Thermodynamic Analysis and Optimization of the Micro-CCHP System with a Biomass Heat Source

Round 1

Reviewer 1 Report

The authors propose new multiple production systems based on the micro-CCHP cycle with a mass heat source, consisting of subsystems of the absorption refrigeration cycle and a water softener system, aiming to increase the efficiency of the basic cycle and reduce waste.

 

In the bibliographic review presented in the introduction, improve the contextualization and emphasize the importance of the researched topic.

 

Add a last paragraph in section 1 (Introduction) describing the other sections of the article.

 

The citation standard that the journal uses is not (author, date), correct the citation, some examples in lines 52, 55, 59, 80, among others.

 

On line 62, put the word “This” starting with a capital letter.

 

Although the meaning of cycle abbreviations is common, it is important. Inform their meanings at first appearance in the text, for example VCHP Cycle (vapor compression heat pump cycle) among others.

 

In the description of the methodology insert a flowchart with the steps of the method.

 

The authors cite the use of a genetic algorithm for optimization, but the data and specifications of the algorithm were not mentioned in the methodology, only in the results.

Author Response

2023.02.22

 

Manuscript Number: sustainability-2235010

Title: Thermodynamic analysis and optimization of the micro-CCHP system with a biomass heat source

 

Dear Editor and Reviewers,

Thank you very much for e-mailing us the comments raised by the respected reviewer. We considered the comments seriously and hope to be acceptable. The manuscript has been revised taking into account all of the valuable comments and suggestions. We have worked very hard to satisfy comments raised by respected reviewer. The details of the comments raised, the answers and the actions taken are presented here. I would like to thank you and the respected reviewer for very helpful and constructive comments. All of the changes made in the new revised manuscript have been highlighted in yellow color.

Best regards,

Reza Morovati

 

Reviewer 1

The authors propose new multiple production systems based on the micro-CCHP cycle with a mass heat source, consisting of subsystems of the absorption refrigeration cycle and a water softener system, aiming to increase the efficiency of the basic cycle and reduce waste.

 

Q1. In the bibliographic review presented in the introduction, improve the contextualization and emphasize the importance of the researched topic.

Thanks to the attention of the esteemed reviewer, added.

In this research, chemical analysis of urban waste related to Hamedan has been done, estimated the heating value of urban waste incineration. In this way, the approxi-mate amount of energy obtained can be obtained before designing the system [4]. In this research, different compositions of air and steam as a reactor input have been examined and fixed base gasifier behavior in different situations has been specified which demon-strate that, the best amount of air-steam composition with the most heat valuation is 12.26 (lb/s) for air input and 9.989 (lab/s) for steam input [5]. In this research, we first studied renewable energies, followed by technologies related to the biogas system. Biogas systems have been referred to by landfill and discussed comprehensively in this scheme for utili-zation. For this purpose, the input source of this system is considered as the volume of garbage in the city of Germi as the study area. In the next step, the amount of garbage produced in this city was extracted and the Landfill software was used for methane pro-duction potential assessment from this system and the Homer software was used for eco-nomic analysis and reliability evaluation. The most important results are payback period, which is about 10 years, and the amount of electricity produced per year, which is 11658.265 MWh [6]. In this study, the study area of Hamadan city is considered to have an average urban waste production of about 420 tons/month. Homer software has been used to analyze the amount of electricity produced, and economic and environmental analysis has also been done. One of the outstanding results of the research is the production of 229,735 kW/year of electrical energy. Electricity generation with biomass resources will reduce Co2 and Co emissions by 77.2 and 7.96 kg/year, respectively. That cost of ener-gy(COE) for this system is 0.177$/kWh [7].

 

 

Q2. Add a last paragraph in section 1 (Introduction) describing the other sections of the article.

Thanks to the attention of the esteemed reviewer, added.

In this study, a new multiple generation system based on micro-CCHP cycle with biomass heat source is presented. In this proposed system, absorption refrigeration cycle subsystems and water softener system have been used in order to increase the efficiency of the basic cycle and reduce waste. In this research, the microturbine system is modeled with a biomass generator, which is used to model the thermodynamic relationships governing the various components of the studied system. The general goal of this research is to in-crease the energy efficiency and exergy of the system, and to achieve this goal, the waste heat of the generator after recovery has been used as the starter of the absorption refrigeration cycle.

 

Q3. The citation standard that the journal uses is not (author, date), correct the citation, some examples in lines 52, 55, 59, 80, among others.

Thanks to the attention of the esteemed reviewer, corrected.

 

Q4. On line 62, put the word “This” starting with a capital letter.

Thanks to the attention of the esteemed reviewer, corrected.

 

 

Q5. Although the meaning of cycle abbreviations is common, it is important. Inform their meanings at first appearance in the text, for example VCHP Cycle (vapor compression heat pump cycle) among others.

Thanks to the attention of the esteemed reviewer, added.

 

Q6. In the description of the methodology insert a flowchart with the steps of the method.

Thanks to the attention of the esteemed reviewer.

 

Q7. The authors cite the use of a genetic algorithm for optimization, but the data and specifications of the algorithm were not mentioned in the methodology, only in the results.

Thanks to the attention of the esteemed reviewer.

In the design of thermal systems, the optimization of thermodynamic conditions is used to determine the maximum efficiency of energy and exergy. In this article, the genetic algorithm method is used in EES software. The genetic algorithm method can be suitable compared to other methods available in the software. In the single-objective optimization method, the objective function is to determine the maximum energy efficiency or exergy of the system, but in multi-objective optimization, the objective function is to simultaneously determine the maximum energy efficiency and exergy of the system (Zare et al., 2012). The ranges of thermodynamic parameters for optimization are the same ranges examined in the parametric study of the system. For the system presented in this research, the maximum of the multi-objective function is expressed as follows.

 

                                       

 

 

Reviewer 2

Overall observations: The paper is interesting; however, it needs several modifications before it can become more publishable.

 

Q1. There are several grammatical corrections that need to be done throughout the paper.

Thanks to the attention of the esteemed reviewer, checked by Grammerly software

Q2. Please make sure you have included all the nomenclatures as used in the text, which may be briefly described. Please include all the short forms/abbreviations used in all the equations.

Thanks to the attention of the esteemed reviewer, added.

Q3. In the abstract next to the numbers, the unit should be used so that the audience can understand better, for example in line 41: 74.2.

Thanks to the attention of the esteemed reviewer, added.

Q4. The method of referencing is to use the journal template. For example, in line 52.

Thanks to the good question of the esteemed reviewer, corrected.

Q5. Added new research in the introduction.

Thanks to the good question of the esteemed reviewer, added.

In this research, chemical analysis of urban waste related to Hamedan has been done, estimated the heating value of urban waste incineration. In this way, the approximate amount of energy obtained can be obtained before designing the system [4]. In this research, different compositions of air and steam as a reactor input have been examined and fixed base gasifier behavior in different situations has been specified which demonstrate that, the best amount of air-steam composition with the most heat valuation is 12.26 (lb/s) for air input and 9.989 (lab/s) for steam input [5]. In this research, we first studied renewable energies, followed by technologies related to the biogas system. Biogas systems have been referred to by landfill and discussed comprehensively in this scheme for utilization. For this purpose, the input source of this system is considered as the volume of garbage in the city of Germi as the study area. In the next step, the amount of garbage produced in this city was extracted and the Landfill software was used for methane production potential assessment from this system and the Homer software was used for economic analysis and reliability evaluation. The most important results are payback period, which is about 10 years, and the amount of electricity produced per year, which is 11658.265 MWh [6]. In this study, the study area of Hamadan city is considered to have an average urban waste production of about 420 tons/month. Homer software has been used to analyze the amount of electricity produced, and economic and environmental analysis has also been done. One of the outstanding results of the research is the production of 229,735 kW/year of electrical energy. Electricity generation with biomass resources will reduce Co2 and Co emissions by 77.2 and 7.96 kg/year, respectively. That cost of energy(COE) for this system is 0.177$/kWh [7].

Wang et al. [11] presented a Bi-level sizing optimization of a distributed solar hybrid CCHP system considering economic, energy, and environmental objectives. Delgado et al. [12] presented an integration of cycles by absorption for the production of desalinated water and cooling. Askari et al. [13] presented at the exergo-economic analysis of two novel combined ejector heat pump/humidification-dehumidification desalination systems.

 

Q6. Figures 1,2 aren’t clear.

Thanks to the attention of the esteemed reviewer, corrected.

Q7. Added reference to all equations.

Thanks to the attention of the esteemed reviewer, added.

Q8. Added reference number in Figures 3,4 and 5.

Thanks to the attention of the esteemed reviewer, added.

Q9. To improve the conclusion part, it is suggested to add future works as well.

Thanks to the good question of the esteemed reviewer, corrected.

Future works can be mentioned as follows:

Thermo-mechanical energy level approach integrated with exergoeconomic optimi-zation.

Energetic and exergetic analysis of a biomass-fueled CCHP system integrated with other heat resources.

 Multi-criteria evaluation biomass-fueled CCHP system.

 

Q10. Reference should be updated.

Thanks to the attention of the esteemed reviewer, updated.

Q11. Add some sources that are not mentioned. For example, [35]

Thanks to the attention of the esteemed reviewer, corrected..

Reviewer 3

Thermodynamic analysis and optimization of micro-CCHP system are presented in this paper. Overall, it is well written. The reviewer has some comments that might be helpful for authors to improve the paper.

 

Q1. In section 2, it is not clear how the energy and the exergy are linked in the model. Are they analyzed separately?

Thanks to the attention of the esteemed reviewer, according to section 2, energy and exergy analyzes are considered separately.

Q2. Comparison with existing CHP studies can be enhanced, e.g., 10.1016/j.apenergy.2015.01.102 and 10.1109/TSG.2022.3210014, which have also conducted research on thermal dynamics analysis, modelling and optimization.

Thanks to the attention of the esteemed reviewer.

Q3. Fig 1 is not so accurate as there should be a heating network connecting heat source and load. And the heating network model seems absent in this paper.

Thanks to the attention of the esteemed reviewer, As shown in Figure 1, the waste heat in the turbine is absorbed by the ejector and then it is converted from the ejector into useful heat for use as required heat by the heat exchanger.

Q4. I cannot find the optimization model easily, i.e., objective function and constraints, in the paper.

Thanks to the good question of the esteemed reviewer.

 In the design of thermal systems, the optimization of thermodynamic conditions is used to determine the maximum efficiency of energy and exergy. In this article, the genetic algorithm method is used in EES software. The genetic algorithm method can be suitable compared to other methods available in the software. In the single-objective optimization method, the objective function is to determine the maximum energy efficiency or exergy of the system, but in multi-objective optimization, the objective function is to simultaneously determine the maximum energy efficiency and exergy of the system (Zare et al., 2012). The ranges of thermodynamic parameters for optimization are the same ranges examined in the parametric study of the system. For the system presented in this research, the maximum of the multi-objective function is expressed as follows.

 

MOF=((w_1×ղ_t) + (w_2×ղ_x))                   (20)

w_1  + w_2  = 1

0 ≤  w_1,w_2   ≤1

 

Reviewer 2 Report

Overall observations: The paper is interesting; however, it needs several modifications before it can become more publishable.

1. There are several grammatical corrections that need to be done throughout the paper.

2. Please make sure you have included all the nomenclatures as used in the text, which may be briefly described. Please include all the short forms/abbreviations used in all the equations.

3. In the abstract next to the numbers, the unit should be used so that the audience can understand better, for example in line 41: 74.2.

4. The method of referencing is to use the journal template. For example, in line 52.

5. Added new research in the introduction.

6. Figures 1,2 aren’t clear.

7. Added reference to all equations.

8. Added reference number in Figures 3,4 and 5.

9. To improve the conclusion part, it is suggested to add future works as well.

10. Reference should be updated.

11. Add some sources that are not mentioned. For example, [35]

 

Author Response

2023.02.22

 

Manuscript Number: sustainability-2235010

Title: Thermodynamic analysis and optimization of the micro-CCHP system with a biomass heat source

 

Dear Editor and Reviewers,

Thank you very much for e-mailing us the comments raised by the respected reviewer. We considered the comments seriously and hope to be acceptable. The manuscript has been revised taking into account all of the valuable comments and suggestions. We have worked very hard to satisfy comments raised by respected reviewer. The details of the comments raised, the answers and the actions taken are presented here. I would like to thank you and the respected reviewer for very helpful and constructive comments. All of the changes made in the new revised manuscript have been highlighted in yellow color.

Best regards,

Reza Morovati

 

Reviewer 1

The authors propose new multiple production systems based on the micro-CCHP cycle with a mass heat source, consisting of subsystems of the absorption refrigeration cycle and a water softener system, aiming to increase the efficiency of the basic cycle and reduce waste.

 

Q1. In the bibliographic review presented in the introduction, improve the contextualization and emphasize the importance of the researched topic.

Thanks to the attention of the esteemed reviewer, added.

In this research, chemical analysis of urban waste related to Hamedan has been done, estimated the heating value of urban waste incineration. In this way, the approxi-mate amount of energy obtained can be obtained before designing the system [4]. In this research, different compositions of air and steam as a reactor input have been examined and fixed base gasifier behavior in different situations has been specified which demon-strate that, the best amount of air-steam composition with the most heat valuation is 12.26 (lb/s) for air input and 9.989 (lab/s) for steam input [5]. In this research, we first studied renewable energies, followed by technologies related to the biogas system. Biogas systems have been referred to by landfill and discussed comprehensively in this scheme for utili-zation. For this purpose, the input source of this system is considered as the volume of garbage in the city of Germi as the study area. In the next step, the amount of garbage produced in this city was extracted and the Landfill software was used for methane pro-duction potential assessment from this system and the Homer software was used for eco-nomic analysis and reliability evaluation. The most important results are payback period, which is about 10 years, and the amount of electricity produced per year, which is 11658.265 MWh [6]. In this study, the study area of Hamadan city is considered to have an average urban waste production of about 420 tons/month. Homer software has been used to analyze the amount of electricity produced, and economic and environmental analysis has also been done. One of the outstanding results of the research is the production of 229,735 kW/year of electrical energy. Electricity generation with biomass resources will reduce Co2 and Co emissions by 77.2 and 7.96 kg/year, respectively. That cost of ener-gy(COE) for this system is 0.177$/kWh [7].

 

 

Q2. Add a last paragraph in section 1 (Introduction) describing the other sections of the article.

Thanks to the attention of the esteemed reviewer, added.

In this study, a new multiple generation system based on micro-CCHP cycle with biomass heat source is presented. In this proposed system, absorption refrigeration cycle subsystems and water softener system have been used in order to increase the efficiency of the basic cycle and reduce waste. In this research, the microturbine system is modeled with a biomass generator, which is used to model the thermodynamic relationships governing the various components of the studied system. The general goal of this research is to in-crease the energy efficiency and exergy of the system, and to achieve this goal, the waste heat of the generator after recovery has been used as the starter of the absorption refrigeration cycle.

 

Q3. The citation standard that the journal uses is not (author, date), correct the citation, some examples in lines 52, 55, 59, 80, among others.

Thanks to the attention of the esteemed reviewer, corrected.

 

Q4. On line 62, put the word “This” starting with a capital letter.

Thanks to the attention of the esteemed reviewer, corrected.

 

 

Q5. Although the meaning of cycle abbreviations is common, it is important. Inform their meanings at first appearance in the text, for example VCHP Cycle (vapor compression heat pump cycle) among others.

Thanks to the attention of the esteemed reviewer, added.

 

Q6. In the description of the methodology insert a flowchart with the steps of the method.

Thanks to the attention of the esteemed reviewer.

 

Q7. The authors cite the use of a genetic algorithm for optimization, but the data and specifications of the algorithm were not mentioned in the methodology, only in the results.

Thanks to the attention of the esteemed reviewer.

In the design of thermal systems, the optimization of thermodynamic conditions is used to determine the maximum efficiency of energy and exergy. In this article, the genetic algorithm method is used in EES software. The genetic algorithm method can be suitable compared to other methods available in the software. In the single-objective optimization method, the objective function is to determine the maximum energy efficiency or exergy of the system, but in multi-objective optimization, the objective function is to simultaneously determine the maximum energy efficiency and exergy of the system (Zare et al., 2012). The ranges of thermodynamic parameters for optimization are the same ranges examined in the parametric study of the system. For the system presented in this research, the maximum of the multi-objective function is expressed as follows.

 

                                       

 

 

Reviewer 2

Overall observations: The paper is interesting; however, it needs several modifications before it can become more publishable.

 

Q1. There are several grammatical corrections that need to be done throughout the paper.

Thanks to the attention of the esteemed reviewer, checked by Grammerly software

Q2. Please make sure you have included all the nomenclatures as used in the text, which may be briefly described. Please include all the short forms/abbreviations used in all the equations.

Thanks to the attention of the esteemed reviewer, added.

Q3. In the abstract next to the numbers, the unit should be used so that the audience can understand better, for example in line 41: 74.2.

Thanks to the attention of the esteemed reviewer, added.

Q4. The method of referencing is to use the journal template. For example, in line 52.

Thanks to the good question of the esteemed reviewer, corrected.

Q5. Added new research in the introduction.

Thanks to the good question of the esteemed reviewer, added.

In this research, chemical analysis of urban waste related to Hamedan has been done, estimated the heating value of urban waste incineration. In this way, the approximate amount of energy obtained can be obtained before designing the system [4]. In this research, different compositions of air and steam as a reactor input have been examined and fixed base gasifier behavior in different situations has been specified which demonstrate that, the best amount of air-steam composition with the most heat valuation is 12.26 (lb/s) for air input and 9.989 (lab/s) for steam input [5]. In this research, we first studied renewable energies, followed by technologies related to the biogas system. Biogas systems have been referred to by landfill and discussed comprehensively in this scheme for utilization. For this purpose, the input source of this system is considered as the volume of garbage in the city of Germi as the study area. In the next step, the amount of garbage produced in this city was extracted and the Landfill software was used for methane production potential assessment from this system and the Homer software was used for economic analysis and reliability evaluation. The most important results are payback period, which is about 10 years, and the amount of electricity produced per year, which is 11658.265 MWh [6]. In this study, the study area of Hamadan city is considered to have an average urban waste production of about 420 tons/month. Homer software has been used to analyze the amount of electricity produced, and economic and environmental analysis has also been done. One of the outstanding results of the research is the production of 229,735 kW/year of electrical energy. Electricity generation with biomass resources will reduce Co2 and Co emissions by 77.2 and 7.96 kg/year, respectively. That cost of energy(COE) for this system is 0.177$/kWh [7].

Wang et al. [11] presented a Bi-level sizing optimization of a distributed solar hybrid CCHP system considering economic, energy, and environmental objectives. Delgado et al. [12] presented an integration of cycles by absorption for the production of desalinated water and cooling. Askari et al. [13] presented at the exergo-economic analysis of two novel combined ejector heat pump/humidification-dehumidification desalination systems.

 

Q6. Figures 1,2 aren’t clear.

Thanks to the attention of the esteemed reviewer, corrected.

Q7. Added reference to all equations.

Thanks to the attention of the esteemed reviewer, added.

Q8. Added reference number in Figures 3,4 and 5.

Thanks to the attention of the esteemed reviewer, added.

Q9. To improve the conclusion part, it is suggested to add future works as well.

Thanks to the good question of the esteemed reviewer, corrected.

Future works can be mentioned as follows:

Thermo-mechanical energy level approach integrated with exergoeconomic optimi-zation.

Energetic and exergetic analysis of a biomass-fueled CCHP system integrated with other heat resources.

 Multi-criteria evaluation biomass-fueled CCHP system.

 

Q10. Reference should be updated.

Thanks to the attention of the esteemed reviewer, updated.

Q11. Add some sources that are not mentioned. For example, [35]

Thanks to the attention of the esteemed reviewer, corrected..

Reviewer 3

Thermodynamic analysis and optimization of micro-CCHP system are presented in this paper. Overall, it is well written. The reviewer has some comments that might be helpful for authors to improve the paper.

 

Q1. In section 2, it is not clear how the energy and the exergy are linked in the model. Are they analyzed separately?

Thanks to the attention of the esteemed reviewer, according to section 2, energy and exergy analyzes are considered separately.

Q2. Comparison with existing CHP studies can be enhanced, e.g., 10.1016/j.apenergy.2015.01.102 and 10.1109/TSG.2022.3210014, which have also conducted research on thermal dynamics analysis, modelling and optimization.

Thanks to the attention of the esteemed reviewer.

Q3. Fig 1 is not so accurate as there should be a heating network connecting heat source and load. And the heating network model seems absent in this paper.

Thanks to the attention of the esteemed reviewer, As shown in Figure 1, the waste heat in the turbine is absorbed by the ejector and then it is converted from the ejector into useful heat for use as required heat by the heat exchanger.

Q4. I cannot find the optimization model easily, i.e., objective function and constraints, in the paper.

Thanks to the good question of the esteemed reviewer.

 In the design of thermal systems, the optimization of thermodynamic conditions is used to determine the maximum efficiency of energy and exergy. In this article, the genetic algorithm method is used in EES software. The genetic algorithm method can be suitable compared to other methods available in the software. In the single-objective optimization method, the objective function is to determine the maximum energy efficiency or exergy of the system, but in multi-objective optimization, the objective function is to simultaneously determine the maximum energy efficiency and exergy of the system (Zare et al., 2012). The ranges of thermodynamic parameters for optimization are the same ranges examined in the parametric study of the system. For the system presented in this research, the maximum of the multi-objective function is expressed as follows.

 

MOF=((w_1×ղ_t) + (w_2×ղ_x))                   (20)

w_1  + w_2  = 1

0 ≤  w_1,w_2   ≤1

 

Reviewer 3 Report

Thermodynamic analysis and optimization of micro-CCHP system are presented in this paper. Overall, it is well written. The reviewer has some comments that might be helpful for authors to improve the paper.

In section 2, it is not clear how the energy and the exergy are linked in the model. Are they analyzed separately?

Comparison with existing CHP studies can be enhanced, e.g., 10.1016/j.apenergy.2015.01.102 and 10.1109/TSG.2022.3210014, which have also conducted research on thermal dynamics analysis, modelling and optimization. 

Fig 1 is not so accurate as there should be a heating network connecting heat source and load. And the heating network model seems absent in this paper.

I cannot find the optimization model easily, i.e., objective function and constraints, in the paper.

 

Author Response

2023.02.22

 

Manuscript Number: sustainability-2235010

Title: Thermodynamic analysis and optimization of the micro-CCHP system with a biomass heat source

 

Dear Editor and Reviewers,

Thank you very much for e-mailing us the comments raised by the respected reviewer. We considered the comments seriously and hope to be acceptable. The manuscript has been revised taking into account all of the valuable comments and suggestions. We have worked very hard to satisfy comments raised by respected reviewer. The details of the comments raised, the answers and the actions taken are presented here. I would like to thank you and the respected reviewer for very helpful and constructive comments. All of the changes made in the new revised manuscript have been highlighted in yellow color.

Best regards,

Reza Morovati

 

Reviewer 1

The authors propose new multiple production systems based on the micro-CCHP cycle with a mass heat source, consisting of subsystems of the absorption refrigeration cycle and a water softener system, aiming to increase the efficiency of the basic cycle and reduce waste.

 

Q1. In the bibliographic review presented in the introduction, improve the contextualization and emphasize the importance of the researched topic.

Thanks to the attention of the esteemed reviewer, added.

In this research, chemical analysis of urban waste related to Hamedan has been done, estimated the heating value of urban waste incineration. In this way, the approxi-mate amount of energy obtained can be obtained before designing the system [4]. In this research, different compositions of air and steam as a reactor input have been examined and fixed base gasifier behavior in different situations has been specified which demon-strate that, the best amount of air-steam composition with the most heat valuation is 12.26 (lb/s) for air input and 9.989 (lab/s) for steam input [5]. In this research, we first studied renewable energies, followed by technologies related to the biogas system. Biogas systems have been referred to by landfill and discussed comprehensively in this scheme for utili-zation. For this purpose, the input source of this system is considered as the volume of garbage in the city of Germi as the study area. In the next step, the amount of garbage produced in this city was extracted and the Landfill software was used for methane pro-duction potential assessment from this system and the Homer software was used for eco-nomic analysis and reliability evaluation. The most important results are payback period, which is about 10 years, and the amount of electricity produced per year, which is 11658.265 MWh [6]. In this study, the study area of Hamadan city is considered to have an average urban waste production of about 420 tons/month. Homer software has been used to analyze the amount of electricity produced, and economic and environmental analysis has also been done. One of the outstanding results of the research is the production of 229,735 kW/year of electrical energy. Electricity generation with biomass resources will reduce Co2 and Co emissions by 77.2 and 7.96 kg/year, respectively. That cost of ener-gy(COE) for this system is 0.177$/kWh [7].

 

 

Q2. Add a last paragraph in section 1 (Introduction) describing the other sections of the article.

Thanks to the attention of the esteemed reviewer, added.

In this study, a new multiple generation system based on micro-CCHP cycle with biomass heat source is presented. In this proposed system, absorption refrigeration cycle subsystems and water softener system have been used in order to increase the efficiency of the basic cycle and reduce waste. In this research, the microturbine system is modeled with a biomass generator, which is used to model the thermodynamic relationships governing the various components of the studied system. The general goal of this research is to in-crease the energy efficiency and exergy of the system, and to achieve this goal, the waste heat of the generator after recovery has been used as the starter of the absorption refrigeration cycle.

 

Q3. The citation standard that the journal uses is not (author, date), correct the citation, some examples in lines 52, 55, 59, 80, among others.

Thanks to the attention of the esteemed reviewer, corrected.

 

Q4. On line 62, put the word “This” starting with a capital letter.

Thanks to the attention of the esteemed reviewer, corrected.

 

 

Q5. Although the meaning of cycle abbreviations is common, it is important. Inform their meanings at first appearance in the text, for example VCHP Cycle (vapor compression heat pump cycle) among others.

Thanks to the attention of the esteemed reviewer, added.

 

Q6. In the description of the methodology insert a flowchart with the steps of the method.

Thanks to the attention of the esteemed reviewer.

 

Q7. The authors cite the use of a genetic algorithm for optimization, but the data and specifications of the algorithm were not mentioned in the methodology, only in the results.

Thanks to the attention of the esteemed reviewer.

In the design of thermal systems, the optimization of thermodynamic conditions is used to determine the maximum efficiency of energy and exergy. In this article, the genetic algorithm method is used in EES software. The genetic algorithm method can be suitable compared to other methods available in the software. In the single-objective optimization method, the objective function is to determine the maximum energy efficiency or exergy of the system, but in multi-objective optimization, the objective function is to simultaneously determine the maximum energy efficiency and exergy of the system (Zare et al., 2012). The ranges of thermodynamic parameters for optimization are the same ranges examined in the parametric study of the system. For the system presented in this research, the maximum of the multi-objective function is expressed as follows.

 

                                       

 

 

Reviewer 2

Overall observations: The paper is interesting; however, it needs several modifications before it can become more publishable.

 

Q1. There are several grammatical corrections that need to be done throughout the paper.

Thanks to the attention of the esteemed reviewer, checked by Grammerly software

Q2. Please make sure you have included all the nomenclatures as used in the text, which may be briefly described. Please include all the short forms/abbreviations used in all the equations.

Thanks to the attention of the esteemed reviewer, added.

Q3. In the abstract next to the numbers, the unit should be used so that the audience can understand better, for example in line 41: 74.2.

Thanks to the attention of the esteemed reviewer, added.

Q4. The method of referencing is to use the journal template. For example, in line 52.

Thanks to the good question of the esteemed reviewer, corrected.

Q5. Added new research in the introduction.

Thanks to the good question of the esteemed reviewer, added.

In this research, chemical analysis of urban waste related to Hamedan has been done, estimated the heating value of urban waste incineration. In this way, the approximate amount of energy obtained can be obtained before designing the system [4]. In this research, different compositions of air and steam as a reactor input have been examined and fixed base gasifier behavior in different situations has been specified which demonstrate that, the best amount of air-steam composition with the most heat valuation is 12.26 (lb/s) for air input and 9.989 (lab/s) for steam input [5]. In this research, we first studied renewable energies, followed by technologies related to the biogas system. Biogas systems have been referred to by landfill and discussed comprehensively in this scheme for utilization. For this purpose, the input source of this system is considered as the volume of garbage in the city of Germi as the study area. In the next step, the amount of garbage produced in this city was extracted and the Landfill software was used for methane production potential assessment from this system and the Homer software was used for economic analysis and reliability evaluation. The most important results are payback period, which is about 10 years, and the amount of electricity produced per year, which is 11658.265 MWh [6]. In this study, the study area of Hamadan city is considered to have an average urban waste production of about 420 tons/month. Homer software has been used to analyze the amount of electricity produced, and economic and environmental analysis has also been done. One of the outstanding results of the research is the production of 229,735 kW/year of electrical energy. Electricity generation with biomass resources will reduce Co2 and Co emissions by 77.2 and 7.96 kg/year, respectively. That cost of energy(COE) for this system is 0.177$/kWh [7].

Wang et al. [11] presented a Bi-level sizing optimization of a distributed solar hybrid CCHP system considering economic, energy, and environmental objectives. Delgado et al. [12] presented an integration of cycles by absorption for the production of desalinated water and cooling. Askari et al. [13] presented at the exergo-economic analysis of two novel combined ejector heat pump/humidification-dehumidification desalination systems.

 

Q6. Figures 1,2 aren’t clear.

Thanks to the attention of the esteemed reviewer, corrected.

Q7. Added reference to all equations.

Thanks to the attention of the esteemed reviewer, added.

Q8. Added reference number in Figures 3,4 and 5.

Thanks to the attention of the esteemed reviewer, added.

Q9. To improve the conclusion part, it is suggested to add future works as well.

Thanks to the good question of the esteemed reviewer, corrected.

Future works can be mentioned as follows:

Thermo-mechanical energy level approach integrated with exergoeconomic optimi-zation.

Energetic and exergetic analysis of a biomass-fueled CCHP system integrated with other heat resources.

 Multi-criteria evaluation biomass-fueled CCHP system.

 

Q10. Reference should be updated.

Thanks to the attention of the esteemed reviewer, updated.

Q11. Add some sources that are not mentioned. For example, [35]

Thanks to the attention of the esteemed reviewer, corrected..

Reviewer 3

Thermodynamic analysis and optimization of micro-CCHP system are presented in this paper. Overall, it is well written. The reviewer has some comments that might be helpful for authors to improve the paper.

 

Q1. In section 2, it is not clear how the energy and the exergy are linked in the model. Are they analyzed separately?

Thanks to the attention of the esteemed reviewer, according to section 2, energy and exergy analyzes are considered separately.

Q2. Comparison with existing CHP studies can be enhanced, e.g., 10.1016/j.apenergy.2015.01.102 and 10.1109/TSG.2022.3210014, which have also conducted research on thermal dynamics analysis, modelling and optimization.

Thanks to the attention of the esteemed reviewer.

Q3. Fig 1 is not so accurate as there should be a heating network connecting heat source and load. And the heating network model seems absent in this paper.

Thanks to the attention of the esteemed reviewer, As shown in Figure 1, the waste heat in the turbine is absorbed by the ejector and then it is converted from the ejector into useful heat for use as required heat by the heat exchanger.

Q4. I cannot find the optimization model easily, i.e., objective function and constraints, in the paper.

Thanks to the good question of the esteemed reviewer.

 In the design of thermal systems, the optimization of thermodynamic conditions is used to determine the maximum efficiency of energy and exergy. In this article, the genetic algorithm method is used in EES software. The genetic algorithm method can be suitable compared to other methods available in the software. In the single-objective optimization method, the objective function is to determine the maximum energy efficiency or exergy of the system, but in multi-objective optimization, the objective function is to simultaneously determine the maximum energy efficiency and exergy of the system (Zare et al., 2012). The ranges of thermodynamic parameters for optimization are the same ranges examined in the parametric study of the system. For the system presented in this research, the maximum of the multi-objective function is expressed as follows.

 

MOF=((w_1×ղ_t) + (w_2×ղ_x))                   (20)

w_1  + w_2  = 1

0 ≤  w_1,w_2   ≤1

 

Round 2

Reviewer 1 Report

The authors complied with the recommendations and made the proposed corrections.

Reviewer 2 Report

Accept.