# Evaluation and Optimization of the Annual Performance of a Novel Tri-Generation System Driven by Geothermal Brine in Off-Design Conditions

^{*}

## Abstract

**:**

_{3}-H

_{2}O mixture as a working fluid for the whole tri-generation system. A sensitive analysis of off-design conditions is carried out to study the effect of operational parameters on the system performances prior to optimizing its performance. The simulation show that the system is able to cover required heating and cooling demands. The optimization is applied considering the maximum exergy efficiency (scenario 1) and minimum total exergy destruction rate (scenario 2). The optimization results show that the maximum mean exergy efficiency in scenario 1 is achieved as 44.67% at the expense of 14.52% increase in the total exergy destruction rate in scenario 2. The minimum mean total exergy destruction rate in scenario 2 is calculated as 2980 kW at the expense of 8.32% decrease in the exergy efficiency in scenario 1.

## 1. Introduction

- to define heating and cooling demand in winter and summer conditions (different ambient temperatures) to evaluate the system performance using operational data of an existing geothermal district heating network in the German Molasse basin [24]. In particular, the geothermal source, mean ambient temperatures and heating/cooling demands are based on this case;
- to validate the power part (Kalina cycle) and to verify the cooling part in order to confirm the validity of the simulation model;
- to determine the main operational parameters to analyze the system;
- to develop and apply an off-design model of the tri-generation system;
- to apply the quasi-stationary simulation of a tri-generation system in different weather conditions to fulfill the heating and cooling demands;
- to obtain mean annual system performances;
- to optimize the system considering two criteria, maximum exergy efficiency and minimum total exergy destruction rate.

## 2. Methodology

#### 2.1. Description of the System

_{2}and then to absorber (ABS) (stream 17) through PU3. The ammonia-water solution at the outlet of the ABS (state 1) is forced to the medium pressure level (state 2) by PU1 and is led to SHE. This stream at the outlet of the SHE (stream 3) which is heated in the SHE via saturated liquid (state 11) from SEP. The stream 3 goes to GEN to heat with the geothermal water following to divide into two saturated liquid and vapor streams (stream 4 and 5). The vapor stream coming from the GEN (state 5) is cooled through rectifier (REC) and again the stream is divided into liquid and vapor phase to provide a strong ammonia solution (stream 7). The pure ammonia is saturated in the CON

_{1}(stream 18) and is led through the evaporator (EVA) via EX

_{1}. In the EVA, the pure ammonia solution is heated by absorbing heat and can produce a cooling demand in the summer condition (stream 39–40). The stream coming from EVA (stream 20) leads to ABS and is mixed with stream 17 via PU3 and the proposed system is completed. The heat sink streams (streams 31–36) are used as coolant and the water- ethylene glycol streams 39 and 40 are utilized to cover the cooling demand. The water streams 29 and 30 are used to produce heating demand. Moreover, it is worthwhile to indicate that in the proposed system, two different evaporators are applied in summer and winter. In summer days, when the tri-generation mode is required, the evaporator for cooling is applied to the system. In winter days, when no cooling demand is required, the geothermal fluid coming from GEN (stream 27) is led through the evaporator for heating. In this regard, the useful productions in the tri-generation system are outlined as follows:

- -
- heating via domestic heat exchanger
- -
- power generation via turbine
- -
- cooling via evaporator

#### 2.2. Assumption

- -
- Pressure and heat losses in the heat exchangers and pipelines are neglected.
- -
- The isotropic efficiency for pumps is considered as constant.
- -
- The changes of kinetic and potential energies are negligible.
- -
- The state of leaving streams of absorber, condenser, generator and rectifier is saturated.
- -
- In the cold season when heating demand is required, the extracted stream of geothermal fluid from the generator is used in the evaporator to supply the needed heat (stream 27–28) in the evaporator in the absorption heat pump cycle. In the summer days, the stream 27 goes to reinjection well and the cooling demand is produced in the evaporator for cooling.

#### 2.3. Off-Design Model

#### 2.4. Heating and Cooling Demand Profiles

#### 2.5. Exergetic Evaluation

- on winter days:$${\dot{E}}_{D,tot}={\dot{E}}_{in}-({\dot{W}}_{net}+{\dot{E}}_{heating})-({\dot{E}}_{L,ABS}+{\dot{E}}_{L,CON1}+{\dot{E}}_{L,CON2}+{\dot{E}}_{L,REC})$$
- on summer days:$${\dot{E}}_{D,tot}={\dot{E}}_{in}-({\dot{W}}_{net}+{\dot{E}}_{heating}+{\dot{E}}_{cooling})-({\dot{E}}_{L,ABS}+{\dot{E}}_{L,CON1}+{\dot{E}}_{L,CON2}+{\dot{E}}_{L,REC})$$

## 3. Results and Discussion

#### 3.1. Validation and Verification

#### 3.2. Parametric Analysis

_{1}, CON

_{2}is increased. According to Equation (21), the total exergy destruction rate takes locally minimum values.

_{1}, CON

_{2}, is decreased by increasing ${\mathrm{T}}_{\mathrm{gen}}$. In this regard, according to Equation (21) the total exergy destruction rate decreases with an increase in ${\mathrm{T}}_{\mathrm{gen}}$.

#### 3.3. Discussion of Parametric Analysis

- -
- There is a local optimum value in the exergy efficiency at the specific value of $\mathrm{TIP}=16.3\text{}\mathrm{bar}$ and ${\mathrm{T}}_{\mathrm{gen}}=51.5$ °C in the typical day of WWC. In the other typical day categories, the exergy efficiency has local optimum at the different values of TIP and ${\mathrm{T}}_{\mathrm{gen}}$ in comparison to typical day of WWC.
- -
- The total exergy destruction rate in minimized locally at the specific values of $\mathrm{TIP}=16.53\text{}\mathrm{bar}$ in the typical day of WWC. This value of TIP is changed in the other typical day categories in order to minimize locally the total exergy destruction rate.
- -
- -
- In the hot days; TSF, TWF, SWX and SSX, with an increase in the ${\mathsf{\delta}\mathrm{T}}_{\mathrm{CON}1}$ the exergy efficiency decreases which is in reverse for other category days.
- -
- The values of ${\mathsf{\delta}\mathrm{T}}_{\mathrm{CON}1}$ and ${\mathsf{\delta}\mathrm{T}}_{\mathrm{CON}1}$ are limited by the ambient temperature and take different range in different typical day categories.

#### 3.4. The Optimized Quasi-Steady State Results For Different Typical Days

_{1}(${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{CON}1}$) in maximizing the exergy efficiency is almost higher than the one in minimizing the total destruction rate. However, the heat sink temperature difference in the CON

_{2}(${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{CON}2}$) in the first scenario is lower than the one in the second one.

## 4. Conclusions

- The required heating demand is covered by the geothermal mass flow division ratio in both winter and summer conditions. This value is decreased with a reduction in heating demand.
- There is a local optimum for the exergy efficiency and the total destruction rate at specific values of Turbine inlet pressure.
- With an increase in generator temperature, there is a local maximum in exergy efficiency, however, the total exergy destruction rate is decreased.
- Under optimization condition, the maximum annual exergy efficiency is obtained as 44.67% at the expense of 14.52% increase in the total exergy destruction rate in comparison to second scenario.
- The ooptimization results show the minimum mean total exergy destruction rate of the system is calculated as 2980 kW at the expense of 8.32% decrease in the exergy efficiency in the first scenario.
- Considering both exergy efficiency and total exergy destruction rate in off-design condition, the best enhancement through the optimization process is achieved on the typical day WWC with 53.21% of exergy efficiency and 2570 kW of total exergy destruction rate.
- Comparing the optimization results for maximum exergy efficiency and minimum total exergy destruction rate depicts a better performance improvement obtained in the second scenario.

## Author Contributions

## Funding

## Conflicts of Interest

## Nomenclature

ABS | absorber | TIP | turbine inlet pressure |

BOI | boiler | TUR | turbine |

CON | condenser | $\dot{\mathrm{W}}$ | power ($\mathrm{kW}$) |

DEP | dephlepmator | $\mathrm{X}$ | ammonia concentration |

DHE | domestic heat exchanger | ||

EVA | evaporator | Subscripts and abbreviations | |

${\mathrm{e}}_{\mathrm{ch}}^{0}$ | standard chemical exergy | 0 | ambient |

EX | expansion valve | CD | cooling demand |

$\dot{\mathrm{E}}$ | exergy rate | ch | chemical |

$\mathrm{e}$ | Specific exergy | D | destruction |

GEN | generator | geo | Geothermal hot water |

$\mathrm{h}$ | specific enthalpy | HD | heating demand |

$\mathrm{M}$ | Molar weight | L | loss |

$\dot{\mathrm{m}}$ | mass flow rate | p | product |

$\mathrm{P}$ | pressure | ph | physical |

Pu | pump | pp | pinch point |

${\mathrm{r}}_{\mathrm{geo}}$ | Geothermal mass flow division ratio | Greek symbols | |

$\mathrm{s}$ | specific entropy | ${\mathsf{\eta}}_{\mathsf{{\rm I}}\mathsf{{\rm I}}}$ | Exergy efficiency |

SHE | solution heat exchanger | ${\mathsf{\eta}}_{\mathrm{is}}$ | isentropic efficiency |

SEP | separator | $\mathsf{\zeta}$ | Ammonia concentration |

$\mathrm{T}$ | temperature | ${\mathrm{Y}}_{\mathrm{D},\mathrm{k}}^{*}$ | ratio of exergy destruction for a certain component |

## Appendix A

**Table A1.**Detailed parameters of the optimization calculation (a) maximum exergy efficiency (b) minimum exergy.destruction rate.

WWF | WWC | WSF | WSC | TWC | TSC | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|

${T}_{ambient}$ (°C) | −0.13 | −5.68 | 2.27 | 1.1 | 7.37 | 4.81 | ||||||

${\dot{Q}}_{heating}\text{}(MW)$ | 11.8 | 11.66 | 11.8 | 10.,79 | 6.3 | 6.15 | ||||||

${\dot{Q}}_{cooling}\text{}(MW)$ | - | - | - | - | - | - | ||||||

(a) | (b) | (a) | (b) | (a) | (b) | (a) | (b) | (a) | (b) | (a) | (b) | |

Decision operational variables | ||||||||||||

$\mathrm{TIP}$ (bar) | 16.4 | 15.7 | 17.5 | 17 | 17 | 17.5 | 18.4 | 20.3 | 20.5 | 21.9 | 19.5 | 22.5 |

${\mathrm{T}}_{\mathrm{gen}}$ (°C) | 57.66 | 62.02 | 52.65 | 57.5 | 57.32 | 61.82 | 58 | 61.48 | 58.2 | 57.94 | 55 | 58.9 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{ABS}}$ (°C) | 15.8 | 9.8 | 11.2 | 5.5 | 12.6 | 6.4 | 14 | 5.6 | 15 | 8.6 | 6.897 | 5.2 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{CON}1}$ (°C) | 19.69 | 23.4 | 17.67 | 25.1 | 17 | 20.83 | 18.75 | 21.71 | 13.72 | 13.5 | 12.48 | 15.81 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{CON}2}$ (°C) | 5 | 5 | 5.2 | 5 | 5 | 5 | 5.2 | 5 | 5 | 5 | 5 | 5 |

Calculated parameters in the off-design conditions | ||||||||||||

${\mathsf{\eta}}_{\mathrm{s},\mathrm{tur}\text{}}(\%)$ | 84 | 68 | 85 | 70 | 84 | 64 | 85 | 64 | 85 | 81 | 84 | 76 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{pp}}$ (°C) | 17.99 | 34.5 | 19.16 | 35.3 | 16.85 | 33 | 17.67 | 29.6 | 13.28 | 16.66 | 15.86 | 22.32 |

${\mathrm{T}}_{\mathrm{eva}}$ (°C) | - | - | - | - | - | - | - | - | - | - | - | - |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{ABS}}={\mathrm{T}}_{32}-{\mathrm{T}}_{31}$ (°C) | 17.83 | 14.7 | 12.61 | 9.77 | 14.13 | 10.1 | 15.54 | 9.01 | 15.43 | 6.55 | 12 | 8.1 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{CON}1}={\mathrm{T}}_{36}-{\mathrm{T}}_{35}$ (°C) | 16.48 | 15.45 | 17.68 | 16.52 | 16.56 | 15.49 | 16.4 | 15.57 | 13.55 | 8.6 | 12.44 | 15.8 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{CON}2}={\mathrm{T}}_{40}-{\mathrm{T}}_{39}$ (°C) | 7.06 | 18.07 | 7.98 | 19.2 | 7.062 | 16.27 | 6.88 | 14.26 | 3.67 | 13.5 | 3.751 | 7.45 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{REC}}={\mathrm{T}}_{34}-{\mathrm{T}}_{33}$ (°C) | 10.81 | 14.5 | 11.81 | 16.34 | 9.485 | 12.47 | 9.37 | 11.59 | 5.14 | 5.3 | 5.426 | 5.7 |

**Table A2.**Detailed parameters of the optimization calculation (a) maximum exergy efficiency (b) minimum exergy destruction rate.

TSF | TWF | SWX | SSX | |||||
---|---|---|---|---|---|---|---|---|

${T}_{ambient}$ (°C) | 13.81 | 15.42 | 15.67 | 17.24 | ||||

${\dot{Q}}_{heating}\text{}(MW)$ | 4.79 | 5.69 | 2.99 | 2.9 | ||||

${\dot{Q}}_{cooling}\text{}(MW)$ | 1.78 | 1.9 | 2.58 | 2.5 | ||||

(a) | (b) | (a) | (b) | (a) | (b) | (a) | (b) | |

Decision operational variable | ||||||||

$\mathrm{TIP}$ (bar) | 20 | 21.7 | 19.5 | 25.2 | 20 | 26.06 | 20.2 | 29.6 |

${\mathrm{T}}_{\mathrm{gen}}$ (°C) | 67.62 | 67.62 | 61.02 | 64.7 | 58.96 | 65 | 60.81 | 66.85 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{ABS}}$ (°C) | 12.11 | 7.81 | 12.71 | 7.69 | 11.61 | 11.51 | 12.01 | 7.55 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{CON}1}$ (°C) | 14.2 | 14.2 | 7.02 | 10.12 | 4.99 | 10.12 | 5 | 10.12 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{CON}2}$ (°C) | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 |

Calculated parameters in the off-design conditions | ||||||||

${\mathsf{\eta}}_{\mathrm{s},\mathrm{tur}}$ (%) | 71 | 60 | 079 | 66 | 80 | 71 | 79 | 56 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{pp}}$ (°C) | 25.47 | 26.01 | 14.65 | 15.14 | 14.22 | 12.46 | 14.84 | 11.78 |

${\mathrm{T}}_{\mathrm{eva}}$ (°C) | 10.58 | 10.14 | 9.7 | 7.1 | 11.57 | 6.522 | 14.89 | 15.5 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{ABS}}={\mathrm{T}}_{32}-{\mathrm{T}}_{31}$ (°C) | 13.64 | 9.29 | 12.76 | 7.7 | 10.74 | 4.07 | 11.38 | 7.13 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{CON}1}={\mathrm{T}}_{36}-{\mathrm{T}}_{35}$ (°C) | 14.13 | 14.13 | 6.55 | 9.37 | 3.83 | 7.79 | 3.9 | 8.11 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{CON}2}={\mathrm{T}}_{40}-{\mathrm{T}}_{39}$ (°C) | 7.215 | 8.9 | 3.3 | 5.23 | 2.5 | 3.71 | 2.7 | 13.11 |

${\mathsf{\delta}\mathrm{T}}_{\mathrm{air},\mathrm{REC}}={\mathrm{T}}_{34}-{\mathrm{T}}_{33}$ (°C) | 4.311 | 4.5 | 3.1 | 3.22 | 2.45 | 2.43 | 2.4 | 2.42 |

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**Figure 3.**Verification results for absorption refrigeration cycle for the present work and with previously published data by [43].

**Figure 4.**The effect of the TIP (

**a**) on exergy efficiency and total exergy destruction rate (

**b**) on the turbine specific work and mass flow rate.

**Figure 5.**The influence of the ${\mathrm{T}}_{\mathrm{gen}}$ (

**a**) on exergy efficiency and total exergy destruction (

**b**) on the net produced power and input exergy to the system.

**Figure 6.**The variation of exergy efficiency and the total exergy destruction rate with the temperature differences at the condensers exit.

**Figure 7.**The mean energy and exergy efficiencies as well as the mean total exergy destruction rate of each typical day under optimization condition based on maximum exergy efficiency.

**Figure 8.**The mean energy and exergy efficiencies as well as the mean total exergy destruction rate of each typical day under optimization condition based on minimum total exergy destruction rate.

Parameter | Symbol | Value |
---|---|---|

Dead state pressure $(bar)$ | ${\mathrm{p}}_{0}$ | 1 |

Dead state temperature (°C) | ${\mathrm{T}}_{0}$ | ${T}_{0}+5$ |

Geothermal hot water temperature (°C) [24] | ${\mathrm{T}}_{\mathrm{in},\mathrm{geo}}$ | 138 |

Geothermal hot water mass flow rate (kg/s) [24] | ${\dot{\mathrm{m}}}_{\mathrm{geo}}$ | 120 |

Ambinet temperature (°C) [24] | ${\mathrm{T}}_{\mathrm{amb}}$ | −5.68 |

Heating demand $(MW)$ [24] | ${\dot{\mathrm{Q}}}_{\mathrm{heating}}$ | 11.8 |

Evaporator temperature (°C) [24] | ${\mathrm{T}}_{\mathrm{eva}}$ | 5 |

Turbine inlet pressure (bar) [31] | $\mathrm{TIP}$ | 20 |

Ammonia concentration in the boiler (%) [32] | ${\mathsf{\zeta}}_{\mathrm{B}}$ | 50 |

Supply heating temperature (°C) [24] | ${\mathrm{T}}_{33}$ | 90 |

Return heating temperature (°C) [24] | ${\mathrm{T}}_{32}$ | 60 |

Turbine isentropic efficiency$\text{}(\%)$ [12] | ${\mathsf{\eta}}_{\mathrm{is},\mathrm{tur}}$ | 85 |

Pump isentropic efficiency $(\%)$ [22] | ${\mathsf{\eta}}_{\mathrm{is},\mathrm{pump}}$ | 75 |

${(\mathbf{U}\mathbf{A})}_{\mathbf{d}\mathbf{e}\mathbf{s}\mathbf{i}\mathbf{g}\mathbf{n}}\text{}(\mathbf{k}\mathbf{W}/\mathbf{K})$ | ${(\dot{\mathbf{m}})}_{\mathbf{d}\mathbf{e}\mathbf{s}\mathbf{i}\mathbf{g}\mathbf{n}}(\mathbf{k}\mathbf{g}/\mathbf{s})$ | |
---|---|---|

Domestic heat exchanger | 313.2 | 92.64 |

Boiler | 723.5 | 13.37 |

Generator | 71.24 | 17.11 |

Solution heat exchanger | 37.11 | 17.11 |

Absorber | 343.9 | 263.8 |

Condenser 1 | 128.6 | 110.4 |

Condenser 2 | 514.4 | 1110 |

Dephlegmator | 3.066 | 12.39 |

Evaporator for heating | 24.18 | 1.74 |

Evaporator for cooling | 1014 | 2.082 |

**Table 3.**Test reference years according to VDI 4655 [38].

Climate Zone | Number of Typical Days (Frequency of the Different Typical Days) | |||||||||
---|---|---|---|---|---|---|---|---|---|---|

WWF | WWC | WSF | WSC | TWC | TSC | TSF | TWF | SWX | SSX | |

… | ||||||||||

TRY12 | 23 | 57 | 2 | 16 | 91 | 18 | 8 | 27 | 104 | 19 |

TRY13 | 29 | 91 | 6 | 19 | 72 | 10 | 15 | 37 | 73 | 13 |

TRY14 | 22 | 115 | 5 | 25 | 81 | 15 | 11 | 42 | 42 | 7 |

… |

**Table 4.**Corresponding mean values of heating, cooling and ambient temperature for different typical days categories.

WWF | WWC | WSF | WSC | TWC | TSC | TSF | TWF | SWX | SSX | |
---|---|---|---|---|---|---|---|---|---|---|

n = 29 | n = 91 | n = 6 | n = 19 | n = 72 | n = 10 | n = 15 | n = 37 | n = 13 | n = 73 | |

${\mathrm{T}}_{\mathrm{ambient}}$ (°C) [24] | −0.13 | −5.68 | 2.27 | 1.1 | 7.37 | 4.81 | 13.81 | 15.42 | 15.67 | 17.24 |

${\dot{\mathrm{Q}}}_{\mathrm{heating}}\text{}(\mathrm{MW})$ [24] | 11.68 | 11.66 | 11.8 | 10.79 | 6.3 | 6.15 | 4.79 | 5.69 | 2.99 | 2.9 |

${\dot{\mathrm{Q}}}_{\mathrm{cooling}}\text{}(\mathrm{MW})$ | - | - | - | - | - | - | 1.78 | 1.9 | 2.43 | 2.48 |

**Table 5.**Validation results of the power ammonia-water Kalina cycle operating conditions gained from present work (a) with reported data for the existing power plant in Húsavík [16] (b).

Point | $\mathbf{Temperature}\text{}(\mathbf{K})$ | $\mathbf{Pressure}\text{}(\mathbf{k}\mathbf{P}\mathbf{a})$ | Ammonia Concentration $(\mathbf{k}\mathbf{g}\frac{\mathbf{N}{\mathbf{H}}_{3}}{\mathbf{k}\mathbf{g}}\mathbf{s}\mathbf{o}\mathbf{l}\mathbf{u}\mathbf{t}\mathbf{i}\mathbf{o}\mathbf{n})$ | |||
---|---|---|---|---|---|---|

(a) | (b) | (a) | (b) | (a) | (b) | |

1 | 281.15 | 281.15 | 4.6 | 4.6 | 0.82 | 0.82 |

2 | 281.20 | 281.15 | 35.3 | 35.3 | 0.82 | 0.82 |

3 | 314.26 | 314.15 | 34.3 | 34.3 | 0.82 | 0.82 |

4 | 336.10 | 336.15 | 33.3 | 33.3 | 0.82 | 0.82 |

5 | 389.15 | 389.15 | 32.3 | 32.3 | 0.82 | 0.82 |

6 | 389.15 | 389.15 | 32.3 | 32.3 | 0.973 | 0.97 |

7 | 389.15 | 389.15 | 32.3 | 32.3 | 0.498 | 0.5 |

8 | 316.21 | 316.15 | 6.6 | 6.6 | 0.973 | 0.97 |

9 | 319.11 | 319.15 | 31.3 | 31.3 | 0.498 | 0.5 |

10 | 319.18 | 319.15 | 6.6 | 6.6 | 0.82 | 0.82 |

11 | 303.16 | 303.15 | 5.6 | 5.6 | 0.82 | 0.82 |

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## Share and Cite

**MDPI and ACS Style**

Akbari Kordlar, M.; Heberle, F.; Brüggemann, D.
Evaluation and Optimization of the Annual Performance of a Novel Tri-Generation System Driven by Geothermal Brine in Off-Design Conditions. *Appl. Sci.* **2020**, *10*, 6532.
https://doi.org/10.3390/app10186532

**AMA Style**

Akbari Kordlar M, Heberle F, Brüggemann D.
Evaluation and Optimization of the Annual Performance of a Novel Tri-Generation System Driven by Geothermal Brine in Off-Design Conditions. *Applied Sciences*. 2020; 10(18):6532.
https://doi.org/10.3390/app10186532

**Chicago/Turabian Style**

Akbari Kordlar, Mehri, Florian Heberle, and Dieter Brüggemann.
2020. "Evaluation and Optimization of the Annual Performance of a Novel Tri-Generation System Driven by Geothermal Brine in Off-Design Conditions" *Applied Sciences* 10, no. 18: 6532.
https://doi.org/10.3390/app10186532