Performance of air source air conditioning water heater using trombone coil dummy condenser with different diameter and pipe length

2020 ◽  
Vol 14 (2) ◽  
pp. 6743-6752
Author(s):  
A. Aziz ◽  
A. Samri ◽  
R. I. Mainil ◽  
A. K. Mainil
Keyword(s):  
Air Conditioning ◽  
Room Temperature ◽  
Cooling Capacity ◽  
Water Circulation ◽  
Hot Water ◽  
Cooling Load ◽  
Water Heater ◽  
Pipe Length ◽  
Coil Diameter ◽  
Compressor Power

The Air Source Air Conditioning Water Heater (ASACWH) performance as an energy source to heat water in the tank using dummy condenser type of trombone coil with different diameter and pipe length without hot water circulation has been investigated. The diameter and length of the dummy condenser pipe are intensely affected by ACWH performance. In this study, cooling capacity, Coefficient of Performance (COP), compressor power and room temperature were evaluated in three types of trombone coil (6.4 mm coil diameter with a length of 7.9 m, 6.4 mm coil diameter with a length of 5.3 m, and 9.5 mm coil diameter with a length of 5.3 m) with different cooling load variation. This study used cooling load with a variation of 0 W, 1000 W, 2000 W, and 3000 W without hot water circulation in the simulation room. It was found that the ASACWH using a pipe with a coil diameter of 6.4 mm and length of 7.9 m performed the highest cooling capacity and COP, and produced more comfortable room temperature than the other two pipes. The results indicated that when the cooling load icreased from 0 W to 3000 W, the compressor power increased by 11.3%, 6.3%, and 9.3%, using the 6.4 mm coil diameter with 7.9 m length, 6.4mm diameter of the coil with 5.3m length and 9.5mm coil diameter with 5.3m length, respectively.

scholarly journals Experimental Investigation of a Split Air Conditioning Using Condensate as Direct Evaporative Cooling

2021 ◽  
Vol 86 (1) ◽  
pp. 140-153
Author(s):  
Azridjal Aziz ◽  
Muhammad Rif’at Syahnan ◽  
Afdhal Kurniawan Mainil ◽  
Rahmat Iman Mainil
Keyword(s):  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Air Conditioner ◽  
Direct Evaporative Cooling ◽  
Compressor Power ◽  
Discharge Pressure ◽  
Air Conditioning Systems

Split air conditioning systems produce reasonable amount of condensate which is usually not utilized and thrown away to the environment. On the other hand, it consumes a lot of energy during operation. The aim of this study is to investigate the improvement of air conditioning systems performance utilizing condensate. A direct evaporative cooling using condensate is incorporated on a 0.74 ton-cooling capacity of split air conditioning to decrease the air temperature before entering the condenser. Performances of the split air conditioning with and without direct evaporative cooling are compared and presented in this paper. The results show that the use of direct evaporative cooling using condensate into the air before passing through the condenser reduces the compressor discharge pressure. The decrease of the condenser pressure led to 4.7% and 7% reduction of power consumption for air conditioner without cooling load and air conditioner with 2000 W cooling load, respectively. The cooling effect and coefficient of performance (COP) increase with the decrease of compressor power. The use of direct evaporative cooling with condensate into the air before entering the condensing system can enhance the system performance and protect the environment.

scholarly journals Thermal Performance Analysis of Low-GWP Refrigerants in Automotive Air-Conditioning System

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Yousuf Alhendal ◽  
Abdalla Gomaa ◽  
Gamal Bedair ◽  
Abdulrahim Kalendar
Keyword(s):  
Air Conditioning ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Exergy Destruction ◽  
Air Conditioning System ◽  
Capacity Coefficient ◽  
Automotive Air Conditioning ◽  
Automotive Air Conditioning System ◽  
Compressor Power ◽  
Low Global Warming Potential

The energy and exergy of low-global warming potential (GWP) refrigerants were investigated experimentally and theoretically. Refrigerants with a modest GWP100 of  ≤ 150 can be sufficient for bringing down emissions which were concerned for the automotive air-conditioning system. Three types of low-GWP refrigerants, R152a, R1234yf, and R1234ze(E), were examined with particular reference to the current high-GWP of R134a. The effect of different evaporating and condensing temperatures in addition to compressor speed was considered. The purpose was to bring a clear view of the performance characteristics of possible environment friendly alternatives of R134a. The analysis was carried out with compressor power, cooling capacity, coefficient of performance, exergy destruction, and exergy efficiency. It was noted that the total exergy destruction of R1234yf was reduced by 15% compared to that of R134a. The refrigerant R1234ze(E) has the highest energetic and exergetic performance compared with the other investigated refrigerants.

Design and Modeling of One Refrigeration Ton Solar Assisted Adsorption Air Conditioning System

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
M. Alkhair ◽  
M. Y. Sulaiman ◽  
K. Sopian ◽  
C. H. Lim ◽  
E. Salleh ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Hot Water ◽  
Activated Carbon Fiber ◽  
Coefficient Of Performance ◽  
Weather Data ◽  
Adsorption System ◽  
Water Storage Tank ◽  
Chilled Water

The modeling of the performance of a one refrigeration ton (RT) solar assisted adsorption air-conditioning refrigeration system using activated carbon fiber/ethanol as the adsorbent/adsorbate pair has been undertaken in this study. The effects of hot water, cooling water, chilled water inlet temperatures, and hot water and chilled water flow rates were taken into consideration in the optimization of the system and in the design of the condenser, evaporator, and hot water storage tank. The study includes analysis of the weather data and its effect on both the adsorption system and the cooling load. This is then followed by estimation of the cooling capacity and coefficient of performance (COP) of the adsorption system as a function of the input parameters. The results of the model will be compared to experimental data in a next step.

scholarly journals ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ КОНДИЦІЮВАННЯ ЗОВНІШНЬОГО ПОВІТРЯ СИСТЕМИ КОМБІНОВАНОГО ТИПУ

2019 ◽  
pp. 9-14
Author(s):  
Євген Іванович Трушляков ◽  
Андрій Миколайович Радченко ◽  
Микола Іванович Радченко ◽  
Сергій Анатолійович Кантор ◽  
Веніамін Сергійович Ткаченко
Keyword(s):  
Heat Load ◽  
Air Conditioning ◽  
Rational Design ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Energetic Efficiency ◽  
Cooling Load ◽  
Air Conditioner ◽  
Outdoor Air ◽  
Air Conditioning System

One of the most attractive reserves of enhancing the energetic efficiency of air conditioning systems is to provide the operation of refrigeration compressors in nominal or close to nominal modes by choosing rational design cooling loads (cooling capacities) and their distribution according to a cooling load behaviour within the overall design (installed) cooling load band to match current changeable climatic conditions and provide close to maximum annual cooling capacity generation according to cooling duties. The direction of increasing the efficiency of outdoor air conditioning in combined central-local type systems by rationally distributing the heat load - cooling capacity of the central air conditioner into zones of variable heat load in accordance with current climatic conditions and its relatively stable value, i.e. cooling capacity required for further air cooling at the entrance to the indoor recirculation air conditioning system is justified. By comparing the values of the excessive production of cold and its deficit within every 3 days for a rational design heat load of the air conditioning system (cooling capacity of the installed refrigeration machine), which provides close to maximum annual production of cold, and the corresponding values of the excess and deficit of cooling capacity in accordance with current climatic conditions during July substantiated the feasibility of accumulating the excess of cooling capacity of a central air conditioner at low current loads and its use for covering cooling deficit at elevated heat loads through pre-cooling the outdoor air. It is developed a scheme of a combined central-local air conditioning system, which includes the subsystems for the outdoor air conditioning in a central air conditioner and the local indoor recirculated air conditioning.

Performance Evaluation of a 4.5 kW (1.3 Refrigeration Tons) Air-Cooled Lithium Bromide/Water Hot-Water-Fired Absorption Unit

2007 ◽  
Author(s):  
Abdolreza Zaltash ◽  
Andrei Petrov ◽  
Randall Linkous ◽  
Edward Vineyard ◽  
David Goodnack ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Air Conditioning ◽  
Cooling Tower ◽  
Lithium Bromide ◽  
Cooling Capacity ◽  
Hot Water ◽  
Next Generation ◽  
Absorption Chiller ◽  
Flow Rates ◽  
Absorption Chillers

During the summer months, air-conditioning (cooling) is the single largest use of electricity in both residential and commercial buildings with the major impact on peak electric demand. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. Thermally activated absorption air-conditioning (absorption chillers) can provide overall peak load reduction and electric grid relief for summer peak demand. This paper describes an innovative absorption technology based on integrated rotating heat exchangers to enhance heat and mass transfer resulting in a potential reduction of size, cost, and weight of the “next generation” absorption units. This absorption chiller (RAC) is a 4.5 kW (1.3 refrigeration tons or RT) air-cooled lithium bromide (LiBr)/water unit powered by hot water generated using the solar energy and/or waste heat. Typically LiBr/water absorption chillers are water-cooled units which use a cooling tower to reject heat. Cooling towers require a large amount of space and increase start-up and maintenance costs. However, RAC is an air-cooled absorption chiller which requires no cooling tower. The purpose of this evaluation is to verify RAC performance by comparing the Coefficient of Performance (COP or ratio of cooling capacity to thermal energy input) and the cooling capacity results with those of the manufacturer. The performance of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled environment at various hot and chilled water flow rates, air handler flow rates, and ambient temperatures. Temperature probes, mass flow meters, rotational speed measuring device, pressure transducers, and a web camera mounted inside the unit were used to monitor the RAC via a web control-based data acquisition system using Automated Logic Controller (ALC). Results showed a COP and cooling capacity of approximately 0.58 and 3.7 kW respectively at 35°C (95°F) design condition for ambient temperature with 40°C (104°F) cooling water temperature. This is in close agreement with the manufacturer data of 0.60 for COP and 3.9 kW for cooling capacity. Future work will use these performance results to evaluate the potential benefits of rotating heat exchangers in making the “next-generation” absorption chillers more compact and cost effective without any significant degradation in the performance. Future studies will also evaluate the feasibility of using rotating heat exchangers in other applications.

scholarly journals Numerical Study of Integrated Solar Photovoltaic–Thermal Module with a Refrigeration System for Air-Conditioning and Hot Water Production under the Tropical Climate Conditions of Singapore

2018 ◽  
Vol 26 (03) ◽  
pp. 1850021 ◽  
Author(s):  
Swapnil Dubey ◽  
Alison Subiantoro
Keyword(s):  
Air Conditioning ◽  
Numerical Study ◽  
Power Saving ◽  
Tropical Climate ◽  
Cooling Capacity ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Solar Photovoltaic ◽  
Refrigeration System ◽  
Climate Conditions

Thermal systems of buildings in the tropics are highly energy intensive. In this study, a novel integrated solar photovoltaic–thermal–refrigeration (PVTR) system used to produce hot water and air-conditioning in the tropical climate conditions of Singapore was analyzed. A dynamic simulation model was formulated for the analysis. Mathematical models were developed for the PV sandwich attached with a solar flat plate collector and for the main components of the refrigeration system. Thorough investigation of the electrical and thermal performances of the system were conducted through the analysis of coefficient of performance (COP), cooling capacity, water temperature and heat capacity in water heater, photovoltaic (PV) module temperature and PV efficiency. The results show that attractive electrical and thermal performance can be achieved with a maximum annual cooling COP of 9.8 and a heating COP of 11.3. The PV efficiency and power saving were 14% and 53%, respectively. The annual cooling, heating and PV energy produced were 9.7, 15.6 and 1.6[Formula: see text]MWh, respectively. The financial payback period of the system was 3.2 years and greenhouse gas (GHG) emission reduction annually was 12.6 tons of CO2 equivalents (tCO2e).

scholarly journals Real Air-Conditioning Performance of Ejector Refrigerator Based Air-Conditioner Powered by Low Temperature Heat Source

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 711
Author(s):  
Tongchana Thongtip ◽  
Natthawut Ruangtrakoon
Keyword(s):  
Heat Source ◽  
Thermal Comfort ◽  
Water Temperature ◽  
Test Performance ◽  
Air Conditioning ◽  
Cooling Water ◽  
Hot Water ◽  
Cooling Load ◽  
Air Conditioner ◽  
Comfort Condition

In this present work, the air-conditioning test performance of an ejector refrigerator-based air-conditioner (ERAC) was proposed. The ERAC was operated as the water chiller to produce the cooling load up to 4.5 kW. The chilled water temperature was later supplied to the fan-coil unit for producing the thermal comfort condition. The cooling water used to cool the condenser was achieved from the cooling tower which was operated under the hot and humid ambient. This is to demonstrate the feasibility of using the ERAC in real working conditions. The cooling load supplied to the air-conditioned space was applied by the air heater. The ERAC could efficiently be operated to produce the thermal comfort condition which was driven by the hot water temperature (Thot) of 90–98 °C. The system performance could vary with the heat source temperatures, cooling load, primary nozzle, and air-conditioned space temperature. The optimal performance was determined when varying the Thot, and, hence, the optimal Thot was indicated. The optimal Thot varied significantly with variations in the working condition. The test results demonstrated high potential to further using the ejector refrigeration system in the actual air conditioning application.

Experimental Research on Air-Conditioning with Supplying Hot-Water

2012 ◽  
Vol 170-173 ◽  
pp. 2541-2545
Author(s):  
Jun Po Zhu ◽  
Ting Xiang Jin
Keyword(s):  
Experimental Research ◽  
Air Conditioning ◽  
Hot Water ◽  
Experimental Results ◽  
Coefficient Of Performance ◽  
Water Heater ◽  
Air Conditioning System ◽  
Static Heating ◽  
Maximum Coefficient ◽  
Heating Mode

This paper developed the air-conditioning system with supplying hot water. The system can work in three modes: only refrigeration, only supplying hot water and refrigeration with supplying hot water. The experimental results showed that the system is more effective than traditional systems, the maximum coefficient of performance (COP) is about 5.34 at refrigeration mode, the COP is 5.78 at static heating mode of heating, and the COP is 4.5 at refrigeration and water heater mode.

INDOOR TEMPERATURE CONTROL AND ENERGY SAVING POTENTIAL OF SPLIT- TYPE AIR CONDITIONING SYSTEM USING FUZZY LOGIC CONTROLLER

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Henry Nasution ◽  
Afiq Aiman Dahlan ◽  
Azhar Abdul Aziz ◽  
Ulul Azmi ◽  
Amirah Haziqah Zulkifli ◽  
...  
Keyword(s):  
Energy Saving ◽  
Temperature Control ◽  
Air Conditioning ◽  
Fuzzy Logic Controller ◽  
Internal Heat ◽  
Cooling Capacity ◽  
Maximum Speed ◽  
Cooling Load ◽  
Air Conditioning System ◽  
Increase Energy Efficiency

Variable speed compressor (VSC) offers a wider range of cooling capacity control according to the cooling load of the system. The on/off controller consumes larger energy as the compressor is always working at maximum speed despites the cooling load and continuously on and off to prevent from over cool the room. This study focused on the implementation of VSC to increase energy efficiency with better temperature control inside the room for split unit air conditioning system. The experiments are done at room temperature of 23 and 24oC with internal heat load of 500 and 1000 W. The proposed system indicates as much 37% of energy saving as compared to on/off controller

A Study of Cooling Load Calculation of Stratified Air Conditioning System for Large Space Based on the Simultaneously Solving Model

2014 ◽  
Vol 672-674 ◽  
pp. 1755-1761 ◽  
Author(s):  
Ning Cai ◽  
Chen Huang
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Cooling Capacity ◽  
Cooling Load ◽  
Large Space ◽  
Air Conditioning System ◽  
Load Calculation ◽  
Environment Experiment ◽  
Wall Surface Temperature

A calculation method for cooling load of stratified air conditioning system based on the simultaneously solving model is presented. Thermal environment experiment under summer condition is carried out in a large space building, indoor air temperature, inner wall surface temperature and cooling capacity were obtained; the stratified air conditioning cooling load calculated by the simultaneously solving model is compared with air conditioning cooling capacity in experiment, the relative error is 14%, taking the loss of cooling capacity and leakage loss, it can be thought that the simultaneously solving model can be used to calculate cooling load of stratified air conditioning system.

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