217 results about "Thermodynamic model" patented technology

A refrigeration system comprising a compressor for compressing a refrigerant, a condenser for condensing refrigerant to a liquid, an evaporator for evaporating liquid refrigerant from the condenser to a gas, an inner control loop for optimizing a supply of liquid refrigerant to the evaporator, and an outer control loop for optimizing a level of refrigerant in the evaporator, said outer control loop defining a supply rate for said inner control loop based on an optimization including measurement of evaporator performance, and said inner control loop optimizing liquid refrigerant supply based on said defined supply rate. Independent variables, such as proportion of oil in refrigerant, amount of refrigerant, contaminants, non-condensibles, scale and other deposits on heat transfer surfaces, may be estimated or measured. A model of the system and/or a thermodynamic model approximating the system, for example derived from temperature and pressure gages, as well as power computations or measurements, is employed to determine or estimate the effect on efficiency of deviance from an optimal state. Various methods are provided for returning the system to an optimal state, and for calculating a cost-effectiveness of employing such processes.

A data storage and retrieval system such as a robotic library has a large plurality of removable storage media, such as tape cartridges, for purposes of I/O. To enhance performance and reliability of the library, a thermodynamic model of the library is constructed and stored in the library, and environmental conditions such as the temperature, humidity, and flow rate of cooling air coming into, flowing through, and leaving the library are monitored. The thermodynamic model of the library includes an acceptable operating range for the library in a psychrometric chart; and the product of the effective thermodynamic mass and specific heat of the library.

Techniques for determining and using a thermodynamic model that characterizes a thermodynamic response of an enclosure conditioned by an HVAC system are disclosed. To determine a thermodynamic model, temperature information when the HVAC system operates in a first state may first be received. A response interval may then be determined where the response interval indicates an estimated time between when the HVAC system begins operating in the first state and when the temperature within the enclosure begins to change in a direction associated with the first state. Weighting factors corresponding to basis functions may then be determined, where the weighted basis functions characterize the temperature trajectory of the enclosure in response to the HVAC system operating in the first state. The basis functions may include a first basis function that is evaluated from a time that the HVAC system begins operating in the first state until a time when the response interval ends, and a second basis function that is evaluated beginning at the time when the response interval ends.

A method for diagnosing potential faults reflected in operational data for a turbine engine includes the steps of generating a diagnostic pattern for the operational data and comparing the diagnostic pattern with a plurality of historical patterns, to thereby identify one or more likely potential faults reflected in the operational data. The diagnostic pattern comprises a plurality of scalars. Each scalar represents an arithmetic relationship between values of the operational data and values predicted by a baseline thermodynamic model. Each historical pattern is linked to one or more specific faults.

An operations support system for an engine includes a diagnostics unit configured to receive engine data from the engine and to generate condition indicators based on the engine data using a thermodynamic model. The thermodynamic model is based on component maps associated with the engine. The system further includes a fault classification unit coupled to the diagnostic unit and configured to generate health indicators based on the condition indicators.

In a method for ascertaining temperatures (tqm, tqh, tom, tok) in an oil-cooled transformer, the transformer terminal voltages (2), the winding currents (3) and the ambient temperature (6) are measured. Furthermore, the status (5) of fans and pumps and the switch position (4) of a stepping switch are established. The measured and established variables (2, 3, 4, 5, 6) are fed to a thermohydraulic model (7), in which state variables (19) are calculated with auxiliary variables (9), which are losses (10) in the transformer, heat transfer parameters (11), flow resistances (13) and the oil flow (12), and a hydraulic network of the oil circuit, which has branches and nodes. The state variables (19) are the average temperatures (tqm) and the hotspot temperatures (tqh) in loss-producing parts of the transformer and the average oil temperatures in branches (tom) and in nodes (tok) of the hydraulic network of the oil circuit. When there is a change in the variables measured and established (2, 3, 4, 5, 6), the auxiliary variables (9) are adapted appropriately, and the rate of change of the state variables (19) is subsequently ascertained and new state variables (19) are consequently calculated. With this method, temperatures (tqm, tqh, tom, tok) and their changes in the transformer are ascertained without temperature sensors, whereby the optimum operation of the transformer is ensured, an early detection of errors and risks takes place and the optimum point in time for service work can be established.

An accurate thermodynamic model of an Active Lean NOx (ALNC) Catalyst is presented. The model takes into account hydrocarbon storage and release mechanisms of the ALNC, as well as the degradation in the ALNC hydrocarbon conversion efficiency due to ageing, and thus provides a more accurate estimate of an exotherm generated by hydrocarbon combustion in the ALNC. The estimated exotherm can them be used to detect system degradation and identify components responsible for the degradation.

The invention discloses a method for optimized setting of air conditioner temperature in an office building and relates to a dynamic setting method for changing a set value of the air conditioner temperature in real time according to indoor and outdoor environmental factors. To improve the dynamic setting of the air conditioner temperature, a simplified room thermodynamic model is established; in the model, the air conditioning opening is performed in the daytime, and natural ventilation is performed at night. The dynamic relations between the air conditioner load and environmental variables such as outdoor temperature, hot material temperature and the indoor temperature set value are established through the analysis of the room model. With the air conditioner load as an objective function and according to the limiting conditions that the human comfort index PMV value is within the regulated range, an optimized model of the air conditioner temperature set value is established; and optimization solution is performed on the model, so as to obtain the optimal air conditioner temperature set value at each moment. The obtained dynamic temperature set value can guarantee the good thermal comfort level for indoor workers and can effectively reduce energy consumption of the air conditioner.

The invention discloses a modeling and controlling strategy for a central air conditioner with a fresh air system. The modeling and controlling strategy includes the following steps of building a thermodynamic model of a building where the central air conditioner is installed, namely, the relation between indoor and outdoor temperatures and the cold capacity of the building; building an energy consumption model of the central air conditioner with the fresh air system, namely the relation between the air conditioner load and decision variables; determining a control strategy, namely determining the target function, control variables, constraint conditions and the like; and working out the highest adjusting potential of the load of the central air conditioner, comparing the adjusting results of different control modes, researching the system load of the central air conditioner and participating in load tracing. By finely building the model and determining the cooperative optimization strategy of the control variables, a scientific theory support is provided for the central air conditioner with the fresh air system to participate in operation of a power system.

The invention discloses a commercial building HVAC control method based on multi-agent deep reinforcement learning. The method comprises the following steps: (1) on the premise of maintaining indoor temperature and air quality in a comfortable range, modeling a multi-region commercial building HVAC energy cost minimization problem into a Markov game, and designing a corresponding environment state, behavior and award function; (2) training a deep neural network by using a multi-agent actor-attention-reviewer reinforcement learning algorithm; and (3) in practical application, obtaining decisions about the position of an HVAC air valve and the air supply rate of each region according to the trained deep neural network and new environment state input. Compared with an existing method, the method provided by the invention does not need to know any priori information of a building thermodynamic model and uncertainty parameters, and has greater energy cost saving potential and higher expandability.

In accordance with an exemplary embodiment, an operations support system for an engine is provided. A diagnostics unit is configured to receive engine data from the engine and to generate condition indicators based on the engine data using a thermodynamic model, the thermodynamic model being based on component maps associated with the engine. An emissions calculation unit is coupled to the diagnostic unit and configured to calculate emissions information for the engine based on the condition indicators. A graphical user interface is coupled to the emissions calculation unit and configured to display the emissions information.

The invention discloses an engine thermodynamic simulation model calibration method based on multi-objective optimization. The method comprises steps as follows: S101, acquiring engine structure parameters and engine test data; S102, establishing a one-dimensional engine thermodynamic model; S103, establishing a coupling calculation model of the one-dimensional engine thermodynamic model and multi-objective optimization software; S104, selecting calibration parameters and setting ranges of the calibration parameters; S105, setting a calibration objective; S106, selecting a corresponding test design and optimization algorithm; S107, executing simulation iteration; S108, performing result analysis by using decision-making tools in the multi-objective optimization software. The method is based on computer simulation analysis, a multi-objective optimization algorithm and a numerical simulation technique are combined, automation of the calibration process is realized, accurate models can be calibrated quickly, the follow-up engine development is supported, the development efficiency is improved, the development cost is saved, and the development cycle is shortened.

The invention discloses a solar heat pump hot water system control strategy optimization method based on machine learning. The method includes the steps that an air source heat pump thermal model anda solar collector thermal model are constructed; related data are collected; a hot water system model is constructed; load prediction is conducted; and strategy optimization is conducted. According tothe solar heat pump hot water system control strategy optimization method, a thermodynamic model of a system is constructed, an input-output relationship of a heat collection process of an air sourceheat pump and a solar collector is established, a KNN(K-Nearest Neighbor) supervised learning algorithm in machine learning is utilized to realize hourly prediction of a hot water load, a predicted value is used as a demand load value, the established thermal models are utilized to analyze an optimal control strategy and the energy saving rate of the system, thus a theoretical basis is provided for engineers, and it is ensured that the hot water system operates more stably and energy-efficiently.

The invention relates to a system for calibrating apparatus (28) for acquiring the pressure in a cylinder (10) of a motor vehicle diesel engine, of the type comprising a cylinder pressure sensor (30) associated with the cylinder and means (32) for conditioning the signal delivered by the sensor (30) as a function of conditioning parameters. The calibration system comprises means (64) for collecting a signal delivered by the cylinder pressure sensor (30), an information processing unit (34) adapted to determine the values of the conditioning parameters as a function of a polytropic thermodynamic model of the evolution of the pressure in the cylinder, a reference pressure of the pure compression phase of the cycle of the cylinder, and the signal delivered by the pressure sensor (30) and collected by the collecting means (64), and means (66) for modifying the values of the conditioning parameters in the acquisition apparatus (28) as a function of the values of the conditioning parameters determined by the information processing unit (34).

The invention relates to a modeling method for a heterogeneous azeotropic rectification solvent dehydrating tower of an industrial purified terephthalic acid (PTA) device. In the method, the vapor-liquid balance experimental data of an acetic acid, n-propyl acetate, water, p-xylene and methyl acetate quinary mixture system are associated and fitted with the binary interaction parameters of the quinary mixture system according to a thermodynamic property model; and according to the process data of the solvent dehydrating tower under the actual device design condition, a heterogeneous azeotropic rectification solvent dehydrating tower model of the industrial PTA device under the design condition is established, the accuracies of the thermodynamic model and parameters thereof of the quinary mixture system in a laboratory and a rectification tower mathematical steady model are verified, key parameters representing the separating property of the solvent dehydrating tower under the actual condition are acquired, the model is corrected and a process mechanism steady model capable of accurately describing the operating characteristics of the solvent dehydrating tower under the actual condition is established.

A method for climate control for an interior of a motor vehicle includes acquiring climatically relevant data of the interior and/or surroundings of the vehicle, creating a thermodynamic model of a vehicle climate system, the model including at least one of a first thermal capacity of the interior and a first heat loss of the interior, introducing into the interior a quantity of air having a temperature different from an existing interior temperature, calculating at least one of a second thermal capacity of the interior and a second heat loss of the interior existing after the air quantity is introduced into the interior, and adapting the thermodynamic model to include at least one the second thermal capacity and the second heat loss.