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and the larger ownership of the electronic equipment.
Among the equipment, the significant one that leading to
the swift growth of electricity consumption could be
sharply increase of ownership of the air-conditioners in
households.
2.2. Results Gained by Air Conditioning Energy
Saving Actions in Chengdu
Since 2003, because of the rising intension condition of
power supply in China[3],the Chinese government
started to promote electrical demand side management
(DSM). In 2004, the National Development and Reform
Commission (NDRC) and the State Electricity Regula-
tory Commission (SERC) issued jointly <Guidance for
strengthen the power demand side management> to sup-
port DSM action. In 2007, General Office of the State
Council released <Notification abou t strictly ex ecutio n of
air-conditioning temperature control standard in public
buildings > ([2007] NO.42) to regulate air-conditioning
saving management.
Chengdu government and power grid worked together
to organize a series of actions on cooling load demand
side management in summer to control the cooling load.
In order to reduce the energy burden, Chengdu power
grid en couraged th eir customer s to choose a new style of
air-conditioners to save more electricity with lower elec-
tricity price, this may help avoiding the appearance of
black out. This action has acquired preliminary achieve-
ments by some commercial customers, but met limited
excitement with residential customers[4].
3. Theory
In this section, all theories and applications will be ex-
pounded specifically. And heat pumps air-conditioners
are considered to replace conventional air-conditioners in
order to reduce the consumption of the electricity in the
Sichuan power market, the reduction of the energy con-
sumption will not only contribute to protect the power
grid to avoid black out, but also bring a financial benefits
to those customers for their electricity bills.
Ground source heat pump systems are based on the
shallow geothermal of rock and earth mass, ground water
and surface water as resources for both heating and
cooling[6]. This is a new central air conditioning system
that depends on renewable resources for both heating and
cooling and can meet the achievement of “energy saving
and emission reduction”.
3.1. The Components and Features of GSHP
Ground source heat pumps are consisting of water-source
heat pump unit which can provide cooling or heating to
the buildings, a shallow geothermal heat exchanging
system and a central air conditioning system in the inte-
rior of the buildings. There are three types of GSHP due
to the different heat transfer medium, they are Ground
water heat pumps, Surface water heat pumps, and Buried
pipe Ground source heat pumps. Heat pump units can
also divide into two types by methods of operation,
screw heat pump units and water switch heat pump u nits.
In this project, air-conditioners are used for the central
air-conditioning system for the whole community, there-
fore screw heat pump units is more suitable than the
other one for cooling and heating[7]. This system fea-
tures characteristics as shown below[6]:
Ground source heat pump technology is a technol-
ogy with high efficiency energy saving, non-pollution,
and low cost of the operation which relies on shallow
geothermal resources for both cooling and heating. Not
only for air conditioning, can it also supp ly hot water for
residents‟ living. It has been referred as the “Green air
conditioning technology” in the 21st Century. Currently,
there are two types of GSHP in air conditioning market,
they are grou nd wa ter technolo g y and bu r ied p ip e g rou nd
source technology.
Ground source heat pump has the ability to reduce
the emission of greenhouse gas sharply. As most of the
resources are coming from the underground soil when
the GSHP system generates heating in winter, less than
half resources are generated by electricity. Hence it can
be used instead of a heating boiler, so that there could be
approximately 70% of greenhouse gas emission reduced
for the environment. Moreover, there is no need for any
special geothermal field or geothermal water to apply for
the system, normal soil (over -3.5℃) can meet the tech-
nical operation conditions of GSHP. Meanwhile, it will
not pollute and deplete the underground wa ter.
GSHP uses renewable resources; there is no re-
source exhaustion problem for this technology.
High efficiency but low cost. For heating, the coef-
ficient of performance (COP) could reach at most of 5.0,
but this of the normal boiler is only between 0.7 and 0.9,
70% of energy can be saved and there is also about half
reduction of the operation cost. For cooling, the conven-
tional electrical refrigeration air-conditioners spend 40%
of energy more than GSHP, which could make the elec-
trical bill more expensive. Hence, there is an economical
benefit while using GSHP.
3.2. Economic Efficiency and Energy
Conservation of GSHP
Ground source heat pump can work together with
an energy storage device to realize propose of electricity
load shifting suggested by the power grid company. A
battery can store electricity during the off-peak time,
which is at a very low price compare with peak time. In
this situation, customers can save much money on elec-
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