do not run at their maximum efficiency and the temperature of the working fluid may be higher than desired prior to entering the next compression stage or air-end. Users may modulate water/coolant flow to the cooler in a way to lower the discharge temperature at each compression stage.

The present disclosure is directed to a fluid compression system having at least two compression stages, in other words, at least a first air-end and a second air-end, configured to compress a working fluid. The fluid compression system includes a first intercooler, a second intercooler, and an aftercooler configured to reduce the temperature of the working fluid after the working fluid is compressed by the first and second air-ends at each of the two compression stages, and a coolant circulation system having at least one throttle valve that regulates the flow of a coolant flowing through the coolant circulation system. The throttle valve modulates the coolant flow of the coolant circulation system to lower a desired air-end temperature of the fluid compression system.

The throttle valve for the coolant circulation system can be used with any type of device having a cooler or heat exchanger and should not be limited to the illustrative fluid compressor system shown in any of the accompanying figures. The term “working fluid” should be understood to include any compressible fluid medium that can be used in the fluid compressor system as disclosed herein. It should be understood that air is a typical working fluid, but different fluids or mixtures of fluid constituents can be used and remain within the teaching of the present disclosure. Therefore, terms such as working fluid, air, compressible gas, etc. can be used interchangeably in the present disclosure. For example, in some embodiments it is contemplated that ambient air, a hydrocarbon gaseous fuel including natural gas or propane, or inert gases including nitrogen or argon may be used as a primary working fluid.

The term “coolant” should be understood to include any fluid medium that can be used in the coolant circulation system as disclosed herein, where the fluid is used to reduce or regulate the temperature of the fluid compression system. It should be understood that water is a typical coolant, but different fluids or mixtures of fluid constituents can be used and remain within the teaching of the present disclosure. Therefore, terms such as water, coolant, heat-transfer fluid, refrigerant, etc. can be used interchangeably in the present disclosure. For example, in some embodiments it is contemplated that water, a liquid coolant mixture including water, corrosion inhibitors, and antifreeze, or liquid gases including liquid nitrogen, may be used as a coolant.

Detailed Description of Example Embodiments

Referring generally toFIGS.1through6, a fluid compressor system100is shown. The fluid compressor system100includes a first air-end101, a second air-end102, a third air-end103, a coolant circulation system106having a first intercooler108having a first front end109A, and a second intercooler110having a second front end109B. The coolant circulation system106includes a coolant collecting header112and a coolant supplying header114. In embodiments, the fluid compressor system100further includes an aftercooler118in fluid connection with the coolant circulation system106.

In example embodiments, the fluid compressor system100may include at least one motive source (not shown) driving the first air-end101, the second air-end102, and the third air-end103. An inlet air filter filters an incoming compressible working fluid (e.g., air, gas, etc.) prior to the working fluid entering the first air-end101. The motive source may be operable for driving the first air-end101, the second air-end102, and the third air-end103via a drive shaft. The motive source may be an electric motor, an internal combustion engine, a fluid-driven turbine, or the like.

In the example embodiment shown inFIGS.1through6, the fluid compressor system100has three compression stages. However, in other embodiments, the fluid compression system100may have two compression stages, including a first air-end, a second air-end, and a coolant circulation system having one intercooler and one aftercooler. In other example embodiments, the fluid compressor system100may include more than three compression stages with the corresponding number of air-ends and intercoolers disposed, where the intercoolers are configured to cool a working fluid delivered by each corresponding air-end.

The first air-end101receives the working fluid and compresses the working fluid in a first stage compression process. This first stage compression process also increases the temperature of the working fluid. The first intercooler108is located downstream from the first air-end101and upstream from the second air-end102. The first intercooler108cools down the working fluid delivered by the first air-end101prior to entering the second air-end102. In embodiments, the fluid compressor system100includes a first interstage moisture separator (not shown) to separate moisture from the working fluid prior to entering the second air-end102.

The second air-end102receives the working fluid and further compresses it, increasing its temperature. A second intercooler110receives the compressed working fluid from the second air-end102and cools it down prior to delivering the working fluid to the third air-end103. In embodiments, the fluid compressor system100includes a second interstage moisture separator (not shown) to separate moisture from the working fluid prior to entering the third air-end103.

The third air-end103receives the working fluid and further compresses it, increasing its temperature. An aftercooler118receives the compressed working fluid from the third air-end103and cools it down prior to discharging the compressed working fluid through a discharge outlet or delivering the compressed working fluid to a processing system for further processing.

In example embodiments (not shown) the fluid compressor system includes a temperature monitoring and control system for staged inlet temperatures. The temperature monitoring and control system may include a first air-end temperature sensor, a second air-end temperature sensor, a third air-end temperature sensor, and a fluid compressor system discharge temperature sensor. The first air-end temperature sensor, the second air-end temperature sensor, and the third air-end temperature sensor may each sense a temperature of the working fluid at the discharge of each corresponding compression stage.

With respect toFIG.3, an example embodiment of the coolant circulation system106is shown. The coolant circulation system106circulates a coolant to the first intercooler108, the second intercooler110, and the aftercooler118. However, in embodiments having more than three compression stages, the coolant circulation system106circulates through each one of the respective intercoolers and aftercoolers of the fluid compression system100.

The coolant circulation system106includes a coolant supplying header114and a coolant collecting header112. The coolant supplying header114includes a main coolant supplying pipeline113that supplies a coolant flow to a first coolant inlet120A at the first front end109A of the first intercooler108, a second coolant inlet120B at the second front end109B of the second intercooler110, and a third coolant inlet120C of the aftercooler118. The coolant supplying header114connects the first intercooler108, the second intercooler110, and the aftercooler118in parallel with each other.

The coolant collecting header112includes a main coolant collecting pipeline111that aggregates the coolant flow exiting each one of the first intercooler108, the second intercooler110, and the aftercooler118. The main coolant collecting header112is connected to a first coolant outlet122A of the first intercooler108, a second coolant outlet122B of the second intercooler110, and a third coolant outlet122C of the aftercooler118. The coolant collecting header112connects the first intercooler108, the second intercooler110, and the aftercooler118in parallel with each other.

The flow of coolant within the coolant circulation system106may be driven by a pump (not shown). As shown, the coolant flow circulating in the coolant supplying header114is split into a first flow stream, a second flow stream, and a third flow stream. The first flow stream passes into the first intercooler108, where the working fluid delivered by the first air-end101is cooled. After splitting from the first flow stream, the second flow stream is directed to the second intercooler110, where the working fluid delivered by the second air-end102is cooled. After splitting from the second flow stream, the third flow stream is directed to the aftercooler118, where the working fluid delivered by the third air-end103is cooled. The first flow stream, second flow stream, and third flow stream merge back together into the same coolant flow stream in the coolant collecting header112after the heat exchanging process at each respective one of the first intercooler108, the second intercooler110and the aftercooler118.

Referring toFIGS.1and4, a first throttle valve130A is mounted to the first front end109A of the first intercooler108. The first throttle valve130A regulates the coolant flow discharged by the first coolant outlet122A prior to being collected into the coolant collecting header112. A second throttle valve130B is mounted to the second front end109B of the second intercooler110. The second throttle valve130B regulates the coolant flow discharged by the second coolant outlet122B prior to being collected into the coolant collecting header112.

In the embodiment shown inFIG.5, the first throttle valve130A includes valve body132A, a bonnet134A, a seating element136A (e.g., plug, disk, etc.), a stem138A, a cage140A, a seat142A, and a handwheel144A. The handwheel144A may be rotated between an open position and a closed position, with a definite number of positions between the open position and the closed position. At the open position shown inFIG.5, the coolant flow is free to exit the first intercooler108into the coolant collecting header112through the first coolant outlet122A. As the handwheel144A is rotated, the stem138A is threaded into the bonnet134A and the seating element136A starts restricting the coolant flow exiting the first intercooler108. In the fully closed position (not shown), the seating element136A is fully seated into the seat142A, and the first coolant outlet122A is fully shutoff. The first throttle valve130A adjusts the rate at which the coolant flows out of the first intercooler108back into the coolant collecting header112of the coolant circulation system106. It should be understood that the second throttle valve130B includes a respective one of each of the same components of the first throttle valve130A. In embodiments, the first throttle valve130A and the second throttle valve130B are globe valves. In other embodiments, the first throttle valve130A and the second throttle valve130B may be ball valves, gate valves, butterfly valves, needle valves, pinch valves, diaphragm valves, among others.

The first throttle valve130A and the second throttle valve130B help the fluid compressor system100run at a higher efficiency and may help a user to direct the coolant flow in an efficient way. For example, by being able to regulate the coolant flow exiting the first intercooler108and/or the second intercooler110, the coolant flow from the first intercooler108and/or the second intercooler110may be restricted and directed to another element of the coolant circulation system106that may require a higher coolant flow to operate.

In embodiments, if one of the air-end temperature sensors of the temperature monitoring and control system senses that an inlet or outlet temperature from one or more of the air-ends is too high, the coolant flow can be partially restricted from one of the intercoolers and directed to the respective intercoolers that cool the working flow of the mentioned air-ends. For example, if the first intercooler108is discharging the working fluid at a temperature that is higher than a desired predetermined temperature range, a user may fully open the first throttle valve130A and partially close the second throttle valve130B to flow the coolant fluid flow of the first intercooler108at a higher coolant fluid flow rate than the rest of the coolant circulation system106.

In example embodiments (not shown), the first throttle valve130A is connected to the first coolant inlet120A and the second throttle valve130B is connected to the second coolant inlet120B. In such embodiments, the throttle valve regulates the coolant flow supplied by the coolant supplying header114into each one of the first intercooler108and the second intercooler110. In other embodiments (not shown), a third throttle valve may be disposed at the third coolant outlet122C or at the third coolant inlet120C of the aftercooler118.

In example embodiments, the coolant circulation system106is in fluid communication with intercoolers that cool the working fluid of the fluid compressor system100and oil coolers (not shown) that cool an oil flow provided to the compression stages (for example, in contact-cooled air-ends) and other rotating elements of the fluid compressor system. Each of the oil coolers may include a respective coolant inlet in fluid communication with the coolant supplying header and a coolant outlet in fluid communication with the coolant collecting header of the coolant circulation system106.

In the embodiment shown, the first throttle valve130A and the second throttle valve130B are manually operated. However, in other embodiments (not shown), the throttle valves may be automatic throttle valves. For example, the throttle valves may be pneumatic throttle valves, electrical throttle valves, among other automatic throttle valves. The automatic throttle valves may be remotely controlled by a control system or programmed to actuate at specific hours of the day. The control system controlling the first throttle valve130A and the second throttle valve130B may be in communication with the temperature monitoring system monitoring the first air-end temperature sensor, the second air-end temperature sensor, the the third air-end temperature sensor, and the fluid compressor system discharge temperature sensor.

In implementations, the coolant circulating system106may be retrofitted into existing fluid compressor systems and heat exchanger systems. The application of a throttle valve in the coolant circulating system106is not limited to fluid compression systems, as any equipment having a heat exchanging application where a coolant circulation system supplies a coolant flow to several cooling elements may benefit from the increased efficiency as a result of the coolant circulation system having at least one throttle valve. Other applications include, but are not limited to, HVAC systems, refrigeration systems, gas turbines, petrochemical plants, etc.

While the subject matter has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character. In reading the claims, it is intended that when words such as “a,” “an,” or “at least one” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Unless specified or limited otherwise, the terms “mounted,” “connected,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.