Cooling Potential of Ship Engine Intake Air Cooling and Its Realization on the Route Lineâ€
, Roman Radchenko 2, Mykola Radchenko 2,*, Andrii Radchenko 2 and Victoria Kornienko 2
Round 1
Reviewer 1 Report
The study focuses on improving the engine performance by reducing the temperature of the intake air by utilizing the heat of the exhaust gas for operating a refrigeration system. The study is scientifically sound. However, the authors are requested to address some of the concerns given below:
1) There are lot of grammatical mistakes with some sentences making no sense at all.
2) The literature survey should be increased and the novelty and objectives should be clearly defined.
3) The words "id est." should be clarified.
4) If possible the authors can add images of the engine along with the chiller plant
5) The authors should include nomenclature, if there is no provision for the same in the template, kindly include a table
6) The authors should explain the sea-route as it is necessary to understand the fluctuations in the results and explain the ambient conditions
Author Response
Comments and Suggestions for Authors.
The study focuses on improving the engine performance by reducing the temperature of the intake air by utilizing the heat of the exhaust gas for operating a refrigeration system. The study is scientifically sound. However, the authors are requested to address some of the concerns given below:
1) Remark. There are lot of grammatical mistakes with some sentences making no sense at all.
The author response.
All the text was corrected to avoid grammatical mistakes and clear up the sense.
2) Remark. The literature survey should be increased and the novelty and objectives should be clearly defined.
The author response.
The part "Introduction" was corrected by accenting on the main points of the research and amplifying the novelty of general results to be achieved and objectives.
"In reality, any combustion engine with EIAC by waste heat recovery chillers can be considered as a power plant with in-cycle trigeneration focused to enhance basic engine efficiency. A sustainable operation of the engine at stabilized low intake air temperature is impossible without determining rational design cooling capacity of the chiller and EIAC system in the whole."
"The purpose of this work is to evaluate the potential of cooling intake air in ship main diesel engine and its realization in rationally designed EIAC system with ejector chiller, transforming the engine exhaust heat, that provides a sustainable operation of the engine with high fuel efficiency due to stabilized low intake air temperature in real climatic conditions on the ship route."
3) Remark. The words "id est." should be clarified.
The author response.
The corrections were made
4) If possible the authors can add images of the engine along with the chiller plant
The author response.
The supplement with image of the engine along with the chiller plant was added
5) Remark. The authors should include nomenclature, if there is no provision for the same in the template, kindly include a table
The author response.
A nomenclature was added
6) Remark. The authors should explain the sea-route as it is necessary to understand the fluctuations in the results and explain the ambient conditions
The author response. The fluctuations in the results as CDH and fuel reduction accordingly, depended on the sucked air temperature drop due to cooling air at varying current ambient air temperatures, as well as cooling capacities Q0 required for cooling sucked air with varying temperatures and humidity and needed COP of the chiller accordingly are caused by rapidly changing climatic conditions along the ship route.
Dear Reviewer, thank you very much for high quality revision of the paper, providing its essential improvement.
Reviewer 2 Report
The present paper deals with ' Cooling potential of ship engine intake air cooling and its realization on the route line'. It is a useful and relevant study on the subject of practical application. While I still have some suggestions for the Authors that should be considered during the revision of the paper:
1. The part of ‘Introduction’ is poorly organized.
2. What platform is the mathematical model of this work built on? Moreover, the model is not validated against published papers or experiment data.
3. The coordinate representation in Figure 6 is unclear; for example, the reader is not clear whether ΣBe corresponds to the left or right side of the y coordinate. The same for Figure 7,8,9.
4. The author only gave the change of air temperature and humidity during the voyage in the research process, so I was curious about how the ship's working condition changed.
5. The conclusions should be rewritten more concisely to only include the key research findings.
6. Line 398, ‘In order to increase a depth of air cooling’. I’m confused about this, please make more explanation.
Author Response
Comments and Suggestions for Authors.
The present paper deals with ' Cooling potential of ship engine intake air cooling and its
realization on the route line'. It is a useful and relevant study on the subject of practical
application. While I still have some suggestions for the Authors that should be considered during
the revision of the paper:
- Remark. The part of ‘Introduction’ is poorly organized.
The author response. The part ‘Introduction’ was corrected by accenting on the main points of the research and amplifying its aim and general results to be achieved.
"In reality, any combustion engine with EIAC by waste heat recovery chillers can be considered as a power plant with in-cycle trigeneration focused to enhance basic engine efficiency. A sustainable operation of the engine at stabilized low intake air temperature is impossible without determining rational design cooling capacity of the chiller and EIAC system in the whole."
"The purpose of this work is to evaluate the potential of cooling intake air in ship main diesel engine and its realization in rationally designed EIAC system with ejector chiller, transforming the engine exhaust heat, that provides a sustainable operation of the engine with high fuel efficiency due to stabilized low intake air temperature in real climatic conditions on the ship route."
- Remark. What platform is the mathematical model of this work built on? Moreover, the model is not validated against published papers or experiment data.
The author response. The mathematical model includes the calculations of engine intake air cooling processes and cooling capacities by using the basic heat balances (3)-(6) and verified well-known program "mandieselturbo" of MAN diesel manufacture to determine the EIAC processes on fuel consumption of diesel engine and exhaust gas parameters.
The influence of intake air temperatures on fuel consumption of diesel engine and exhaust gas parameters was determined by using the program MAN Diesel Turbo, CEAS Engine Calculations [Online], available at: https://marine.man-es.com/two-stroke/ceas. 2019 [2].
"The values of engine specific fuel consumption reduction Δbe in response to sucked air temperature drop Δta on the ship route were calculated by program "mandieselturbo" [2]." (page 4).
According to [2-4] the error of calculations is less than 3 %.
"The authors developed the original method of EIAC system rational designing focused to define a design thermal load (cooling capacity) through comparing both actual values of CDH needed for cooling sucked air to a target cooled air temperature ta2 , on one hand, and available CDH number, on the other hand. The latter is determined proceeding from the exhaust heat converted to cooling capacity with a definite COP according to the chiller applied" (page 3, 4, equations 4-6).
"The values of temperature tamb and relative humidity φamb of ambient air along the route are taken each 3 hours (Fig. 2) based on the meteorological data by using the verified well-known program "meteomanz.com" [67]." METEOMANZ, http://meteomanz.com, last accessed 2021/12/21
The application of CDH as primary criterion simplifies the calculations of fuel reduction by equation (6) supplemented by program "mandieselturbo", as well as "the optimum design cooling capacity, that provides the maximum rate of the summary ΣCDH number increment"(Fig.13) with minimum sizes of the chiller and EIAC system in the whole.
- Remark. The coordinate representation in Figure 6 is unclear; for example, the reader is not clear whether ΣBe corresponds to the left or right side of the y coordinate. The same for Figure
7,8,9.
The author response.
ΣBe corresponds to the right side of the y coordinate.
Figures 6 and 7 were corrected. Thank you very much.
- Remark. The author only gave the change of air temperature and humidity during the voyage in the research process, so I was curious about how the ship's working condition changed.
The author response.
The authors investigate the efficiency of conversion of diesel engine exhaust gas heat for engine intake air cooling (EIAC), estimated by fuel saving and CDH number as a primary criterion, and the potential for its enhancement to provide "a sustainable operation of the engine with high fuel efficiency due to stabilized low intake air temperature in real climatic conditions on the ship route". The operation of the ship with a concrete head-velocity characteristic of the propeller screw was not the object of the research.
- Remark. The conclusions should be rewritten more concisely to only include the key research
findings.
The author response.
The conclusions were rewritten more concisely to include the key results.
- Remark. Line 398, ‘In order to increase a depth of air cooling’. I’m confused about this, please make more explanation.
The author response.
A phrase "a depth of air cooling" means the air temperature drop due to cooling.
The text was corrected.
Dear Reviewer, thank you very much for high quality revision of the paper, providing its essential improvement.
Round 2
Reviewer 2 Report
The authors have addressed all my suggestions
