HVAC Water Chillers and Cooling Towers ( Free E-Book )
Introductions
There are two fundamental types of HVAC systems designed to satisfy building cooling requirements: direct expansion (DX) systems, in which there is direct heat exchange between the building air and the refrigerant, and secondary refrigerant systems that utilize chilled water as an intermediate heat exchange medium to transfer heat from the building air to the refrigerant.
Chilled water systems are the heart of central HVAC cooling, providing cooling throughout a building or group of buildings from one source. Centralized cooling offers numerous operating, reliability, and efficiency advantages over individual DX systems and, on a life-cycle basis, can have significantly lower total cost.
Every central HVAC cooling system is made up of one or more refrigeration machines, or water chillers, designed to collect excess heat from buildings and reject that heat to the outdoor air. The water chiller may use the vapor compression refrigeration cycle or the absorption refrigeration cycle.
Vapor compression refrigeration compressors may be of the reciprocating, helical screw, or centrifugal type with electric or gas-fired engine prime movers.
The heat collected by the water chiller must be rejected to the atmosphere. This waste heat can be rejected by air-cooling, in a process that transfers heat directly from the refrigerant to the ambient air, or by water-cooling, a process that uses water to collect the heat from the refrigerant and then to reject that heat to the atmosphere. Water-cooled systems offer advantages over air-cooled systems, including smaller physical size, longer life, and higher operating efficiency. The success of their operation depends, however, on the proper sizing, selection, application, operation, and maintenance of the cooling tower.
Thus, the goal of this book is to provide the HVAC designer, the building owner and his operating and maintenance staff, the architect, and the mechanical contractor with definitive and practical information and guidance relative to the application, design, purchase, operation, and maintenance of water chillers and cooling towers. The first half of the book discusses water chillers and the second half addresses cooling towers.
Each of these two topics is treated in separate sections, each of which is divided into three basic parts: Fundamentals (Part I) presents the basic information about systems and equipment. How they work and their various components are described and discussed.
In Design and Application (Part II), equipment sizing, selection, and application are discussed. In addition, the details of piping, control, and water treatment are presented. Finally, special considerations such as noise control, electrical service, fire protection, and energy efficiency are examined.
Finally, Operations and Maintenance (Part III) takes water chillers and cooling towers from commissioning through routine maintenance. Chapters on purchasing equipment include guidelines and recommended specifications for procurement.
This is not an academic textbook, but a book designed to be useful on a day to- day basis and provide answers about water chiller and cooling tower use, application, and problems. Extensive checklists, design and troubleshooting guidelines, and reference data are provided.
https://drive.google.com/file/d/1Krs-IwbbOGWILDeVz0UxxJPL6MIz6xrj/view?usp=sharing
تعليقات
إرسال تعليق