In processing equipment services, processors should focus on five stages to get the most out of a contemporary industrial refrigeration system:
·
Lowering the costs of installation and maintenance
·
Improving productivity
·
Assuring the food safety
·
Following FSMA and HACCP requirements
·
Switching to more environmentally friendly refrigerants
Combining techniques can bring a number of advantages. This post
will look at five techniques to improve the efficiency of industrial
refrigeration systems.
1.
Lowering Costs of Installation
and Maintenance
By utilizing communication networks, distributed controls can
minimize the number of hardwired device runs to the central PLC system,
lowering installation costs. They can also provide more versatility and
dependability.
When you give a piece of equipment intelligence, it may function
as a stand-alone gadget if the rest of the system goes down. Assume a processor
wish to add a few evaporator systems
to a facility with a centralized PLC system. Instead of increasing the IO of
the centralized PLC system and adding modules, dispersed controls may be
attached to the additional evaporators and communicated with the main PLC
system.
Distributed controls can also save time and money in new
installations by reducing the length of wire lines between IO points. Because
there are fewer runs, there are fewer copper wires, lowering the cost.
Installing new technology into older or legacy systems is
another approach to save money. Installation costs can be reduced by reusing
existing cables and, where possible, existing IO.
To install sophisticated control systems, the majority of
industrial supervisory control system vendors require new technologies.
Fortunately, some companies have developed a software library for linking to
older controllers, compressors, condensers, vessels, and the latest technology
evaporators. This reduces the number of controllers that need to
be replaced in the future.
While older controllers may need to be changed if they are
hazardous or in bad shape, a processor may save money on the cost of a new
controller, labor to repair it, and field wiring by not replacing them.
Equipment run times are recorded and synchronized with the
manufacturer's suggested maintenance plan in predictive maintenance. Facilities
can evaluate the data points collected from various devices in the facility and
detect subtle variations in behavior that might signal equipment concerns.
Taking care of these issues reduces machine downtime, which in turn reduces
production downtime.
2.
Improving Productivity
Intelligent condenser control, intelligent compressor control,
and load management are three of the most effective techniques to boost
efficiency.
The sliding valve in the screw compressor exposes part of the
rotor within, reducing the machine's capacity correspondingly. If the slide
valve is 90% full, for example, 10% of the capacity can be recycled back into
the suction chamber. Because the input power remains constant, the machine
becomes less efficient as its capacity is lowered. How can this be resolved?
Compressor control that is intelligent or autonomous compressor sequencing can
enhance efficiency.
Many machine rooms run their machines on their own setpoints
rather than in a coordinated manner. If the machines are operated in a
coordinated manner, they may be run more efficiently by permitting only the
amount of compressor capacity required to sustain cooler or freezer production.
Floating suction is a gadget that may also be utilized. Pressure
and temperature are closely linked in all refrigeration systems. This feature
may be used by an operator to better meet the facility's load needs by floating
the system suction pressure higher. Reduced compressor operation is the payoff
for this investment.
How much can a processor expect to save if these guidelines are
followed? Let's start with the definition of a tonne of refrigeration: The
electricity required to melt or freeze 2,000 kg of ice each day is equal to one
tonne of refrigeration. Furthermore, 1 tonne of refrigeration equals 12,000
BTUs or 3.5 KW.
Assume that the cost of 1 kW is $0.12 for the sake of argument.
The cost savings for a 50-ton decrease per day is $506.40 per day or $184,836
per year.
Intelligent condenser control is the second key method for
enhancing efficiency. Automatic condenser staging and floating pressure with
wet-bulb management are the two primary types available. In an industrial
refrigeration system, condensers can account for up to 20% of the total energy
usage. They have a direct impact on the overall efficiency of the business.
This can be reduced by controlling the condensing equipment based on wet-bulb
temperature or humidity.
When a bulb thermometer is wrapped with a water-soaked towel, it
reads the temperature as a wet bulb. The wet-bulb temperature would be the same
as the ambient air temperature if the relative humidity was 100%. Due to
evaporative cooling, the wet-bulb temperature is lower than the dry-bulb
temperature when the humidity is lower. The wet-bulb temperature is the lowest
temperature that can be obtained by evaporating water under present
environmental circumstances.
The condenser pressure should be kept as low as feasible in
order to save energy. As the compressor's braking horsepower per tonne of
refrigeration required decreases, the return is perceived as enhanced
compressor efficiency. At lower discharge pressures, screw compressors run more
efficiently. Lowering discharge pressure, on the other hand, might have an
impact on other parts of the facility, so keep an eye out for potential side
effects. Liquid injection and evaporator
system defrost are two areas that should be scrutinized.
Ambient circumstances must also be considered. It will be more
difficult to maintain a lower discharge pressure just by turning on all of the
equipment and allowing it to operate at 100% if it is really hot outdoors.
Instead, get the wet-bulb temperature by combining humidity and temperature.
The lowest discharge pressure feasible for evaporative
condensers is equal to the saturated liquid pressure at the wet-bulb
temperature plus the condenser approach temperature. It is feasible to
establish the minimum condensing pressure using a wet bulb and utilize that
number as the condenser pressure's floating setpoint. The amount of labor
required by the compressor can be minimized by combining floating suction with
floating discharge pressure control, lowering energy consumption.
Load control is the third and most important way to boost
efficiency. Depending on the time of day, electric companies charge varying
fees. It is feasible to shift load needs to off-peak hours when kilowatt use is
less expensive, thanks to contemporary control technologies. During these
periods, the cooling is turned down to a considerably lower setpoint, and the
facility relies on a battery or a flywheel for power. This permits the system
to be turned off during the day when energy costs are minimal.
Many power providers base their tariffs on both demand and the
time of day. The highest 15 minutes of average usage determines the demand fee.
Processors can track energy use in different regions of the plant to counteract
this problem. When kilowatt use rises, the load is reduced to lower total
demand. For example, if a cold-storage facility has six evaporators working and
is already at capacity, four of them can be turned off to minimize demand. Peak
demand costs can be considerably reduced using this method.
3.
Assuring Food Safety
Monitoring the temperature within the cold storage is one
approach to assure food safety. Many advanced control systems can run
facilities automatically and without human interaction. The controls issue
automatic alarms and have pre-programmed reactions to any problems that
develop. More Industrial Internet of Things (IIOT) and web-based interfaces for
remote monitoring are becoming accessible, and enhanced analytics make
condition monitoring more straightforward.
4.
Following FSMA and HACCP
Requirements
The Food Safety Modernization Act (FSMA) and Hazard Analysis and
Critical Control Point (HACCP) rules, notable to the requirements for automatic
reporting, can be made easier to comply with automated monitoring. Data may be
recorded and saved for a longer amount of time in modern control systems.
Facilities can prepare reports for subsequent examination using past data.
During third-party audits, the reports can also be utilized for food process,
verification, and safety evaluations.
5.
Switching to More
Environmentally Friendly Refrigerants
This lends itself nicely to the shift to more climate-friendly
refrigerants, continuing the thread of continuous monitoring and automated
reactions. Having safety and dependability helps with the shift to alternative
refrigerants, whether the system is using ammonia, propane, carbon dioxide, or
low GWP HFOs. Advanced algorithms allow the system to be adjusted to the new
refrigerants while being as energy efficient as possible, as well as leak
detection for staff safety.
No comments:
Post a Comment