Use Of Plate Heat Exchangers Research Articles

Thermo-hydraulic rating of a gasketed-plate heat exchanger for methanol heating

The use of plate heat exchangers is desirable since they have a simple compact construction, are reliable, and very efficient at small temperature difference between fluids. In the present work the thermo-hydraulic rating of a proposed gasketed-plate heat exchanger was carried out, in order to heat a methanol stream. A safety factor of 1.62, a percent over surface of 3.91% and a cleanliness factor of 0.962 was obtained. The calculated values of the pressure drops for both the hot water and methanol streams were 47,199.05 Pa and 78,414.61 Pa, respectively, while the pumping power required for those both streams were 4.81 kW and 11.38 kW, respectively. The proposed gasketed-plate heat exchanger can be used for the requested heat transfer service since the percent over surface is lower than 25% and the calculated pressure drop of both streams are below the maximum permissible pressure drop established by the process.

Cost and Emissions Reduction in CO2 Capture Plant Dependent on Heat Exchanger Type and Different Process Configurations: Optimum Temperature Approach Analysis

The performance of a plate heat exchanger (PHE), in comparison with the conventional shell and tube types, through a trade-off analysis of energy cost and capital cost resulting from different temperature approaches in the cross-exchanger of a solvent-based CO2 capture process, was evaluated. The aim was to examine the cost reduction and CO2 emission reduction potentials of the different heat exchangers. Each specific heat exchanger type was assumed for the cross-exchanger, the lean amine cooler and the cooler to cool the direct contact cooler’s circulation water. The study was conducted for flue gases from a natural-gas combined-cycle power plant and the Brevik cement plant in Norway. The standard and the lean vapour compression CO2 absorption configurations were used for the study. The PHE outperformed the fixed tube sheet shell and tube heat exchanger (FTS-STHX) and the other STHXs economically and in emissions reduction. The optimal minimum temperature approach for the PHE cases based on CO2 avoided cost were achieved at 4 °C to 7 °C. This is where the energy consumption and indirect emissions are relatively low. The lean vapour compression CO2 capture process with optimum PHE achieved a 16% reduction in CO2 avoided cost in the cement plant process. When the available excess heat for the production of steam for 50% CO2 capture was considered together with the optimum PHE case of the lean vapour compression process, a cost reduction of about 34% was estimated. That is compared to a standard capture process with FTS-STHX without consideration of the excess heat. This highlights the importance of the waste heat at the Norcem cement plant. This study recommends the use of plate heat exchangers for the cross-heat exchanger (at 4–7 °C), lean amine cooler and the DCC unit’s circulation water cooler. To achieve the best possible CO2 capture process economically and in respect of emissions reduction, it is imperative to perform energy cost and capital cost trade-off analysis based on different minimum temperature approaches.

Modern methods of intensification of heat exchange processes in plate apparatuses

The heat supply system of the Russian Federation is characterized by significant wear and tear of equipment: heating networks and boilers. At the same time, an important element of heat supply systems equipment is heat exchangers of various designs, which are used in boilers, IHP, thermal power plants, and nuclear power plants. Various heat exchange equipment used in modern heat power engineering is considered. It is established that the use of plate heat exchangers is a more appropriate engineering solution than shell-and-tube heat exchangers, due to economic factors and operational advantages. The method of intensification of heat transfer of the heated liquid by means of technological depressions of spherical shape located according to the linear law is considered.

Performance Simulation of Plate Heat Exchanger Based on ANSYS ICEM

A three-dimensional geometric model was established by ANSYS ICEM according to the structure of a plate heat exchanger. And the thermodynamic performance under different working conditions is simulated. The pressure field, temperature field, velocity field and flow pattern were analyzed based the simulated results. The heat transfer performance and resistance performance of heat exchanger under different flow rates and inlet temperature difference of cold and hot fluids are compared and analyzed. The results provide support for the more efficient use of plate heat exchangers under different working conditions.

ANALYSIS OF HEAT EXCHANGERS NETWORKS FOR ABSORPTION CLEANING UNITS IN HIGH CAPACITY GASIFICATION PLANTS

The basic heat exchangers networks of big gasification plants with fossil fuel gasification are considered. The main logistical factors that influence process flowsheets configurations of gasification plants are underlined such as natural quality and components content of fuel to be gasified, range of target products, environmental legislation and demands including regulations for greenhouse gases emission, location relatively to big industrial sites, possibilities of wastes conversion into saleable products. The essential ways of the efficiency enhancement of heat exchangers networks are formulated for integrated gasification plants of combined cycle. The existing systems of syngas absorption cleaning in big gasification plants are discussed. The ways of energy saving retrofit of such systems are defined. The use of plate heat exchangers is considered as perspective for heat transfer components of gases removal systems.

Определение рационального количества теплоутилизаторов для коровника на 400 голов

Introduction . Matters of selection and use of units for exhausted air heat utilization in the barn room are considered. The work objective is rationale for choosing the number of heat recovery devices that provide the greatest economic benefit when operating in the room for 400 animals. Materials and Methods . Determination of the number of energy-saving equipment units is due to several factors. The key one is the ever varying amount of air exchange in the barn depending on the outer air parameters. At this, the operating conditions in the southern regions of the country are taken into account. Mathematical models describing dependence of the technical-and-economic indices on the number and operating period of the disposal plants are proposed. The correlationregression analysis of the dependences obtained is made. The technical-and-economic assessment of the use of heat exchangers is carried out on its basis. Contour plots of the objective functions of the electric power consumption and operating costs are presented depending on the operating period and the capacity of energy-saving plants. A comparison method is used to identify the most efficient performance of the heat exchanger with the varying value of air exchange. Research Results. The desired number of heat exchangers, which provide the required air exchange in the livestock house, is determined. New mathematical models are developed for calculating the efficiency of utilization facilities taking into account the capacity and operating period. Dependences of the change in running costs on the performance efficiency of the utilizers are established. The number and type of the heat recovery units is determined. When these utilizers are in use, the greatest net present value is achieved. Discussion and Conclusions . The results obtained can be used to develop energy-saving systems under stock-rearing. The proposed mathematical models for calculating operational costs allow for a pre-feasibility study on the use of plate heat exchanger in livestock buildings.

Experimental investigation and numerical modelling of a compact wet air-to-air plate heat exchanger

Air-to-air plate heat exchangers are widely used for domestic and industrial scale HVAC applications. The wide use of plate heat exchangers makes their control and optimisation critical for improving overall system performance. The application of plate heat exchangers has recently been demonstrated in domestic scale dehumidifier and heat pump clothes dryer systems. In the case of the domestic dehumidifier, the plate heat exchanger, referred to as an evaporator economizer, reduces the sensible load of moist air, and raises the drying efficiency of the system. However, they have shown to contribute to the latent cooling process also. There is little information regarding control and optimisation of air-to-air plate heat exchangers operating under wet operating conditions typical of domestic scale dehumidification and heat pump clothes drying.In this work, a plate heat exchanger was designed and constructed to experimentally investigate several different conditions for optimizing the moisture extraction rate for application of a plate heat exchanger as an energy recovery device. The test configurations include varied tilt angle, thermal effectiveness control, varied duct aspect ratio and varied air volume flow rate and moist air conditions that are applicable to domestic scale dehumidification systems. The research findings show that a modest tilt angle of up to −20°, relative to a reference setting of the hot-side face area being parallel to the horizontal, the pressure drop can be reduced by 33% with a corresponding decrease in the moisture extraction rate of 8%. Furthermore, a study of different ducting configurations shows that deactivating cold-side ducts, while fixing the active hot-side, allows for a greater range of hot-side temperature difference control, while maintaining a relatively high MER compared with deactivating hot-side ducts while keeping the active cold-side ducts fixed.The experimental data obtained in this work has been used to extend the validity of a recently developed numerical model for a wet air-to-air plate heat exchanger expanding its working range of hot-side and cold-side moist air inlet conditions, airflow conditions and ducting configurations and duct aspect ratios. This model provides for a quantitative approach when engineering emerging advanced domestic scale dehumidification and heat pump clothes drying systems.

Thermal Integration of SOFC and Plate Heat Exchanger Desorber

SOFCs are a potential candidate for use as Auxiliary Power Units (APU’s) on board heavy duty trucks. Heat from the SOFC exhaust is generally used either for cabin heating or for recuperative heat exchange and even after that there is still a considerable amount of high quality heat available. The unique selling point of an SOFC is the availability of both electricity and high quality heat. Not using the heat from an SOFC stack is tantamount to using only half the available useful energy from the fuel. The ongoing research work reported here focuses on the design & development of a compact Solid Oxide Fuel Cell –Vapour Absorption Refrigeration System (SOFC-VARS) unit for refrigerated truck applications. This report presents a numerical model and simulation for thermal integration of an SOFC stack with a plate heat exchanger desorber via a specially designed tube in tube heat exchanger with internal fins where thermal oil is heated to the required desorber temperature and then serves as the coupling fluid in the plate heat exchanger desorber. The sizing of the heat exchanger and desorber has been carried out to fit a small refrigerated van, to cater to a 1 kW cooling load. The modelling focuses on the heat transfer aspects at the SOFC and heat exchanger end and on both heat & mass transfer aspects at the desorber end. The results show that a plate heat exchanger desorber is able to produce the required quantity of refrigerant needed for a 1 kW cooling load. A thorough sensitivity analysis on the plate heat exchanger desorber has also been carried out to identify the parameters that affect desorption performance the most and the parameters that have least effect on the desorption performance. The use of plate heat exchangers as desorbers not only gives a high heat transfer surface needed for desorption but also leads to considerable reduction in desorber volume when compared to conventional falling film desorbers. Based on the results obtained from modelling, appropriate design maps have been drawn which showcase the sizing of the plate heat exchanger desorber and the SOFC stack and also the mass flow rate of thermal oil needed.

Searches of cost effective ways for amine absorption unit design in CO2 post-combustion capture process

There is an increasing interest in post-combustion CO2 capture related to climate change and further use of the captured CO2 in enhanced oil and gas recovery, as well as a feed to produce products such as methanol or dimethylether, the use in hot dry rock technologies, etc. The currently used post-combustion capture method based on MEA (monoethanolamine) absorption without stream split has significant steam consumption to regenerate the amine solution. In this work, the HEN ADU (Heat Exchanger Network of an Absorption Desorption Unit) is analysed using the Process Integration methodology. It is supplemented with the search of economically viable options of desorption column parameters by computer modelling and the use of compact PHEs (plate heat exchangers) with intensified heat transfer. Based on the presented case study, the variation of temperature approach inside the rich/lean heat exchanger is considered. Its influence on the heat consumption, the energy efficiency and the investment cost of the HEN ADU unit are discussed. The use of PHEs in HEN ADU allows with the same or even smaller purchased cost of heat exchangers to save up to 13% more energy as compare to HEN with conventional shell and tube heat exchangers.

Thermal Integration of SOFC and Plate Heat Exchanger Desorber

A Plate Heat Exchanger (PHE) desorber is thermally integrated with an SOFC stack via a specially designed tube in tube heat exchanger with internal fins in which thermal oil is heated to the required desorber temperature and then serves as the coupling fluid in the PHE desorber. A modelling approach has been adopted where the PHE desorber is solved for heat and mass transfer using MATLAB & EES and the tube in tube heat exchanger with internal fins has been modelled and optimized using COMSOL multiphysics. The results show that the PHE desorber is able to produce the required quantity of refrigerant needed for a 1 kW cooling load. The use of PHEs as desorbers not only gives a high heat transfer surface area but also leads to considerable reduction in desorber volume when compared to conventional falling film desorbers.

Investigation of the new corrugation pattern for low pressure plate condensers

The use of Plate Heat Exchangers (PHEs) as condensers for low pressure vapour is limited mostly because of relatively high pressure drop of condensing media. To overcome this obstacle the new principle of plate corrugation for low pressure plate-and-frame condensers is proposed. The proposed plate for condenser has the heat transfer area that consists of several differently corrugated sections along its length. Channels formed by such plates have the variable cross-section area. Pressure drop of single phase fluid in channels of such pattern was investigated experimentally and correlations for friction factor were obtained for each channel part formed by different sections of the plates. Based on analogy between heat and momentum transfer the equations to calculate film heat transfer coefficients in single phase flow and during condensation are proposed. To calculate condenser performance and local process parameters, the one dimensional mathematical model is used. Its validity is confirmed by comparison with literature data for condensation in PHE channels of investigated type. Case study results have shown the advantages of proposed approach. It enables to reduce considerably, about 40%, the pressure drop of condensing media, along with maintaining the level of heat transfer enhancement.

On the pressure drop in Plate Heat Exchangers used as desorbers in absorption chillers

The influence of the pressure drop in Plate Heat Exchangers (PHE) in the boiling temperature of LiBr–H 2O and NH 3–H 2O solutions is studied. For the NH 3–H 2O solution, the pressure drop-temperature saturation relationship estates that high pressure drops can be allowed in the solution with negligible changes in the saturation temperature, and in the PHE performance. Besides, in the case of the LiBr–H 2O solution, as the working pressure is usually very low, the analysis of the pressure drop must be taken as a main limiting parameter for the use of Plate Heat Exchangers as vapour generators. In this case, the pressure drop may considerably change the boiling temperature of the solution entering the heat exchanger and therefore a higher heating fluid temperature may be required. A guideline to design these systems is proposed.

The use of plate heat exchangers to improve energy efficiency in phosphoric acid production

This paper originated as a part of a comprehensive research project designed to develop ecologically sustainable, environmentally friendly, resource- and energy-saving industrial process technology for the production of a wide class of phosphorus containing substances. The essential feature of the research was designed for the replacement of tubular heat exchangers with Plate heat exchangers (PHEs) and for the installation of these units in new locations in the processes to optimally improve energy efficiency and to prevent pollution. Despite the severe operating conditions in the production of phosphoric acid PHEs of various designs find the application in these processes. For such a corrosive environment as a phosphoric acid production plant, the Hastelloy G30 alloy is used as the material for the plates and synthetic rubber EPDM is used as the material for inter-plate gaskets. The analysis of the data shows, that using mixed groupings of plates in the unit allows one to obtain optimal solutions. The simulation of barometric mixing condenser recycled water cooling with plate heat exchanger shows the possibility of an application which minimizes the waste water pollution by closing the condenser cooling water circuit. Software was developed for calculations of units working both with liquid and phase changing streams.

Evaporation in plate type heat exchangers

This paper describes conventional film and forced circulation evaporators and proceeds to discuss the use of plate heat exchangers as a viable alternative in evaporation duties.