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Expander Operated Gas Processing
April, 2015
Expander Operated Gas Processing:
Cooler NGL (Natural Gas Liquid) temperatures and maximized
uptime with Helidyne’s NGL Expander design.
Specifications:
Flowrates
1-10 mmscfd
Max. Pressure
1440 psi
Min. Temperature
-50 °F
Power Generation
up to 50 kW
Author:
Joseph James
Mechanical Engineer
April, 2015
L’
Expander Operated Gas Processing
April, 2015
Table of Contents
Executive Summary
1
Introduction
2
JT Skid Configuration
3
JT/MRU Skid Configuration
4
Expander Skid Configuration
5
How It Works
6
Empirical Data
8
Mathematical Validation
11
Package Design
13
Contact Us
14
© Helidyne LLC 2015
Expander Operated Gas Processing
April, 2015
Executive Summary
Executive Summary:
The birth of fracking and remote well operations have proven to be a very effective method for
well exploration. Unfortunately, infrastructure development is years behind well exploration, making
gaseous product transportation an economic impossibility. Consequently remote well and NGL
processing equipment are the only viable means of keeping production high. Liquefying as much of the
wellhead gas as possible makes trucking transports possible, however this creates challenges when
trying to maximize wellhead gas recovery. Despite all efforts, over 150 million cubic feet of natural gas is
flared reach day in the remote areas of North Dakota.
Figure 1
Helidyne’s NGL drop out package offers a
solution that helps minimize gas flared, reduces
downtime, and generates electricity as its biproduct. Typically, the wellhead gas is cooled
through a high-pressure / JT cooling system. The
cooling process condenses the “Heavy” gasses into a
liquid that makes remote transport economically
viable. The temperature of the outlet of this system
dictates how much heavy liquids can be recovered
(the lower the temperature, the more NGL drop
out). Depending on wellhead gas composition, these
Helidyne’s Model
“JT” skids have the capability of reaching
4400 Expander
temperatures of -30 °F. Since the Helidyne Expander
extracts energy from the high pressure fluid and also utilizes the JT effect, it will always produce a colder
exhaust gas than any JT valve. This results in more heavy drop-outs and higher revenue for the
customer. On average, the Helidyne Expander will produce a 10-30 °F colder exhaust temperature than
a JT valve. This document illustrates a few configurations used within industry, empirical data of the
Helidyne Expander, and how the Helidyne NGL drop out package is different.
Figure 2
Helidyne’s 2013 Model 4400 Offshore Power Generation Package (2 units)
© Helidyne LLC 2015
Pg. 1
Expander Operated Gas Processing
April, 2015
Introduction
Introduction:
Drilled oil will always produce a well head gas that needs to be separated from the oil. The
flowrate of the separated gas varies from well to well. The most common wells produce about 3-5
mmscfd of well head gas. This separated gas contains rich components like propane and butanes with a
methane mol % ranging from 40% (wetter gas) to 80% (dryer gas). Because these sites are in remote
locations, there typically is no infrastructure (including grid power) to help transport the gas. Shipping
the gas via freight isn’t economical as the transport cost per cubic foot is unreasonable. Liquefying these
gases reduces the volume to a more economical size
to transport to a refinery.
A Helidyne Expander
will produce lower NGL
temperatures than any
JT valve. Always.
There are several approaches to liquefying
these NGL’s. The most common method is by a heat
exchanger coupled with a JT skid. In this scenario, the
wellhead gas is pumped up from 30-40 psi up to 1000
psi. The temperature of the gas is increased to 100150 °F at this high pressure. It then goes through a
heat exchanger that lowers the temperature to 20-50
°F while keeping it at that high pressure (some of the heavy gases liquefy at this stage and drop out). The
gas is then fed through a JT valve which uses the Joule Thompson affect to lower the fluid temperature
as it passes from a high to low pressure system. This JT valve typically drops the pressure down to 100400 psi, and cools the gas to somewhere between -30 and -10 °F. Heavy gases liquefy and are dropped
out from the main gas stream. The desired ending product is to have a high methane content exhaust
gas (typically between 80% and 90% methane).
Sometimes, if the wellhead gas is extremely rich (40%-60% methane), a MRU
(mobile/mechanical refrigeration unit) will be installed in line to cool the gas further. Rich gasses have a
smaller change in temperature when utilizing the JT affect and so the assistance of a MRU is required.
These refrigeration units also require an on-site generator and consume approximately 125 kW (all of
which are expenses to the well head owner).
A Helidyne Expander is a
self-starting, fully
automated, mechanical
device that utilizes only
one electric motor.
The Helidyne Expander package replaces
the JT valve and removes the need for a MRU for
rich gas wellheads. By having the additional
capability of extracting fluid energy from the gas
stream, the resultant temperatures are between
10 and 30 °F lower than a JT valve, and
comparable with the operation of an assisting
MRU. But, unlike the MRU, the Helidyne
Expander produces power instead of consuming
it; removing any need for an on-site generator or
the MRU itself.
© Helidyne LLC 2015
Pg. 2
Expander Operated Gas Processing
April, 2015
Introduction
Below are two of the most common NGL drop out skid configurations. The first diagram (figure
3) shows a JT skid configuration, which is typically used for a leaner well head gas (70% methane content
or higher). The second diagram (figure 4) shows the typical configuration for a well head that provides a
rich gas (Methane content as low as 40%). Richer gases have steeper “p vs h” charts (see page 7), which
renders the JT affect less affective. This is why additional cooling
from a generator powered refrigeration unit is required.
JT Skid Configuration
Figure 3
(Typically used for leaner well head
gas applications, methane > 70%)
9
1
2
Shell and Tube
Heat Exchanger
Reciprocating
Compressor
8
3
6
5
JT Throttling
Valve
Separator
Tank #2
Separator
Tank #1
NGL
Collection
Tank
State
1
2
3
4
5
6
7
8
9
Pressure
30 to 40 psi
1000 psi
1000 psi
150 psi
1000 psi
150 psi
150 psi
150 psi
150 psi
© Helidyne LLC 2015
4
Temperature
50 to70 °F
100 to 150 °F
30 to 60 °F
30 to 60 °F
30 to 60 °F
-30 to 0 °F
-30 to 0 °F
-30 to 0 °F
30 to 70 °F
7
Flow Description
Rich wellhead gas (methane content between 40% and 80%)
Hot, high pressure wellhead gas
Cooled, high pressure wellhead gas/liquid mixture
Dropped out liquids collected from tank #1
Cooled, high pressure wellhead gas (higher methane content then states 1-3)
Cold, low pressure gas/liquid mixture
Dropped out liquids collected from tank #2
Cold, low pressure gas (>80% methane content), used for heat exchanger
Cooled, low pressure “lean” gas sent for processing
Pg. 3
Expander Operated Gas Processing
April, 2015
Introduction
Figure 4
12
JT/MRU Skid
Configuration
(Typically used for rich well head
gas applications, methane < 70%)
1
2
Shell and Tube
Heat Exchanger
Reciprocating
Compressor
11
Mobile Refrigeration Unit
(MRU)
3
9
8
6
5
JT Throttling
Valve
Separator
Tank #3
Separator
Tank #2
Separator
Tank #1
10
4
7
125 kW
Generator
NGL
Collection
Tank
Figure 2
State
1
2
3
4
5
6
7
8
9
10
11
12
Pressure
30 to 40 psi
1000 psi
1000 psi
150 psi
1000 psi
150 psi
150 psi
150 psi
150 psi
150 psi
150 psi
150 psi
© Helidyne LLC 2015
Temperature
50 to70 °F
100 to 150 °F
30 to 60 °F
30 to 60 °F
30 to 60 °F
-30 to 0 °F
-30 to 0 °F
-30 to 0 °F
-50 to -20 °F
-50 to -20 °F
-50 to -20 °F
10 to 70 °F
Flow Description
Rich wellhead gas (methane content between 40% and 80%)
Hot, high pressure wellhead gas
Cooled, high pressure wellhead gas/liquid mixture
Dropped out liquids collected from tank #1
Cooled, high pressure wellhead gas (higher methane content than states 1-3)
Cold, low pressure gas/liquid mixture
Dropped out liquids collected from tank #2
Cold, low pressure gas( higher methane content then states 1-6)
Extra cold, low pressure gas/liquid mixture
Dropped out liquids from tank #3
Extra cold, low pressure gas used for heat exchanger (>80% methane content)
Cooled, low pressure “lean” gas sent for processing
Pg. 4
Expander Operated Gas Processing
April, 2015
Introduction
Below is the configuration for a Helidyne Expander NGL drop-out skid. As shown in the tables,
using a Helidyne Expander combines the simplicity of a JT configuration, while producing the cold
temperatures of a JT/MRU Skid. The Helidyne expander is a mechanical device (with self-cleaning rotors)
that only utilizes one electric motor (runs the oil pump). This translates to 1000’s of hours of runtime
without maintenance. As previously mentioned, the bi-product of using a Helidyne Expander is available
shaft power capable of producing up to 50 kW of electricity. This can be used to operate a control room,
run climate control for operators, power heating equipment to
prevent potential system freezes, or drive any auxiliary device.
Figure 5
Expander Skid
Configuration
(Applications include both
dry and wet gas wells)
9
1
2
Shell and Tube
Heat Exchanger
Reciprocating
Compressor
8
9
5
3
Helidyne Expander
6
Separator
Tank #1
Up to 50 kW of
available shaft power.
NGL
Collection
Tank
State
1
2
3
4
5
6
7
8
9
Pressure
30 to 40 psi
1000 psi
1000 psi
150 psi
1000 psi
150 psi
150 psi
150 psi
150 psi
© Helidyne LLC 2015
4
Temperature
50 to70 °F
100 to 150 °F
30 to 60 °F
30 to 60 °F
30 to 60 °F
-50 to -20 °F
-50 to -20 °F
-50 to -20 °F
10 to 70 °F
Separator
Tank #2
7
Flow Description
Rich wellhead gas (methane content between 40% and 80%)
Hot, high pressure wellhead gas
Cooled, high pressure wellhead gas/liquid mixture
Dropped out liquids collected from tank #1
Cooled, high pressure wellhead gas (higher methane content then states 1-3)
Cold, low pressure gas/liquid mixture
Dropped out liquids collected from tank #2
Cold, low pressure gas (>80% methane content), used for heat exchanger
Cooled, low pressure “lean” gas sent for processing
Pg. 5
Expander Operated Gas Processing
April, 2015
How It Works:
How It Works
Figure 6
The Helidyne Expander is a positive displacement, planetary rotor design.
In other words, the volume ratio from inlet to exhaust is 1:1 and can be assumed
to behave like a hydraulic motor (for compressible flows only, Mach < .3). Rotors
(3 or 4 rotor configuration) are designed with a helical twist that mesh with an
adjacent rotor when assembled together. The rotors turn the same direction and
as they do, a cavity inside the rotor mesh will grow and shrink through the
rotation of the rotors. This passes a “packet” of gas during operation.
During operation, the inlet of the rotors is always open to the gas source,
thus maintaining a constant fluid density. After turning half a rotation, the inlet
closes completely enclosing the gas in the cavity. After which, the rotors open on
the backside exhausting the gas. As the leading packet of gas is being exhausted,
the following packet of gas is entering on the front end creating 2 power cycles
per revolution.
Rotors at starting position
(beginning of a cycle)
Rotors at full torque position
(half cycle or quarter turn)
Gas “Packet”
Shaft power produced by the expander is calculated using the hydraulic
power equation (due to the 1:1 ratio):
̇
𝑃𝑠ℎ𝑎𝑓𝑡 = ∆𝑝𝑉𝐴𝑐𝑡𝑢𝑎𝑙
𝑅𝑜𝑡𝑜𝑟 𝐸𝑣𝑜𝑙
Where:
𝑃𝑠ℎ𝑎𝑓𝑡 = 𝑆ℎ𝑎𝑓𝑡 𝑝𝑜𝑤𝑒𝑟
∆𝑝 = 𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑎𝑐𝑟𝑜𝑠𝑠 𝑡ℎ𝑒 𝑟𝑜𝑡𝑜𝑟𝑠
̇
𝑉𝐴𝑐𝑡𝑢𝑎𝑙
𝑅𝑜𝑡𝑜𝑟 = "actual" flow rate 𝑡ℎ𝑟𝑜𝑢𝑔ℎ 𝑡ℎ𝑒 𝑟𝑜𝑡𝑜𝑟𝑠
𝐸𝑣𝑜𝑙 = 𝐸𝑥𝑝𝑎𝑛𝑑𝑒𝑟 𝑉𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑖𝑐 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦
1
Figure 7
Shape of a “Gas Packet” that
flows through the Expander
However, the power the expander produces is the byproduct of using
a Helidyne Expander for a NGL application, not the objective. Gas cooling is
the primary purpose for this application and is desired to be maximized. As per
its definition, an expander captures energy within a fluid by having it perform
work on a mechanical device (usually a rotor or a blade). This reduces the
enthalpy (internal energy plus the product of volume and pressure), which
reduces the heat content of the fluid. JT valves use the Joule Thompson affect
which is an isenthalpic process (enthalpy remains constant), and all wasted energy is turned to heat.
Using an expander converts that energy into shaft power, thus cooling the gas more than a JT system.
Each fluid composition has a spectrum of cooling capability called the isentropic range.
Removing all the potential energy from a fluid stream would be an “ideal isentropic process” (or in other
words, a system with 100% efficiency). Depending on expander efficiency, the enthalpy removed will lie
somewhere between its isentropic and isenthalpic temperatures.
© Helidyne LLC 2015
Pg. 6
Expander Operated Gas Processing
April, 2015
How It Works
To illustrate this concept, below is a pressure versus enthalpy diagram called a “Mollier Chart”.
This specific chart uses methane as the fluid. The green lines show the isothermal process, black shows
the isentropic process, and the brown line is the saturated state bell curve. The black dot shows the
initial state of this particular example (1000 psi @ 30 °F). The red line shows the cooling process of an
isenthalpic process (or JT process). Since an expander removes energy, the reduced enthalpy lowers the
temperature further as shown by the purple line. The maximum amount of cooling physically possible
for this example without an external heat pump is shown by the blue line. Notice all three scenarios
have the same exhaust pressure (150 psi) but different temperatures.
Figure 8
The change in enthalpy is calculated by:
∆ℎ = 𝔑𝑖𝑛 𝑍𝑖𝑛 𝑇𝑖𝑛 𝐸𝑣𝑜𝑙 (1 −
𝑝𝑜𝑢𝑡
)
𝑝𝑖𝑛
2
Where:
∆ℎ = 𝐶ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑒𝑛𝑡ℎ𝑎𝑙𝑝𝑦
𝔑𝑖𝑛 = 𝑅𝑒𝑎𝑙 𝑔𝑎𝑠 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡
𝑍𝑖𝑛 = 𝑇ℎ𝑒 𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑎𝑏𝑖𝑙𝑖𝑡𝑦 𝑓𝑎𝑐𝑡𝑜𝑟 𝑎𝑡 𝑡ℎ𝑒 𝑒𝑥𝑝𝑎𝑛𝑑𝑒𝑟 𝑖𝑛𝑙𝑒𝑡
𝑝𝑖𝑛 = 𝐸𝑥𝑝𝑎𝑛𝑑𝑒𝑟 𝑖𝑛𝑙𝑒𝑡 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒
𝑝𝑜𝑢𝑡 = 𝐸𝑥𝑝𝑎𝑛𝑑𝑒𝑟 𝑜𝑢𝑡𝑙𝑒𝑡 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒
𝑇𝑖𝑛 = 𝑅𝑜𝑡𝑜𝑟 𝑖𝑛𝑙𝑒𝑡 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒
𝐸𝑣𝑜𝑙 = 𝐸𝑥𝑝𝑎𝑛𝑑𝑒𝑟 𝑣𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑖𝑐 𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦
Which is derived from the conservation of energy:
𝑃𝑠ℎ𝑎𝑓𝑡 = 𝑚̇∆ℎ
3
Where:
𝑚̇ = 𝐸𝑥𝑝𝑎𝑛𝑑𝑒𝑟 𝑖𝑛𝑙𝑒𝑡 𝑚𝑎𝑠𝑠 𝑓𝑙𝑜𝑤𝑟𝑎𝑡𝑒
© Helidyne LLC 2015
Pg. 7
Expander Operated Gas Processing
April, 2015
How It Works / Empirical Data
Equation 2 shows that higher pressure ratios and greater expander efficiencies will yield lower
temperatures. Or in terms of the above Mollier Chart (figure 8), the greater the pressure ratios and
expander efficiencies, the closer the purple line gets to the blue line and higher isentropic efficiency.
Current Helidyne Expander volumetric efficiencies are approximately 20-40% (depending on the
application). As machining processes become more advanced, leakage within the expander system will
be reduced increasing volumetric efficiency and produce lower exhaust temperatures.
The Helidyne Expander has a unique design that allows it to be the only expander on the market
that can be used in the harsh conditions of an NGL application. The rotor design for the current Model
4400 allows for pressure drops of up to 1440 psi, flows up to 10 mmscfd, and generate up to 50 kW of
power. However, the most important capability of the Helidyne expander is its ability to process 2 phase
expansion while at the same time be self-cleaning. This quality alone makes the Helidyne Expander a
more effective and reliable replacement for the JT and MRU configurations.
Empirical Data:
The Helidyne Expander has been tested using air, nitrogen, and pipe line natural gas in order to
validate the above mathematical models. Helidyne’s test site is located in St. George, Utah at the Red
Rock Generation Facility. The site includes a 1300 HP natural gas fueled compressor, PLC operated
control room, and a piping infrastructure to run various tests (see figure 9). This test site is capable of
producing a flow of 6 mmscfd at 1000 psi using pipeline natural gas or nitrogen (tests using air
performed at a different location).
Figure 9
The Helidyne Red Rock Test Site located in St. George, Utah
© Helidyne LLC 2015
Pg. 8
Expander Operated Gas Processing
April, 2015
Empirical Data
Several 24 hour tests were completed using pipe line quality natural gas. These tests were
designed to measure various system performances including pressure/flow variance, stability, and
exhaust cooling. The power produced was controlled by using a flow control valve upstream that
regulated the pressure to the expander. “System Pressure” is the line pressure upstream of the control
valve, “expander inlet pressure” is the line pressure between the flow control valve and the expander
(and is the pressure used to compare with a JT process), and the “exhaust pressure” is the line pressure
after the expander.
Figure 10 shows the results of the first half of a 24 hour test. The first graph displays the
expander having a varying system pressure (dark blue line, ranging from 450 to 850 psi) while
maintaining a 15 kW power output (teal line). Besides testing system stability, this provided different
system temperatures that varied with system pressure.
The second graph shows the temperatures of the system before the flow control valve (red line),
the temperatures right before the expander (the purple line), and the exhaust gas temperature (green
line). A set of data points are selected and displayed below the temperature graph. The chart below
shows exact values measured at half mid-way through the test. These values will be used to compare
the performance of the Helidyne Expander versus a JT valve.
Figure 10
Time Stamp
System Pressure
Expander Inlet Pressure
Exhaust Pressure
© Helidyne LLC 2015
10/20/2014 18:00
557.80 psi
350.08 psi
49.30 psi
System Temperature
Inlet Temperature
Exhaust Temperature
Power
92.6 °F
82.3 °F
53.1 °F
14.94 kW
Pg. 9
Expander Operated Gas Processing
April, 2015
Empirical Data
The numbers in the chart in figure 10 can be reproduced using NIST (National Institute of
Standards and Technology) data and also give the exhaust temperature of a JT valve under the same
application (see figure 11). This validates equations 1-3 (note: pressures are absolute):
Figure 11
Line 1 = System State
Line 2 = Expander Inlet State
Line 3 = Rotor Inlet
Line 4 = Expander Exhaust
Isenthalpic Process
Line 6 = JT Temperature
Drop (for comparison)
As figure 11 shows, the Helidyne Expander has a 13 degree cooler temperature than if the test
was ran with a JT valve. This is because the expander extracts fluid energy from the flow and converts it
to mechanical work. As equation 2 shows, a greater pressure ratio will yield a greater change in
enthalpy, which translates to cooler temperatures. The above test had a 300 psi drop across the
expander (as per the 15 kW protocol
requirement). If a greater power was desired,
the pressure drop across the expander could be
raised to the available 500 psi drop and the
exhaust gas would be a lower temperature than
line 4 in figure 11.
The Helidyne Expander’s
versatile profile includes
flows from 1-10 mmscfd,
pressures up to 1440 psi,
and temperatures down
to -50 °F.
It is important to note that exhaust
temperatures will vary depending on fluid
composition, pressure drop, initial temperature,
and flowrate (affects expander volumetric
efficiency). The ollier chart in figure 8 shows
how methane at high pressures and
temperatures has, at some points, very curvy
temperature lines. In other words, methane promotes very good cooling when dropping from warmer,
higher to lower pressures. But, when the fluid composition changes by reducing the methane mol
percentage, the isothermal lines become steeper much like on the left hand side of figure 8’s methane
chart. This makes JT cooling less affective in cooling wellhead gas. Each well will have its own fluid
composition, flow, temperature, and pressures that will produce unique results when using a Helidyne
Expander.
L’
Pg. 10
Expander Operated Gas Processing
April, 2015
Mathematical Validation
Mathematical Validation:
𝑃𝑠ℎ𝑎𝑓𝑡 = 𝑚̇∆ℎ
14.94 𝑘𝑊 + 4.8 𝑘𝑊 (𝑃𝑎𝑟𝑎𝑠𝑖𝑡𝑖𝑐 𝐿𝑜𝑠𝑠𝑒𝑠) = 19.74 𝑘𝑊 = 𝑚̇ ∙ 16.12
𝑘𝐽
𝑘𝑔
𝑘𝐽
𝑘𝑔
𝑚̇ =
𝑘𝐽
16.12
𝑠
19.74
𝑚̇ = 1.225
𝑘𝑔
𝑠
̇
𝑚̇ = 𝜌𝑉𝐴𝑐𝑡𝑢𝑎𝑙
𝑊ℎ𝑒𝑟𝑒:
𝜌 = 𝐹𝑙𝑢𝑖𝑑 𝐷𝑒𝑛𝑠𝑖𝑡𝑦
̇
𝑉𝐴𝑐𝑡𝑢𝑎𝑙
=
̇
𝑉𝐴𝑐𝑡𝑢𝑎𝑙
𝐸𝑥𝑝𝑎𝑛𝑑𝑒𝑟 𝐼𝑛𝑙𝑒𝑡
𝑚̇
𝜌
𝑘𝑔
𝑠
=
𝑘𝑔
16.727 3
𝑚
1.225
̇
𝑉𝐴𝑐𝑡𝑢𝑎𝑙
𝐸𝑥𝑝𝑎𝑛𝑑𝑒𝑟 𝐼𝑛𝑙𝑒𝑡 = .073
𝑚3
𝑠
Converting to standard flowrate:
𝑉̇𝑠𝑡𝑑 =
𝑉̇𝑠𝑡𝑑
𝑝
𝑇
𝑉̇𝑎𝑐𝑡𝑢𝑎𝑙 (𝑝𝑎𝑐𝑡 ) (𝑇𝑠𝑡𝑑 )
𝑠𝑡𝑑
𝑎𝑐𝑡
𝑍𝑖𝑛
𝑙𝑏𝑠
𝑚3 363.08 𝑖𝑛2 519.7°𝑅
. 073 𝑠 (
)(
)
𝑙𝑏𝑠
542.0°𝑅
13 2
𝑚3
𝑖𝑛
=
= 2.036
. 96
𝑠
Calculating equation 1:
̇
𝑃𝑠ℎ𝑎𝑓𝑡 = ∆𝑝𝑉𝐴𝑐𝑡𝑢𝑎𝑙
𝐸𝑣𝑜𝑙
∆𝑝 = [300.78
𝑙𝑏𝑠
𝑙𝑏𝑠
𝑁
− 125 2 (𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒𝑑 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑑𝑟𝑜𝑝 𝑡ℎ𝑟𝑜𝑢𝑔ℎ 𝑡ℎ𝑒 𝑚𝑎𝑛𝑖𝑓𝑜𝑙𝑑)] = 1,211,958.2 2
2
𝑖𝑛
𝑖𝑛
𝑚
Converting Standard back into actual:
̇
𝑉𝐴𝑐𝑡𝑢𝑎𝑙
=
© Helidyne LLC 2015
𝑉̇𝑠𝑡𝑑 𝑍𝑖𝑛
𝑝
𝑇
(𝑝𝑎𝑐𝑡 ) (𝑇𝑠𝑡𝑑 )
𝑠𝑡𝑑
𝑎𝑐𝑡
Pg. 11
Expander Operated Gas Processing
April, 2015
̇
𝑉𝐴𝑐𝑡𝑢𝑎𝑙
𝑅𝑜𝑡𝑜𝑟
𝑚3
(. 97)
𝑚3
𝑠
=
= .097
𝑙𝑏𝑠
𝑠
238.08 2 519.7°𝑅
𝑖𝑛
(
)(
)
𝑙𝑏𝑠
535.4°𝑅
13 2
𝑖𝑛
1.7742
Calculating Volumetric Efficiency:
𝐸𝑣𝑜𝑙 =
𝑉̇𝐶𝑎𝑣𝑖𝑡𝑦
̇
𝑉𝐴𝑐𝑡𝑢𝑎𝑙
𝑅𝑜𝑡𝑜𝑟
Where:
𝑉̇𝐶𝑎𝑣𝑖𝑡𝑦 = 𝐺𝑒𝑜𝑚𝑒𝑡𝑟𝑖𝑐 𝑐𝑎𝑣𝑖𝑡𝑦 𝑓𝑙𝑜𝑤𝑟𝑎𝑡𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑟𝑜𝑡𝑜𝑟𝑠 = .0166
𝐸𝑣𝑜𝑙
𝑚3
𝑓𝑜𝑟 𝑡ℎ𝑒 𝑀𝑜𝑑𝑒𝑙 4400
𝑠
𝑚3
. 0166 𝑠
=
= .171
𝑚3
. 097
𝑠
𝑃𝑠ℎ𝑎𝑓𝑡 = (1211958.2
𝑁
𝑚3
)
097
(.
) (. 171) = 20.10 𝑘𝑊
𝑚2
𝑠
𝑂𝑢𝑡𝑝𝑢𝑡 𝑝𝑜𝑤𝑒𝑟 = 𝐸𝐺𝑒𝑛𝑒𝑟𝑎𝑡𝑜𝑟 (𝑃𝑠ℎ𝑎𝑓𝑡 − 𝑃𝑑𝑟𝑎𝑔 ) = .99(20.10 𝑘𝑊 − 4.8𝑘𝑊) = 15.15 𝑘𝑊 ≈ 14.94 𝑘𝑊
And finally equation 2:
∆ℎ = 𝔑𝑖𝑛 𝑍𝑖𝑛 𝑇𝑖𝑛 𝐸𝑣𝑜𝑙 (1 −
𝑝𝑜𝑢𝑡
)
𝑝𝑖𝑛
𝑙𝑏𝑠
62.3 2
𝑘𝐽
𝑘𝐽
𝑖𝑛
∆ℎ = (. 518
) (. 97)(297°𝐾)(. 171) (1 −
) = 18.8
𝑙𝑏𝑠
𝑘𝑔°𝐾
𝑘𝑔
238.08 2
𝑖𝑛
And comparing equation 2 results to empirical data from the NIST Chart in figure 11:
893.15
𝑘𝐽
𝑘𝐽
− 877.03
=
𝑘𝑔
𝑘𝑔
16.12
𝑘𝐽
𝑘𝐽
≈ 18.8
𝑘𝑔
𝑘𝑔
NOTE: Thermodynamic calculations will have a greater margin of error than power
calculations due to the inherent approximations in thermodynamic modeling.
These empirically validated, mathematical models allow calculations for any natural gas
composition to be possible. If given the inlet pressure, outlet pressure, and inlet temperature; the
power produced and change in enthalpy can be predicted. As stated previously, a Helidyne Expander will
always produce lower temperatures than a JT valve, as well as produce comparable temperatures as a
MRU configuration with the bi-product being usable shaft power.
© Helidyne LLC 2015
Expander Operated Gas Processing
April, 2015
Package Design
Package Design:
Pg. 12
Insulated NGL
Collection Tanks
Model 4400
Helidyne Expander
Insulated Heat
Exchanger
Skid Connections
Generator
(Or any device
requiring shaft power)
Onboard PLC/HMI
Onboard Battery System
© Helidyne LLC 2015
Pg. 13
Expander Operated Gas Processing
April, 2015
Contact Us
Contact Us:
Address:
1425 Redledge Rd. Suite 102
Washington, Utah 84780
Office Phone:
435-627-1805
Email:
sales@helidynepower.com
For More Information about our products and
services, please visit our website:
www.HelidynePower.com
© Helidyne LLC 2015. All rights reserved. No part of this document or its contents may be reproduced, republished, publicly
displayed, uploaded, translated, transmitted, or distributed without the prior written consent of Helidyne LLC. Information
contained in this document is subject to change without notice and is provided on an “as-is” basis. Helidyne LLC. Disclaims all
warranties, expressed or implied, including, but not limited to, warranties of non-infringement, accuracy and fitness for a
particular purpose, except as provided by written agreement.
© Helidyne LLC 2015
Pg. 14