RECIPROCATING COMPRESSOR FLOW SENSING
Systems, methods, and non-transitory media for monitoring a reciprocating compressor determining a valve opening of a valve disposed in the reciprocating compressor using a sensor and determining a first location of a piston of the reciprocating compressor at the valve opening. The monitoring also includes determining a valve closing of the valve using the sensor and determining a second location of the piston at the valve closing. Furthermore, the monitoring includes estimating a volumetric efficiency based at least in part on the first and second location.
1 . A method for monitoring reciprocating compressor operation, comprising:
determining a valve opening of a valve disposed in the reciprocating compressor using a sensor;
determining a first location of a piston of the reciprocating compressor at the valve opening;
determining a valve closing of the valve using the sensor;
determining a second location of the piston at the valve closing; and
estimating a volumetric efficiency based at least in part on the first and second location.
2 . The method of claim 1 , wherein the sensor comprises a vibration sensor.
3 . The method of claim 1 , wherein the sensor comprises a proximity sensor.
4 . The method of claim 1 , wherein estimating the volumetric efficiency comprises:
determining a distance between the first and second locations; and
dividing the distance by a length of a bore in which the piston moves.
5 . The method of claim 1 , wherein estimating the volumetric efficiency comprises the following equation:
VE
=
D
o
-
D
c
l
b
*
100
where D o is the distance to the first location from an end of a bore in which the piston travels, D c is the distance to the second location from the end of the bore, and l b is a physical displacement length of the piston.
6 . The method of claim 1 , comprising calculating flow rate through the reciprocating compressor based at least in part on the estimated volumetric efficiency.
7 . The method of claim 5 , wherein calculating the flow rate comprises using the following equation:
Q
=
0.0509
P
s
T
s
Z
std
Z
s
(
DISP
)
*
VE
where P s is a pressure of suction, T s is a temperature at suction, Z std is a compressibility factor of the fluid being compressed at standard conditions, Zs is a compressibility factor of the fluid at actual conditions around the reciprocating compressor, and DISP is a displacement of the reciprocating compressor.
8 . The method of claim 6 , comprising operating the reciprocating compressor based at least in part on the calculated flow rate.
9 . The method of claim 1 , comprising operating the reciprocating compressor based at least in part on the calculated flow rate.
10 . A system, comprising:
a reciprocating compressor having a piston and a valve; and
a controller configured to monitor valve closures of the valve, wherein the controller comprises a processor configured to:
receive an indication of the valve opening from a sensor coupled to the reciprocating compressor;
determine a first location of the piston at the valve opening;
receive an indication of the valve closing from the sensor;
determine a second location of the piston at the valve closing; and
estimate a volumetric efficiency based at least in part on the first and second location.
11 . The system of claim 10 , wherein the sensor comprises a vibration sensor.
12 . The system of claim 10 , wherein the sensor comprises a proximity sensor.
13 . The system of claim 10 , wherein the controller is configured to calculate flow rate through the reciprocating compressor based at least in part on the estimated volumetric efficiency
14 . The system of claim 10 , wherein valve comprises a suction valve of a chamber of the reciprocating compressor.
15 . The system of claim 10 , wherein the valve comprises an discharge valve of a chamber of the reciprocating compressor.
16 . The system of claim 10 , wherein the system comprises a multiple-stage compression scheme including the reciprocating compressor in one of a plurality of stages, and the processor is configured to:
determine flow through each of the plurality of stages;
determine a loss in flow between adjacent stages of the plurality of stages; and
if the change in flow exceeds a threshold, attribute the loss to a leak in or between the corresponding stages.
17 . A non-transitory computer-readable medium comprising executable instructions that, when executed, cause a processor to:
receive an indication of a valve opening of a valve of a reciprocating compressor from a sensor coupled to the reciprocating compressor;
determine a first location of a piston of the reciprocating compressor at the valve opening;
receive an indication of the valve closing from the sensor;
determine a second location of the piston at the valve closing; and
estimate a volumetric efficiency for the reciprocating compressor based at least in part on the first and second location.
18 . The non-transitory, computer-readable medium of claim 17 , wherein the sensor comprises a vibration sensor.
19 . The non-transitory, computer-readable medium of claim 17 , wherein estimating the volumetric efficiency is based on a distance between the first and second locations.
20 . The non-transitory, computer-readable medium of claim 17 , wherein the instructions are configured to cause the processor to calculate a flow rate based at least in part on the estimated volumetric efficiency.