Technical Field
The present disclosure relates to the field of power generation, hot water and chilled
water production, which can be used in any process unit. Power is generated in a
thermodynamic process with hot stream generated in solar panels, preferably
5 concentrated solar panels due to better efficiency and temperature. Waste low grade
heat, available in the process stream within any process unit, which has to discarded
in air/water cooler may be utilized by heating it further with solar energy based on
the heat stable properties of the process stream. A thermodynamic process such as a
kalina/ organic rankine cycle recovers waste low grade heat from process stream to
10 generate power. The present disclosure also relates to utilizing adsorption
refrigeration technique to produce chilled water, which in turn can be utilized in the
process industries for low temperature applications such as air handling units (AHU)
etc. Particularly the present disclosure relates to the integration of solar with a
thermodynamic process and adsorption refrigeration technique, to better utilize
15 available energy for producing power, hot water and chilled water. The use of
thermal energy storage devices can help in optimizing the whole process based on
availability of solar energy.
Background
20 In recent days, the utilization of low-level heat gained momentum with various
thermodynamic cycles similar to the Rankine cycles being developed for producing
power and other thermodynamic cycles like absorption and adsorption cycles for
producing chilled water. Hybrid cycles producing power and chilled water like
Goswami cycle are also being pursued on case-to-case basis.
25
With the increased concern for energy, due to increased fuel prices and also due to
the detrimental effects caused by increasing the emissions by burning fuels, low
level heat recovery as well as alternative energy is also gaining momentum. Coming
to process units, heat is required to carry out various unit operations and also in some
30 cases like in the case of exothermic reactions, heat is released. The process stream of
this high temperature may be needed to be cooled before the next operation or before
3
being sent to storage or to other units based on the design configuration. In such
cases heat is generally recovered in the form of steam and utilized. But if the quality
of heat is not good enough to generate steam that can be used or there is less demand
of steam in the process, the process stream is cooled in either air or water coolers and
5 the energy, generally referred as low-level heat if the temperature is around 100-
150oC, is lost to atmosphere. Though low-level heat doesn’t have standard
definition, it varies from process to process and also technology to technology. This
low-level heat can be utilized in various technologies or thermodynamic cycles as
mentioned above. It could be more economical when the low-level heat can be raised
10 further beyond some temperature either to go for steam generation or any other
utility which need high temperature like in case of process-process heat exchange.
CN100425925C discloses an electricity generating, air conditioning and heating
apparatus utilizing natural working substance and solar energy or waste heat, which
15 is composed of a solar energy collector or a waste heat collector, a pump, a turbine,
an electric generator, a refrigerator, and a heat exchanger that are connected together
by pipelines, wherein an inlet and an outlet of the solar energy collector or the waste
heat collector are respectively connected with an outlet of the pump and an inlet of
the turbine and form a natural working substance loop, and natural working
20 substance with low-boiling point in liquid state reaches the state of supercritical
pressure after pressurized by the pump orderly and is then heated to be supercutical
fluid with high temperature and high pressure by the solar energy collector or the
waste heat collector. Although this patent discloses process for generation of the
electricity, there is still a requirement for more efficiently utilize the energy from the
25 process stream and produce hot and cold water.
CN101893327B discloses a solar-powered water heating and heat-electricity
converting device. The device comprises a water storage tank, a heat exchanger, a
turbine, a fractional condensation unit and at least one evacuated tube collector
30 connected in series/in parallel, wherein the water outlet of the evacuated tube
collector is connected with the water inlet of the water storage tank; the water outlet
4
of the water storage tank is connected with the hot side inlet of the heat exchanger;
the hot side outlet of the heat exchanger is connected with the water inlet of the
evacuated tube collector through a first circulating water pump; the cold side of the
heat exchanger is connected with the turbine and the fractional condensation unit
5 through a kalina circulating secondary loop respectively; and the turbine is
connected with an electric generator through a transmission case. This patent
discloses the solar powered water heater producing electricity and hot water,
however the residual heat/ low temperature heat in the stream is not utilized/ wasted.
The requirement of an integrated process for better energy recovery is needed.
10
EP1890035B1 discloses solar concentrator plant that works in rankine cycle and
using a combination of two-dimensional and three-dimensional solar
concentrators, characterized in that it uses only water as a working fluid and
wherein:
15 • the two-dimensional solar concentrator means are designed to provide 82% of the
thermal power needed for the power block, heating the water from approximately
50°C to 330°C generating saturated water vapor and
• the three-dimensional solar concentrator means, consisting of a heliostat field and a
central receiver tower, are designed to provide no less than 18% of the thermal
20 power needed for the thermal power block, heating the water beyond the temperature
already attained using the two-dimensional solar concentrator means generating
overheated water vapor.
This document discloses the solar concentrator comprising a rankine cycle. This
25 process is not energy efficient and this is a requirement of an energy efficiency
process.
Further, solar energy technologies are being available in economic sense with costs
of various kinds of solar panels getting reduced year on year. Solar energy as a
30 renewable source of energy is gaining importance with installations across the globe
particularly in direct conversion of solar energy to power. Though a cleaner source
5
of energy, it suffers from low efficiency. Alternatively, utilizing the solar thermal
energy directly by using solar thermal collectors like the concentrating solar panels
(CSP) can be of direct utility for process industries. The solar thermal collectors
come in different configurations like unglazed collector, flat plate glazed collectors,
5 evacuated tube CPC collector, parabolic trough etc. Using these collectors, the
process streams can be either heated directly or indirectly. In direct heating, the
process fluid can go to the collector and gets heated up. In indirect heating, another
working medium is used. Firstly, the working medium gets heated up and then it
exchanges the heat with the process fluid. Thus, the working medium loops in
10 between the process fluid and the thermal collector. Coming to efficiency of these
various solar thermal collectors, they vary with respect to temperature they operate.
Thus, an unglazed collector is more efficient at low temperatures compared to flat
plate glazed one. Similarly, the efficiency of various collectors varies with respect to
temperature. Thus, the choice of solar collectors could be based on the application
15 and the location of their installation and the time they would operate. Generally, a
parabolic dish concentrated solar panel may be used for general high temperature
applications as losses due to atmospheric scattering are generally minimal. Further,
power tower may be also preferred for very high temperature applications.
20 The present disclosure overcomes the problems of the current technology by the
claimed process and system.
Summary of the invention
The following presents a simplified summary of the disclosure in order to provide a
25 basic understanding of some aspects of the disclosure. This summary is not an
extensive overview of the present disclosure. It is not intended to identify the
key/critical elements of the disclosure or to delineate the scope of the disclosure. Its
sole purpose is to present some concept of the disclosure in a simplified form as a
prelude to a more detailed description of the disclosure presented later.
30
6
The present disclosure provides a process and an apparatus for production of hot
water, power, chilled water in series through kalina cycle and adsorption
refrigeration cycle using solar thermal energy. The present invention is for using the
solar thermal energy in tandem with the process units for site utility system in an
5 efficient and optimum manner. Power is generated in a thermodynamic process with
hot stream generated in solar panels, preferably concentrated solar panels. Waste low
grade heat, available in the process stream within any process unit, which has to
discarded in air/water cooler may be utilized by heating it further with solar energy
based on the heat stable properties of the process stream. Or a separate working
10 fluid, for example water, can be used which is heated in solar panel and a
thermodynamic process such as a kalina/ organic rankine cycle recovers waste low
grade heat from process stream to generate power.
In a simple kalina cycle, the working medium liquid is pumped to an increased
15 pressure before sending it to evaporator where evaporation of flow using heat
generates both liquid and gas. The gas is separated from liquid in a gas-liquid
separator before it goes to an expander for production of shaft work. The expanded
working medium is in partial condensed stage which is totally condensed by
air/water cooler/condenser before it goes as inlet to pump to complete the cycle. The
20 efficiency of a simple kalina cycle is around 10-15 %. various advances in kalina
cycles includes additional equipment like recuperators, absorbers, super heaters etc.
to maximize the cycle efficiency.
Further the present invention relates to utilizing adsorption refrigeration cycle to
25 produce chilled water, which in turn can be utilized in the process industries for low
temperature applications. In adsorption refrigeration cycle, the refrigerant or
adsorbate vapour molecules adsorb onto the surface of a solid instead of dissolving
into a liquid. In adsorption system, an adsorber adsorbs the refrigerant vapour into a
solid, while in absorption system, an absorber absorbs the refrigerant vapour into a
30 liquid. Adsorption refrigeration also includes a generation process where refrigerant
vapour molecules desorbing from the solid. Though various combinations of
7
adsorbent and refrigerant are used, one pair is active carbon fiber and ammonia
being an adsorbent and refrigerant respectively.
The adsorption refrigeration cycle comprises
5 - desorbing the refrigerant from the chamber, by heating the chamber;
- liquifying the refrigerant;
- evaporating the refrigerant to produce a cooling effect.
The present process and apparatus also employ a thermal energy storage device
which is configured to store thermal energy. A thermal energy storage device
10 optimizes the power production and meets varying demand of power. The storage
device could be used to either produce constant power at varying process conditions,
gas turbine operation etc. Various high temperature thermal energy storage materials
viz. oils/wax, molten salts, liquid metals etc. can be incorporated.
15 Particularly the present disclosure relates to the integration of solar with a
thermodynamic process and adsorption refrigeration technique, to better utilize
available energy for producing power, hot water and chilled water.
Brief description of accompanying drawings
20 The above and other aspects, features, and advantages of certain exemplary
embodiments of the present disclosure will be more apparent from the following
description taken in conjunction with the accompanying drawings in which:
FIG.1is a schematic representation of a typical solar energy providing hot water,
25 power and chilled water.
FIG.2 is a schematic representation of a process and apparatus for production of hot
water, chilled water and electricity using solar energy.
FIG.3is a schematic layout of a process and apparatus for production of hot water,
chilled water and electricity using solar energy.
8
FIG. 4 is a schematic representation of a typical low-level heat recovery
configuration- kalina cycle along with thermal energy storage and adsorption
refrigeration cycle.
FIG. 5 is a schematic representation of atypical low-level heat recovery
5 configuration- kalina cycle (process stream directly routed to solar panel).
Detailed description of the invention
The following description with reference to the accompanying drawings is provided
to assist in a comprehensive understanding of exemplary embodiments of the
10 disclosure. It includes various specific details to assist in that understanding but these
are to be regarded as merely exemplary.
Accordingly, those of ordinary skill in the art will recognize that various changes
and modifications of the embodiments described herein can be made without
15 departing from the scope of the disclosure. In addition, descriptions of well-known
functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to
the bibliographical meanings but are merely used by the inventor to enable a clear
20 and consistent understanding of the disclosure. Accordingly, it should be apparent to
those skilled in the art that the following description of exemplary embodiments of
the present disclosure are provided for illustration purpose only and not for the
purpose of limiting the disclosure as defined by the appended claims and their
equivalents.
25
It is to be understood that the singular forms “a,” “an,” and “the” include plural
referents unless the context clearly dictates otherwise.
By the term “substantially” it is meant that the recited characteristic, parameter, or
30 value need not be achieved exactly, but that deviations or variations, including for
example, tolerances, measurement error, measurement accuracy limitations and other
9
factors known to those of skill in the art, may occur in amounts that do not preclude
the effect the characteristic was intended to provide.
Features that are described and/or illustrated with respect to one embodiment may be
5 used in the same way or in a similar way in one or more other embodiments and/or
in combination with or instead of the features of the other embodiments.
It should be emphasized that the term “comprises/comprising” when used in this
specification is taken to specify the presence of stated features, integers, steps or
10 components but does not preclude the presence or addition of one or more other
features, integers, steps, components or groups thereof.
The present disclosure discusses production of hot water, power, chilled water in
series through a combination of a kalina cycle and an adsorption refrigeration cycle
15 using solar thermal energy. Solar energy can be harnessed either in the form of
power or directly to heat. Direct utilization of solar energy as heat is a well-practiced
phenomenon, but to improve energy recovery and efficiency, various techniques
which are generally called as concentrated solar power technologies (CSP) are
implemented. CSP technologies generally use mirrors to reflect the incoming
20 sunlight and concentrate it onto the receivers that collect and harness solar energy
and convert it to usable heat. Various designs of CSP are in application viz.
parabolic trough, tower, dish, fresnel etc. The application of various CSP
technologies depend on the cost, area required, peak and operating temperature
provided etc. A typical dish type concentrated solar panel provides thermal energy
with the peak temperature that goes as high as around 300-350o
25 C which can be
utilized to heat any process liquid. Further, tower type designed can provide
temperatures even beyond 350oC.Typically, water/ thermic fluid is circulated which
collects heat from solar panel and provides to downstream applications. Though the
solar energy availability is intermittent in nature as energy is available only in few
30 hours of the day, the thermal energy storage is utilized to maintain continuous
thermal energy availability for the downstream applications. Thus, application of
10
thermal energy storage at the hot fluid side from the outlet of solar energy can help
to improve the stability of downstream operation, availability throughout the day and
sustainable operations. This can help in better return on investment too. Various
parameters like area required, energy generated, thermal efficiency, concentration
5 ratio, footprint ratio etc., differentiate various solar technologies.
In a typical example as shown in FIG.1, cold water (8) is taken into dish type
concentrated solar panel (2). Typically, it has thermal efficiency around 50-70% and
provides a better concentration ratio of greater than 350 and footprint ratio greater
than 250. Generally, a concentrated solar panel of around 90-100 m2
10 can produce 2-3
lakhs kcal of energy per day based on its geographical location, season, age,
atmospheric conditions etc. The cold water (8) gets heated up to 350 oC. This energy
can be stored by passing in through a thermal energy storage device(7) which can be
used when the solar energy is not available. Alternatively having a thermal energy
15 storage device (7) can help to provide a sustainable temperature to downstream
applications thus acting as a buffer for energy. The stream is then sent to
downstream applications, typically part of it is used for steam generation (10). In an
alternative method, a separate water stream may collect energy from the thermal
storage device (7). In such case energy collected by cold water (8) from solar panel
20 (2) heats the water which is then used to store energy in thermal energy storage
device (7). In other alternative, any process stream (1) which is to be either cooled in
air/water coolers may be heated in solar panel (2), based on its compatibility to
higher temperatures and then loses its energy in thermal energy storage. Steam has
various applications and also it can be further used in a steam turbine to produce
25 mechanical energy of power (13) by a generator as well. The remaining part of hot
water (3) is directly used for any application viz. process heat transfer, drying etc.
where the temperature falls below around 150-200oC which can be categorized
generally as low-level heat. There are various low level heat recovery applications.
One among them is kalina cycle (4) to produce power (13), though it helps to
30 improve energy recovery of the system, its efficiency is low so to improve the
overall heat recovery, the adsorption refrigeration cycle (5) is implemented to
11
recover very low-level heat from the kalina cycle (4) in an adsorption refrigeration
cycle (5) to produce chilled water (6). Producing chilled water (6) through
adsorption refrigeration cycle (5) also helps in reduction of cooling water
requirement of kalina cycle (4) as well. Further, chilled water (6) can pass through
5 cold thermal energy storage device (7) for latent or sensible cool storage. As a part
of hot water (3) is converted to steam (10) and is not recycled, make-up water (18) is
added to complete the cycle. A pump is used to maintain the required pressure in the
system. A tank may also be used to have hold up.
10 In a simple kalina cycle, the working medium liquid is pumped to an increased
pressure before sending it to evaporator where evaporation of flow using heat
generates both liquid and gas. The gas is separated from liquid in a gas-liquid
separator before it goes to an expander for production of shaft work. The expanded
working medium is in partial condensed stage which is totally condensed by
15 air/water cooler/condenser before it goes as inlet to pump to complete the cycle. The
efficiency of a simple kalina cycle is around 10-15 % or above. Various advances in
kalina cycles includes additional equipment like recuperators, absorbers, super
heaters etc. to maximize the cycle efficiency by another 0.5-5 % or above. In a
typical recuperator, the heat available in the liquid working fluid from the bottom of
20 the separator is used to preheat the cold working fluid coming out of the pump
before going to the evaporator. The absorbers are employed to recover the partially
condensed, expanded working fluid coming out of the expander. Superheaters are
employed to further heat the gas coming out of the separator with another heating
medium before going to expander/turbine. Liquid expanders/turbines are employed
25 to recover the pressure energy in the liquid coming from the bottom of the separator
to generate electrical or mechanical energy. Ejectors are also employed for a similar
purpose but generally to raise the pressure of the gas coming out of the gas expander.
Other modifications like employing various heat exchangers based on heat available
to raise the temperature of working fluid, employing multiple turbines/ expanders
30 etc. are also practiced. Thus, the efficiency is further improved by 0.5-5 % and
12
above. Not all these above-mentioned equipment or modifications may be observed,
and it is case to case basis.
The adsorption refrigeration or simply the adsorption chiller is a combination of an
5 adsorbent and refrigerant to produce cooling effect. Generally, low grade heat, any
stream having temperature above 50-60oC, can be used in adsorption chiller. The
adsorption chamber of the chiller is filled with a solid adsorbent material (for
example zeolite, silica gel, alumina etc.). In neutral state, the adsorbent bed has
adsorbed the refrigerant, generally water. When heated, the solid desorbs refrigerant
10 vapour, which is liquefied by cooling. This liquid refrigerant then provides a cooling
effect at the evaporator from its enthalpy of vaporization. In the final stage the
refrigerant vapour is again adsorbed on the adsorbent beds completing the cycle.
Adsorption refrigeration (solid based) comes with added advantages in comparison
15 to absorption refrigeration and other mechanical refrigeration. Adsorption chillers
are reported to be consuming less power. Adsorption chiller is relatively quiet as it
requires no compressor. It can operate at temperatures below that of absorption
refrigeration and also offers wide temperature range operation. Also, it is robust
compared to absorption refrigeration which suffers from leakages due to ease of
20 corrosion with air leakages etc. Both adsorption refrigeration and absorption
refrigeration can operate on low grade heat or thermal energy, but adsorption
refrigeration can work in very low temperature in the range of 50-60oC where
absorption refrigeration tends to be infeasible.
25 The present disclosure discusses production of hot water, power, chilled water in
series through kalina cycle and adsorption cycle using solar thermal energy.FIG. 2
and FIG 3 is a schematic layout of a process and apparatus for production of hot
water, chilled water and electricity using solar energy.
30 Referring to FIG.2 and FIG. 3, the working fluid (1) water is initially passed through
a solar thermal collector (2) and gets heated up producing hot water (3). The hot
13
water (3) has typically range of 300-350°C as peak temperatures. The actual
temperature depends on various factors like atmospheric condition, time of day,
location, dust, etc. Part of hot water (3) goes for steam production (10) which is used
to produce power through a steam turbine whereas the remaining goes for the
5 downstream a kalina cycle unit (4). The waste low grade heat from steam turbine
may also be sent to a kalina cycle (4) or organic rankine cycle unit to recover heat
and generate power (13).
In kalina cycle (4), power (13) is generated with hot water (3) acting as heating
medium. Further, the exhaust temperature of the turbine is generally above 30o
10 C
based on various factors like the type of process fluid in the cycle, operating
temperature and pressure range etc. In some cases, it could be as high as >60-70oC.
Also, the turbine discharge is generally partially condensed and has to be further
condensed and send to inlet of pump where the pressure of the working fluid is
15 raised to complete the cycle. But the amount of energy in this stream is again large in
quantity as the efficiency of these cycles lie in the range of 10-15 % only. Thus, by
further utilizing this very low-grade heat, in an adsorption refrigeration cycle (5),
chilled water (6) can be generated. This will help in reduction of cooling water/ air
cooler load of the thermodynamic cycles also. Adsorption refrigeration cycles as
discussed above can perform even at temperature as low as 50o
20 C. Thus, chilled water
(6) is generated using very low-grade heat. This chilled water (6) can be utilized for
pre-cooling in low temperature applications, air handling units (AHU) etc. Though
adsorption refrigeration can perform at low temperatures, the efficiency increases
with increase in inlet temperature by around 80-90oC based on the adsorption and
25 working fluid pairs. Thus, the process in the kalina cycle has to be modified
accordingly for optimum operation of the entire process and based on the
requirement of hot water, power and chilled water wherever employed.
Further, incorporating a thermal energy storage device (7) can help in optimizing the
30 energy uses as well as meeting the demand variations and solar energy source
availability. The storage device could be used to produce constant hot water (3),
14
power (13), chilled water (6) at varying process conditions or optimize the system as
a whole to meet fluctuations in demand of these utilities. The heat storage device (7)
can be installed either on the hot water (3) coming out of the solar thermal collector
(2) or at the exit of kalina cycle (4) turbine exhaust, or on the chilled water (6) side
5 or wherever suitable based on the cost operational and safety aspects.
In a typical low level heat recovery system like in case of kalina cycle as shown in
FIG.4, the hot water (3) exchanges heat with a mixture of ammonia and water (11) in
an evaporator (14). The process starts with an ammonia and water mixture (11)
10 which is pumped to a high pressure. It passes through an evaporator (14) where the
vapor phase is generated. The mixture then goes to a separator (15) wherein the
vapor phase leaves to turbine for generating power (13). The liquid phase then mixes
with the turbine outlet fluid before it is condensed in a condenser (17) using cooling
water. To improve the efficiency, the liquid from the separator (15) bottom is used to
15 preheat the feed from the pump outlet before the evaporator (14). The efficiency of
kalina cycle (4) is generally very less, may be around 10-15 %. Further, it requires
cooling water in the condenser (17) to bring back the temperature of ammonia-water
mixture (11) to the feed conditions. To improve the energy efficiency further, low
level heat from the mixed stream of turbine outlet and hot side fluid coming out of
20 recuperator (16) is recovered into an adsorption refrigeration cycle (5) to produce
chilled water (6). The adsorption refrigeration cycle (5) requires hot stream
preferably above 50 °C to produce chilled water (6). It further requires cooling water
and power for its operation. This chilled water is also having multiple applications.
As, the operation of kalina cycle is dependent on the upstream units, to provide a
25 uniform and continuous hot water flow required for an adsorption refrigeration cycle
(5), high temperature thermal energy storage device (7) may be utilized. To maintain
hot temperatures for the adsorption refrigeration cycle (5), the process changes viz.
change in flow rate of ammonia-water mixture, composition of ammonia-water
mixture, upstream/ downstream temperature of low-level heat etc. may be employed.
30
15
FIG. 5 represents a typical low-level heat recovery configuration- kalina cycle
wherein the process stream (1) at low temperature gets heated in solar panel (2). This
high temperature stream then loses heat in exchanger (12) or in thermal energy
storage (7) with another stream like in this case water for production of hot water,
5 chilled water, etc.
The process stream (1) is initially passed through a solar thermal collector (2) and
gets heated up producing hot water (3). Part of hot water (3) goes for steam
production (10) which is used to produce power through a steam turbine whereas the
remaining goes for the downstream a kalina cycle unit (4). The waste low grade heat
10 from steam turbine may also be sent to a kalina cycle (4) or organic rankine cycle
unit to recover heat and generate power (13).
The present disclosure thus describes an efficient process of utilizing energy through
an optimum configuration of using solar energy in kalina cycle followed by
15 adsorption refrigeration cycle. The capital expenditure (CAPEX) of the entire system
can be optimized.
The present disclosure relates to a process for power generation, hot water and
chilled water production, comprising steps of:
20 a. passing a working fluid through a solar thermal collector and producing hot
working fluid;
b. at least a portion of the hot working fluid is passed through the combination of a
kalina cycle and an adsorption refrigeration cycle, to generate power and chilled
water
25 c. at least a portion of the hot working fluid is passed through thermal energy storage
device for thermal energy storage;
d. at least a portion of the chilled water is passed through a thermal energy storage
device for thermal energy storage;
16
wherein the hot working fluid is first passed through the kalina cycle to generate
power and the low temperature working fluid is passed through adsorption cycle to
produce chilled water.
5 One of the embodiments of the present invention, wherein the working fluid is water
or any other thermic fluid, specifically the working fluid is water.
Yet another embodiment of the invention, wherein the solar thermal collector is a
dish type solar heater which heats the working fluid, and the working fluid is heated
10 to a temperature of around 300 to 400°C or above.
Yet another embodiment of the invention, wherein the solar thermal collector is a
solar tower type which heats the working fluid to a temperature higher than 350 to
500°C or above.
15
One of the embodiments of the present process, wherein the kalina cycle comprises
- increasing the pressure of a working medium through pump;
- the pressurized working medium is passed through an evaporator, which produces
gas liquid mixture;
20 - the gas is separated from liquid by a gas liquid separator;
- the gas is passed through a turbine to generate mechanical energy or electricity;
- the depressurized gas liquid mixture is condensed to produce the working medium.
One of the embodiments of the present process, wherein the adsorption cycle
comprises
25 - desorbing the refrigerant from the chamber, by heating the chamber;
- liquifying the refrigerant;
- evaporating the refrigerant to produce a cooling effect.
One of the embodiments of the process, wherein the thermal energy is stored in
30 thermal energy storage (TES) device. There are three kinds of TES systems, namely:
1) sensible heat storage that is based on storing thermal energy by heating or cooling
17
a liquid or solid storage medium (e.g. water, sand, molten salts, rocks); 2) latent heat
storage using phase change materials or PCMs (e.g. from a solid state into a liquid
state); and 3) thermo-chemical storage (TCS) using chemical reactions to store and
release thermal energy.
5
The present disclosure relates to an apparatus for power generation, hot water and
chilled water production comprises
- a solar thermal collector which heats a working fluid, to produce a hot working
fluid;
10 - a kalina cycle and an adsorption cycle combination, which utilizes the hot working
fluid and produces power and chilled water;
- a thermal energy storage device for storing at least a portion of the thermal energy
in the hot working fluid;
- a thermal energy storage device (7) for storing at least a portion of the thermal
15 energy in the chilled water (6);
wherein, the hot working fluid is first passed through the kalina cycle to generate
power and the low temperature working fluid is passed through adsorption
refrigeration cycle to produce chilled water.
20 One of the embodiment of the invention relates to an apparatus, wherein the working
fluid is water.
Yet another embodiment of the invention, wherein the solar thermal collector is solar
heater.
25 One another embodiment of the invention wherein the kalina cycle comprises, pump,
evaporator, gas liquid separator, shaft and condenser; and the adsorption cycle
comprises a refrigerant adsorbed in a chamber, condenser and evaporator.
Advantages:
30 Various uses of solar thermal energy as envisaged can be listed as below:
18
1) The solar thermal energy can be used to heat water to produce hot water. Hot
water is generally required in various operations like in case of DM water
heating before deaerators, heating process streams etc.
2) The solar thermal energy can be used to produce steam from boiler feed
5 water. This can replace the requirement of fuel firing in boilers thereby
reducing GHG emission also.
3) In process units, there is plenty of low-level heat available which are
generally discarded in an air/water cooler due to unviable heat recovery
option. The heat source potential of these streams could be utilized by
10 heating them further in solar thermal collectors. Thus, a very low-grade heat
can be augmented to low grade heat. By doing this, energy and costs related
to air/water cooling can be saved.
4) The solar thermal energy can be used to heat the process streams directly or
indirectly, thus meeting the need of a furnace sometimes.
15 5) The solar thermal energy can be used to generate electricity. Part of high
energy heat source can be tapped as electrical or shaft work (mechanical
energy) by passing it through a steam turbine to produce power. The waste
low grade heat from steam turbine may also be sent through a
thermodynamic process, like kalina cycle, organic rankine cycle (ORC),
20 etc.to recover heat and generate power.
6) The solar thermal energy can be used to produce chilled water by using the
heat in vapour absorption refrigeration or vapour adsorption refrigeration
cycle etc.
The following are the advantages of the system and the process of the invention:
25 • efficient process of utilizing energy;
• Even lower temperature (energy) 50 to 90
oC can be recovered by the present
invention;
• Adsorption cycle consumes less power compared to other methods used to
produce chilled water with less corrosion and air leakages.
30 • Environment friendly
• Economical process.

WE CLAIM:
1. A process for power (13) generation, hot water (3) and chilled water (6)
production, comprising steps of:
a. passing a working fluid (1) through a solar thermal collector (2) and producing hot
5 working fluid (3);
b. at least a portion of the hot working fluid (3) is passed through the combination of
a kalina cycle (4) and an adsorption refrigeration cycle (5), to generate power (13)
and chilled water (6);
c. at least a portion of the hot working fluid (3) is passed through a thermal energy
10 storage device (7) for thermal energy storage;
d. at least a portion of the chilled water (6) is passed through a thermal energy
storage device (7) for thermal energy storage;
characterized in that, the hot working fluid (3) is first passed through the kalina cycle
(4) to generate power (13) and the low temperature working fluid is passed through
15 adsorption refrigeration cycle (5) to produce chilled water (6).
2. The process as claimed in claim 1, wherein the working fluid (1) is water.
3. The process as claimed in claim 1, wherein the solar thermal collector (2) is a
20 solar heater which heats the working fluid (1).
4. The process as claimed in claim 3, wherein the working fluid (1) is heated in the
solar thermal collector (2) to a temperature of from 300° to 400° C or above.
25 5. The process as claimed in claim 1, wherein the thermal energy storage device (7)
is a hot thermal energy storage device and/or a cold thermal energy storage device.
6. An apparatus for power (13) generation, hot water (3) and chilled water (6)
production comprises
30 - a solar thermal collector (2) which heats a working fluid (1), to produce a hot
working fluid (3);
21
- a kalina cycle (4) and an adsorption refrigeration cycle (5) combination, which
utilizes the hot working fluid (3) and produces power (13) and chilled water (6);
- a thermal energy storage device (7) for storing at least a portion of the thermal
energy in the hot working fluid (3);
5 - a thermal energy storage device (7) for storing at least a portion of the thermal
energy in the chilled water (6);
characterized in that, the hot working fluid (3) is first passed through the kalina cycle
(4) to generate power (13) and the low temperature working fluid is passed through
the adsorption refrigeration cycle (5) to produce chilled water (6).
10
7. The apparatus as claimed in claim 6, wherein the working fluid (1) is water.
8. The apparatus as claimed in claim 6, wherein the solar thermal collector (2) is
solar heater.
15
9. The apparatus as claimed in claim 6, wherein the kalina cycle (4) comprises, pump
(20), evaporator (14), gas liquid separator (15), shaft and condenser (17); and the
adsorption cycle (5) comprises a refrigerant adsorbed in a chamber, condenser (17)
and evaporator (14).