Sustainable District Cooling Guidelines
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Overview of Chiller Compressors
Overview of Chiller Compressors Course No: M04-027 Credit: 4 PDH A. Bhatia Continuing Education and Development, Inc. 22 Stonewall Court Woodcliff Lake, NJ 07677 P: (877) 322-5800 [email protected] OVERVIEW OF CHILLER COMPRESSORS Overview In HVAC industry, the refrigeration machine that produces chilled water is referred to as a “Chiller”. A chiller package operates either on the principles of vapor compression or vapor absorption. The vapor compression system uses mechanical energy in the form of electric motor to drive the cooling cycle whereas absorption chillers use heat to drive the process. The vapor compression chiller system, which is far more prominent in commercial buildings, consists of four major components: the compressor, evaporator, condenser and expansion device all packaged as a single unit. The classification of vapor compression chiller packages is generally by the type of compressor: centrifugal, reciprocating, and screw being the major ones. Chillers are the largest consumer of energy in a commercial building and it is therefore important to understand the relative benefits and limitations of various types in order to make the right economic decisions in chiller installation and operation. This course will talk about the type of compressor used in the water cooled chiller. The course is divided into 3 parts: Part - I: Types of Chiller Compressors Part – II: Comparison of Chiller Compressors Part –III: Economic Evaluation of Chiller Systems PART I - TYPES OF CHILLER COMPRESSORS Most cooling systems, from residential air conditioners to large commercial and industrial chillers, employ the refrigeration process known as the vapor compression cycle. At the heart of the vapor compression cycle is the mechanical compressor. -
Fifth-Generation District Heating and Cooling Substations: Demand Response with Artificial Neural Network-Based Model Predictive Control
energies Article Fifth-Generation District Heating and Cooling Substations: Demand Response with Artificial Neural Network-Based Model Predictive Control Simone Buffa 1,*, Anton Soppelsa 1 , Mauro Pipiciello 1, Gregor Henze 2,3,4 and Roberto Fedrizzi 1 1 Eurac Research, Institute for Renewable Energy, Viale Druso 1, 39100 Bolzano, Italy; [email protected] (A.S.); [email protected] (M.P.); [email protected] (R.F.) 2 Department of Civil, Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, CO 80309-0428, USA; [email protected] 3 National Renewable Energy Laboratory, Golden, CO 80401, USA 4 Renewable and Sustainable Energy Institute, Boulder, CO 80309, USA * Correspondence: simone.buff[email protected]; Tel.: +39-0471-055636 Received: 16 July 2020; Accepted: 11 August 2020; Published: 21 August 2020 Abstract: District heating and cooling (DHC) is considered one of the most sustainable technologies to meet the heating and cooling demands of buildings in urban areas. The fifth-generation district heating and cooling (5GDHC) concept, often referred to as ambient loops, is a novel solution emerging in Europe and has become a widely discussed topic in current energy system research. 5GDHC systems operate at a temperature close to the ground and include electrically driven heat pumps and associated thermal energy storage in a building-sited energy transfer station (ETS) to satisfy user comfort. This work presents new strategies for improving the operation of these energy transfer stations by means of a model predictive control (MPC) method based on recurrent artificial neural networks. The results show that, under simple time-of-use utility rates, the advanced controller outperforms a rule-based controller for smart charging of the domestic hot water (DHW) thermal energy storage under specific boundary conditions. -
4. Hvac and Refrigeration System
4. HVAC AND REFRIGERATION SYSTEM Syllabus HVAC and Refrigeration System: Vapor compression refrigeration cycle, Refrigerants, Coefficient of performance, Capacity, Factors affecting Refrigeration and Air conditioning system performance and savings opportunities. Vapor absorption refrigeration system: Working principle, Types and comparison with vapor compression system, Saving potential 4.1 Introduction The Heating, Ventilation and Air Conditioning (HVAC) and refrigeration system transfers the heat energy from or to the products, or building environment. Energy in form of electricity or heat is used to power mechanical equipment designed to transfer heat from a colder, low-ener- gy level to a warmer, high-energy level. Refrigeration deals with the transfer of heat from a low temperature level at the heat source to a high temperature level at the heat sink by using a low boiling refrigerant. There are several heat transfer loops in refrigeration system as described below: Figure 4.1 Heat Transfer Loops In Refrigeration System In the Figure 4.1, thermal energy moves from left to right as it is extracted from the space and expelled into the outdoors through five loops of heat transfer: – Indoor air loop. In the leftmost loop, indoor air is driven by the supply air fan through a cool- ing coil, where it transfers its heat to chilled water. The cool air then cools the building space. – Chilled water loop. Driven by the chilled water pump, water returns from the cooling coil to the chiller’s evaporator to be re-cooled. – Refrigerant loop. Using a phase-change refrigerant, the chiller’s compressor pumps heat from the chilled water to the condenser water. -
Performance Prediction of a Solar District Cooling System in Riyadh, Saudi T Arabia – a Case Study ⁎ G
Energy Conversion and Management 166 (2018) 372–384 Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman Performance prediction of a solar district cooling system in Riyadh, Saudi T Arabia – A case study ⁎ G. Franchini , G. Brumana, A. Perdichizzi Department of Engineering and Applied Sciences, University of Bergamo, 5 Marconi Street, Dalmine 24044, Italy ARTICLE INFO ABSTRACT Keywords: The present paper aims to evaluate the performance of a solar district cooling system in typical Middle East Solar cooling climate conditions. A centralized cooling station is supposed to distribute chilled water for a residential com- District cooling pound through a piping network. Two different solar cooling technologies are compared: two-stage lithium- Parabolic trough bromide absorption chiller (2sABS) driven by Parabolic Trough Collectors (PTCs) vs. single-stage lithium-bro- Absorption chiller mide absorption chiller (1sABS) fed by Evacuated Tube Collectors (ETCs). A computer code has been developed Thermal storage in Trnsys® (the transient simulation software developed by the University of Wisconsin) to simulate on hourly basis the annual operation of the solar cooling system, including building thermal load calculation, thermal losses in pipes and control strategy of the energy storage. A solar fraction of 70% was considered to size the solar field aperture area and the chiller capacity, within a multi-variable optimization process. An auxiliary com- pression chiller is supposed to cover the peak loads and to be used as backup unit. The two different solar cooling plants exhibit strongly different performance. For each plant configuration, the model determined the optimal size of every component leading to the primary cost minimization. -
How Does a Recirculating Chiller Do Heating?
How does a Recirculating Chiller do Heating? Mitchell Howard, Technical Manager March 2019 © Applied Thermal Control 2019 What is this guide for? To explain how ATC’s chillers can heat as well as cool. • Heat of compression adds energy to refrigerant • Act of compression itself causes temperature to rise. • Electrical energy input to compressor enters refrigerant through conduction as refrigerant circulates. • Hot Gas Bypass (HGB) capacity control • Instead of allowing hot gaseous refrigerant to pass into the condenser to do conventional refrigeration, it is redirected into the evaporator via a discharge bypass valve (DBV or HGBV). 2 © Applied Thermal Control 2019 Reverse-Carnot Cycle Thermodynamic model used when chiller cools. 6 5 4 7 1. Compressor suction port draws refrigerant in. 2. Compression increases pressure and heat. 3. Sensible cooling begins at the condenser. 4. Sensible cooling completed; state change starts. 3 5. State change in condenser –constant temp and pressure 6. Latent cooling completed; further sensible cooling to point 7 ensures liquid supply. This is subcooling. 7. Expansion process begins at the inlet to TEV. 8 2 8. Expansion is achieved by reducing pressure through a Pressure tiny orifice. Low pressure and temperature seen at outlet. 9. Inlet to evaporator provided with refrigerant already going 9 1 through state change. 10. Boiling (evaporation) process continues in the evaporator. 11. Liquid cannot be compressed; additional sensible heating 10 11 applied before gaseous refrigerant can enter compressor. This is known as superheat. Heat Content (Enthalpy) (Energy per unit Mass) 3 © Applied Thermal Control 2019 Why does a compressor heat? Due to isentropic compression and electric motor inefficiency. -
District Cooling Systems
DEPARTMENT OF TECHNOLOGY AND BUILT ENVIRONMENT TECHNOLOGICAL AND ECONOMIC EVALUATION OF DISTRICT COOLING WITH ABSORPTION COOLING SYSTEMS IN GÄVLE (SWEDEN) Elixabet Sarasketa Zabala June 2009 Master’s Thesis in Energy Systems uuir Master Programme in Energy Systems Examiner: Ulf Larsson Supervisor: Åke Björnwall Preface This investigation, as final Thesis Project of Master in Energy Systems (University of Gävle), was started to carry out in February, in collaboration with the company Gävle Energi AB. Many people have been involved answering my questions, providing me with information and so forth; some of those are mentioned below. First of all, I would like to thank Åke Björnwall, my supervisor at Gävle Energi AB, very much for his attention, help and support. His knowledge, comments, guidance and advices have been essential for the development of my work. Needless to say that I have learnt a lot from him. Secondly, I would like to thank the rest of workers at Gävle Energi AB, who have done everything they can to help me, in addition to make pleasant my stay in the company. I would also like to thank Ulf Larsson at the University of Gävle for his help. Furthermore, I am very grateful for all information I have received from other companies. Finally, I do not forget the invaluable support of my mother, Rosa, during all my studies. No one mentioned, no one forgotten. Gävle, June 2009 Elixabet Sarasketa Zabala Abstract Gävle Energi AB is a company which produces electricity as well as heat that is delivered through a district heating network in the municipality of Gävle. -
AAON Chiller Controls
www.AAON.com CHILLER CONTROLS The AAON Chiller Controllers are designed to maximize the capabilities of the AAON LF, LN, and LZ Series premium performance chiller products. These chiller controls are designed, engineered, and supported by AAON. Benefits • Sequences Fully Tested to Ensure High Performance Operation • Part of the Orion Controls System, compatible with AAON VCCX2 Rooftop Unit Controller • Prism 2 Software Interface for setup and configuration • LCD Displays on the Main Chiller Controller and Associated Modules for Status and Diagnostics • Factory Installed Touch Screen PC Interface is Available for Large Chiller Systems • BTL Certified BACnet MS/TP Interface AAON DESIGNED, ENGINEERED AND SUPPORTED CHILLER CONTROLS CHILLER CONTROLLER FEATURES The AAON Controllers can control chillers and outdoor mechanical rooms with pumping packages, waterside economizers, boilers, and vestibule conditioning. Each Chiller Main Controller and associated Modules have an LCD display for Status and Diagnostics, works with Prism 2 Software for full setpoint and configuration, and is BTL BACnet MS/TP certified. INCLUDED ON AAON EQUIPMENT LF SERIES CHILLER º LF Chiller Controls used with On/Off and Variable Capacity Scroll Compressor Systems LF CHILLER CONTROLLER º DX Barrel Chiller Controls used with VFD Controlled Compressor Systems LF CHILLER CONTROLLER LN SERIES CHILLER º DX Barrel Chiller Controls used with STANDARD FEATURES VFD Controlled Compressor Systems º Controls 1 or 2 Circuit DX Chillers LZ SERIES CHILLER - Single or Tandem Compressors -
District Energy Enters the 21St Century
TECHNICAL FEATURE This article was published in ASHRAE Journal, July 2015. Copyright 2015 ASHRAE. Posted at www.www.burnsmcd.com .org. This article may not be copied and/or distributed electronically or in paper form without permission of ASHRAE. For more information about ASHRAE Journal, visit www.ashrae.org. District Energy Enters The 21st Century BY STEVE TREDINNICK, P.E., MEMBER ASHRAE; DAVID WADE, P.E., LIFE MEMBER ASHRAE; GARY PHETTEPLACE, PH.D., P.E., MEMBER ASHRAE The concept of district energy is undergoing a resurgence in some parts of the United States and the world. Its roots in the U.S. date back to the 19th century and through the years many technological advancements and synergies have developed that help district energy efficiency. This article explores district energy and how ASHRAE has supported the industry over the years. District Energy’s Roots along with systems serving groups of institutional build- District energy systems supply heating and cooling ings, were initiated and prospered in the early decades to groups of buildings in the form of steam, hot water of the 1900s and by 1949 there were over 300 commercial or chilled water using a network of piping from one or systems in operation throughout the United States. Of more central energy plants. The concept has been used course, systems in the major cities of Europe also gained in the United States for more than 140 years with the favor in Paris, Copenhagen and Brussels. In many cases first recognized commercial district energy operation district steam systems were designed to accept waste originating in Lockport, N.Y. -
Production of District Heating, District Cooling, Electricity and Biogas Our
Our dream – a city free from fossil fuels Application – First Global District Energy Climate Awards Production of district heating, district cooling, electricity and biogas Borås Energi och Miljö AB, Sweden Borås Energi och Miljö AB, is a municipally owned company and part of Borås Stadshus AB. Contact: Jonas Holmberg – Head of Marketing, +46 33 35 72 20, [email protected] www.borasenergimiljo.se Part of Borås Stadshus AB Borås is Sweden’s 13th largest municipally. Around 64,000 people live in Borås City, and over 100,000 The accumulator tank. throughout the municipality. Borås Energi och Miljö AB (BEM) is a municipally owned company that handles refuse and the production of district heating, cooling and electricity in the municipality of Borås. The company has a vision of a city free from fossil fuels. BEM runs a number of facilities and services, all of which contribute to the reduction of greenhouse gas emissions in one way or another. The term “emissions” used in thes document usally refers to greenhouse gases. First off, please watch our company movie for a quick tour of our company. Click here to watch the movie. We harness all energy streams Whenever they sort their household waste, travel on Today Borås City is a pioneer when it comes to working biogas buses, relax at home with comfortable district in harmony with the biological cycle, and we look on heating or spend time at an office with pleasant district combustible household refuse as a valuable energy cooling, the inhabitants of Borås play an important role resource – energy that would otherwise be wasted. -
Expert Chiller and Boiler Repair and Servicing Is an EMCOR Services
Chiller & Boiler Services -Customized preventive CHILLER AND BOILER maintenance programs SERVICE AND REPLACEMENT: -Chiller services and retrofits -Boiler and burner repair Expert chiller and boiler and maintenance -Cooling tower replacements repair and servicing is an and upgrades -Design/Build EMCOR Services Aircond specialty. -Automated Controls -Water Treatment With decades of expertise, from the waterside to the controls, our factory- trained and state-certified chiller and boiler technicians are equipped to perform emergency service, preventive, and contract maintenance and repairs for all commercial and industrial properties to help maintain reliable operation of their equipment. Chiller Service and Replacement When properly maintained, chillers not only provide critical comfort needs to the people and the equipment in the buildings but also help reduce your operation costs through increased energy efficiency when properly maintained. EMCOR Services Aircond’s EPA and factory-certified experts are your resource for comprehensive, high-quality chiller services. And since we’re brand neutral, we have vast experience servicing machines from all manufacturers. Our services include: » Centrifugal Chillers » Refrigerant conversion » Water/Air-Cooled Screw Chillers » Retubing » Scroll Air-Cooled Chillers » System & equipment retrofits By combining the proper chemicals with experienced technical services, we » Reciprocating Chillers » Tube cleaning help keep your cooling systems free of » Absorption Chillers » Non-destructive testing, including: corrosion and mineral deposits, as well » Medical Chillers - Eddy current tube analysis as bacteriological and organic fouling. » Chiller Rentals - Infrared scanning The result is maximum performance, » Refrigerant Management - Refrigerant analysis reliability and value. » Cooling Towers - Spectrographic oil analysis » Refrigeration - Vibration analysis » Process Piping Boiler Service and Replacement Consider servicing, upgrading or replacing your boilers to eliminate any possible downtime. -
Solar Cooling Used for Solar Air Conditioning - a Clean Solution for a Big Problem
Solar Cooling Used for Solar Air Conditioning - A Clean Solution for a Big Problem Stefan Bader Editor Werner Lang Aurora McClain csd Center for Sustainable Development II-Strategies Technology 2 2.10 Solar Cooling for Solar Air Conditioning Solar Cooling Used for Solar Air Conditioning - A Clean Solution for a Big Problem Stefan Bader Based on a presentation by Dr. Jan Cremers Figure 1: Vacuum Tube Collectors Introduction taics convert the heat produced by solar energy into electrical power. This power can be “The global mission, these days, is an used to run a variety of devices which for extensive reduction in the consumption of example produce heat for domestic hot water, fossil energy without any loss in comfort or lighting or indoor temperature control. living standards. An important method to achieve this is the intelligent use of current and Photovoltaics produce electricity, which can be future solar technologies. With this in mind, we used to power other devices, such as are developing and optimizing systems for compression chillers for cooling buildings. architecture and industry to meet the high While using the heat of the sun to cool individual demands.” Philosophy of SolarNext buildings seems counter intuitive, a closer look AG, Germany.1 into solar cooling systems reveals that it might be an efficient way to use the energy received When sustainability is discussed, one of the from the sun. On the one hand, during the time first techniques mentioned is the use of solar that heat is needed the most - during the energy. There are many ways to utilize the winter months - there is a lack of solar energy. -
District Cooling Concepts Applied in China.”
“District Cooling Concepts applied in China.” Bernt Andersson District Cooling 2016 a Climate Solution Dubai, November 2016 [email protected] District Cooling Very limited development of District Cooling systems, first systems developed early 2000; Standard approach for cooling is split units for apartments and building or block level chilled water plants; Indoor design temperature is +26 C (77 F) For District Cooling systems a combination of compression chillers, absorption chillers and Ice Thermal Energy Storage are common; Almost all District Cooling plants with Ice Thermal Energy Storage have dual duty, single evaporator chillers and large heat exchangers between the glycol circuit and chilled water circuit for day time operation as well as heat exchangers between the Ice Thermal Energy Storage and the chilled water circuit; In almost all cases where both District Heating and District Cooling are developed the pipe network is two pipe system that are used for heat supply in winter and cooling supply in the summer; [email protected] Mean Monthly Temperature Climate Zones Coldest Hottest Severe Cold ≤ -10 °C ≤ 25 °C Cold -10–0 °C 18–28 °C Temperate 0–13 °C 18–25 °C Hot Summer and Cold Winter 0–10 °C 25–30 °C Hot Summer and Warm Winter > 10 °C 25–29 °C Source: Berkely Labs [email protected] Compression Chillers with Ice Thermal Energy Storage Concepts Best Practice Dual duty chillers with two evaporators where the chilled water evaporator is connected in series with the directly connected Thermal