المعدات والأنظمة
Thermal Storage (HVAC)
Thermal energy may be stored in three main ways: – Sensible Storage – Latent Storage – Thermo-Chemical Storage. In addition, the two common thermal storage strategies employed are: – Load Levelling Strategy – Load Shifting Strategy
Variable Refrigerant Flow (VRF) Benefits
VRF systems are available either as heat pump systems or as heat recovery systems for those applications where simultaneous heating and cooling is required. In addition to providing superior comfort, VRF systems offer design flexibility, energy savings, and cost effective installation. A VRF system offers flexible installation and energy-saving cooling and heating comfort and should be considered as an alternative to traditional systems for those applications where zoning or part load operation is required.
Hydropneumatic Tank Sizing
Hydropneumatic tanks are primarily used in a domestic water system for draw down purposes when the pressure booster system is off on no-flow shutdown (NFSD). The NFSD circuitry turns the lead pump off when there is no demand on the system. While the system is off in this condition, the hydropneumatic tank will satisfy small demands on the system. Without the tank, the booster would restart upon the slightest call for flow such as a single toilet being flushed or even a minute leak in the piping system. Hydropneumatic tank sizing is dependent on two factors: – Length of time you wish the pumps to remain off in a no-flow situation. – The tank location in relation to the pressure booster.
الأنابيب النموذجية لتسخين البخار
The piping and radiator connections shown in this section are diagrammatic and illustrate the proper method of making piping connections in steam heating processes. – Two pipe steam systems radiator connections – Piping connections for unit heaters (steam) – Two pipe– #steam trap installations – Two Pipe Steam Systems Convector Connections – Exposed #Pipe #Coils– Two Pipe Steam – One pipe #steam systems radiator connections – One pipe steam systems #convector connections – One pipe steam systems convector connections
Refrigerant Piping (Part1)
Good piping design results in a balance between the initial cost, pressure drop, and system reliability. The initial cost is impacted by the diameter and layout of the piping. The pressure drop in the piping must be minimized to avoid adversely affecting performance and capacity. Because almost all field-piped systems have compressor oil passing through the refrigeration circuit and back to the compressor, a minimum velocity must be maintained in the piping so that sufficient oil is returned to the compressor sump at full and part load conditions. Several HVAC systems require field refrigeration piping to be designed and installed on-site. Examples include Condensing units, Direct expansion (DX) coil in air handlers, Remote evaporators with air-cooled chillers and Chiller with a remote air-cooled condensers. This Guide covers R-22, R-407C, R-410A, and R-134a used in commercial air conditioning systems.
Datacenter Liquid Cooling Methods
A variety of liquids could be considered for Data Center applications. When liquids are employed within separate cooling loops that do not communicate thermally, the system is considered to be air cooling. The most obvious illustration covers the chilled-water CRACs that are usually deployed at the periphery of many of today’s data centers. At the other end of the scale, the use of heat pipes or pumped loops inside a computer, wherein the liquid remains inside a closed loop within the server, also qualifies as air-cooled electronics, provided the heat is removed from the internal closed loop via airflow through the electronic equipment chassis.
صيانة وتنظيف الفولاذ المقاوم للصدأ
Stainless steel provides its superior corrosion resistance by developing a surface film of chromium oxide during the manufacturing process. In order to ensure maximum corrosion protection, stainless steel must be kept clean and have an adequate supply of oxygen to combine with the chromium in the stainless steel to form “chromium-oxide”, a protective passivation layer. Stainless steel is the most cost effective material of construction available to extend the life of a cooling tower, closed circuit cooler or evaporative condenser in HVAC-R industry.
Cooling Towers (Free Cooling Operation)
Cooling towers are used to dissipate heat from air conditioning or industrial process systems. Many of the air conditioning systems currently in use only operate during the summer cooling season, but there are numerous air conditioning and process systems that require cooling year-round. In some cases, the entire cooling system is required to operate during the winter. The cooling tower is required to provide the same 85° F (30° C) or colder water to the system as it does in the summer, but it does so at lower ambient temperatures. However, there are some applications designed to use the cooling tower for “free cooling”. Free cooling is when chilled water is cooled by cooling tower water through the use of heat exchangers without the use of refrigerant compressors. Free cooling can be accomplished when ambient conditions allow the cooling tower to produce “chilled water” for the system.
Cooling Towers (Capacity Control)
يمكن لأنظمة التبريد المجانية أن تحقق وفورات كبيرة لأصحاب هذه الأنظمة. ومع ذلك، فإن مقدار التوفير المحتمل في الطاقة المتاح يعتمد بشكل كامل تقريبًا على التصميم العام للنظام وعلى اختيار المعدات المستخدمة في النظام. بشكل عام، يجب على المصمم أن يوازن بين تكلفة المعدات الأعلى وفرص أكبر لتوفير الطاقة. ولحسن الحظ، فإن هذه الوفورات - والتكاليف المرتبطة بها - قابلة للقياس الكمي بشكل معقول حتى يتمكن المصممون من اتخاذ خيارات ذكية مسترشدة بمعلومات موثوقة. سوف تصف هذه المقالة طرق التحكم في السعة في مخططات تصميم التبريد المجانية.
Constant Air Volume (CAV) Systems
HVAC air systems can be either centralized or decentralized. Centralized air systems receive their cooling and heating energy from a remote central plant. Decentralized HVAC air systems contain the central heating and cooling plant equipment within the air system itself. HVAC air systems can also be constant air volume (CAV) or variable air volume (VAV). CAV systems deliver constant supply airflow at a variable temperature. VAV systems deliver variable supply airflow at a constant temperature. CAV and VAV air systems can be further subdivided into systems that condition a single temperature zone and systems that condition multiple temperature zones.
الضوابط والأتمتة
التبريد السائل المباشر إلى الشريحة: مستقبل الإدارة الحرارية لمراكز البيانات عالية الكثافة
ارتفعت كثافة طاقة مركز البيانات إلى 12-30 كيلووات لكل حامل، مما يجعل التبريد بالسوائل ضروريًا. تعرف على كيفية عمل أنظمة التوصيل المباشر بالرقاقة أحادية الطور وثنائية الطور، ومعايير اختيار مادة التبريد، واعتبارات التصميم الحاسمة للخراطيم والأنابيب والوصلات في مراكز البيانات الحديثة عالية الكثافة.
مخططات التحكم في التدفئة والتهوية وتكييف الهواء (HVAC).
في منشور المدونة هذا، سنقدم بعضًا من مخططات التحكم في التدفئة والتهوية وتكييف الهواء (HVAC) الأكثر شيوعًا. وسنقدم أيضًا شرحًا موجزًا لكل مخطط وكيفية عمل مكوناته معًا. تعد مخططات التحكم في التدفئة والتهوية وتكييف الهواء (HVAC) أدوات أساسية لتصميم أنظمة التدفئة والتهوية وتكييف الهواء (HVAC) وتركيبها وصيانتها. وهي توفر تمثيلاً مرئيًا لمكونات النظام وكيفية ترابطها وكيفية التحكم فيها. يمكن استخدام هذه المعلومات لاستكشاف المشكلات وإصلاحها وتحسين الأداء واتخاذ قرارات مستنيرة بشأن ترقيات النظام.