scholarly journals Cold production reducing energy costs using ozone-friendly refrigerants

2021 ◽  
Vol 937 (2) ◽  
pp. 022091
Author(s):  
T L Ripol-Saragossi ◽  
I A Smychok

Abstract The article considers ways to reduce energy costs in the cold using ozone-safe refrigerants production. In this case, it is necessary to include an air-cooled heat exchanger-pre-condenser in the technological scheme of refrigeration. The conditions for the pre-capacitor for a certain performance selection are formulated. The results of the presented calculations prove a decrease in the annual energy consumption for cold production in comparison with the technological scheme with external cooling and a cascade system. The energy consumption reducing principle of the installation due to the air pre-condenser can also be realized by installing a heat-exchanger on the discharge of low-temperature compressors to heat water for the enterprise needs, receiving free heat energy all year round.

2011 ◽  
Vol 201-203 ◽  
pp. 2850-2853
Author(s):  
Shou Juan Wang ◽  
Fan Gong Kong ◽  
Jia Chuan Chen ◽  
Gui Hua Yang

Pulping parameters in neutral deinking of old newsprint (ONP) and its impacts on deinking efficiency were investigated as well as comparison with alkaline deinking was carried out in this paper. The results showed that the low pulping consistency and short pulping time mostly contributed to the removal of ink in neutral pulping stage. The optimum pulping conditions of ONP were as follows: deinking agent, 0.6%~1.0%; pulping consistency, 6%~8%; pulping time, 15min; pulping temperature, 40°C. The low temperature in pulping stage of ONP neutral deinking process could greatly improve the deinking efficiency and reduce heat energy consumption. The comparison of neutral deinking and alkaline deinking of ONP showed that low pulping consistency contributed to the ink removal for neutral deinking, however, high pulping consistency benefit the alkaline deinking. Neutral deinked pulp had better H2O2 bleachability than alkaline deinked pulp, and could save 60% H2O2, when the brightness was similar to that of alkaline pulp.


2016 ◽  
Vol 13 (3) ◽  
pp. 4891
Author(s):  
Mustafa Kırlı ◽  
Tekmez Kulu

That the energy, as an important production factor, is a non-replaced element is an undeniable fact while the businesses perform their basic functions. In macro scale the economies of the countries and in micro scale businesses must manage the energy well in order to obtain their goals. In that sense, energy management should be organized as an independent unit within the institutions; it should take precautions to reduce the energy costs and to increase the operation productivity of the businesses. In the modern understanding of business administration, energy management has the functions such as reducing the costs in a business, increasing the competitiveness, increasing the operating profits, increasing the operation productivity, wise use of energy and reducing environmental pollution. Energy accounting is an information system that follows, records and reports the energy consumption and energy costs regularly. Energy accounting has a significant contribution in achieving the expected success of energy management. Energy accounting has benefits in many fields such as reducing energy supply costs, reducing energy consumption costs and making budgets of the business in the context of energy management. Energy accounting motivates and activates all the units of the business in terms of reducing energy costs by performing the duties which are expected from it. Özetİşletmeler temel işlevlerini yerine getirirken, önemli bir üretim faktörü olarak enerjinin; ikame edilemeyecek bir unsur olduğu yadsınamaz bir gerçektir. Makro ölçekte ülke ekonomilerinin ve mikro ölçekte de işletmelerin amaçlarına ulaşabilmeleri için enerjiyi etkin bir şekilde yönetmeleri gerekir. Bu bağlamda, enerji yönetimi, kurumlarda bağımsız bir birim olarak örgütlenmeli; enerji maliyetlerini azaltacak ve işletme faaliyet verimliliğini arttıracak önlemleri almalıdır. Çağdaş işletmecilik anlayışında enerji yönetimi; bir işletmede maliyetlerin azaltılması, rekabet gücünün arttırılması, işletme karlılığının arttırılması, işletme verimliliğinin arttırılması, enerjinin akılcı kullanımı ve çevre kirliliğinin azaltılması gibi işlevlere sahiptir. Enerji muhasebesi, enerji tüketimini ve enerji maliyetlerini düzenli bir şekilde izleyen, kaydeden ve raporlayan bir bilgi sistemidir. Enerji yönetiminin kendisinden beklenen başarıyı sağlamasında; enerji muhasebesinin önemli bir katkısı vardır. Enerji muhasebesi, enerji yönetimi kapsamında işletmelere; enerji tedarik maliyetlerini azaltmada, enerji kullanım maliyetlerini azaltmada, işletme bütçelerinin yapılması gibi bir çok alanda faydalar sağlar. Enerji muhasebesi, kendisinden beklenen görevleri yerine getirerek; işletmenin tüm birimlerini, enerji maliyetlerini düşürme konusunda motive etmekte ve harekete geçirmektedir.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Amour Othman Muhunzi ◽  
Yusufu Abeid Chande Jande ◽  
Revocatus Lazaro Machunda

A numerical study for heat exchanger for spray-assisted low-temperature desalination system is presented for an existing low-temperature desalination unit at Arusha Technical College. This is aimed at recognizing the effect of mass flow and physical parameters like tube layout (diameter and length) on the overall heat transferred and the pressure drop in the shell-and-tube heat exchanger (STHX), as well as the impact of these parameters on the heat transfer coefficient and the overdesign of the STHX. Also, the study provides a suitable mathematical model for the replacement of the current condensation unit which tends to reduce energy consumption by reducing some of the electrical components in the system. A Math CAD model was developed using the Delaware method to obtain the mentioned parameters. The results show that at 0.8 kg/s flow rate a maximum heat transfer coefficient of 23212 W/m2K is achieved in a minimum diameter of 10 mm within a maximum tube length of 1000 mm heat exchanger and the pressure drop seems to be very low in a range of 0.328-0.957 Pa from all configurations. The configuration with 1000 mm tube length and 10 mm diameter performed well on the mass flow of 0.3 kg/s-0.8 kg/s by providing a suitable overall heat transfer coefficient of 2306-2539 W/m2K, while 12.8 is a maximum overdesign coefficient achieved on 0.8 kg/s mass flow. The study results show the possibility of using STHX instead of the current condensation unit in implementing a proposed system layout with the minimum effect of energy consumption.


2019 ◽  
Vol 23 (3) ◽  
pp. 15-25
Author(s):  
Edvins Terehovics ◽  
Ivars Veidenbergs ◽  
Dagnija Blumberga

Abstract Reducing energy consumption in industry has become an important aspect on a global scale. Energy efficiency is one way of reducing energy consumption and promoting competitiveness. Increasing energy costs, security of energy supply, emissions from energy production have shown that current freezer design solutions are not sustainable. The food industry has a common tendency, whereby energy costs are only of secondary importance, unlike other production costs, resulting in minimal monitoring of energy consumption. Electricity consumption for freezer operation amounts to 20 % of total electricity consumption. Within the framework of this study, electricity consumption for fish freezing and storing frozen fish and finished products, as well as the coefficient of performance (COP) for compressors and parameters affecting COP were analyzed. From the results it can be concluded that the specific consumption of electricity in freezing of fish is lower than that of frozen fish storage. The two-stage compressor COP ranges from 2.4 to 3.7, but the single-stage compressor COP ranges from 3.7 to 5.5. The pressure in the condenser and ammonia vapor temperature after the compressor is affected by the temperature of the water used to cool the condenser and compressors. As the temperature of the water used for cooling increases, the condenser and ammonia vapor temperature after the compressor increase, which in turn reduces the compressor COP.


2010 ◽  
Vol 160-162 ◽  
pp. 1388-1393
Author(s):  
Li Fu Gao

Highlighted with its advantage of convenience, low energy consumption and sanitation, low temperature floor radiate heating system has been favored and been used in most heating areas since it was introduced into china in mid 80’s,But it is generally believed that floor heating system alone can not meet heating design requirement for large room located in cold area and is only deemed as an assistant heating methods.This article has proved by monitoring data collected from low temperature floor radiate heating system designed for large room in cold area that it is well enough to apply low temperature floor radiate heating system alone with reasonable design and running control and modification of heat exchanger.


Author(s):  
Lihua Dong ◽  
Hongyu Huang ◽  
Noriyuki Kobayashi

The present research of adsorption heat pump system for heating application mainly focuses on its miniaturization and high output. When the adsorption heat pump is downsized the heat energy is insufficient to meet heating application. In addition, a large amount of low-temperature heat energy in industry has not been utilized but discharged into the atmosphere as waste heat. To improve energy efficiency and reduce carbon dioxide emission, it is important to effectively utilize the low-temperature heat source which is usually discarded as waste heat. In order to solve the problem between the miniaturization and the high output, a miniature all-in-one type adsorption heat pump which can effectively utilize waste heat is designed. In this design, a heat exchanger coated with adsorption material is used as an adsorber or desorber, and another heat exchanger is used as an evaporator or condenser. A seal unit is formed by assembling two heat exchangers into a vacuum tight container and is connected to the surroundings only by hydraulic piping. Moreover, the adsorbent is a functional adsorbent material-zeolite (AQSOA FAM-Z02, Mitsubishi Plastics) which can be regenerated by utilizing the low-temperature heat energy between 75 and 100°C. In this paper the design and experimental performance of this all-in-one type adsorption heat pump are described.


Author(s):  
Mohammed Mostafa Abdulghafoor ◽  
Raed Abdulkareem Hasan ◽  
Zeyad Hussein Salih ◽  
Hayder Ali Nemah Alshara ◽  
Nicolae Tapus

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