U.S. patent application number 11/922379 was filed with the patent office on 2010-07-01 for method for producing hot water utilizing combined heat resources of solar energy and heat pump in the manner of heating water at multilpe stages and accumulating energy and a device especially for carrying out the method.
Invention is credited to Ge Pan.
Application Number | 20100163016 11/922379 |
Document ID | / |
Family ID | 37595047 |
Filed Date | 2010-07-01 |
United States Patent
Application |
20100163016 |
Kind Code |
A1 |
Pan; Ge |
July 1, 2010 |
Method for Producing Hot Water Utilizing Combined Heat Resources of
Solar Energy and Heat Pump in the Manner of Heating Water at
Multilpe Stages and Accumulating Energy and a Device Especially for
Carrying Out the Method
Abstract
A method for producing hot water and a device especially for
carrying out the method are provided. The method utilizes combined
heat resources of solar energy and heat pump in the manner of
heating water at multiple stages and accumulating energy. The
device comprises solar energy collector, heat pump, electrical
heater, water tank, and control unit. The device also includes
water-heating tanks with multiple stages. A heating means with
multiple stages at different temperatures is formed either by the
solar energy collector or by the collector and the heat pump. The
outputting end of the two or more heating stages constituted by the
solar energy collector or by the collector and the heat pump is
connected through ducts to the corresponding water-heating tanks. A
predetermined amount of produced water heated at multiple stages is
respectively stored in the water-heating tanks. Compared with the
prior art, the present invention is endowed with the performance of
making use of the solar energy to the greatest extent and utilizing
off-peak electricity more efficiently as a supplementary heating
means. Furthermore, the arranging fee of the device is reduced and
its adaptation of mounting is improved.
Inventors: |
Pan; Ge; (Shanghai,
CN) |
Correspondence
Address: |
ZHEN ZHENG LU
1730 HUNTINGTON DRIVE #304
DUARTE
CA
91010
US
|
Family ID: |
37595047 |
Appl. No.: |
11/922379 |
Filed: |
June 27, 2006 |
PCT Filed: |
June 27, 2006 |
PCT NO: |
PCT/CN2006/001476 |
371 Date: |
December 17, 2007 |
Current U.S.
Class: |
126/613 ;
126/615; 126/634; 126/714 |
Current CPC
Class: |
Y02B 10/70 20130101;
Y02B 10/20 20130101; F24D 11/0221 20130101 |
Class at
Publication: |
126/613 ;
126/714; 126/615; 126/634 |
International
Class: |
F24J 2/42 20060101
F24J002/42; F24J 2/00 20060101 F24J002/00; F24J 2/04 20060101
F24J002/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 28, 2005 |
CN |
200510027212.X |
Claims
1. A method for producing hot water utilizing combined heat
resources of a solar energy and a heat pump in a manner of heating
water at multiple stages and accumulating energy, comprising a
process of heating with solar energy collectors, a process of
heating with the heat pumps, and a process of heating with an
electrical heater, wherein a process of producing hot water is a
combination of heating the water in a circulating water-heating
tank for the collector of multi-stage heating and in conflux hot
water tank of multi-stage heating at multiple stages by the solar
energy collector, the heat pump, or the electrical heater
simultaneously or respectively; production and consumption of the
hot water is of a timesharing mode, i.e., a certain amount of hot
water produced in advance by heating periodically at multiple
stages is stored in the conflux hot water tank of multi-stage
heating and an energy accumulation water tank for being supplied
for a next period.
2. The method for producing hot water utilizing combined heat
resources of solar energy and heat pump in a manner of heating
water at multiple stages and accumulating energy as claimed in
claim 1, wherein said combination of heating the water in the
circulating water-heating tank for the collector of multi-stage
heating and in the conflux hot water tank of multi-stage heating at
multiple stages with the solar energy collector, the heat pump, or
the electrical heater simultaneously or respectively includes:
completely utilizing the solar energy collector for heating and
storing the hot water in sunny days; using the heat pump or the
electrical heater for complementary heating and storing the hot
water at night when an off-peak electricity is available; and using
the heat pump for instant heating and storing the hot water
according to a required certain amount of hot water storage volume
when it is not sunny day and the off-peak electricity is not
available as well.
3. A device especially for carrying out a method for producing hot
water utilizing combined heat resources of solar energy and heat
pump in a manner of heating water at multiple stages and
accumulating energy, comprising at least one solar energy
collector, a water pump, at least one heat pump, at least one
electrical heater, at least one water tank, and a control unit,
wherein said water tanks comprises a circulating water-heating tank
for the collector, a conflux hot water tank of multi-stage heating,
and a energy accumulation water tank, wherein the solar energy
collector is connected to the circulating water-heating tank for
the collector, the circulating water-heating tank for the collector
is connected to the conflux hot water tank of multi-stage heating,
and the conflux hot water tank of multi-stage heating is connected
to the energy accumulation water tank; the heat pump and the
electrical heater are arranged with the water tanks; a start
control of the solar energy collector, the water pump, and the heat
pump, and the electrical heater are electrically connected to the
control unit respectively.
4. A device especially for carrying out a method for producing hot
water utilizing combined heat resources of solar energy and heat
pump in a manner of heating water at multiple stages and
accumulating energy as claimed in claim 3, wherein said energy
accumulation water tank has more than one water tanks, including a
warm water storage tank of multi-stage heating and a final
temperature water storage tank; the conflux hot water tank of
multi-stage heating, the warm water storage tank of multi-stage
heating, and the final temperature water storage tank are connected
in parallel.
5. A device especially for carrying out a method for producing hot
water utilizing combined heat resources of solar energy and heat
pump in a manner of heating water at multiple stages and
accumulating energy as claimed in claim 3, wherein said circulating
water-heating tank for the collector has one or more water tanks,
and the last one of the interconnected one or more circulating
water-heating tanks for the collector also functions as a conflux
hot water tank of multi-stage heating.
6. A device especially for carrying out a method for producing hot
water utilizing combined heat resources of solar energy and heat
pump in a manner of heating water at multiple stages and
accumulating energy as claimed in claim 3, wherein when the heat
pump and the electrical heater are arranged with the water tanks,
the heat pump or the electrical heater is disposed on and outside
the water tanks of multi-stage heating.
7. A device especially for carrying out a method for producing hot
water utilizing combined heat resources of solar energy and heat
pump in a manner of heating water at multiple stages and
accumulating energy as claimed in claim 3, wherein said heat pump
comprises one or more heat pumps disposed on the conflux hot water
tank of multi-stage heating and the final temperature water storage
tank and disposed there-between, so as to form heat pumps for
heating at multiple stages, and the heat pumps for heating at
multiple stages are directly or indirectly connected in series.
8. A device especially for carrying out a method for producing hot
water utilizing combined heat resources of solar energy and heat
pump in a manner of heating water at multiple stages and
accumulating energy as claimed in claim 3, wherein said warm water
storage tank of multi-stage heating and the final temperature water
storage tank are further connected to bypass pipelines in parallel,
and the bypass pipelines have one-way valves for supplying water or
heating water from the warm water storage tank of multi-stage
heating to the final temperature water storage tank.
9. A device especially for carrying out a method for producing hot
water utilizing combined heat resources of solar energy and heat
pump in a manner of heating water at multiple stages and
accumulating energy as claimed in claim 3 or 4, wherein electric
control valves are disposed on water pipes connected in parallel
between the conflux hot water tank of multi-stage heating, the warm
water storage tank of multi-stage heating, and the final
temperature water storage tank.
10. A device especially for carrying out a method for producing hot
water utilizing combined heat resources of solar energy and heat
pump in a manner of heating water at multiple stages and
accumulating energy as claimed in claim 3, wherein a connecting
pipe for discharging water is disposed on the warm water storage
tank of multi-stage heating and the final temperature water storage
tank, and a hot water booster pump is additionally disposed on the
connecting pipe for discharging water.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a field of utilizing solar
energy, and more particularly to a method for producing hot water
utilizing combined heat resources of solar energy and heat pump in
a manner of heating water at multiple stages and accumulating
energy and a device especially for carrying out the method.
BACKGROUND OF THE INVENTION
[0002] The sun generates a large amount of energy. The radiant
energy reaching the earth's surface from the sun each year equals
to the energy generated by about 130 trillion tons of standard
coals, but it is still dispersal, discontinuous, and unstable.
Although the total amount of solar radiant energy reaching the
earth's surface is great, its energy-flux density is very low. So a
large area is needed to receive the radiation in order to get a
certain radiant power. The discontinuance and instability means
that the solar radiant energy is restricted by natural conditions
such as days and nights, seasons, geographical latitudes, altitudes
above sea level, as well as random factors such as clear, gloomy,
cloudy, and rainy days. To eliminate these defects, an energy
accumulation problem shall be solved and other auxiliary energies
are needed to make sure that solar energy can be used round the
clock. The energy used for building, such as for producing hot
water, can be generated by low-ordered renewable energy sources;
otherwise, it would be a waste of power if the high-ordered
electric energy is used. Therefore, one of the most important
indexes for a solar water heating system is to make sure that the
solar energy can be used to the maximum extant and that the system
effectively stores the energy. Meanwhile, the output temperature of
the hot water must be maintained above 45.degree. C. (which meets
the industrial standard), and the heat water can be used round the
clock in all weathers. In short, it must be at least guaranteed
that the hot water above 45.degree. C. can be supplied for 24 hours
a day and 365 days a year, and if possible, it must be guaranteed
that the heated water at a secondary temperature, e.g., 30.degree.
C.-40.degree. C. can be supplied for 24 hours a day and 365 days a
year. Then, if an electrical heater is used, the off-peak
electricity must be fully made use by the device to make sure that
the running cost is the lowest. Besides, the arranging cost of the
device can be reduced and meanwhile the adaptation for mounting the
device is enhanced, which is further helpful for combining the
device with the building integrally.
[0003] According to the prior art, there are two main technical
means to solve the energy accumulation problem for a solar water
heating system: one is to enlarge the volume of the energy
accumulation water tank; the other is to increase the energy
accumulation density per unit of the energy accumulation medium. In
terms of the first solution, the published CN1403760A "Energy
System Using Multiple Complementary Energies" provides a technical
solution to supply hot and cool water using a solar energy
collection and other complementary energies together with an energy
accumulation water tank. The energy accumulation water tank
includes a hot water chamber and a cold water chamber, which are
separated apart by a heat-insulating material. The solar energy
collecting system and a ground source heat pump system are
connected to the energy accumulation water tank respectively. As
shown in accompanying figures, the production and consumption of
hot water in this solution is of a real-time mode. When a certain
amount of hot water is output, the same amount of cold water needs
to be input therein to make sure the heat exchange between the
solar energy collector and the heat storage water tank goes on
well. Since the cold water will be input at any time, it is
impossible to supply a certain amount of hot water above 45.degree.
C. for 24 hours a day and 365 days a year if a non-heat storage
water tank of a normal size is used. Moreover, in sunny days, as
the temperature at the upper part of the heat storage water tank
gradually goes up, the energy collecting efficiency of the solar
energy collecting system declines gradually from noon. Therefore,
the overall thermal performance of the system is quite low. If the
energy is accumulated by means of enlarging the volume of the heat
storage water tank, the water in the lower part always has a low
temperature, which does not make sufficient contributions for the
everyday output of hot water. Besides, the water at a lower
temperature gets bacteria more easily, and gets the supplied water
being polluted. Furthermore, the hot water can be easily mixed with
the cold water if no separation and heat preservation technique is
used, so the water in the upper part of the tank does not easily
reach the required output temperature, and the water tank is too
large to be fully utilized. In addition, the hot water chamber and
the cold water chamber are arranged independently for seasonal use,
which reduces the application rate greatly, but increases the
arranging fee.
[0004] The feature of auxiliary heating using the electric heat
pump technology is energy saving. Its power consumption is 1/3, or
even lower, of the common electrical heating elements with the same
thermal-electrical efficiency. However, the efficiency of the
electric heat pump is limited by the required temperature and the
temperature range of the hot source, and it will be frosted below
the critical temperature. If the temperature difference in heating
is too large, it will be easily damaged. Moreover, it's preferred
to use off-peak electricity to produce hot water with the electric
heat pump, as the electrical power is in shortage.
[0005] To solve the above problems, the applicant brings forward a
water-heating device using solar energy collection and electrical
heating in China Invention Patent Application No. 200510025652.1,
in which the water-heating device includes a solar energy
collector, a heat pump, and an electrical heating element. A
certain amount of hot water produced by the solar energy collector,
the heat pump, or the electrical heating element is stored in a
water tank, such that the hot water is stored and supplied in a
timesharing mode, so as to ensure that the hot water above
45.degree. C. is supplied for 24 hours a day and 365 days a year,
and that the solar energy can be utilized to the maximum extent and
only the off-peak electricity is used. However, the water-heating
device in this technical solution still has some problems, for
example, the solar energy cannot be fully utilized when the area
for installing the solar energy collector is limited, and
meanwhile, the heat pump must be used to make up the insufficient
part where the solar energy is insufficient. So the great amount of
cheap energy such as the off-peak electricity is needed. However,
it is difficult to get sufficient off-peak electricity at night for
family users whose lead-in current capacity is fixed. Meanwhile,
the water tank must be relatively large to realize the effects of
accumulating the energy and reducing the cost, which increases the
arranging fee for the water-heating device. For a large-scale
concentrated water-heating device, enlarging the volume of the
water tank not only increases the arranging fee, but also brings
the problems of mounting on the roof and support capacity of the
mounting surface. Moreover, the area for mounting the solar energy
collector is reduced, so the adaptation of mounting is
affected.
SUMMARY OF THE INVENTION
[0006] A main object of the present invention is to provide a
method for producing hot water utilizing combined heat resources of
solar energy and heat pumps in a manner of heating water at
multiple stages and accumulating energy, so as to produce hot water
by utilizing solar energy, heat pumps or electrical heaters in a
timesharing mode. Upon meeting the requirements of supplying hot
water at or above 45.degree. C. for 24 hours a day and 365 days a
year, the solar energy is utilized to the maximum extent before
using the energy of the heat pump or the off-peak electricity.
Therefore, a predetermined amount of water is produced at a lowest
cost in a manner of heating at multiple stages, which is used for
energy accumulation and supplying of hot water at different
temperature levels in the timesharing mode. If the mounting area
for the collector is inadequate, an output water temperature for
the collector can be set to a secondary level to enhance the
collecting efficiency, which also solves the problem of load
distribution caused by mounting water tanks on the roof
collectively, reduce the arranging fee, and expand the adaptation
of mounting.
[0007] Another object of the invention is to provide a device
especially for carrying out the heating method. The device is a
combination of heating structures working in a timesharing mode,
including solar energy collectors, heat pumps, electrical heaters,
water tanks, and control unit. Upon meeting the requirements of
supplying hot water at or above 45.degree. C. for 24 hours a day
and 365 days a year, the solar energy is utilized to the maximum
extent before using the energy source of the heat pump or the
off-peak electricity. Therefore, a lowest cost is achieved by
heating water at multiple stages, and the hot water produced by
heating in advance and by heating at multiple stages in a
timesharing mode is used for energy accumulation and supplying
water in the timesharing mode according to different temperature
level settings. If the mounting area for the collector is
inadequate, an output water temperature of the collector can be set
to a secondary level to enhance the collecting efficiency, which
enables the energy accumulation water tanks to be arranged
separately, reduces the arranging fee, and expands the adaptation
of mounting.
[0008] The method for producing hot water utilizing combined heat
resources of solar energy and heat pump in a manner of heating
water at multiple stages and accumulating energy of the present
invention is realized through the following technical solutions.
The method for producing hot water utilizing combined heat
resources of solar energy and heat pump in a manner of heating
water at multiple stages and accumulating energy includes a process
of heating with solar energy collectors, a process of heating with
heat pumps, and a process of heating with electrical heaters.
wherein the process of producing hot water is a combination of
heating water in circulating water-heating tanks for the collector
of multi-stage heating and in conflux hot water tanks of
multi-stage heating at multiple stages with the solar energy
collectors, the heat pumps, and the electrical heaters
simultaneously or respectively. The production and consumption of
hot water is of a timesharing mode, that is, a certain amount of
hot water produced by heating periodically at multiple stages can
be produced in advance and stored in the conflux hot water tanks of
multi-stage heating and in an energy accumulation water tank for
being supplied in the timesharing mode for a next period. The
combination of heating the water in the circulating water-heating
tanks for the collectors and in the conflux hot water tanks of
multi-stage heating at multiple stages with the solar energy
collectors, the heat pumps, and the electrical heaters
simultaneously or respectively includes: completely utilizing the
solar energy collectors for heating and storing the hot water in
sunny days; using the heat pump or the electrical heater for
complementarily heating and storing the hot water at night when
off-peak electricity is available; using the heat pump for instant
heating and storing the hot water according to a required certain
amount of hot water storage volume when it is not sunny day and the
off-peak electricity is not available as well.
[0009] The device especially for carrying out the method for
producing hot water utilizing combined heat resources of solar
energy and heat pumps in the manner of heating water at multiple
stages and accumulating energy of the present invention is realized
through the following technical solution. The device especially for
carrying out the method for producing hot water utilizing combined
heat resources of solar energy and heat pump in a manner of heating
water at multiple stages and accumulating energy includes solar
energy collector, water pump, heat pump, electrical heater, water
tanks, and control unit. The water tanks include a circulating
water-heating tank for the collector, conflux hot water tank of
multi-stage heating, and energy accumulation water tank, in which
the solar energy collector is connected to the circulating
water-heating tank for the collector, the circulating water-heating
tank for the collector is connected to the conflux hot water tank
of multi-stage heating, and the conflux hot water tank of
multi-stage heating is connected to the energy accumulation water
tank, the heat pump and the electrical heater are arranged with the
water tanks, and a start control of the solar energy collector, the
water pump, and the heat pump and the electrical heater are
electrically connected to the control unit respectively. The energy
accumulation water tank has more than one water tanks, including
the warm water storage tank of multi-stage heating and the final
temperature water storage tank. The conflux hot water tank of
multi-stage heating, the warm water storage tank of multi-stage
heating, and the final temperature water storage tank are connected
in parallel. The device can include one or more circulating
water-heating tanks for the collector, and the last one of the
interconnected one or more circulating water-heating tanks for the
collector can also be used as the conflux hot water tank of
multi-stage heating. When the heat pump and the electrical heater
are arranged with the water tanks, the heat pump or the electrical
heater is disposed on and outside the water tanks of multi-stage
heating. The device can include one or more heat pumps disposed on
the conflux hot water tank of multi-stage heating and the final
temperature water storage tank or disposed there-between to form
heat pumps for heating at multiple stages, and the heat pumps for
heating at multiple stages can be directly or indirectly connected
in series. The warm water storage tank of multi-stage heating and
the final temperature water storage tank are connected to bypass
pipelines in parallel, and the bypass pipeline has a one-way valve
through which the warm water storage tank of multi-stage heating
supplies or heats the water to the final temperature water storage
tank. Electrical control valves are disposed in the water pipes
connected in parallel between the conflux hot water tank of
multi-stage heating, the warm water storage tank of multi-stage
heating, and the final temperature water storage tank. A connecting
pipe for discharging water is disposed on both the warm water
storage tank of multi-stage heating and the final temperature water
storage tank, and a hot water booster pump can be further disposed
on the connecting pipe for discharging water.
[0010] The advantages of the method for producing hot water
utilizing combined heat resources of solar energy and heat pump in
the manner of heating water at multiple stages and accumulating
energy of the present invention are described as follows. Due to
the adopted process of producing hot water can be the combination
of heating the water in the circulating water-heating tank for the
collector and in the conflux hot water tank of multi-stage heating
at multiple stages with the solar energy collector, the heat pump,
and the electrical heater simultaneously or respectively, in which
the production and consumption of hot water is of a timesharing
mode, that is, a certain amount of hot water produced periodically
by heating at multiple stages can be produced in advance and stored
in the conflux hot water tank of multi-stage heating and in the
energy accumulation water tank for being supplied in a timesharing
mode for a next period. Therefore, the device can completely
utilize the solar energy collector for heating and storing the hot
water in sunny days, use the heat pump for heating and storing the
hot water according to a required certain amount of hot water
storage volume when it is not sunny day and the off-peak
electricity is not available as well, and use the heat pump or the
electrical heater for complementarily heating and storing the hot
water at night when off-peak electricity is available. The certain
amount of produced hot water can be stored in the water tank of
multi-stage heating and the energy accumulation water tank
respectively after being heated at multiple stages, so as to ensure
that solar energy is utilized to the maximum extent before using
the energy source of the heat pump or off-peak electricity for
heating, such that a higher solar energy utilization rate and a
lower running cost compared with the prior art are achieved, and
thus ensuring that the hot water output from the device meets the
requirements of supplying waters at or above 45.degree. C. for 24
hours a day and 365 days a year. Besides, the hot water produced by
heating at multiple stages in the timesharing mode can be stored
and supplied at different temperature levels in the timesharing
mode, so the volume of the energy accumulation water tank can be
reduced substantially, which thus further solves the problem of
load distribution caused by mounting water tanks on the roof
collectively. If the mounting area for the solar energy collector
is inadequate, the collector can be set to a secondary output
temperature to enhance the collecting efficiency. Compared with the
prior art, the arranging fee is reduced significantly, and the
adaptation of mounting is improved.
[0011] The advantages of the device especially for carrying out the
method of the present invention are described as follows. Due to
the adopted water tanks include the circulating water-heating tank
for the collector, the conflux hot water tank of multi-stage
heating, and the energy accumulation water tank, in which the solar
energy collector is connected to the circulating water-heating
tank, and the circulating water-heating tank is connected to the
conflux hot water tank, the heat pump and the electrical heater are
arranged with the water tanks, and the start control of the solar
energy collector, the water pump, and the heat pump and the
electrical heater are electrically connected to the control unit
respectively. As the water tank of multi-stage heating and the
multi-stage heating setting described above are adopted, upon
meeting the requirements of supplying hot water above 45.degree. C.
for 24 hours a day and 365 days a year, the device utilizes the
solar energy to the maximum extent before using the energy source
of the heat pump and the off-peak electricity for heating, so as to
achieve the lowest cost. The hot water produced by heating in
advance in a timesharing mode and by heating at multiple stages can
be stored and supplied in a timesharing mode according to different
temperature level settings. Furthermore, as the conflux hot water
tank of multi-stage heating is connected to the energy accumulation
water tank, the predetermined amount of hot water produced can be
stored in the water tank of multi-stage heating and the energy
accumulation water tank respectively after being heated at multiple
stages. Moreover, since the energy accumulation water tank can be
mounted separately, the volume of the energy accumulation water
tank is significantly reduced, and meanwhile, the adaptation for
mounting the hot water device is improved. If the mounting area for
the solar energy collectors is inadequate, the output water
temperature of the collectors is set at the secondary water
temperature to enhance the collecting efficiency, so the solar
energy utilization ratio becomes higher and the running cost
becomes lower compared with the prior art, and the arranging fee
for the device is also significantly reduced.
[0012] The process of utilizing the method for producing hot water
and the device especially for carrying out the method of the
present invention and the beneficial effects thereof are described
below by means of comparing with the prior art. In the prior art,
the solar energy collection and the ground source heat pump are
taken as auxiliary energies, and both of them are used to supply
heating and cooling after being connected to the energy
accumulation water tank; the energy accumulation water tank
includes a hot water chamber and a cold water chamber separated
apart by a heat-insulating material. Therefore, the production and
consumption of hot water according to the prior art are of a
real-time mode, which cannot meet the requirements of supplying the
rated amount of hot water above 45.degree. C. for 24 hours a day
and 365 days a year. Though the ground source heat pump for
auxiliary heating is energy saving, as the volume of the hot water
chamber in the energy accumulation water tank is too large, and the
supply of water is relied on instant heating when it is not a sunny
day but cloudy or rainy, such electrical heating process mainly
uses the high-price peak electricity, which makes the power
consumption structure unreasonable. Furthermore, since the heat
storage water tank of a larger volume is used to accumulate energy,
the temperature of water in the lower half of the heat storage
water tank is always relatively low, in addition to easily getting
bacteria and polluting the output water, the hot water can be
easily mixed with the cold water as the above two heating processes
are adopted, and thus, the water producing efficiency is reduced,
the energy accumulation effect is affected, and a part of the
effective heat storage volume for the water tank is wasted. In
addition, the hot water chamber and the cold water chamber are
arranged independently for seasonal use, so the utilization rate is
lowered greatly, and the arranging fee is too high, which further
affects the adaptation of mounting the device on the roof.
Moreover, the running cost is relatively high as the thermal
efficiency of the collector is affected by temperature rise or
limited mounting area.
[0013] The production and consumption of hot water of the present
invention is of the timesharing mode, that is, the predetermined
amount of hot water produced periodically by heating at multiple
stages is stored in the conflux hot water tank of multi-stage
heating and the energy accumulation water tank for being supplied
for a next period in the timesharing mode, i.e., the predetermined
amount of hot water produced in advance is stored in the energy
accumulation water tank for being supplied at different
temperatures in the timesharing mode, which merely ensures
supplying hot water at a fixed temperature in the timesharing mode
between two off-peak electricity periods in the morning and at
night of the next day. The predetermined volume of hot water
produced in advance before the off-peak electricity periods are
over is the volume of hot water at a fixed temperature required to
be supplied in the timesharing mode between two off-peak
electricity periods in the morning and at night of the next day,
which occupies 80%-90% of the capacity of the final temperature
water storage tank. Between the two off-peak electricity periods in
the morning and at night of the next day, the predetermined hot
water periodically produced by heating at multiple stages is
repeatedly produced in advance and stored in the conflux hot water
tank of multi-stage heating and the energy accumulation water tank
for being supplied for a next period in the timesharing mode.
Compared with the prior art, the present invention completely
solves the problems relevant to accumulating the energy and
reducing the running cost.
[0014] Because the water tanks include the circulating
water-heating tank for the collector of multi-stage heating, the
conflux hot water tank of multi-stage heating, and the energy
accumulation water tank, the final temperature hot water is stored
alone, so the hot water and cold water cannot be mixed, and the
effective heat storage volume of the water tanks is relatively
large, which avoids being wasted. Another advantage of disposing
the conflux hot water tank of multi-stage heating lies in that, the
circulating heat collection pipelines between the solar energy
collector in the front and the circulating water-heating tank are
greatly shortened, so the flow resistance of the heat exchange
cycle is reduced substantially; the circulation heat collection
pipelines between the circulating water-heating tank for the solar
energy collector and the conflux hot water tank of multi-stage
heating are replaced by top water single-pipe flow-down gap
transmission mode, so the heat loss for the heat preservation of
the heat collection pipelines in the hot water circulation
transmission then is eliminated. Therefore, the thermal efficiency
of the device is significantly improved, which is higher than the
heat collection and heat transmission efficiencies of the prior art
that uses the solar energy collector for heating.
[0015] The start control of the solar energy collector, the water
pump, and the heat pump and the electrical heater are electrically
connected to the control unit respectively, the solar energy
collector is connected to the circulating water-heating tank for
the collector of multi-stage heating, the circulating water-heating
tank is connected to the conflux hot water tank of multi-stage
heating, the conflux hot water tank is connected to the energy
accumulation water tank, the heat pump and the electrical heater
are arranged with the water tanks. Therefore, on sunny days, the
device completely utilizes the solar energy collector to heat and
store hot water, the water in the circulating water-heating tank
for the collector of multi-stage heating is heated by the solar
energy collector; during the off-peak electricity period at night,
the heat pump is used for complementarily heating and storing the
warm water in the water tanks by heating at multiple stages, or the
electrical heater including an electric heat pump is preferentially
used for heating; in winter, when the environmental temperature is
too low that the heat pump cannot operate normally, an electrical
heating element can be used to replace the electric heat pump, and
moreover, the electric heat pump or the electrical heater can also
be used sufficiently for heating under the power during the
off-peak electricity period at night, so as to balance the loads in
peak and off-peak electricity periods of the existing electric
network. Compared with the prior art, the present invention can
meet the requirements of supplying hot water above 45.degree. C.
for 24 hours a day and 365 days a year.
[0016] In addition, if the mounting area of the solar energy
collector is inadequate, with the above multi-stage heating
setting, the working temperature of the collector can be set as the
secondary water output temperature, the heat pump is then used for
complementary heating, and thus, the efficiency of the collector is
improved to compensate the insufficiency for the mounting area of
the collector. Compared with the prior art, the present invention
achieves a higher solar energy utilization rate, and a higher
utilization rate of the off-peak electricity for complementary
heating. After adopting the multi-stage heating setting, the volume
of a single water tank is reduced, and can be mounted at a position
other than the roof. Compared with the prior art, the present
invention can solve the problem of the supporting capability of the
roof and can avoid influencing the appearance of the roof, and more
space previously occupied by the water tanks on the roof is vacated
for the solar energy collector, and thus, the arranging fee of the
device is reduced, and the adaptation for mounting the
water-heating device is improved.
[0017] As the conflux hot water tank of multi-stage heating is
connected to the energy accumulation water tank, and the energy
accumulation water tank includes a warm water storage tank of
multi-stage heating and a final temperature water storage tank
arranged up and down and connected in parallel. Compared with the
prior art, the present invention can store and supply hot water at
a secondary temperature of 30.degree. C.-40.degree. C. for daily
washing. In winter, the hot water of above 45.degree. C. can be
stored, and the warm water cannot reach the required final
temperature can be recycled. In summer, the warm water storage tank
of multi-stage heating can be converted to the final temperature
water storage tank for storing extra heats. Therefore, the present
invention realizes the feature of giving priority to achieving
maximum thermal efficiency in winter while achieving maximum heat
storage capability in summer. As the hot water storing capability
of the device is almost doubled, after sunset, the device still has
sufficient storage capacity to accommodate warm water sufficient
for being discharged from the solar energy collector, the
circulating water-heating tank for the collector, and the conflux
hot water tank of multi-stage heating, so the heating and heat
exchanging efficiency for the solar energy collector in the next
day is not influenced, and thus, the device can utilize the solar
energy to the maximum extent to reduce the running cost. Compared
with the prior art, the device of the present invention has a
higher heat collection efficiency, and an increased capability of
outputting hot water at different temperatures.
[0018] Furthermore, since the device is disposed with the warm
water storage tank of multi-stage heating, it can store the water,
at the secondary or final temperature. In this way, for urgent
need, the heat pump can be used for instant heating and energy
accumulation according to the predetermined hot water storage
volume setting in the peak electricity period without sunshine, so
as to supplement or heat and supply water to the final temperature
water storage tank, and thus, it is ensured that the hot water
above 45.degree. C. is supplied for 24 hours a day and 365 days a
year at the lowest running cost, which exceeds the capability of
the prior art. Therefore, the techniques of the present invention
have substantial improvement and progress compared with the prior
art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a schematic structural view of a device according
to a first embodiment of the present invention.
[0020] FIG. 2 is a schematic structural view of a device according
to a second embodiment of the present invention.
[0021] FIG. 3 is a schematic structural view of a device according
to a third embodiment of the present invention.
[0022] FIG. 4 is a schematic structural view of a device according
to a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The method for producing hot water utilizing combined heat
resources of a solar energy and a heat pump in a manner of heating
water at multiple stages and accumulating energy and the device
especially for carrying out the method of the present invention are
further illustrated below with reference to the embodiments.
[0024] FIG. 1 is a schematic structural view of a device according
to a first embodiment of the present invention, which includes at
least one solar energy collector 1, a control unit 2, at least one
heat pump 3, at least one water tank 4, at least one booster pump
5, at least one water-heating tank 6, at least one electrical
heater 7, and at least one electric control valve 8.
[0025] The water-heating tank 6 is a water tank for heating at
multiple stages formed by two or more multi-stage heating water
tanks 611 and 612. The multi-stage heating water tank 611 is a
conflux hot water tank of multi-stage heating, and the multi-stage
heating water tank 612 is a warm water storage tank of multi-stage
heating. The multi-stage heating water tank 611 includes
circulating water-heating tank for the collector of multi-stage
heating 610 and the conflux hot water tank of multi-stage heating
611. The hot water tanks of multi-stage heating 611 and 612 are
mounted in front of the final temperature water storage tank 4. The
tanks are arranged sequentially according to the temperature of the
heating stages, that is, the circulating water-heating tank 611
with a lower heating temperature is positioned in front, 612 with a
slightly higher heating temperature is in the back, and the
circulating water-heating tanks 611 and 612 are connected to the
final temperature water storage tank via pipelines. Combined water
tanks capable of accumulating energy and heating as published in
CN2544229Y formed by a water heating tank and a heat storage water
tank can also be applied as the water tanks herein.
[0026] The solar energy collector 1 and the heat pump 3 can form a
multi-stage heating unit of different temperatures. The multi-stage
heating output of the multi-stage heating unit formed by the solar
energy collector 1 and the heat pump 3 is connected to the
corresponding multi-stage heating water tank 6 via pipelines. The
electrical heater includes an electrical heating element and an
electric heat pump. The multi-stage heating water tank can include
the electrical heating element 7. The solar energy collector, the
water tank, the water pump, the water-heating tank, the start
control of the heat pump, the electric control valve, and the
electrical heating element are electrically connected to the
control unit 2 respectively. A predetermined amount of hot water
produced by heating at multiple stages is stored in more than one
energy accumulation water tanks, including the warm water storage
tank 612 of multi-stage heating and the final temperature water
storage tank 4.
[0027] The multi-stage heating hot water tank further includes the
circulating water-heating tank 610 for the collector of multi-stage
heating and the conflux hot water tank 611 of multi-stage heating.
The secondary warm water heated by the solar energy collector
passes through several circulating water-heating tanks 610, then
flows into the conflux hot water tank 611 to become the final
temperature hot water of 45.degree. C., which is then supplied to
the final temperature water storage tank 4 for storage via the
electrical control valve 8 and the pipelines as shown in FIG. 1.
Alternatively, when the final temperature water storage tank is
full, the water of the final temperature or the secondary
temperature flows into the warm water storage tank 612 for backup
through the electrical control valve 8 and the pipelines connected
in parallel, and it can be further heated by the heat pump whenever
necessary and then flow into the final temperature water storage
tank 4 for storage through the bypass heating pipe of the heat pump
shown in FIG. 1. If the solar energy is insufficient or the
mounting area for the solar energy collector is not adequate, the
temperature of the hot water output from the collector can be set
to about 30.degree. C.-40.degree. C., then the water flows into the
warm water storage tank 612 for storage, or output to the final
temperature water storage tank 4 for storage after being heated by
the heat pump. For this reason, the warm water storage tank and the
final temperature water storage tank 4 both include connecting
pipes and the booster pump 5 for outputting the hot water, and the
warm water storage tank supplies hot water to the final temperature
water storage tank as a supplementary via a one-way valve, or
directly supplies the hot water of a final temperature to the final
temperature water storage tank after the water is heated by a heat
pump in the back.
[0028] The heat pump 3 is an air source heat pump using the heat in
the air as the heat source. In addition, the heat pump 3 can also
be other different heat pumps such as a water source heat pump, a
ground source heat pump, or any combination thereof, for example, a
combination of a water source heat pump using wastewater discharged
from living and building districts as the heat source and an air
source heat pump. The heat pump 3 includes one or more heat pumps
of multi-stage heating, and two heat pumps of multi-stage heating
311 and 312 are used here, both of which are disposed between the
multi-stage heating water tank and the final temperature water
storage tank, e.g., at a position on or outside the multi-stage
heating water tank. The heat pump 311 in the front is connected to
the conflux hot water tank 611, the heat pump 312 in the back is
connected to the warm water storage tank 612 first and then to the
final temperature water storage tank. The two heat pumps of
multi-stage heating are indirectly connected in series as shown in
FIG. 1. In addition, the heat pumps can be connected directly or
indirectly with one another in parallel. According to the design,
the predetermined amount of produced hot water accounts for about
80%-90% of the total volume of the warm water storage tank of the
secondary output or of the final temperature water storage tank.
Moreover, output circulating pipelines of the heating or air
conditioning unit can be connected between the multi-stage heating
water tanks via heat exchangers.
[0029] The solar water-heating device mainly composed of the solar
energy collector includes heat exchange circulation pipelines
connected in a manner of direct flow, circulating reflux, or a
combination thereof. Here, the natural circulating reflux pipeline
connection is used. The process of producing hot water is a
combination of heating at multiple stages with the solar energy
collector, the heat pump, or the electrical heater, including a
process of heating with the solar energy collector, a process of
heating with the heat pump, and a process of heating with the
electrical heater. In sunny days, the solar energy collector is
used for heating; at night when the off-peak electricity is
available, the heat pump is used for heating; when it is not sunny
day and the off-peak electricity is not available, different heat
pumps are chosen for heating and energy accumulation according to
the predetermined amount of hot water storage volume; in winter
nights when the off-peak electricity is available but the
environmental temperature is too low for the heat pump to run
normally, the electrical heater is used for heating. In addition,
if there is no electricity supply, gas heating, e.g., by a gas heat
pump, can be used to replace the electric heating by the electrical
heater to form a combination.
[0030] The predetermined amount of hot water periodically produced
by heating at multiple stages will be produced in advance, and
stored in the conflux hot water tank and the energy accumulation
water tank for being supplied in a timesharing mode. The volume of
the predetermined amount of hot water produced periodically by
heating at multiple stages refers to the volume of hot water at a
predetermined temperature that needs to be supplied in the
timesharing mode between two off-peak electricity periods in the
morning and at night of the next day. The predetermined temperature
is the temperature of the output hot water specified in technical
standards on solar water heating devices which the present
invention is applied. In the applicable district of China, the
temperature of output hot water is 45.degree. C. according to the
current new technical standard. In addition, through the warm water
storage tank 612, the water-heating device can also supply warm
water at the secondary temperature of 30.degree. C.-40.degree. C.
for daily washing for 24 hours a day and 365 days a year. The two
water tanks for storing the predetermined amount of hot water both
include temperature and water level sensors, so as to control and
manage the stored water with the control program of the control
unit 2.
[0031] The solar energy collector 1 is a three-dimensional solar
energy collector that can be mounted on a wall, and through using
the technical solution of CN2558931Y, the damages to the appearance
of buildings can be prevented, and meanwhile, the
vertically-mounted collector can guarantee long-term and steady
output of heats at a high efficiency once being vertically mounted
on a wall, which is the critical point in terms of vertically
mounting the collector on the wall. The three-dimensional solar
energy collector can be mounted vertically, slantingly,
horizontally, or in a combination of the above mounting modes.
Here, the combination of vertical and slanting mounting modes is
adopted.
[0032] The water tanks include the heating water tank and the heat
storage water tank, which can include or not include energy
accumulation materials. In addition to normal water tanks with a
single volume, the parallel-connected water tanks for volume water
heaters can also be used, the details are described in CN2656881Y,
"Parallel Connected Water Tank for Volume Water Heater".
[0033] FIG. 2 is a schematic structural view of a device according
to a second embodiment of the present invention, which includes at
least one solar energy collector 1, a control unit 2, at least one
heat pump 3, a final temperature water storage tank 4, a booster
pump 5, at least one water-heating tank 6, at least one electrical
heating element 7, and at least one electric control valve 8. In
FIG. 2, multi-stage heating units of different temperatures are
formed between the solar energy collector 1 and the heat pump 3,
and meanwhile, two multi-stage heating outputs formed by the
multi-stage heating units of the solar energy collector are
connected to corresponding multi-stage heating water tanks 610 and
611 via pipelines.
[0034] The multi-stage heating water tank includes the electrical
heating element 7. The multi-stage heating outputs formed by the
multi-stage heating units of different temperatures constituted by
the solar energy collector and the heat pump are connected to the
corresponding multi-stage heating water tank 6 via pipelines. The
multi-stage heating outputs include the output of circulating
heating the multi-stage heating water tank and the output of
directly heating the output of the multi-stage heating water tank.
The solar energy collector, the water tank, the water pump, the
water-heating tank, the heat pump, and the electrical heater are
electrically connected to the control unit 2 respectively. The
predetermined amount of produced hot water is heated at multiple
stages, and then separately stored in the warm water storage tank
612 and the final temperature water storage tank 4.
[0035] The water tank is a combined water tank for energy
accumulation and heating formed by the water-heating tank and the
heat storage water tank. The water-heating tank 6 is a multi-stage
heating water tank composed of three multi-stage heating water
tanks 610, 611, and 612. The warm water storage tank of multi-stage
heating is disposed in front of the final temperature water storage
tank or the heat storage water tank 4. There can be one or more
circulating water-heating tanks for the collector as shown in FIGS.
2 and 3. When a plurality of circulating water-heating tanks for
the collector is connected in series, the last circulating
water-heating tank 611 can function as the conflux hot water tank
of multi-stage heating as well. The circulating water-heating tanks
610 and 611 for the collector of multi-stage heating are used to
form a multi-stage heating unit with each other between the solar
energy collectors, and further used to form another multi-stage
heating unit with the heat pump 3. These units are arranged
according to a sequence of the temperature for the multi-stage
heating, i.e., the heating unit with a lower heating temperature is
disposed in the front, and the heating unit with a slightly higher
temperature is disposed in the back. The multi-stage heating water
tanks 611 and 612 are connected to the final temperature water
storage tank respectively via pipelines.
[0036] The primary hot water heated by the solar energy collector
first flows into the circulating water-heating tank 610 for the
collector of multi-stage heating, and then flows into the
circulating water-heating tank for the collector of multi-stage
heating or the conflux hot water tank 611, where the water is
heated again by the heat pump or the electrical heater to reach the
final temperature, and thus, the hot water of the final temperature
is stored in the final temperature water storage tank 4. When the
final temperature water storage tank 4 is full, the water is set to
the final temperature or the secondary temperature and sent to the
warm water storage tank 612 for backup. At this time, the warm
water storage tank can be converted to the final temperature water
storage tank, so the hot water storage capacity of the device is
almost doubled, and the water can also be re-heated by the heat
pump at any moment and sent to the final temperature water storage
tank 4 for storage. For this reason, both the warm water storage
tank 612 and the final temperature water storage tank 4 can include
the connecting pipes and the booster pump 5 for outputting the hot
water. The hot water in the warm water storage tank 612 can be
supplied to the final temperature water storage tank via bypass
pipelines and one-way valves connected in parallel, or heated by
the heat pump at the back, and then, the hot water at the final
temperature is supplied to the final temperature water storage
tank.
[0037] The heat pump 3 includes one or more heat pumps of
multi-stage heating. Here, two heat pumps of multi-stage heating
311 and 312 directly connected in series are used, or a two-stage
heat pump can be used as an equivalent. In this manner, the hot
water of the final temperature can be produced by heating at
multiple stages using the off-peak electricity directly in winter.
Furthermore, if the electric heat pump cannot normally work because
of the low temperature in winter, the electrical heating element in
the hot water tank of multi-stage heating can be used to replace
the manner of multi-stage heating. All of the heat pumps of
multi-stage heating are disposed between the warm water storage
tank 612 and the final temperature water storage tank 4.
[0038] The solar energy collector 1 is mounted by means of a
combination of vertical and slanting mounting modes. For example,
most solar energy collectors are mounted vertically to the wall,
and others are mounted slantingly to the wall. Besides the solar
energy collectors, the solar water heating device also includes
heat exchange circulation pipelines connected in a forced
circulating reflux mode. The solar energy collector 1 forms
multi-stage heating units of different temperatures, for example,
two different temperatures, which are connected in series as shown
in FIG. 2. The collector with a lower temperature output is
disposed in the front, and the collector with a slightly higher
temperature output is disposed in the back. The hot water after
being heated at multiple stages will be directly sent to the final
temperature water storage tank 4 for storage. When the solar energy
is insufficient, the water flows into the warm water storage tank
612 for backup, and can be reheated by the heat pump and then sent
to the final temperature water storage tank 4 for storage.
[0039] FIG. 3 is a schematic structural view of a device according
to a third embodiment of the present invention, which includes a
solar energy collector 1, a control element 2, at least one heat
pump 3, a final temperature water storage tank 4, a booster pump 5,
at least one heating water tank 6, and at least one electrical
heating element 7. In FIG. 3, the solar energy collector 1 and the
heat pump 3 can form multi-stage heating units of different
temperatures. The multi-stage heating outputs formed by the
multi-stage heating units for the solar energy collector and the
heat pump are connected to corresponding multi-stage heating water
tank 6 via pipelines. The multi-stage heating water tank can
include an electrical heating element 7. The solar energy
collector, the water tank, the water pump, the water-heating tank,
the heat pump, and the electrical heater are electrically connected
to the control unit 2 respectively. A predetermined amount of
produced hot water is heated at multiple stages and be separately
stored in the warm water storage tank 612 and the final temperature
water storage tank 4.
[0040] The water tank includes a water-heating tank and a heat
storage water tank. The water-heating tank 6 is a multi-stage
heating water tank formed by two multi-stage heating water tanks
611 and 612 disposed in front of the final temperature water
storage tank 4. The circulating water-heating tank 611 with a lower
temperature is disposed in the front, and the conflux hot water
tank 612 with a slightly higher temperature is disposed in the
back. The water tanks of multi-stage heating 611 and 612 are
connected to the final temperature water storage tank via
pipelines.
[0041] The hot water of the final temperature heated by the solar
energy collector directly flows into the final temperature water
storage tank 4 for storage under the control of the control unit 2.
If the solar energy is insufficient or the mounting area of the
solar energy collector is not adequate, the secondary hot water
produced flows into the warm water storage tank 612 for storage,
and can be supplied to the final temperature water storage tank 4
for storage after being further heated by the heat pump.
[0042] The heat pump 3 includes two air source heat pumps of
multi-stage heating connected in series between the warm water
storage tank of multi-stage heating and the final temperature water
storage tank. The heat pump of multi-stage heating 311 in the front
is connected to the warm water storage tank 611, and the heat pump
of multi-stage heating 312 in the back is connected to the final
temperature water storage tank.
[0043] The solar energy collector 1 is a three-dimensional solar
energy collector mounted on a wall vertically, so as to prevent
damaging the appearance of buildings. The solar water heating
device mainly composed of the solar energy collector includes heat
exchange circulation pipelines connected in a natural circulating
reflux mode. The predetermined amount of hot water produced in
advance is stored in the water tanks for being supplied in the
timesharing mode. The two hot water tanks for storing predetermined
amount of hot water include the temperature and water level
sensors, so as to control and manage the stored water using the
control program of the control unit 2. In addition to normal water
tanks with a single volume, the parallel-connected water tanks for
volume water heaters can also be used, so the water tanks of
appropriate sizes and shapes can be used to reduce the space
occupied by the water tanks.
[0044] FIG. 4 is a schematic structural view of a device according
to a fourth embodiment of the present invention, which includes at
least one solar energy collector 1, a control unit 2, at least one
heat pump 3, a final temperature water storage tank 4, a booster
pump 5, at least one water-heating tank 6, and at least one
electrical heater 7. In FIG. 4, the solar energy collector 1 forms
a multi-stage heating unit of different temperatures, and
meanwhile, the solar energy collector 1 and the heat pump 3 form
another multi-stage heating unit of different temperatures. The
multi-stage heating outputs formed by both units are connected to
the corresponding heat storage water tanks via pipelines through
the conflux hot water tank. The multi-stage heating water tanks can
include the electrical heating element 7, and the solar energy
collector, the water tank, the water pump, the water-heating tank,
the heat pump, and the electrical heating element are electrically
connected to the control unit 2 respectively. The predetermined
amount of hot water produced is heated at multiple stages and then
separately stored in the warm water storage tank 612 and the final
temperature water storage tank 4.
[0045] The solar energy collector 1 is a two-dimensional solar
energy collector mounted slantingly. The solar water heating device
mainly composed of the solar energy collector includes heat
exchange circulation pipelines, which are connected in a manner of
direct flow, circulating reflux, or a combination thereof. Here,
the forced circulating reflux connection manner is used.
[0046] The water tank is a combined water tank for energy
accumulation and heating formed by a water-heating tank and a heat
storage water tank. The water-heating tank 6 is a multi-stage
water-heating tank formed by three circulating water-heating tanks
610, 611, and 612 for the collector. The warm water storage tank of
multi-stage heating is disposed in front of the final temperature
water storage tank 4. The water tanks are arranged in a sequence
according to the temperature of the multi-stage heating, and
connected to the final temperature water storage tank via
pipelines. The warm water storage tank and the final temperature
water storage tank 4 both include the booster pump 5 for outputting
the hot water.
[0047] The hot water tank of multi-stage heating includes the
multi-stage heating water tanks 610 and 611. The primary hot water
heated by the solar energy collector flows into the warm water
storage tank 612 via the conflux hot water tank 611; then, the hot
water is heated to reach the final temperature; and under the
control of the control unit 2, the hot water of the final
temperature directly flows into the final temperature water storage
tank 4 for storage. If the solar energy is insufficient or the
mounting area of solar energy collector is not adequate, the
produced secondary water flows into the warm water storage tank 612
for storage, and can be supplied to the final temperature water
storage tank 4 for storage after being further heated by the heat
pump. The predetermined amount of hot water produced in advance is
stored in the water tanks for being supplied in a timesharing mode.
The two water tanks for storing the predetermined amount of hot
water both include the temperature and water level sensors, so as
to control and manage the stored water with the control program of
the control unit 2.
[0048] The heat pump 3 includes two heat pumps of multi-stage
heating 311 and 312 disposed between the multi-stage heating water
tank and the final temperature water storage tank. The heat pump of
multi-stage heating 311 in the front is connected to the conflux
hot water tank 611, and the heat pump of multi-stage heating 312 in
the back is disposed between the warm water storage tank of
multi-stage heating and the final temperature water storage tank.
The two heat pumps of multi-stage heating are indirectly connected
in series as shown in FIG. 4, and other arrangements are the same
as that of the third embodiment of the present invention.
[0049] The working process and principles of the present invention
are described as follows. In sunny days, the solar energy collector
is used to heat the water in the multi-stage heating water tank; in
the off-peak electricity period at night, the heat pump is firstly
used to heat the water in the multi-stage heating water tank; in
winter when the environmental temperature is too lower for the heat
pump to run normally, the electrical heating element or the gas
heat pump can be used to replace the electric heat pump to heat the
water. The predetermined amount of hot water produced in advance is
stored in the water tanks for being supplied in the timesharing
mode, so as to supply the required amount of hot water at a certain
temperature between two off-peak electricity periods in the morning
and at night of the next day.
[0050] The collector of the solar energy water-heating device
absorbs the solar energy and converts it into heats through the
circulating heat exchange pipelines and the circulating water tank
of multi-stage heating, for heating the water in the water tanks.
When in cloudy and rainy day or in winter, the collecting
efficiency of the solar energy collector reduces, so the water tank
4 does not have sufficient stored hot water for being supplied in
the next period. At this time, the heat pump powered by the
off-peak electricity is used for heating the water in the water
tank in the off-peak electricity period at night. In the off-peak
electricity periods at winter nights, when the environmental
temperature is too low for the heat pump to run normally, the
electrically heating element in the multi-stage heating water tank
is used instead for heating the water. The predetermined amount of
hot water produced during the off-peak electricity period can only
guarantee the required amount of hot water for being supplied in
the timesharing mode between two off-peak electricity periods in
the morning and at night of the next day. This amount is only
80%-90% of the volume of the warm water storage tank of multi-stage
heating or the final temperature water storage tank, so after the
sunset, it still has sufficient storage capacity for accommodating
the warm water discharged from the solar energy collector, the
circulating water-heating tank for the collector, and the conflux
hot water tank of multi-stage heating, and thus, the multi-stage
heating efficiency for the solar energy collector in the next day
is not influenced. When the final temperature water storage tank is
full, the multi-stage heated hot water output from the front is
switched to flowing into the warm water storage tank 612 for being
stored as the hot water of final temperature. Whenever necessary,
the hot water still can be sent to the final temperature water
storage tank with a transfer pump via bypass pipelines.
Alternatively, if the solar energy is insufficient or the mounting
area of the solar energy collector is not adequate, the secondary
warm water is first supplied to the warm water storage tank 612 for
storage, and it can be heated by the heat pump at any moment or in
the off-peak electricity period and then sent to the final
temperature water storage tank for storage. If it is not sunny day
or if the off-peak electricity is not available, the heat pump is
used to heat the water and store the hot water according to the
predetermined amount of hot water storage setting. In another
aspect, as the circulating water-heating tank for the collector in
the front also functions as the conflux hot water tank of
multi-stage heating, the warm water storage tank of multi-stage
heating 612 and the final temperature water storage tank 4 can be
installed indoors or at other positions of a building without
affecting the roof for supporting the device, so as to eliminate
the disadvantages of mounting on the roof and the restrictions of
supporting capacity of the roof. Therefore, more area is saved for
mounting the solar energy collector, and the workload and
difficulty for mounting the water tank on the roof are greatly
reduced. Meanwhile, the influences on the appearance of buildings
are significantly lowered, and thus, the application and the
adaptation for mounting the water-heating device are greatly
improved.
[0051] The control unit does not start the heat pump in the back
for instant heating the stored water until the hot water in the
water tank is insufficient, for example, lower than a corresponding
lowest water level setting for a certain period of time, and the
temperature of the water stored in the warm water storage tank 612
is also lower than 45.degree. C. In this manner, it is guaranteed
to supply hot water over 45.degree. C. for 24 hours a day and 365
days a year. Moreover, the water-heating device can also supply the
warm water at the secondary temperature of about 30.degree.
C.-40.degree. C. from the warm water storage tank 612. Under the
precondition that the solar energy can be utilized to the maximum
extent, the heat pump or the electrical heater powered by the
off-peak electricity at night is used for heating the water, so as
to reduce the load difference between peak and off-peak periods of
the electric network.
[0052] Moreover, if the mounting area of the solar energy collector
is not adequate, as this device uses the multi-stage heating
manner, the working temperature of the collector can be set to the
secondary output temperature. Therefore, the collector works more
efficiently to compensate the insufficient mounting area for the
collector. The warm water storage tank of multi-stage heating can
store both hot water of the secondary temperature and hot water of
the final temperature, so the size of the water storage tank is
reduced, and the water storage tank can be separated from the roof,
and thus, the problems of the supporting capacity and appearance
impacts are solved, and the mounting area for the collector is
expanded. Therefore, the arranging fee of the device is reduced and
its adaptation of mounting is improved.
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