Overview
In the Recovery 2.0 system we treat energy like any other commodity and as such we attempt to
classify energy into different types.
Heat is one major type of energy and within the recovery process we try to define the quality of the Heat into various
grades,
typically identified by combinations of temperature and pressure that may originate from different
sources.
Energy in fluid = kinetic energy (V) + pressure energy (P) + internal or temperature energy (T)
Enthalpy = pressure energy (P) + internal or temperature energy (T)
Heat Engines
Traditional methods to harness energy from a working fluid commonly rely upon the ability of a heat engine to convert a
Pressure/Temperature flow into motion.
Historically systems have been set up to operate a Rankine cycle to take
advantage
of a phase change in a working fluid in an
evaporation/condensation
cycle to harvest high temperature & high pressure to drive a rotary turbine.
The use of an Organic Rankine Cycle
ORC
facilitates harvesting energy from lower quality temperature/pressure flows by using carbon or hydrocarbon based working fluids
with a lower evaporation point, typically below 300 degree centigrade.
The use of inorganic working fluids such as molten metals, minerals or salts may increase the working temperatures
up to 1,500 degree centigrade.
Heat engines that do not rely on a phase change of the working fluids utilize a Brayton Cycle to convert pressure/temperature
into
motion.
This is most commonly seen in the flow of gases in a compression/expansion cycle.
The establishment of general industrial classifications of heat is important in the understanding of how to manage
the wide range of temperature
Gradients.
The
standards
for the classification of enthalpy in relationship to Ambient, above ambient and below ambient pressures and temperature
may be a benchmark for the heat energy and waste heat recovery industry.
This standardization is a key factor to establish defined, tradable grades of thermal energy
which allow for the classification of potential recovery rates and harvesting methods.
Understanding the dynamics of
Waste Heat
and recognizing the potential opportunities to harvest energy through
Heat Exchange
or other methods is a critical skill.
Waste Heat
Co-locating a thermal waste recovery facility at a source site that generates
Waste Heat
may provide a
ongoing supply of low cost energy.
This site choice ties the destiny of the facility directly to the ongoing operation of a third party.
Waste Heat may be channeled through a heat exchanger or into a
Temperature Gradient
capture system.
Scavenging waste heat may be achieved through various
Harvesting Methods
and may provide an extraordinary yield from a passive opportunity.
Potential Heat Recovery
In an operation like the Recovery 2.0 system, where you have access to both steam heat and compressed air expansion cooling,
you have a continuos potential temperature differential
gradient
of hundreds of degrees.
By designing a structurally engineered environment you may be able to optimize the collection to
harness
this massive energy potential.
Strategic use of thermal insulation materials with a reflective surface may also enhance the energy recovery rate
and
storage
potential.
Smaller temperature gradients exist throughout the Recovery 2.0 facility and provide many opportunities to
harvest heat energy for direct onsite electricity generation or for
Heat Exchange.
This approach represents an example of a symbiotic
Multi-Stage
Energy Management Strategy.
It is important in a Multi-Stage approach to be aware that the total available harvestable energy diminishes at each step.
The
scale
of the energy harvest can get quite small rapidly (in only a couple of stages).
This low recovery yield situation may be somewhat offset due to the passive nature of some of the steps.
Heat Exchange
I heard a rumor that there is no such thing as cold, only the absence of heat.
The natural flow is always from HOT to COLD.
Traditional
Heat Exchange
systems are thought of as a method for cooling, refrigeration or freezing.
The extraction of heat from hot areas to cold areas (or to areas where there is an absence of heat)
presents an opportunity to capture or harness energy from that
transfer.
Temperature Gradient
and
Thermal Energy Storage
Some common methods to make use of a heat
source
is to transfer into some sort of district heat distribution network.
Current efforts are more focused on the development of on site direct heat to electricity technologies.
There is an ongoing challenge to maintain a continuous Cold Side Heat Sink to maximize the
energy conversion potential of the available Hot Side Heat Source.
This factor may determine the choice of the style or method selected for use in the Recovery 2.0 system.
Organic Rankine Cycle (ORC)
The use of any number of
working fluids
may provide some unique combinations for specific heat transfer parameters.
An Organic Rankine Cycle (ORC) system has the potential to convert low grade heat sources directly into
electricity.
Ammonia ORC Cycle
The use of
Ammonia
as a working fluid in an Organic Rankine Cycle (ORC) may have some specific advantages.
With a small differential in hot side to cold side gradient manipulation that hovers above and below the phase change point,
an Ammonia cycle may be a viable
sidestream
energy harvesting loop.
A rapid repeating cycle of the Ammonia phase change may be able to produce adequate pressure to drive a turbo
that enables the generation of electricity. Ammonia expands with an 850:1 volume ratio at the phase change from
liquid to gas.
The strategic location of an Ammonia ORC Transfer Loop in line with existing working fluid pipelines
that are able to supply the required Hot Side / Cold Side temperature gradient differential,
may drive an Ammonia Cycle module.
Pumped Heat Energy Storage
Pumped Heat Energy Storage working fluids energy transfer
Compressed Air Expansion
and
Pumped Heat
Storage may be used to meet some of this Cold Side demand.
Heat Pump
Energy Transfer through the use of a heat exchanger is used for various applications most commonly known as heat pumps.
HVAC Heat Pumps
Building Heating, Ventilation and Air Conditioning
HVAC
uses a heat pump to exchange temperature between an indoor environment with the ambient outdoors.
Refrigeration
Residential home refrigerators and commercial refrigeration systems are examples of specific heat pump applications.
Domestic home freezers and industrial freezers operate on the same principals.
The Refrigeration Cycle is based on the natural equilibrium forces of hot moving to cold.
A heat Exchanger will extract any remaining heat from one medium into a colder medium,
so it is potable to cool a cold medium even further as long as the other side of a heat exchanger is an even colder medium.
The heat is rapidly driven and will naturally transport toward the cold side so a typical heat exchange system will
require a pressure or pump to drive the cold side medium through the system.
The speed of the heat transfer is largly determined by the size of the temperature gradient between the hot side and cold side.
One method to generate a rapid cold side heat sink is with the expansion of a compressed gas or vapor,
this may result in a cryo temperature effect.
Ice Making
Commercial ice making, ice is a temporary portable cooling source
We also need to explore the potential of eutectic freeze crystallization as an
energy storage
method.
Energy Storage
- Battery Banks
- Thermal Energy Storage
- Compressed Air Storage
- Exothermic Element Storage
Short Cycle Regeneration
- Hydro Energy
- Wind Energy
- Gravity Energy
- Gradient Energy
Energy Sources
- Solar
- Electricity
- Waste Heat
- Optional Sidestreams
Understanding Energy & Recovery
- Energy as a Commodity
- Recovered Energy
Summary
The challenge is to design for optimum operation by
engineering a system that has the capability to swap from priority or default pathways
as seamlessly and rapidly as possible and the ability to scale up or down each energy pathway module.
Check-out
Recovery 2.0
