TECHNICAL FIELD

The present disclosure relates to an artificial cooling system. In particular, the present disclosure related to an artificial cooling system for providing a cooling means to a geothermal power generation system, and capturing and storing heat from the geothermal power generation system.

BACKGROUND

Geothermal energy-based power plants can operate in a baseload generation mode and a dispatchable generation mode. In the baseload generation mode, the geothermal power plant provides a minimum level of electricity for an electrical grid over a span of time. In the dispatchable generation mode, electricity can be dispatched by the geothermal power plant on demand at the request of power grid operators. Accordingly, geothermal power plants are able to provide the same functionality as current fossil fuelbased power plants, such as coal-based power plants. Advantageously, use of geothermal energy power plants facilitates the integration of renewable energy in the power grid.

Geothermal power plants utilise different power cycles or combinations of power cycles, depending on a geofluid temperature and pressure at a production wellhead of the plant. Example power cycles include steam Rankine cycle and Organic Rankine Cycle (ORC) based plants. Accordingly, different forms of geothermal power plants are operated including, but not limited to: dry steam; single flash; double flash; triple flash; binary (ORC based); and combined cycle (i.e. a combination of flash and binary).

Geothermal reservoirs are typically in the temperature range of 90 °C to 300 °C. This temperature range is lower than that of fossil fuel-based systems and as such, the efficiency of geothermal power plants is typically lower compared to fossil fuel-based power plants. This lower comparative efficiency may be illustrated by the Carnot efficiency, which is the maximum theoretical efficiency that a heat engine may have in a system having a heat source and a heat sink. The heat sink may be an ambient temperature which influences a heat rejection rate or a condenser temperature of the power cycle. The Carnot efficiency is illustrated by the following equation:

Wherein: is the Carnot efficiency;

TL is a temperature of the heat sink; and

TH is a temperature of the heat source.

Accordingly, since the heat source temperature TH is lower for a geothermal power plant than for a fossil-based power plant, the Carnot efficiency q is lower.

Another issue associated with geothermal power generation is related to diurnal and seasonal temperature variations. These temperature variations lead to efficiency and power generation fluctuations due to a change in ambient temperature (i.e. heat source temperature TL), with the power fluctuations being up to 24 % for single-flash geothermal power plants, and up to 22 % for double-flash geothermal power plants. The effect of this fluctuation is even more severe for ORC based geothermal power plants.

T urbines in ORC based geothermal power plants are designed and built around a design point which dictates a set of operating conditions. Deviation from these operating conditions lead to a variation in turbine performance. Ghasemi et al. describe the variation in the isentropic efficiency of a typical organic Rankine cycle turbine as a function of the outlet condition of the turbine. The turbine operates at maximum efficiency only in a small range of condenser temperature around the design point. Variations of condenser temperature of ±10 °C or higher from the design temperature leads to a sharp decrease in turbine efficiency. The overall energy output of an ORC based geothermal power plant may be reduced up to 40 %, depending on the magnitude and duration of such deviations from the design temperature. Furthermore, a high ambient temperature may also increase the power consumption of cooling towers due to an increase in the amount of cooling required. Accordingly, it is desirable to operate within a threshold range of the design temperature. Geothermal power plants utilise dry cooling systems and wet cooling systems to facilitate the cooling of, for example, working fluid vapour. Dry cooling systems utilise air as the main coolant. The air cools the working fluid of the power cycle to facilitate a heat rejection stage of the power cycle, wherein heat is removed from the working fluid vapour. Wet cooling systems utilise water as the main coolant. The water cools the working fluid of the power cycle in the condenser, thereby producing hot water. The hot water is subsequently cooled in a cooling tower through evaporative cooling, leading to a loss of water which must be replenished. Steam based geothermal power plants generally use a wet cooling system. Binary geothermal power plants generally use both dry and wet cooling systems.

Due to the heat transfer coefficient of air being low relative to the heat transfer of water, the air-cooled condensers require a correspondingly higher size, and therefore cost. A higher ambient temperature affects the condenser operating temperatures, thereby negatively impacting the turbine efficiency. To compensate, an increased fan load may be required to increase the airflow of the turbine, thereby leading to an increase in power consumption of the turbine. This negatively impacts the sustainability of geothermal generated by the geothermal power plant.

The present disclosure has been devised to mitigate or overcome at least some of the above-mentioned problems.

SUMMARY OF THE DISCLOSURE

Through sharing of the geothermal power plant cooling load, the current disclosure may allow a geothermal plant to operate at lower condenser temperature, resulting in an increased efficiency.

The integration of current disclosure with a geothermal plant may allow the system to have excess thermal energy in a brine circuit, which can be used to produce additional power and thermal energy.

The present disclosure provides a geothermal power artificial cooling system comprising: an absorption chiller configured to receive a first portion of the first heat from a first heat source and a second heat from a second heat source, said absorption chiller comprising: a generator comprising a first water-refrigerant solution having a first concentration, the generator being configured to receive the first heat, wherein the water-refrigerant solution is configured to separate into a refrigerant vapour and a second water-refrigerant solution having a second concentration in response to the first heat; a condenser in fluid communication with the generator, wherein the condenser is configured to convert the refrigerant vapour into a liquid refrigerant, thereby producing a condenser heat; an evaporator in fluid communication with the condenser, the evaporator being configured to receive the second heat, wherein the evaporator is configured to convert the liquid refrigerant into a refrigerant vapour; and an absorber in fluid communication with the evaporator and the generator, wherein the absorber is configured to: receive the second water-refrigerant solution; receive the refrigerant vapour; and convert the second water-refrigerant solution into the first water-refrigerant solution, thereby producing an absorber heat; and a cooling means configured to dissipate the condenser heat, and the absorber heat.

Preferably, the cooling means is a low temperature thermal energy storage (TES) device in fluid communication with the absorption chiller, configured to receive and store the condenser heat, and the absorber heat. The skilled person will appreciate that the cooling means may be any means suitable for dissipating the condenser heat, and the absorber heat.

Preferably, the artificial cooling system further comprises a high temperature TES device in fluid communication with the absorption chiller, the high temperature TES device configured to: receive and store a second portion of the first heat; and provide a third heat to the absorption chiller

The present disclosure provides a system that may be coupled with a geothermal power generation system. The system includes an absorption chiller coupled with a high temperature TES device and a low temperature TES device to maintain and increase the efficiency of a power cycle of the power generation system during high ambient temperature conditions. The system may advantageously decrease a parasitic load and water consumption of a cooling system used in the power cycle of the geothermal power generation system. In particular, surplus heat from the geothermal power generation system and rejected heat of an absorption cycle of the absorption chiller can be harnessed, thereby promoting a circular economy, increasing energy efficiency and improving the decarbonisation of power and thermal grid to feed district heating network. Furthermore, a cooling effect provided by the evaporator may be used for cooling substances present in the power cycle of the geothermal power generation system.

Advantageously, the present disclosure may provide an increase in the efficiency of the power cycle of a geothermal power plant in situations where an ambient temperature of the geothermal power plant causes a condenser to deviate from a design temperature. The absorption chiller is not limited to an ammonia driven absorption chiller.

Further advantageously, a cooling effect provided by the evaporator may allow the power plant condenser to operate at lower temperature compared to a base case scenario for a condenser temperature for a prevailing ambient temperature of a geothermal power generation system. For example, the condenser temperature may be maintained below 4 to 8 °C, increasing the efficiency of the system.

The low temperature TES device may be any one selected from the range of: a Single Media Thermocline thermal energy storage device; and a phase change material based thermal energy storage device. The skilled person will appreciate that any suitable thermal energy storage device may be used for the low temperature TES device.

The low temperature TES device may advantageously provide a means for capturing heat generated by the absorption chiller. The thermal energy stored on the low temperature TES device may advantageously be used for external heating applications, such as a district heating network, which can be used in low temperature heating applications. Accordingly, thermal energy that would otherwise be wasted is harnessed using the present system.

The high temperature TES device may be any one selected from the range of: a Single Media Thermocline thermal energy storage device; a Dual Media Thermocline thermal energy storage device; and a Sensible heat thermal energy storage. The skilled person will appreciate that any suitable thermal energy storage device may be used for the high temperature TES device.

Preferably, the high temperature TES device is sized such that the third heat supplies the absorption chiller for a period of 2 to 4 hours. The skilled person will understand that the high temperature TES device may be sized to provide the absorption chiller for any suitable period of time.

The high temperature TES device may advantageously provide a means for storing excess thermal energy generated by a geothermal power generation system. The thermal energy stored on the high temperature TES device may be used to provide heat to the generator of the absorption chiller. Advantageously, the excess thermal energy may be used in situations wherein a temperature of the first heat is insufficient for the function of the generator. Accordingly, the high temperature TES advantageously stabilises a thermal energy demand and supply.

The refrigerant may comprise ammonia.

The first heat source may be a geothermal heat source.

The second heat source may be a power generation means. For example, the second heat source may be a power generation means of a geothermal power generation facility.

The second concentration may be less than the first concentration.

Preferably, the system further comprises a recuperator in fluid communication with the absorption chiller. A recuperator is not typically used in ORC plants as a recuperator alone is not considered to contribute to the power output of the plant. Advantageously, in the present invention, a recuperator may be used in combination with the absorption chiller. A portion of the condensing load may be fed to the power cycle through the recuperator. In this way, the condenser temperature may be reduced, allowing thermal efficiency and power output of the system to be increased. The combination of the recuperator and absorption chiller allows a smaller absorption chiller to be used in order to provide an equivalent condenser temperature to a system without a recuperator. In this way, the combination of a recuperator and an absorption chiller allows for a reduction in the amount of energy required. Additionally, the recuperator provides additional thermal energy for heating systems used. In some embodiments, the system further comprises a rectifier in fluid communication with the generator, wherein the rectifier is configured to dehydrate the refrigerant vapour, thereby producing a rectifier heat. In this way, an ammonia driven absorption chiller may be used.

Preferably, the system is configured to allow the use of the excess thermal energy in a brine circuit, which can be used to produce additional power and thermal energy.

It will be appreciated that any features described herein as being suitable for incorporation into one or more aspects or embodiments of the present disclosure are intended to be generalizable across any and all aspects and embodiments of the present disclosure. Other aspects of the present disclosure can be understood by those skilled in the art in light of the description, the claims, and the drawings of the present disclosure. The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic view of a geothermal power generation system comprising an artificial cooling system according to the present disclosure;

Figure 2 is a schematic view of the artificial cooling system integrated with a geothermal power plant having a wet cooling system;

Figure 3 is a schematic view of the artificial cooling system integrated with a geothermal power plant having a dry cooling system; and

Figure 4 is a schematic view of a geothermal power generation system comprising an artificial cooling system according to the present disclosure.

DETAILED DESCRIPTION Figure 1 is a schematic view of a geothermal power generation system 100 comprising an artificial cooling system 101 according to the present disclosure.

The geothermal power generation system 100 comprises the artificial cooling system 101 ; an injection means 102; a power conversion means 104; and an ejection means 106.

The artificial cooling system 101 comprises an absorption chiller 108; a high temperature thermal energy storage (TES) device 110; and a low temperature TES device 112.

The injection means 102 is configured to provide fluid communication between a geothermal power source (not shown) and the geothermal power generation system 100. The injection means 102 comprises a pump and a wellhead, as is known to the person skilled in the art. In particular, the injection means 102 is configured to transfer geothermal fluid from the geothermal power source to the power conversion means 104 of the geothermal power generation system 100. In the present example, the geothermal fluid is a geothermal brine. In other embodiments, the geothermal fluid may be steam or water. The geothermal brine has a temperature varying from 100 °C to 170 °C. In the present example, the injection means 102 is a pump 102. The brine is input to the geothermal power generation system 100 by the pump 102 at a geothermal brine flow rate M _B . Heat is lost from the geothermal brine at a heat loss rate of Q _B .

The power conversion means 104 is configured to generate power from the waste fluid input by the injection means 102. The power conversion means 104 comprises a turbine in communication with a generator in the present example. Accordingly, in the present example, the power conversion means 104 is configured to generate power from the geothermal brine input to the geothermal power generation system 100 by the pump 102. The power conversion means 104 generates power at a turbine output rate W. The turbine output rate W corresponds to the geothermal brine flow rate M _B .

Heat is rejected during the operation of the power conversion means 104. The correlation between a heat rejection rate Q _R-P and the turbine output rate W is provided by the equation: QR-P — FR-P ’

Wherein:

Q _R-P is the heat rejection rate of the power conversion means 104;

W is the work output rate of the power conversion means 104; and FR_ _P is a heat rejection constant of the power conversion means 104.

The heat rejection constant F _R-P is a ratio of the heat rejection rate (jR_p to the work output rate W of the power conversion means 104. The heat rejection constant F _R-P is derived empirically through case studies and thermodynamics, and will be known to the person skilled in the art. The heat rejection constant F _R-P is between 3 and 6 for flash geothermal power plants, and between 7 and 11 for binary geothermal power plants.

The ejection means 106 is a pump 106 configured to pump the geothermal brine from the power conversion means 104 after the geothermal brine has been utilised by the power conversion means 104. In the particular, the pump 106 is configured to pump a first portion of the geothermal brine from the power conversion means 104 to the geothermal power source. The ejection means 106 also comprises a wellhead positioned at a surface level.

The pump 106 is also configured to provide fluid communication between the power conversion means 104 and the high temperature TES device 110. In particular, the pump 106 is configured to transfer a second portion of the geothermal brine from the power conversion means 104 to the high temperature TES device 110 after the geothermal brine has been utilised by the power conversion means 104.

Furthermore, the pump 106 is configured to provide fluid communication between the power conversion means 104 and the absorption chiller 108. In particular, the ejection means 106 is configured to transfer a third portion of the geothermal brine from the power conversion means 104 to the absorption chiller 108 after the geothermal brine has been utilised by the power conversion means 104. When an external electricity demand is higher, the turbine output rate W is higher in order to meet the demand and as such, the heat rejection rate Q _R-P is higher. When the external electricity demand is lower, the turbine output rate W is lower in order to meet the demand and as such, the heat rejection rate Q _R-P is lower. Accordingly, when the external electricity demand is lower, a temperature of the geothermal brine provided to the high temperature TES device 110 is higher since less heat is rejected. Therefore, this excess thermal energy can be stored on the high temperature TES device 110 during low external electricity demand time periods.

The absorption chiller 108 comprises: a generator 108A, a rectifier 108B, a condenser 108C, an evaporator 108D, an absorber 108E, an expansion valve 108F, a solution pump 108G, and a plurality of heat exchangers (not shown). The absorption chiller 108 is in fluid communication with the high temperature TES device 110, the low temperature TES device 112, and the ejection means 106.

The generator 108A comprises a refrigerant. In the present example, the refrigerant is an ammonia-water reservoir having a first ammonia concentration. Alternative refrigerants will be known to a person skilled in the art. The generator 108A is configured to receive a thermal input Q _G at a thermal input rate (j _G from the geothermal brine received from the power conversion means 104 via the pump 106. The thermal input Q _G is received via a heat exchanger (not shown) in fluid communication with the pump 106. The received heat results in the production of ammonia vapour from the ammonia-water solution. The received geothermal brine is preferably at a temperature in the range of 100 °C to 150 °C.

In some embodiments, the received geothermal brine is at a temperature below 100 °C. In this case, the thermal input Q _G is provided by the geothermal brine from the power conversion means, as well as the high temperature TES device 110 via a heat exchanger (not shown).

The generator 108A is in fluid communication with the rectifier 108B, which is in turn coupled to the low temperature TES device 112 via a heat exchanger (not shown). The rectifier 108B may itself be a heat exchanger cooled by a coolant, the coolant being, for example, water. The rectifier 108B is configured to receive the ammonia vapour from the generator 108A. The rectifier 108B is further configured to dehydrate the ammonia vapour, thereby producing dehydrated ammonia. A rectifier heat Q _fl transferred from the ammonia vapour to the coolant at a rectifier heat rate (j _c . The rectifier heat Q _fl is transferred to, and stored in, the low temperature TES device 112 via the heat exchanger. The heat emitted by the rectifier 108B is at a first temperature.

The generator 108A is also in fluid communication with the absorber 108E via the solution pump 108G. During the production of the ammonia vapour in the generator 108A, an ammonia-water solution is transported to the absorber 108E. The ammonia- water solution is of a second ammonia concentration lower than the first ammonia concentration. Therefore, the ammonia-water solution of the absorber 108E comprises a weaker ammonia-water solution than the ammonia-water solution of the generator 108A.

The rectifier 108B is in fluid communication with the condenser 108C, which is in turn in fluid communication with the low temperature TES device 112 via a heat exchanger (not shown). The condenser 108C is configured to receive the dehydrated ammonia from the rectifier 108B. The condenser 108C is further configured to convert the dehydrated ammonia into liquid ammonia through cooling. Accordingly, a condenser heat Q _c is emitted during this phase transition at a condenser heat rate Q _c . The condenser heat Q _c is transferred to, and stored in, the low temperature TES device 112 via the heat exchanger. The heat emitted by the condenser 108C is at a second temperature.

The condenser 108C is in fluid communication with the evaporator 108D via the expansion valve 108F. The expansion valve 108F is configured to reduce a pressure and temperature of the liquid ammonia. In particular, the cooled liquid ammonia enters the evaporator 108D. The evaporator 108D is configured to absorb heat from a substance to be cooled, thereby producing ammonia vapour. The evaporator 108D is able to absorb heat at a heat absorption rate Q _E . The heat absorption rate Q _E required to achieve a target cooling effect can be defined as:

QE ⁼ FCH-RP ’ QRP

Wherein: Q _E is the heat absorption rate of the evaporator 108D

Q _RP is the heat rejection rate of the power conversion means 104;

F _CH -RP is a target cooling constant of the rejected heat from the power conversion means 104.

The target cooling effect is a desired proportion of the heat rejected by the power conversion means 104 to be cooled. Therefore, the target cooling constant F _GH-RP defines a fraction or percentage of the rejected heat from the power conversion means 104 to be cooled by the absorption chiller 108. For example, the target cooling constant F _CH -R may be 0.25, thereby representing a desired cooling effect of 25 % of the heat rejected by the power conversion means.

The heat absorption rate Q _E of the evaporator 108D is correlated to the thermal input Q _G of the geothermal brine by a coefficient of performance COP of the absorption chiller 108:

QE = COP ■ Q _c

Wherein:

Q _E is the heat absorption rate of the evaporator 108D;

Q _G is the thermal input of the geothermal brine; and

COP is the coefficient of performance of the absorption chiller 108.

The pump 106 transfers a first portion, a second portion, and a third portion of the geothermal brine to the geothermal power source, the high temperature TES device 110, and the absorption chiller 108, respectively. For example, in a system wherein the target cooling constant is 0.25, 25 % of the geothermal brine is transferred to the absorption chiller 108, and 75 % of the geothermal brine is transferred to the geothermal power source. The skilled person will appreciate that the target cooling constant may be any value between 0 and 1 and as such, the geothermal brine transferred to the absorption chiller 108 may be any value between 0 % and 100 %.

The evaporator 108D is in fluid communication with the absorber 108E, which is in turn in fluid communication with the low temperature TES device 108J via a heat exchanger. The ammonia vapour is transported to the absorber 108E, wherein the absorber 108E comprises the ammonia-water solution. As the ammonia vapour enters the absorber 108E, it is absorbed by the ammonia-water solution and an ammonia-water solution having a third concentration is produced. The third concentration is greater than the second concentration. The second third concentration may be the same as the first concentration. The ammonia-water solution is transported to the generator 108A via the solution pump 108G. During this absorption process, an absorption heat is emitted by the absorber 108E at an absorption heat rate Q _A . The absorption heat Q^ is transferred to, and stored in, the low temperature TES device 112. The heat emitted by the absorber 108E is at a third temperature.

The ejection means 106 is configured to provide fluid communication between the absorption chiller 108 and a reinjection well (not shown). The reinjection well is itself configured to provide fluid communication between the ejection means 106 and a geothermal power source (not shown). The ejection means 106 is a pump 106 configured to pump a portion of the brine output by the absorption chiller 108 to the reinjection well following the brine providing heat to the generator.

A heat rejection rate Q _R-C H of the absorption chiller 108 is correlated to the thermal input Q _G by a correlating factor:

QR-CH ~ 1-4 ■ QG

Wherein:

Q _R -CH is the h ^eat rejection rate of the absorption chiller 108;

Q _G is the thermal input of the geothermal brine; and

The correlating factor of 1.4 is empirically derived through case studies and thermodynamics. The skilled person will appreciate that the correlating factor may be different for different types of absorption chiller 108.

Accordingly, the heat rejection rate (j _fl-CH of the absorption chiller 108 can be expressed in terms of power conversion means 104 output:

Wherein:

Q _R -CH is the h ^eat rejection rate of the absorption chiller 108;

FCH-RP is the target cooling constant of the rejected heat from the power conversion means 104;

F _{R -P} is the heat loss constant of the power conversion means 104;

W is the work output rate of the power conversion means 104; and COP is the coefficient of performance of the absorption chiller 108.

As discussed above, the heat generated and emitted by the rectifier 108B, the condenser 108C, and absorber 108E is at a first temperature, a second temperature, and a third temperature, respectively. The first temperature is greater than the second temperature. The second temperature is greater than the third temperature. The third temperature is 25 °C to 35 °C. The second temperature is 60 °C to 75 °C.

Heat generated by the rectifier 108B, the condenser 108C, and the absorber 108E is transferred to the low temperature TES device 112 through one or more heat exchangers. The heat rejection rate Q _{R -C} H of the absorption chiller 108 is correlated to the heat generated by the rectifier 108B, the condenser 108C, and the absorber 108E. The low temperature TES device 112 stores the received heat. The low temperature TES device 112 is configured to provide heat to external applications. In the present example, the low temperature TES device 112 supplies heat at a temperature of 60 °C. The skilled person will understand that the temperature may be different.

Accordingly, through defining an optimal set of operating conditions (for example, temperature and pressure) for the absorption chiller 108 and storing the rejected heat Q _R -CH of the absorption chiller 108 in the low temperature TES device 112, the present system 101 can drive a low temperature district heating network.

A geothermal resource utilisation improvement as a result of the present artificial cooling system 101 may be quantified. In particular, an annualised average loss of power production of the geothermal power generation system 100 due to high ambient temperature conditions, F _amb , may be considered. The loss of power production F _amb is dependent on different parameters of the geothermal power generation system 100, such as types of working fluid for a binary plant, and a temperature profile of the ambient conditions. Integration of the artificial cooling system 101 with the geothermal power generation system 100 may result in an increase of geothermal resource utilisation by a factor F _inc defined by:

Wherein:

F _inc is the increase of geothermal resource utilisation factor;

Famb is the ambient temperature conditions;

W is the work output rate of the power conversion means 104;

FCH-RP is the target cooling constant of the rejected heat from the power conversion means 104;

F _R-P is the heat rejection constant of the power conversion means 104; and COP is the coefficient of performance of the absorption chiller 108.

For a typical coefficient of performance COP value of 0.5, and a target cooling constant F _CH -R of 25%, the increase of geothermal resource utilisation factor F _inc will be 335% for flash geothermal power plants, and 650% for binary geothermal power plants. The skilled person will appreciate that these geothermal resource utilisation factor F _inc values are based on the ratio of the heat rejection rate Q _R-P to the work output rate W of the power conversion means 104 being around 4.5 for flash geothermal power plants and 9 for binary geothermal power plants. The skilled person will also appreciate that the geothermal resource utilisation factor F _inc values do not take the contribution from the high temperature TES device 110.

Figure 2 shows the artificial cooling system 101 integrated with a geothermal power plant 200 having a wet cooling system. For example, the geothermal power plant 200 may utilise a flash power cycle. The geothermal power plant 200 comprises an injection means 202; a separator 203; a power generation means 204; a cooling means 206; and an ejection means 208.

The separator 203 is in fluid communication with a geothermal power source (not shown) via the injection means 202. The injection means 202 is similar to the injection means 102 of Figure 1. The separator 203 is configured to receive high-pressure geothermal brine at a temperature of, for example, greater than 200 °C. The separator 203 comprises a lower pressure than the injection means 202 and as such, flashed steam and is generated and separated from the geothermal brine.

The separator 203 is also in fluid communication with the ejection means 208. The geothermal brine is ejected from the separator 203 via the ejection means 208. The ejection means 208 is similar to the ejection means 106 of Figure 1.

The power generation means 204 is in fluid communication with the separator 203. The power generation means 204 is largely similar to the power generation means 204. The power generation means 204 receives the flashed steam from the separator 203, which drives the turbines of the power generation means 204.

The cooling means 206 is in fluid communication with the power generation means 204 via, for example, a pipe. The cooling means 206 comprises a condenser 206A in fluid communication with a cooling tower 206B. The condenser 206A is configured to receive steam from the power generation means 204 via a pump. The steam is at a temperature of around 30 °C to 35 °C. The steam heats up water present in the condenser 206A. The heated up water is transported to the cooling tower 206B at a temperature of around 40 °C to 45 °C. The cooling tower 206B dissipates the heat to the ambient air by evaporation of the water. Accordingly, a portion of the received water is lost to evaporation.

The artificial cooling system 101 is in fluid communication with the condenser 206A and the cooling tower 206B. The artificial cooling system 101 is configured to receive the cooled down water from the cooling tower 206B. The evaporator 108D absorbs heat from the cooled down water, and the water is subsequently returned to the condenser 206A at a temperature of around 20 °C to 25 °C. The artificial cooling system 101 is also in fluid communication with the ejection means 208. The ejection means 208 is configured to provide the geothermal brine to the artificial cooling system 101 at a temperature of around 100 °C to 150 °C. The artificial cooling system 101 operates in the same manner as is described in relation to Figure 1.

In an alternative example, the ejection means 208 is also in fluid communication with the cooling means 206. In situations wherein the temperature of the brine provided by the ejections means 208 to the system 101 is insufficient to power the generator 108A, heat from the condenser 206A provides heat to the brine.

Figure 3 shows the artificial cooling system 101 integrated with a geothermal power plant 300 having a dry cooling system. For example, the geothermal power plant 200 may utilise an Organic Rankine Cycle (ORC) power cycle.

The geothermal power plant 300 comprises an injection means 302; a gas production means 303; a power generation means 304; a cooling means 306; and an ejection means 308.

The gas production means 303 is in fluid communication with a geothermal power source (not shown) via the injection means 302. The injection means is similar to the injection means 102 of Figure 1 . The gas production means comprises a preheater 303A and an evaporator 303B. The preheater 303A is configured to receive geothermal brine at a temperature of, for example, between 150 °C and 200 °C. The preheater 303A is also configured to transfer heat from the geothermal brine to a working fluid having a lower boiling point than the geothermal brine. The heated working fluid is transferred to the evaporator 303B, which is configured to convert the heated working fluid into a superheated gas.

The gas production means 303 is also in fluid communication with the ejection means 308. The geothermal brine is ejected from the preheater 303A via the ejection means 308. The ejection means 308 is similar to the ejection means 106 of Figure 1.

The power generation means 304 is in fluid communication with the gas production means 303. The power generation means 304 is largely similar to the power generation means 204. The power generation means 304 receives the superheated gas from the evaporator 303B, which drives the turbines of the power generation means 304.

The cooling means 306 is in fluid communication with the power generation means 304 via, for example, a pipe. The cooling means 306 comprises a cooling tower 306. The cooling tower 306 is configured to receive the gas from the power generation means 304 via a pump. The gas is at a temperature of around 95 °C to 105 °C. The cooling tower 306 partially dissipates the heat to the ambient air by evaporation of water.

The artificial cooling system 101 is in fluid communication with the cooling tower 306 and the preheater 303A. The artificial cooling system 101 is configured to receive the partially cooled gas from the cooling tower 306. The evaporator 108D absorbs heat from the partially cooled gas, and the water is subsequently transported to the preheater 303A at a temperature of around 20 °C to 25 °C.

The artificial cooling system 101 is also in fluid communication with the ejection means 308. The ejection means 308 is configured to provide the geothermal brine to the artificial cooling system 101 at a temperature of around 100 °C to 150 °C. The artificial cooling system 101 operates in the same manner as is described in relation to Figure 1.

Figure 4 shows a schematic view of a geothermal power generation system 1000 comprising an artificial cooling system 1001 according to the present disclosure. Similar numerals are used for similar parts of embodiments of the present invention. The geothermal power generation system 1000 of Figure 4 works in an analogous way to the geothermal power generation system 100 of Figure 1 , differing in that the geothermal power generation system 1000 of Figure 4 does not use an ammonia absorption chiller and does not use a rectifier. The condenser 1008C is in fluid communication with the generator 1008A.

The description provided herein may be directed to specific implementations. It should be understood that the discussion provided herein is provided for the purpose of enabling a person with ordinary skill in the art to make and use any subject matter defined herein by the subject matter of the claims. It should be intended that the subject matter of the claims not be limited to the implementations and illustrations provided herein, but include modified forms of those implementations including portions of implementations and combinations of elements of different implementations in accordance with the claims. It should be appreciated that in the development of any such implementation, as in any engineering or design project, numerous implementation-specific decisions should be made to achieve a developers’ specific goals, such as compliance with system-related and business related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort may be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having benefit of this disclosure.

Reference has been made in detail to various implementations, examples of which are illustrated in the accompanying drawings and figures. In the detailed description, numerous specific details are set forth to provide a thorough understanding of the disclosure provided herein. However, the disclosure provided herein may be practiced without these specific details. In some other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure details of the embodiments.

It should also be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element. The first element and the second element are both elements, respectively, but they are not to be considered the same element.

The terminology used in the description of the disclosure provided herein is for the purpose of describing particular implementations and is not intended to limit the disclosure provided herein. As used in the description of the disclosure provided herein and appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify a presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

As used herein, the term “if” may be construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. Similarly, the phrase “if it is determined” or “if [a stated condition or event] is detected” may be construed to mean “upon determining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event],” depending on the context. The terms “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; “below” and “above”; and other similar terms indicating relative positions above or below a given point or element may be used in connection with some implementations of various technologies described herein.

While the foregoing is directed to implementations of various techniques described herein, other and further implementations may be devised in accordance with the disclosure herein, which may be determined by the claims that follow. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.