Greenhouse Heating Research Articles

LOW-QUALITY FLAX STRAW BIOMASS HARVESTING FOR SUBSEQUENT USE AS FUEL: A REVIEW

Unfavorable conditions for flax growing, harvesting and dew-retting are the reason for the low-quality flax biomass production. This biomass cannot be processed for fiber or other purposes. Therefore, flax straws are burned in the fields or are used as fertilizer by plowing into the soil, which are not good solutions for the environment and subsequent cultivation operations. The limit values of quality properties of fibre flax stem, flax straw and retted straw for their processing are summarized, which can be used to determine the suitability of flax straw biomass for processing or burning. Low-quality flax biomass is inexpensive, ecofriendly and renewable, it can be used as solid fuel for heating greenhouses or buildings located near the field where the flax is grown. Various techniques of fibre flax and oilseed flax harvesting are presented in the article. The technique of low-quality flax harvesting is recommended, which include flax pulling out or flax cutting, flax threshing, flax straw windrow forming, flax straw natural drying on the field in natural way, flax bale forming, flax bale transporting, flax bale burning. This harvesting technology can be used for low-quality fibre flax and oilseed flax. Flax straw biomass can be baled into three bale types: small rectangular bales, big round bales, and big square bales The main requirements for fuel flax biomass bales are recommended. The boiler for burning flax straw bales must be chosen taking into account the shape and size of the bales. For the efficient operation of boilers, it is necessary to take into account the recommended values ​​of bale bulk density and moisture content of flax biomass.

Evaluation of a biomethane, food and biofertiliser polygeneration system in a circular economy system

Biomethane is a viable alternative to natural gas and diesel for decarbonising hard-to-abate sectors such as agriculture, industry and heavy transport. Unlike conventional biogas upgrading, photosynthetic biogas upgrading cogenerates biomethane, biofertiliser and microalgal bioproducts with the potential to improve resource utilisation and process performance in a circular economy. In this paper, a photosynthetic biogas upgrading-based polygeneration process is proposed and analysed to co-produce biofuel (biomethane), bio-fertiliser (digestate) and food (Spirulina powder, protein supplement) using agricultural feedstock. Based on a multi-criteria performance assessment, the economic and environmental benefits of the process are demonstrated. Thermodynamic performance of the process revealed that reducing the energy for greenhouse heating to cultivate microalgae would enable a higher energy output than input. Using economic allocation, a carbon footprint of biomethane less than 10 gCO2-eq/MJ (lower than 32.9 gCO2-eq/MJ for sustainable biomethane use in transport in the EU Renewable Energy Directive (Recast) (RED-II)); Spirulina protein of 0.8 kgCO2-eq/100 g protein (compared to 50 kgCO2-eq/100 g protein for beef); and digestate of 0.4 kgCO2-eq/kgN (comparing positively to 1.5–3 kgCO2-eq/kgN for synthetic nitrogenous fertiliser) was achieved. Unlike the current RED-II mandated methodology, the analysis established that the energy, CO2 emissions, land and water footprints of each co-product are best represented using an economic allocation principle. Based on the extended nutrition profile, Spirulina as a complete food outperforms most meat and plant-based protein alternatives in terms of CO2 emissions, land, and water footprints.

Biogas driven multigeneration integrated with simultaneous charging-discharging type thermal energy storage system

This work presents a novel and sustainable solution based on combined heat and power (CHP) system integrated with a simultaneous charging-discharging type thermal energy storage tank. The multi-generation system uses biogas as the heat source and is analyzed from the thermodynamic, exergoeconomic, and environmental perspectives. The proposed configuration aims to meet the electrical requirements of a cluster of 20 villages, greenhouse heating, and hot air production for agricultural drying applications. The exhaust gases from the biogas fired turbine are utilized to power a recompression supercritical CO2 and steam Rankine cycle. The additional surplus heat is stored inside a simultaneous charging/discharging type thermal storage tank that provides favorable conditions (50–55 °C) for biogas producing microorganisms to maximizing gas production. The meso-erythritol (sugar alcohol) is used as a phase change material due to its high latent heat and large supercooling (>60 °C), suitable for the present applications. The PCM is characterized on heat flux Differential scanning calorimeter (DSC) and thermophysical properties are evaluated. Further, the exergoeconomic analysis is presented to examine the economic viability of the system which serves as a holistic solution for rural power generation. It is found that the total product unit cost of the system is 12.96 $/GJ and operating charges are 140.5 $/h. The proposed multigenerational system promises a Levelized cost of electricity at 5 ¢ /kWh. The net overall electricity generated by the system is 1432 kW and provides 200 kW of space thermal heating. In addition, hot air is produced at the rate of 9720 kg/h for different agricultural drying applications.

Study of Solar Combined Air Energy Greenhouse Heating System Model

At present, it is difficult to bring centralized heating to rural areas owing to factors such as scattered distribution, distance from towns and cities, and difficulty in laying public pipes. According to research, most rural residents use inefficient household heating facilities, thereby resulting in serious environmental pollution and a decline in the quality of life of residents. In order to alleviate environmental pollution, the use of solar energy, air energy, and other renewable energy for rural heating of such decentralized buildings is of profound significance. This study analyzed the distribution characteristics of solar energy resources and solar combined air energy greenhouse heating system, established and solved a mathematical model of the solar combined air energy greenhouse heating system, calculated solar heat collection and solar heating energy consumption. From the data analysis, the relationship among heat gain power, heating power, and the water temperature of the water storage tank of the heat pump system was obtained. The mathematical model of the storage tank of the solar combined air energy greenhouse heating system was solved, and the operating conditions and volume of the storage tank of the solar combined air energy greenhouse heating system were determined. The study also analyzed the solar heat collection and solar heating energy consumption in Qingdao, thereby pointing out the advantages of the solar combined air energy greenhouse heating system, and finally obtained the best heating scheme.

Comparison of Application Effects of Capillary Radiation Heat Pump and Electric Heating Wire in Greenhouse Seedling Cultivation

Heat pumps with water as heat exchange medium applied in greenhouse heating have not been used for vegetable seedling cultivation. In this work, a multi-connected direct expansion capillary radiation heat pump (MDCRHP) was designed for vegetable seedling cultivation, and a closed local temperature control (CLTC) method was proposed to accurately control air and substrate temperatures in seedling beds, enhance the heating effect and reduce the equipment cost. The results show that the CLTC method can achieve good heating effect and quickly raise air/substrate temperature at a speed of 1 °C/min from 8 °C to about 20 °C within 12 min. The air and substrate temperature fields in the seedling beds were evenly distributed. The temperature differences at different horizontal positions and different heights were less than 1 °C, and the relative humidity was 100%, which is conducive to vegetable grafting seedling. It can be concluded from test results that the MDCRHP had strong adaptability for greenhouse heating and was obviously superior to the electric heating wire (EWH). The output capacity of the compressor can be controlled by adjusting the operation frequency to meet the temperature requirements at different stages of seedling cultivation. Under the conditions of similar external ambient temperature and heating effect in the seedling beds, the energy saving rate of the MDCRHP was 47–50.7% compared with the EWH. The cost of the MDCRHP is about 7.2% lower than that of the conventional heat pump. It takes 3–3.5 years to recover the equipment investment.

Thermal performance of greenhouse heating with loop heat pipe solar collector and ground source heat pump

The hybrid heating system consisting of loop heat pipe solar collector (LHPSC) and ground source heat pump (GSHP) is proposed to control greenhouse temperature in Harbin (the coldest provincial capital of China) in this paper. The combined thermal resistance network and energy balance model is developed to predict transient greenhouse temperature corresponding to the energy supplied by GSHP. The influence of ambient temperature on the thermal performance of greenhouse heating system is analyzed. The results show that the greenhouse temperature fluctuates in the range of 17–24 °C corresponding to the energy of 200 kW intermittently supplied by GSHP, which is reasonable for predicting greenhouse temperature in severely cold regions. As ambient temperature varies from −24 °C to −13 °C, heat loss of maintenance structure, ground, ventilation and water storage tank change in the range of 51.9–73.2 kW, 2.45–3.45 kW, 11.1–15.5 kW and 5.87–6.91 kW, respectively. The maximum thermal efficiency of loop heat pipe solar collector is higher (76.38%) than that of evacuated tube solar collectors (45%–50%), which will be promising for greenhouse heating due to higher thermal efficiency and better environmental adaptability. The results presented in this study will provide further valuable guidelines for designing greenhouse heating system.

Experimental study on the feasibility and thermal performance of a multifunctional air conditioning system using surplus air thermal energy to heat a Chinese solar greenhouse

Maintaining a suitable temperature in the greenhouse in the cold season requires the assistance of the heating system, and renewable energy is advocated to replace traditional energy for greenhouse heating. To adjust the microclimate of the greenhouse, this study proposed a multifunctional air conditioning system that utilizes surplus air thermal energy (SATE), and the heat balance is used to calculate the system performance required for heating. Experimental results show that the system increased the minimum air temperature at night by 2.8 °C, and it also improved in continuous cloudy days, making the greenhouse temperature and humidity at night closer to suitable conditions, and the air temperature is more uniform in time and space. The provided heat energy and heat transfer rate of the multifunctional air conditioning system were 168.8 MJ/d and 4289 W, respectively, which were 95% of the Chinese Solar Greenhouse (CSG) heat demand and 50% of the CSG maximum heat load. Adjusting the temperature difference between water and air can also improve the heat release capacity of the system, and the system still has great potential. The multifunctional air conditioning system heating CSG is feasible, and the system is environmentally friendly and energy-saving, suitable for all kinds of greenhouses, and will have broad application prospects.

Feasibility study and 3E analysis of blowdown heat recovery in a combined cycle power plant for utilization in Organic Rankine Cycle and greenhouse heating

Greenhouse heating plays a key role in the growth and yield of greenhouse crops in cold regions. Moreover, heat loss and energy wastage are abundant in the industry. Therefore, these two subjects are combined in this study to analyze the feasibility of using the steam vent and waste drain flow of a blowdown tank in a combined cycle power plant (CCPP) to provide the required additional heating in a greenhouse by installing a radiant floor heating (RFH) system. For this purpose, a tunnel greenhouse with an east-west orientation is modeled in steady states. In addition, a CCPP integrated with the Organic Rankine Cycle (ORC) is modeled on the energy, exergy, and economic (3E) analysis to comprehensively evaluate the system. The effect of greenhouse heating was analyzed in three months of the year with highest heating demand. According to the results of analyzing four scenarios, the RFH system managed to increase the greenhouse temperature up to 7.5 °C. The results indicated an increase in energy efficiency and exergy efficiency of the system by 0.04% and 0.05%, respectively. Based on the economic analysis, the payback period in the proposed scenario was determined 4.81 years.

Greenhouse heating by energy transfer between greenhouses: System design and implementation

Multi-span greenhouses consume enormous amounts of energy for heating in northern China, resulting in poor profitability and unsustainability. A greenhouse heating system, utilizing energy transfer between greenhouses based on a dual source heat pump, was designed to remedy this issue. The system collects surplus air heat inside Chinese solar greenhouses (CSGs) for heating multi-span greenhouses. Through enabling a greenhouse energy transfer in time and space, improved utilization efficiency of surplus air heat in CSGs is achievable, resulting in an overall reduction of heating costs. This study defines the heating approach and describes the overall system design. The dual source heat pump acts as the core component, with two separate evaporators placed in the CSG and ambient air. Calculations for system sizing are then presented, including a heating load model of multi-span greenhouses, a surplus air heat model of CSGs, the selection of required equipment (dual source heat pump, heat storage tank, and surface air cooler of the combined air conditioning unit), and the area matching. Finally, a case study illustrates the implementation processes of the heating system. The available CSG surplus air heat ranged 100.8–112.6 W m−2 for system sizing, and the minimum area of CSGs was suggested to be twice the multi-span greenhouse area. The pilot test showed that the running status and heating effect of the system was stable. The coefficient of performance (COP) of the heat pump reached 4.3–4.8 when using CSG surplus air heat as the heat source, performing 23–26 % higher than when using ambient air over the same periods. Throughout the entire course of heat collection, dual source heat pumps, switching sources based on their setting, achieved a total COP of 3.4–4.2, increased by 6–11 % compared with air source heat pumps. This study provides a novel heating approach and an energy-saving system for multi-span greenhouses.

Seasonality as value(s) in organic farming: On the conflict on heating greenhouses in France

This article deals with the notion of season, and illustrates an existing conflict, within organic agriculture, between symbolic and economic values. It takes the case of a polemic on the use of heating systems in greenhouse organic farming for tomato production. It asks and demonstrates how the organizations in and of market frame different seasonalities, either placing respect (symbolic value) for seasonality over economics, or vice versa. It identifies critical junctures that shaped the division in organic agriculture toward differing conception of seasonality, which oscillates between market logics in which its distinctiveness is (de)valued, symbolically and economically diminished or reasserted.

Assessment of dehumidification performance of non-corrosive desiccant in hybrid liquid desiccant-vapour compression system

ABSTRACT Air-conditioning (AC) systems, which operate on traditional vapor compression refrigeration (VCR) systems, consume a substantial proportion of the world’s electricity consumed by the building industry. In the scope of decreasing greenhouse gas emissions, energy consumption, heating, ventilation, and air conditioning industries have focused on finding alternatives to electrically operated VCR systems. A combination of a liquid desiccant dehumidification system (LDDS) with a VCR system has been recommended as a superior substitute in warm and moist climates. The focus of this research article is to design and fabricate a small-scale 5 kW hybrid LDDS system by integrating the distinct technologies mentioned above. Additionally, data collected on the vapor pressure of potassium formate (KCOOH) at various solution concentrations and temperatures is being collected to assist in encouraging research and determine the optimal concentration range. In this study, experimental analysis and comparison of dehumidification performance was conducted between two desiccants by analyzing the effects of input variables ( m a , T d , and ω s ) on the output response ( Δ ω , Q d e h , and C O P h ). The results showed that the solution with a 69.92% KCOOH concentration had nearly the same vapor pressure as a solution with a 35% LiCl concentration. Moreover, it was revealed that the lowest values of m a and T d and the highest value of ω s yield maximum values of the output responses. At the same combination of input variables, the KCOOH desiccant has a much higher hybrid system coefficient of performance than the LiCl desiccant.

Prediction Model for the Internal Temperature of a Greenhouse with a Water-to-Water Heat Pump Using a Pellet Boiler as a Heat Source Using Building Energy Simulation

Although smart farms are considered an alternative to traditional agriculture, they require large amounts of energy and high investment costs, hindering their efficient implementation. In the Republic of Korea, the energy supply is primarily for heating rather than cooling, necessitating the accurate prediction of the greenhouse internal temperature to determine the feasibility of agricultural management while using renewable energy. This study developed a model (TRNSYS) for predicting the internal temperature of a greenhouse using building energy simulation. A greenhouse heating experiment was conducted using a hybrid heating system simulated by TRNSYS to analyze the prediction model. The regression analysis of the experimental and simulation results revealed an R2 and RMSE of 0.8834 and 3.61, respectively. A comparative analysis was conducted with the existing hot air heating system to evaluate the heating performance and economic feasibility of the hybrid system. Overall, the heating performance exhibited satisfactory results, whereas the economic analysis, based on life cycle cost, revealed a cost reduction effect of 9.45%. Hence, greenhouse heating using renewable energy can replace conventional fossil fuels with economic advantages. Moreover, the prediction of the internal temperature of the greenhouse will facilitate the design of a systematic smart farm business to prevent duplicate investment.

Study on Heating and Cooling Performance of Air-to-Water Heat Pump System for Protected Horticulture

There is much interest in alternative energy sources for greenhouse heating and cooling, due to the impact of severe climatic conditions and increasing fossil fuel prices. The main objective of this study was to experimentally evaluate the performance of an air-to-water heat pump (AWHP) system to fulfil the cooling and heating energy requirements of a three-spanned greenhouse under local weather conditions in Daegu, South Korea. For this purpose, a system comprising three air-to-water heat pumps, a water storage tank, and fan coil units (FCU)s was designed. Experiments were conducted extensively during the summer and winter seasons. The maximum heating and cooling energy supply to the greenhouse was 210 kcal∙h−1∙m−2 and 230 kcal∙h−1∙m−2, respectively. Based on the outcomes of this study, the AWHP system can provide heating during the winter season. During the summer season, the FCU capacity was insufficient to provide the desired cooling to achieve the setpoint air temperature inside the studied greenhouse. To achieve the desired microclimate during the summer season, the capacity of the FCU or number of FCUs must be increased. Moreover, one AWHP with a water storage tank, was sufficient to provide the required cooling and heating in both seasons. Two additional AWHPs can be used to provide energy to more greenhouse areas in the future. The results can be used as a case study to find a more resilient and reliable source for greenhouse heating and cooling. The average COP of the AWHP in heating mode was 2.2, while on cooling mode, it was 3.2.

Characteristics and trends in geothermal development and use, 1995 to 2020

Production of electricity using geothermal energy started in 1904 at Larderello, Italy with an experimental 10 kWe generator. This was followed by a 250 kWe commercial unit in 1913. Italy was the world's only industrial generator of geothermally fueled electricity until 1958 when New Zealand came on-line with a 11.2 MWe unit built at Wairakei. By 1967, power plants were constructed in Mexico, the United States and Russia, where the first binary cycle power plant was installed in Kamchatka. Other countries followed: by 1970, Japan, Iceland, and China. Since WWII geothermal power has grown at an average rate of 6.2% annually. Electric power from geothermal energy, originally using steam from resources above 150 °C, is now being produced from resources with temperatures as low as 90 °C using the organic Rankine cycle process in binary power units sometimes in combination with district heating projects. Geothermal energy capacity has grown to 15,950 MWe, and 95,098 GWh of electricity produced in 29 countries. These power plants operate with an average capacity factor of 73%, many of them “on-line” over 95% of the time, providing almost continuous base-load power. The geothermally fueled electricity currently being produced serves the equivalent of 63 million people throughout the world.Direct uses of geothermal energy are traditional and well established world-wide. The people of Japan have lived in harmony with the earth's heat for centuries, using it mainly for bathing. Other nations have similarly taken advantage of hot springs for bathing and agriculture/aquaculture uses. There are now many large-scale uses of geothermal energy including district heating in Iceland and China, greenhouse heating in Hungary, and process heating with steam in New Zealand. One of the main advantages of the direct use of geothermal energy is that it can use low-to-moderate resource temperatures. The other advantage is that it can be found, often at shallow depths, almost anywhere in the world. Using ground-source heat pumps extends the use of geothermal energy to temperatures as low as 10 °C. As of 2021, 88 countries have reported some direct applications of geothermal energy with at least 10 others suspected of using this resource. Thermal energy for direct use is used 58.5% for geothermal heat pumps, 18.0% for bathing and swimming, 16.0% for space heating, 3.5% for greenhouse and covered ground heating, 1.6% for industrial applications, 1.3% for aquacultural pond and raceway heating, 0.4% for agricultural drying, 0.2% for snow melting and cooling, and 0.2% for miscellaneous applications. The installed capacity and thermal energy available worldwide today are 107,727 MWt and 1,020,887 TJ/yr. (283,580 GWh/yr.), respectively.

Demonstration study on ground source heat pump heating system with solar thermal energy storage for greenhouse heating

In this study, a demonstration project of a ground source heat pump (GSHP) heating system with seasonal solar thermal energy storage (SSTES) and diurnal solar thermal energy storage (DSTES) is constructed for greenhouse heating. In the non-heating season, the SSTES overcomes the thermal imbalance of GSHP heating for agricultural greenhouses. While in the heating season, the DSTES undertakes part of the heating load of greenhouses, reduces GSHP heating electric energy consumption and improves the annual coefficient of performance of heating system COPsys,y. The experimental data illustrate that the soil temperature of ground heat exchanger (GHE) area is about 0.3 K higher than the initial soil temperature at the end of SSTES, and the COPsys,y of the proposed heating system is 14.3 % higher than that of bank control experiment. The above results demonstrate that the proposed heating system is favorable for greenhouses in cold regions. Further, coupling DSTES can reduce the rated capacity of GSHP and the total length of GHE tube for the newly designed heating system. In addition, the recommended values of two key operating parameters are given based on the experimental data. This study can shed a light on clean and efficient heating for greenhouses in cold regions and provide data support for related research.

TRNSYS Simulation and Experimental Validation of Internal Temperature and Heating Demand in a Glass Greenhouse

The energy demand in greenhouses is enormous, and high-performance covering materials and thermal screens with varying radiometric properties are used to optimise the energy demand in building energy simulations (BES). Transient System Simulation (TRNSYS) software is a common BES tool used to model the thermal performance of buildings. The calculation of the greenhouse internal temperature and heating demand in TRNSYS involves the solution of the transient heat transfer processes. This study modelled the temperature and heating demand of two multi-span glass greenhouses with concave (farm A) and convex (farm B) shapes. This study aims to investigate the influence of the different BES longwave radiation modes on greenhouse internal temperature in different zones and the heating demand of a conditioned zone. The standard hourly simulation results were compared with the experimental data. The results showed that the standard and detailed modes accurately predicted greenhouse internal temperature (the Nash–Sutcliffe efficiency coefficient (NSE) > 0.7 for all three zones separated by thermal screens) and heating demand (NSE > 0.8) for farms A and B. The monthly heating demand predicted by the simple and standard radiation modes for farm A matched the experimental measurements with deviations within 27.7% and 7.6%, respectively. The monthly heating demand predicted by the simple, standard, and detailed radiation modes for farm B were similar to the experimental measurements with deviations within 10.5%, 6.7%, and 2.9%, respectively. In the order of decreasing accuracy, the results showed that the preferred radiation modes for the heating demand were standard and simple for farm A, and detailed, standard, and simple for farm B.

Heat balance modeling of heat pipe biogas-biofertilizer device reactor

The article develops a mathematical model of the modes of change of the indoor air temperature and the loaded biomass temperature over time on the basis of the equilibrium heat balance equation of the reactor of the heat pipe biogas-biofertilizer. Theoretical and experimental studies of changes in air temperature over time in stationary and non-stationary states inside the reactor of a thermal tubular biogas-biofertilizer. According to the results of the study, when the outside air temperature is 10 °C, it is possible to heat the indoor air temperature to 85-90 °C in accordance with the total solar radiation falling on the transparent surface of the device reactor. It is scientifically based to achieve full coverage of the greenhouse heat load using heated water due to the combustion of biogas obtained anaerobically in a water heating boiler as a result of heating of the biomass inside the device.

The impact of geothermal fluid discharge on drainage water and groundwater quality in terms of toxic contaminants in the agricultural Harran Plain, Turkey

The Karaali Geothermal field located in Harran Plain, which has a great agricultural potential for the development of our country, has a great importance because of being a thermal tourism and greenhouse heating source in Sanliurfa province. In this study, the aim was to determine heavy metal contamination, which has direct and indirect serious effects on human health, due to geothermal causes. In this context, a total of 11 sampling points in the Karaali Geothermal fluid (KG), the closest drainage channels where geothermal water is discharged (DW1, DW2, DW3, DW4 and DW5), and the closest groundwater to these points (GW1, GW2, GW3, GW4 and GW5), were sampled during 8 months between May 2020 and March 2021. Heavy metal concentrations were obtained in the order F>Sr>B>Ba>Al>Li>Fe>Cr>V>Mo>Zn>Cu>Zr>Be>Mn>Cd>Co>Pb>Ag>Ni for groundwater and Al>Fe>Sr>F>B>Mn>Ba>Li>Cu>Zn>Cr>Ni>Co>Mo>Be>Pb>Zr>Cd>Ag>V for drainage water. Al, Fe and Mn values were determined to exceed the acceptable values in terms of suitability of the water in the drainage channels for reuse and agricultural irrigation purposes. In groundwater, the limit values in terms of suitability for drinking water were exceeded for Al, B, F, Fe and Mo parameters. In the diagram of pH and metal load, all the samples were classified as “near neutral–high metal.” The study found that six factors in both drainage and groundwater factor analysis separately explained 86.1% and 81.2% of the total variation in the data, respectively. In the cluster, good results were obtained with three different similarity groups for drainage waters and five different similarity groups for groundwater. These results show that the factors responsible for toxic contamination in the drainage channels and especially in the groundwater are primarily related to the use of geothermal fluid in greenhouse cultivation and spa tourism, excessive use of pesticides and fertilizers in agricultural activities, and geogenic processes.

Reduced Atmospheres of Post-impact Worlds: The Early Earth

Impacts may have had a significant effect on the atmospheric chemistry of the early Earth. Reduced phases in the impactor (e.g., metallic iron) can reduce the planet’s H2O inventory to produce massive atmospheres rich in H2. While previous studies have focused on the interactions between the impactor and atmosphere in such scenarios, we investigate two further effects: (1) the distribution of the impactor’s iron inventory during impact between the target interior, target atmosphere, and escaping the target; and (2) interactions between the post-impact atmosphere and the impact-generated melt phase. We find that these two effects can potentially counterbalance each other, with the melt–atmosphere interactions acting to restore reducing power to the atmosphere that was initially accreted by the melt phase. For a ∼1022 kg impactor, when the iron accreted by the melt phase is fully available to reduce this melt, we find an equilibrium atmosphere with H2 column density ∼104 moles cm−2 (pH2 ∼ 120 bars, X H2 ∼ 0.77), consistent with previous estimates. However, when the iron is not available to reduce the melt (e.g., sinking out in large diameter blobs), we find significantly less H2 (7 × 102 − 5 × 103 moles cm−2, pH2 ≲ 60 bars, X H2 ≲ 0.41). These lower H2 abundances are sufficiently high that species important to prebiotic chemistry can form (e.g., NH3, HCN), but sufficiently low that the greenhouse heating effects associated with highly reducing atmospheres, which are problematic to such chemistry, are suppressed. The manner in which iron is accreted by the impact-generated melt phase is critical in determining the reducing power of the atmosphere and resolidified melt pool in the aftermath of impact.

OXIDATION PROCESSES OF HIGH-ALLOYED ALLOYS OF WORKING LAYER AND THE INTERPHASE SURFACES OF BIMETALLIC PAIRS

Methods of improving the quality of regulation of technological parameters by combining various intelligent control algorithms in one automation system, which helps to reduce energy costs by 10-13%, are analyzed. It has been established that heating and ventilation systems have the highest energy consumption for indoor buildings (on average, more than 4,000 m3 of natural gas and almost 1,000 kWh of electricity are consumed per day for heating and ventilation in an industrial greenhouse. Correlation analysis of links between external disturbances and energy costs that ensure compliance with the technology of plant production, confirmed the hypothesis of conditions of uncertainty in the operation of industrial greenhouses are formed by random disturbances, incomplete information about the biological component, with linear correlation coefficients not exceeding r<0.35. both for forecasting energy costs and for the formation of energy efficient management strategies. Based on the use of fuzzy logic methods and genetic algorithm, models for finding and using optimal parameters of PI controller settings adapted to changes in the operating conditions of the automation system have been developed and studied. This provides better regulation in conditions of uncertainty, the time of regulation, over-regulation is reduced by two to three times. To create an energy-efficient microclimate management system in industrial greenhouses, operating in conditions of uncertainty, a neural network model for predicting the energy consumption of natural gas and electricity has been developed. The input parameters of the neural network forecasting model are: the value of external and internal air temperatures of the greenhouse, the value of relative humidity, the solar radiation absorbed by the greenhouse and the level of carbon dioxide in the greenhouse. The outputs of the forecasting model are the values of natural gas and electricity costs. The structural and functional scheme of the temperature and humidity control automation system in industrial greenhouses has been improved by combining intelligent algorithms for stabilizing the operation of technological equipment at the lower management level and optimizing energy costs by forecasting them at the upper level. The introduction of such a system saves up to 13% on natural gas for heating and up to 10% on electricity.