Compressed gas cooling apparatus

Abstract

A compressed gas cooling apparatus in which gas from an upstream compression stage enters an inlet section from an inlet opening and flows to a heat exchanger that cools the gas. The cooled gas then flows from the heat exchanger to the outlet section where the gas is discharged from an outlet opening. Pressure drop within the apparatus is decreased by providing the inlet and outlet sections with ever increasing and decreasing cross-sectional flow areas. In order to further decrease pressure drop due to a swirl within the gas flow imparted from the upstream compression stage, the inlet section is provided with first and second subsections wherein the cross-sectional flow area of the first subsection increases at lesser rate than the second subjection. Alternatively, or in addition, the inlet section can be provided with partitions to divide the gas flow into subflows in order to lessen pressure drop from swirl.

We claim: 
     
         1 . A compressed gas cooling apparatus comprising:
 an inlet section having an inlet to receive a gas from an upstream compression stage;   an outlet section having an outlet to discharge the gas, after having been cooled to a downstream compression stage;   a heat exchanger connecting the inlet section to the outlet section and having gas passages communicating between the inlet section and the outlet section for passage of the gas and coolant passages positioned in a heat transfer relationship with the gas passages for passage of a coolant to cool the gas passing through the gas passages through indirect heat exchange with a coolant;   the inlet section comprising a first inlet portion and a second inlet portion, the first inlet portion located between the inlet and the second inlet portion and the second inlet portion located between the first inlet portion and the heat exchanger; and   each of the first inlet portion and the second inlet portion having an ever increasing transverse cross-sectional flow area, the ever increasing transverse cross-sectional flow area of the second inlet portion increasing at a greater rate than the first inlet portion so that the velocity of the flow of the gas gradually decreases as the gas flows through the inlet section to a lesser extent in the first inlet portion than the second inlet portion and separation of the flow of the gas from sidewalls of each of the first inlet portion and the second inlet portion, due to swirl imparted into the flow of the gas from the upstream compression stage, is inhibited to reduce pressure drop; and   the outlet section comprising one outlet portion of ever-decreasing transverse cross-sectional flow area for flow of the gas from the heat exchanger to the outlet such that velocity of the flow of the gas gradually increases to also reduce pressure drop.   
     
     
         2 . The apparatus of  claim 1 , wherein:
 the first inlet portion, the second inlet portion and the one outlet portion are formed by sets of four sidewalls connected to one another such that the ever-increasing transverse cross-sectional flow area and the ever-decreasing transverse cross-sectional flow area are of rectangular configuration;   the heat exchanger has an inlet side, an outlet side located opposite to the inlet side, the cooling passages extend between the inlet side and the outlet side and each of the inlet side and the outlet side is of rectangular configuration;   the inlet section has a third inlet portion having a first transitional transverse cross-sectional flow area transitioning from a circle, at one end, to define the inlet and at the other end, a rectangle, the other end of the third portion in registry with and connected to one of the sets of four sidewalls forming the first inlet portion;   the one outlet portion is a first outlet portion;   the outlet section has a second outlet portion situated such that the first outlet portion is located between the second outlet portion and the heat exchanger, the second outlet portion having a second transitional transverse cross-section flow area transitioning from a circle, at one end, to define the outlet and at the other end, a rectangle; and   the other end of the second outlet portion is in registry with and connected to a further of the sets of four sidewalls forming the first outlet portion.   
     
     
         3 . The apparatus of  claim 2 , wherein
 another of the sets of four sidewalls forming the second inlet portion, at opposite ends, is in registry with and connected to the one of the sets of four sidewalls and the inlet side of the heat exchanger; and   the further of the sets of four sidewalls forming the first outlet portion, at opposite ends, is in registry with and connected to the other end of the second outlet portion and the outlet side of the heat exchanger.   
     
     
         4 . The apparatus of  claim 2 , wherein:
 the first inlet portion is subdivided into a first set of subpassages by a first set of partition elements oriented such that each of the subpassages is of rectangular configuration;   the second inlet portion is subdivided into a second set of subpassages by a second set of partition elements oriented such that each of the subpassages is of rectangular configuration;   the second set of subpassages having more subpassages than the first set of subpassages.   
     
     
         5 . The apparatus of  claim 4 , wherein:
 the first outlet portion is subdivided into a third set of subpassages by a third set of partition elements;   the first set of partition elements, the second set of partition elements and the third set of partition elements are connected to the sidewalls; and   rectangular, frame-like stiffening members are connected to outer surfaces of each of the sets of the four sidewalls.   
     
     
         6 . The apparatus of  claim 4 , wherein the first set of subpassages has four subpassages and the second set of subpassages has twenty-four subpassages. 
     
     
         7 . A compressed gas cooling apparatus comprising:
 an inlet section having an inlet to receive a gas from an upstream compression stage;   an outlet section having an outlet to discharge the gas, after having been cooled to a downstream compression stage;   a heat exchanger connecting the inlet section to the outlet section and having gas passages communicating between the inlet section and the outlet section for passage of the gas and coolant passages positioned in a heat transfer relationship with the gas passages for passage of a coolant to cool the gas passing through the gas passages through indirect heat exchange with a coolant;   the inlet section comprising one portion having at least one sidewall forming an ever-increasing transverse cross-sectional flow area and partition elements subdividing the ever-increasing transverse cross-sectional flow area into a plurality of subpassages, each having ever-increasing transverse cross-sectional sub-flow areas so that velocity of the flow of the gas gradually decreases as the gas flows through the inlet section and the sub-flow areas reduce separation of the flow of the gas from at least one sidewall, due to swirl imparted into the flow of the gas from the upstream compression stage, thereby reducing pressure drop; and   the outlet section comprising an outlet portion of ever-decreasing transverse cross-sectional flow area for flow of the gas from the heat exchanger to the outlet so that the velocity of the flow of the gas gradually increases as the gas flows in the outlet section to also reduce pressure drop.   
     
     
         8 . The apparatus of  claim 7 , wherein:
 the inlet portion and the outlet portion are formed by sets of four sidewalls connected to one another such that the ever-increasing transverse cross-sectional flow area and the ever-decreasing transverse cross-sectional flow area are of rectangular configuration;   the subpassages are each of rectangular configuration;   the heat exchanger has an inlet side, an outlet side located opposite to the inlet side, the cooling passages extend between the inlet side and the outlet side and each of the inlet side and the outlet side is of rectangular configuration;   the at least one sidewall of the inlet portion is one of the sets of four sidewalls;   a further of the sets of four sidewalls form the outlet portion;   the inlet portion is a first inlet portion, the outlet portion is a first outlet portion, the inlet section has a second inlet portion and the outlet section has a second outlet portion;   the second inlet portion has a first transitional transverse cross-sectional flow area transitioning from a circle, at one end, to define the inlet and at the other end, a rectangle, the other end of the first inlet portion in registry with the one of the sets of four sidewalls forming the first inlet portion;   the second outlet portion has a second transitional transverse cross-section flow area transitioning from a circle, at one end, to define the outlet and at the other end, a rectangle; and   the other end of the second outlet portion is in registry with the further of the sets of four sidewalls.   
     
     
         9 . The apparatus of  claim 8 , wherein:
 the one of the sets of four sidewalls forming the first inlet portion is connected to and in registry with the inlet side of the heat exchanger at a location of the inlet section opposite to the second inlet portion; and   the further of the sets of four sidewalls forming the first outlet portion is connected to and in registry with the outlet side of the heat exchanger at a location of the outlet section opposite to the second outlet portion.   
     
     
         10 . The apparatus of  claim 8  wherein:
 the partition elements of the first inlet portion are a first set of partition elements and the subpassages are a first set of subpassages; 
 the first outlet portion has a second set of partition elements that form a third set of subpassages of rectangular configuration; 
 the first set of partition elements and the second set of partition element are connected to the sidewalls; and 
 rectangular, frame-like stiffening members are connected to outer surfaces of each of the sets of the four sidewalls. 
 
     
     
         11 . The apparatus of  claim 2  or  claim 4  or  claim 5  or  claim 8  or  claim 10 , wherein:
 the heat exchanger is of cross-counter flow arrangement; 
 the cooling passages are formed between a plurality of parallel fins oriented at right angles with respect to the inlet side and the outlet side of the heat exchanger; and 
 the cooling passages are formed by coolant tubes that penetrate the parallel fins for circulation of the coolant and are in an orthogonal orientation with respect to the parallel fins. 
 
     
     
         12 . The apparatus of  claim 11 , wherein:
 the coolant tubes comprise a set of inlet coolant tubes a first set of intermediate coolant tubes, a second set of intermediate coolant tubes and a set of outlet coolant tubes arranged to provide four passes within the heat exchanger;   the heat exchanger has two end portions located opposite to one another and two spaced, transversely extending top and bottom panels connecting the end portions and forming the inlet side and the outlet side of the heat exchanger;   an inlet plenum and an outlet plenum are located side-by-side, are situated at one of the two end portions and are in flow communication with the inlet coolant tubes and the outlet coolant tubes, respectively, to introduce to the coolant into the inlet coolant tubes and to discharge the coolant from the outlet coolant tubes; and   reversal plenums are located at the end portions of the heat exchanger and are configured such that coolant from the inlet tubes flows into the first set of intermediate coolant tubes at the other of the end portions, after having traversed the heat exchanger, coolant from the first set of intermediate coolant tubes flows into the second set of intermediate coolant tubes at the one of the end portions, after having traversed the heat exchanger, coolant from the second set of intermediate coolant tubes flows into the set of outlet coolant tubes, after having traversed the heat exchanger and thereafter, flows from the set of outlet coolant tubes into the outlet plenum.   
     
     
         13 . The apparatus of  claim 11 , wherein the heat exchanger has a condensate disengagement chamber located between the outlet side and the coolant tubes and the parallel fins to allow condensed water to separate from the compressed gas passing through the heat exchanger and an elongated, tube-like drain located at the bottom of the condensate disengagement chamber to collect the condensed water separated from the gas and to discharge the condensed water from the heat exchanger. 
     
     
         14 . The apparatus of  claim 12 , wherein the heat exchanger has a condensate disengagement chamber located between the outlet side and the coolant tubes and the parallel fins to allow condensed water to separate from the compressed gas passing through the heat exchanger and an elongated, tube-like drain located at the bottom of the condensate disengagement chamber to collect the condensed water separated from the gas and to discharge the condensed water from the heat exchanger. 
     
     
         15 . The apparatus of  claim 13 , wherein the coolant tubes are connected to and supported at their ends by two opposed tube sheets.