보고서 정보
주관연구기관 |
경상대학교 GyeongSang National University |
보고서유형 | 최종보고서 |
발행국가 | 대한민국 |
언어 |
한국어
|
발행년월 | 2005-11 |
과제시작연도 |
2004 |
주관부처 |
농림부 Ministry of Agriculture and Forestry |
등록번호 |
TRKO201400023088 |
과제고유번호 |
1380002046 |
사업명 |
농림기술개발 |
DB 구축일자 |
2014-11-29
|
초록
○ 연구결과
「재배사의 구조설계」와 관련된 연구결과
「소요에너지 실태파악 및 에너지 절감 대책」과 관련된 연구 결과
「재배사의 환경요인 최적화」와 관련된 연구 결과
「재배사의 수학적 모형개발 및 환경 시뮬레이션」과 관련된 연구 결과
「경제성 분석」과 관련된 연구 결과
Abstract
▼
Ⅳ. RESULTS
The results are summarized as follows:
1. Results on 『Structural Design of Pleurotus eryngii Cultivation Facility』
1) The structure of Pleurotus eryngii cultivation facilities can be classified into simple and permanent frame type. The simple frame structures were mostly single-
Ⅳ. RESULTS
The results are summarized as follows:
1. Results on 『Structural Design of Pleurotus eryngii Cultivation Facility』
1) The structure of Pleurotus eryngii cultivation facilities can be classified into simple and permanent frame type. The simple frame structures were mostly single-span type, and the permanent frame structures were rather multi-span than simple structures. The scale of cultivation facilities was very diverse regardless of structural type. But as a whole, the length, width, and ridge height were distributed approximately 20.0 m, 6.6∼7.0 m and 4.6∼5.0 m range, respectively. The floor area was about 132∼160 ㎡, and floor was built with concrete to protect mushrooms from various harmful infection.
1-1) The roof slope of the simple and permanent type showed about 41.5° and 18.6∼28.6˚, respectively. The width and layer number of growing bed for mushroom cultivation were around 1.2∼1.6 m, 4 layers in common, respectively.
1-2) Most of the year-round cultivation facilities were equipped with cooler, heater, humidifier, and ventilation fan. Hot water boiler was the most commonly used heating system, others were electric heater or steam boiler.
The industry-type air conditioner has been widely used for cooling. And humidity was controlled mostly by ultra-wave or centrifugal humidifier. But some farmers has been using nozzle system for auxiliary purpose. More than 90% of the mushroom house was equipped with the individually controlled system rather than the complex system. The inside temperature was usually controlled by sensor, but humidity and CO2 concentration was controlled by timer for each growing stage.
1-3) The capacity of medium bottle was generally 850 cc and 1100cc, some farms used 800 cc, 950 cc, 1,200 cc and 13,00 cc. Most of mushroom produced has been usually shipped to either distributing store or joint markethe number of layer for mushroom cultivation was mostly 4 layers, and humidifier and ventilating fan in cultivation facilities were most common equipments. But the inside and outside structural configuration of cultivation facilities and the control system of cooler and heater were quite different from those of Korea.
2) According to the results of literature review on Pleurotus eryngii, layer the number of growing bed in mushroom cultivation was 4 layers in most of other country as in Korea. The humidifier and ventilating fan in cultivation facilities were under similar situation. But the inside and outside structural configuration and the control system for cooler and heater were quite different among the countries including Korea.
3) In case of A, B and C box container(1,500×2,000×2,500mm), it was found that the thermal insulation effect of types coated with thermal insulation coating was improved remarkably more than that of no treatment. And the thermal insulation effects for both steel sheet(steel sheet galvanized of thickness 0.45mm) and sandwich panel type(50mm) were nearly similar.
3-1) There was not a significant difference of thermal insulation effect between thermal insulation coating and water paint coating.
3-2) In case of drum container filled with rough rice, the difference of heat transfer tendency and temperature variation among different surface treatments was nearly similar with that of box types of galvanized steel sheet. And there was considerable time lag of about 6 hours between the temperature of middle part of rice and that of inside or outside surface.
4) The variations of heating and cooling Degree-Hour simulated for Jinju area was clearly seen depending on the setting temperatures. The variations of cooling Degree-Hour depending on setting temperature was much more sensitive than those of heating Degree-Hour. Therefore, it was expected that the variations of required energy in accordance with setting temperature or actual temperature maintained inside of the cultivation house could be estimated and also the estimated results of heating and cooling Degree-Hour could be effectively used for the verification of environmental simulation as well as for the calculation of required energy amounts.
4-1) When the cultivation floor areas are all equal, panel type houses to be constructed by various combinations of materials were found by far more effective than simple type pipe house in the aspect of energy conservation except some additional cost invested initially. And also the energy effectiveness of multi-span house compared to single span together with the prediction of energy requirement depending on the level insulated for the wall and roof area could be estimated. Additionally, structural as well as environmental optimizations are expected to be possible by calculating periodical and/or seasonal energy requirements for those various combinations of insulation level and different climate conditions, etc.
5) In the aspect of spatial use of cultivation facilities, suggested models were shown to be mostly reasonable in the aspect of heating and cooling, micro-meteorological stability, and utility effectiveness per unit floor area, etc.. Especially, the standard models to be suggested so far were thought to be not effective in its surface area and spatial volume per unit floor area as well as its uneffective structural design in the area around ceiling.
5-1) In the results of structural analysis for the models suggested through this study by using those section frames to be found on farms, the panel type structures of both single span and double span were estimated to be over designed, whereas arch-roofed pipe houses were mostly found to be under designed.
2. Results on 『Actual State Required Energy and Measure to Save Eenergy of Pleurotus eryngii Cultivation Facilities』.
1) In case of simple frame type(A-area), ambient temperature during the experiment period was not predominantly different from that of a normal year. The capacity of the hot water boiler and the piping systems were not enough. Maximum air temperature difference between the upper and the lower growth stage during a heating time zone was about 2∼3℃. The max.
and min. relative humidity were ranged approximately 80∼100%, and average relative humidity was ranged approximately 60∼100%. And CO2 concentration increased until to maximum 1,600∼1,800ppm in accordance with growing stage. The illuminance in cultivation house was widely distributed from 20lx to 160lx in accordance with location, and it was maintained lower than the recommended illuminance range of 100∼200lx.
And the average yield per bottle was about 67∼85g. But the optimal productivity might be evaluated by considering the quality and quantity of mushroom production, energy requirements, facility construction, and management cost, etc.
2) In case of simple frame type(B-area), ambient temperature during the experiment period was not predominantly different from that of a normal year. The capacity of the hot water boiler and the piping systems were not very enough. Maximum air temperature difference between the upper and lower growth stage during a heating time zone was about 2.0∼6.0℃. But air cooling systems were enough. As the min. and average relative humidity were ranged approximately 42∼80% and 67∼95%, respectively, the min.
relative humidity was very low maintained. And CO2 concentration maintained very lower than the recommended concentration. The illuminance in cultivation house was widely distributed from 3lx to 60lx in accordance with position. In case of this area, as the average yield per bottle was about 54∼102g, the quantity of mushroom production was mostly the same with average yield(67∼85g) of A-region. But its quality was relatively lower than those of A-region. Electric energy consumption in each cultivation houses was different according to the cultivation term of mushroom and operating condition of the heater or cooler.
3) In case of permanent-frame structure, the maximum, minimum, and average ambient temperatures in the experiment site were ranged about -0.3∼36.5℃, -15.0∼23.5℃, -8.8∼27.9℃, respectively and those of Jinju areas during the experiment period were ranged about -2.1∼ 36.7℃, -13.3∼24.9℃, -7.4∼29.
1℃, respectively. Therefore it was concluded that in the aspect of temperatures these two areas were not quite different from that of a normal year.
3-1) Air temperatures in cultivation house before some improvement of system were maintained somewhat lower than setting temperature, and maximum air temperature difference between the upper and lower growing bed during a heating time period was about 5.1℃, because the capacity of electric heater and air circulation were not enough. But the air temperatures after system improvement were maintained within the limits range of setting temperature without stagnation happing of air. Air temperature distribution was generally distributed uniform.
3-2) The difference between max. and min. air temperature of the second layer (in growing bed) before and after system improvement were ranged approximately 0.5∼3.5℃ and 0.7∼3.9℃, respectively in comparison with average temperature. Relative humidity in cultivation house before improvement was widely ranged about 44∼100%. But as the relative humidity after improvement was ranged approximately 80∼ 100%, it was maintained within the range of relative humidity recommended.
3-3) In case of the early period of germinating and late period of growing, the average CO2 concentration in cultivation house was maintained under
1,000ppm regardless of the system improvement,. And in case of the late period of germinating, growing, and harvesting, CO2 level was maintained respectively high(1,500∼ 2,100ppm)-low (900∼1,400ppm)-high(1,600∼2,100ppm) before system improvement. However after system was improved, average CO2 concentration was maintained about 1,200∼2,400ppm range. The illuminance in cultivation house was widely distributed from 31lx to 65lx in accordance with position, and it was maintained much lower than the recommended illuminance range of 100∼200lx. The acidity level pH of mushroom midium was ranged about 5.0∼6.0, which was some lower range than the recommend acidity range of pH 5.5∼6.5.
3-4) Regardless of cultivation season, house type, or method, yield was relatively ununiform. In case of culture with capacity 1,000cc medium bottle, the average yield per bottle was about 94∼168g. The mushroom of the lowest grade % out of total yields in A and B house was ranged 26∼39% and 23∼36%, respectively. But the mushrooms graded as a super or good, fair, and others out of total yields were about 60%, 10% and 30%, respectively. In case of bottle capacity of 1,300cc, the portion of the lowest grade was less than 3% regardless of the cultivation house type and period. But the average yield weights of 500g per bottle in A- and B-house was 23% and 58%, respectively.
3-5) The electric energy consumed was quite different according to the cultivation season. The electric energy consumed during winter heating season was much more than that of summer cooling season.
3-6) During summer season, air temperature within cultivation house was maintained somewhat higher above setting temperature. But the capacity of cooling systems was generally enough for cooling the air down to setting temperature.
4) In case of heating process, the heat amounts absorbed from evaporator and rejected from condenser were approximately 9,000∼12,000kcal/h and 13,000∼17,000kcal/h, respectively. The heat efficiencies of evaporator and condenser used in this experiment were approximately 79% and 83%, respectively. And the coefficients of performance(COP) for the heat pump and the total heat pump system were ranged about 2.9∼3.5 and 1.5∼2.4, respectively.
4-1) In the case of cooling process, the heat amount absorbed from evaporator was 17,100∼17,700kcal/h. The heat efficiencies of evaporator used in this experiment was about 71∼74%. The coefficients of performance (COP) for heat pump only and the total heat pump system during heating period were approximately 2.9∼3.5 and 1.5∼2.4, respectively, but th COPs of those during cooling period were about 2.71∼2.88 and 1.99∼2.22, respectively.
5) In the natural circulation system, the total heat amounts retrieved by starting recovery soon after sunrise were ranged from 2,460 to 4,110kcal/㎡, while the total heat amounts retrieved by starting recovery after sunset were ranged from 1,270 to 2,580kcal/㎡.
5-1) And the collector efficiency in natural circulation system were ranged from 48.6% to 59.6% when the collected heat was retrieved after sunrise and were 65.8∼78.0% when the collected heat was retrieved soon after sunset.
5-2) When fluid circulation rates were 4.2ℓ/min, 7.0ℓ/min, and 9.7ℓ/min, the collector efficiencies estimated for forced circulation system were 73.1∼88.6%, 78.4∼94.8%, and 64.2%∼74.5%, respectively.
6) In case of complex environment control system, first of all, CO2 sensor and humidity sensor must be developed so that they can be used in wet environment just like in mushroom cultivation house. And also it must be cheap and easy to handle.
7) The air temperature before improvement of the circuit diagram in control panel was controlled within +1.0℃∼-2.0℃ or ±1.0℃ range. But the air temperature after improvement was stabilized within the limits of setting temperature. The relative humidities controlled with humidity sensor were quite different with those measured in cultivation house 7-1) The air temperature in cultivation house was controlled within setting temperature range regardless of season, the capacities of heating and cooling system were enough, and CO2 sensor was working well.
7-2) In order to stably produce the high quality mushroom, the environment control systems and/or equipment failures need to be observed all the time.
8) In order to get rid of the moisture on mushroom surface; ① the reduction of operating time of humidifier, ② the reduction of operation time of ventilation fan, ③ the reduction of RH by heating the air, ④ the reduction of RH by dehumidifying or cooling, ⑤ maintenance of uniform air temperature, etc.
3. Results on 『Optimization of Environment Factors in Pleurotus eryngii Cultivation Facilities』.
1) CO2 promotes development of primordia and depress differentiation of sporophore and gill containing basidia, have an effect on quality. This experiments were conducted to elucidate optimal level of CO2 for King Oyster mushroom(Pleurotus eryngii). The King Oyster mushroom was cultivated under CO2 concentration of 1,600, 2,400, and 3,200ppm. Harvest ratio in normal treatment plot were 98.6, 99.3 and 93.8% at 1,600, 2,400 and 3,200ppm, respectively, so 2,400ppm was optimal. The yield per bottle was 102.5g at 2,400ppm, better than 99.7g at 1,600ppm. The CO2 concentration of 2,400ppm was also the best condition for quality. 6.1 at 2,400ppm was 115% of 1,600ppm's. In thinning treatment plot, quality at 2,400ppm was 9.5 better than 1,600ppm whose quality was 9.4. The yields per bottle were 90.7, 98.2 and 77.3g at 1,600, 2,400 and 3,200ppm respectively. These results show that 2,400ppm was optimal CO2 concentration for quantity of King Oyster mushroom as well as quality.
2) The CO2 concentration in growing house was different according to growth - 28 -
and development days of mushroom. It was maintained uniformly within 80 0∼1,000ppm range in the first period of germinating, but it was increased rapidly from later period of germinating. According to the rapid increase of CO2 concentration in cultivation house, the growth of mushroom was also accelerated.
3) When the inside temperatures were set at 13, 15, and 17℃ during growing period, the experimental plot treated by 15℃ showed the best results in the aspect of yield ratio, yield per bottle, number of available stipe per bottle, total yield and quality. And relatively the lowest grade was found at 13℃.
4) When the setting temperature in cultivation house was fixed at 15℃ (treatment-I plot), was changed by 3-stage from 17℃ to 15℃(treatment-II plot), and was changed by 6-stage from 20℃ to 15℃(treatment-III plot), yield ratio, yield per bottle, number of available stipe per bottle and total yield were attained superiority at Ⅱ-treatment plot regardless of the normal and thinning treatment plot. And relatively the lowest grade was found at treatment-I plot.
5) When the relative humidity in cultivation houses was fixed at 70, 80, and 90% during growing period, yield ratio together with yield per bottle, number of available stipe per bottle, total yield and quality were attained superiority at the experimental plot of 90% RH regardless of the normal and thinning treatment plot. And there was exposed relatively the lowest grade at 70%.
6) When the setting values of the relative humidity by growth and development days were changed by 90, 85 and 80%, yield ratio together with total yield and quality of mushroom were attained superiority at treatment plot long relatively the days maintained by 90% and over.
7) The illuminance in cultivation house was widely distributed in accordance with position. In case of thinning treatment plot, the illuminance was correlated somewhat with the characteristics of sporangium regardless of layer of growing bed. But no significant correlation was found between illuminance and characteristics of sporangium.
4. Results on 『 Mathematical Modelling of a Mushroom House and Environmental Simulation』.
1) Summary
A simulation model describing the mushroom house thermal environment was developed for the purpose of evaluating numeric energy conservation technique and determining the more feasible alternatives.
The solar radiation model was developed to determine the solar radiation incident on the surface of mushroom house and the solar absortance and reflectance of each surface.
A thermal radiation model was included to account for radiation heat loss.
The radiation network method was used to describe the thermal radiation exchange between the mushroom house surfaces and environment. Gas radiation was included to consider the effect of high humidity and CO2 concentration in the mushroom house atmosphere.
The moisture transfer model was coupled to the energy balance model by considering the latent heat of vaporization. A mushroom surface evaporation was described by the respiration of mushroom in proportion to body weight. A mushroom growth equation was developed based on the measued data.
Floor heat transfer was expressed by the finite difference technique and the system of equations was solved numerically to describe the randomly varying boundary conditions at the floor surface.
The last section of mathematical model was logic to control the mushroom house environment within specification limits which are selectable depending on the design criteria for mushroom species or operator's selections. Environmental modification was accomplished with supplemental heating or cooling and forced ventilation. The control of all these processes was based only on the temperature and CO2 concentration from the equilibrium and transient equations.
The energy and mass balance equations were formulated separately in several parts and these parts were solved sequentially by estimating some of the unknown variables in each subroutine. Then the overall solution was determined by an iteration process.
Validation of the simulation model was not achieved so far because of the lack of mushroom behaviour and complexity of control logic between CO2 concentration and temperature setting points. These problems are expected to be solved before long.
Using this developed model, various mushroom house phenomenon were simulated. For a given location and size of mushroom house, there would be different amount of energy requirements for heating and cooling the mushroom house depending on setting temperatures. But for the present, the relationship between CO2 concentration and ventilation rate were not to be simulated owing to the limitation of control logic.
The simulated monthly energy requirements of various setting temperature were analyzed and compared with the results of heating-cooling Degree-Hour.
Also the monthly overall heat transmission coefficients of the mushroom house were estimated. The simulated results indicate the variation depending on the season from 0.0177 in May to 0.0694 in October.
2) Results
A simulation model describing the mushroom house thermal environment was developed for the purpose of evaluating numeric energy conservation technique and determining the more feasible alternatives.
There are several sub-models such as the solar radiation model, thermal radiation model, moisture transfer model, floor heat transfer model, etc., together with the mathematical logic to control the mushroom house environment within the specified limits.
Temperatures of the mushroom house air, mushroom surface, wall surface, and floor surface can be predicted under various weather condition and setting temperature using the computer model developed in this study.
The predicted short term and/or long term simulation results are exepcted to be used in determining heating and cooling capacities. Some of the simulated results related with heating and cooling energy requirements were compared with heating and cooling Degree-Day data. But there is application limitation of this simulated results in the aspect of its reality because this model is not completed in controling CO2 concentration by ventilation logic.
This modelling process would be continued and completed by modifying CO2 control logic together with describing mushroom growth model including heat and CO2 release during respiration process.
5. Results on 『 Life Cycle Economic Analysis』.
1) Summary
To construct a new mushroom house as a substitute for conventional mushroom house, it is necessary to make a relatively large initial investment.
This investment is gradually returned through production income over the lifes of the building together with various facilities equipped in it. Therefore, the most common type of economic analysis of muhroom growth system is a life cycle analysis of the costs and benefits.
The analysis used in this work is the net present method. All future costs and returns of a given mushroom house are discounted to the time of initial investment (present). Then the cost of ownership is compared to the return from the system.
There are a number of factors that affect both the cost of ownership and the return provided by operating the mushroom house. These factors are the initial cost of mushroom, applicable tax credit, salvage value, discount rate, economic life length of each component, maintenance costs, property tax rate, insurance costs, marginal income tax rate, energy price, inflation rate, etc. Values for these parameters must be specified at the outset of the analysis. These values may be known or they may have to be estimated.
The analysis was carried out assuming the mushroom house unit was purchased with equity capital in a single cash payment rather than with borrowed capital that was repaied in installations. The influence of income tax rate, tax credit, and property tax can cause some variation in the cost of the system, but these influence were not considered in this work. Maintenance requirements were assumed to be uniform over the lifes of both mushroom house and facilities equipped in it. But they were assumed to be escalated each year by the general inflation rate. Mushroom production were assumed to accrue in a single lump sum at the end of each year.
This economic analysis may be applicable to nearly any investment in farm facilities to be built for production purposes. This also can be used for economic optimization of any agricultural system, if the variation of system performance with system size and other design parameters can be accurately predicted for the application in question. This analysis method has been developed and coded into a balance sheet for use on a EXCEL program. Using this programmed analysis, a large number of case studies can be performed using different combinations of economic conditions. These results will be very useful to individuals considering investment in a mushroom house, or any similar production system.
By the way of sensitivity analysis for each important parameter, change of the marginal cost-benefit period could be checked. These parameters included in this analysis are as follows; construction cost of mushroom house, cost of cooling system, required cooling and heating energy amounts, unit price of mushroom media bottle, growing number of media bottles, production weight per unit bottle, sale price of mushroom, and annual number of growing period, etc.
2) Results
The analysis used in this work is the net present method. Al future costs and returns of a given mushroom house are discounted to the time of initial investment (present). Then the cost of ownership is compared to the return from the system.
This analysis method has been developed and coded into a balance sheet for use on a EXCEL program. Using this programmed analysis, a large number of case studies can be performed using different combinations of economic conditions. These results will be very useful to individuals considering investment in a mushroom house, or any similar production system.
By the way of sensitivity analysis for each important parameter, change of the m rginal cost-benefit period could be checked. These parameters construction cost of mushroom house, cost of cooling system, required cooling and heating energy amounts, unit price of mushroom media bottle, growing number of media bottles, production weight per unit bottle, sale price of mushroom, and annual number of growing period, etc.
목차 Contents
- 제출문 ... 1
- 요 약 문 ... 2
- SUMMARY ... 17
- CONTENTS ... 34
- 목 차 ... 36
- 제 1 장 연구개발과제의 개요 ... 38
- 제 1 절 연구개발의 목적 및 필요성 ... 38
- 제 2 절 연구개발의 내용 및 범위 ... 41
- 제 2 장 국내외 기술개발 현황 ... 43
- 제 1 절 국내․외 관련기술의 현황과 문제점 ... 43
- 제 2 절 연구결과의 위치 ... 43
- 제 3 절 앞으로 전망 ... 44
- 제 4 절 기술도입의 타당성 ... 44
- 제 3 장 연구개발 수행 내용 및 결과 ... 45
- 제 1 절 재배사의 구조설계 ... 47
- 제 2 절 소요에너지 실태파악 및 에너지 절감 대책 ... 114
- 제 3 절 재배사의 환경요인 최적화 ... 253
- 제 4 절 재배사의 수학적 모형개발 및 환경 시뮬레이션 ... 286
- 제 5 절 경제성 분석 ... 317
- 제 6 절 결론 ... 349
- 제 4 장 목표달성도 및 관련분야에의 기여도 ... 362
- 제 1 절 연구개발 목표달성도 ... 362
- 제 2 절 관련분야 기술발전에의 기여도 ... 363
- 제 5 장 연구개발결과의 활용계획 ... 365
- 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 366
- 제 7 장 참고문헌 ... 368
- 부 록 -1(단동) ... 374
- 부 록 -2(연동) ... 374
- 끝페이지 ... 374
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