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2.1 INTRODUCTION
2.0 SYSTEM DESCRIPTION
The mCHP BoilerMate
A-CLASS
appliance shown
in figure 2.1 is designed to provide improved
space heating and mains pressure hot water and
better electric and heat energy management
when coupled to a domestic Micro Combined
Heat and Power (mCHP) appliance. Any
automatic mCHP unit designed to operate
at flow temperature between 75
o
C and 85
o
C
can be linked to the mCHP BoilerMate
A-CLASS
.
All models are fitted with an electric central
heating and hot water backup/boost facility.
The principal of a mCHP BoilerMate
A-CLASS
is
to separate the heat generator e.g. mCHP
appliance from the fluctuating space heating
and domestic hot water demands by means of
a thermal energy store. The main advantages
and features of this arrangement are: -
• That the hot water can be supplied directly
from the mains at conventional flow rates
without the need for temperature and
pressure relief safety valves or expansion
vessels. This is achieved by passing the
mains water through a plate heat exchanger.
The outlet temperature of the domestic hot
water is maintained by the system controller
at about 52
o
C (at 18 l/min) by regulating the
speed of the pump circulating the primary
water from the store through the plate heat
exchanger.
• it evens out the fluctuating and intermittent
demands for space heating and hot water
and enables the system to meet very high
peak heat energy demands well above the
thermal rating of the mCHP appliance.
• By storing heat energy produced when
demand is low and discharging it when the
demand is high (i.e. during dwelling warm
up phase or when hot water is drawn off),
a smaller heat generator can potentially be
used.
• The use of a thermal store will also increase
the mCHP continuous run times by virtually
eliminating short cycles and thereby
improve the reliability and utilisation
efficiency of the mCHP appliance.
• The thermal store can accept energy from an
other source e.g. solar and this can then be
used for both space heating and domestic
hot water (solar not yet available).
Figure 2.1 mCHP BoilerMate
A-CLASS
Summary of Contents for mCHP BMA 225
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