HEATING
Sweet manufacturer water-source heat pusmavpo urs bene ts of
A manufacturer of chocolate &
confectionery products was looking
for ways to lower the environmental
footprint of its operations. One of
the options under consideration was
reusing the heat generated when
cooling jacketed mixing vessels.
The existing cooling and heating
system in this part of the factory (not
pictured) included several process
chillers as well as a boiler for process
hot water, ensuring the sweet mixture
remains in a transferable liquid form
that can be pumped.
The speci c process in question,
which was being cooled by a chiller
sited alongside it, involved mixing
several ingredients in a 1,000-litre
stainless steel jacketed vessel to
achieve the desired gelatinous
product consistency before being
transferred via temperaturecontrolled
jacketed pipework to a
holding tank further downstream.
Operating this process 16 hours a
consumption of a traditional chiller adds
to the overall saving. Considering that
cooling and heating is provided by the
same power source, a new e ciency
metric called total energy e ciency ratio
(TER) has been introduced. A SCOP of ve
leads to a TER of nine, which means one
unit of power input delivers four units of
cooling and ve units of heating.
Heat recovery can further increase
energy e ciency of heat pumps. Partial
heat recovery, for example, allows the
recovery of energy from the compressor’s
discharge. This provides heating while
day, 365 days a year with a
600kW chiller and a boiler
producing high-temperature
hot water was estimated
to cost approximately
£225,000 and had a TER (total
e ciency ratio) of 1.7, ICS
Cool Energy calculated after a
site survey.
Instead, it proposed
harnessing the heat generated
during the cooling of the vessel and
send it directly to the customer’s
heating circuit as ‘free heating’. To
accomplish that, ICS Cool Energy
installed the i-FH (Industrial Free
Heating/water source heat pump)
unit. In this case, it provided 75ºC hot
water direct to the boiler, lessening
its load substantially. As a result,
the customer reduced energy by
40%, which meant annual energy
costs would drop by nearly half to
£125,000. The new layout generated
a far-improved TER of 4.0.
1.2MW
process cooling system
including Imperium chiller
(above) for a UK brewery
cooling or heating. Chillers with heat
recovery provide heating while cooling.
To optimise cost and annual energy
e ciency, applications that require low- or
medium-temperature heat can be served
by going hybrid, and partially electrify the
heat demand, which allows for exible
switching between consumption of
electricity and fossil fuels. Conventional
means of heating, when only applied to
stretch-heating temperatures at the
extreme winter days, is limited compared
to the annual energy consumption. Hybrid
solutions deliver renewable energy and
help reduce the energy intensity.
Such systems would be expected to
run with little or no downtime. A number
of factors can be considered in the
reliability of the system. This includes
the reputation of the manufacturer,
the product testing the manufacturer
undertakes on every unit, the quality
controls in place during production
and the location of after-sales service
departments.
It’s advisable to work with partners
that not only o er a wide range of
the latest energy-e cient products
in stock and ready for delivery, but
that can also tailor solutions to meet
the exact customers’ requirements.
Vertical industry applications, certain
geographical locations, high or low
ambient temperatures or extreme water
temperatures can necessitate tailored
solutions.
TOTAL COST OF OWNERSHIP
Traditionally, the total cost of ownership
(TCO) comprises all costs associated
with the cooling and heating system. This
includes the purchase cost of the system
(design, development and installation),
running costs (maintenance and repair
costs and time) plus recycling costs or
resale value at the end of its lifecycle.
Customers are advised to prioritise longterm
costs over the initial purchase price
of a system.
Long-term exchange programmes
provide a way to avoid capital investments
while upgrading systems. They o er
access to the latest process heating and
cooling equipment with the exibility of an
operating expense.
Energy e ciency, reliability,
sustainability, options for customisation
and TCO all play a role in nding the right
process heating solution that best ts a
site’s process needs.
72 www.operationsengineer.org.uk Winter 2021
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