EVALUATION OF SMART BOOSTER FANS AND DAMPERS FOR ADVANCED HVAC SYSTEMS

ABSTRACT There is potential to significantly reduce CO2 emissions by increasing the efficiency and reducing the duty cycle of HVAC systems by using smart booster fans and dampers. Smart booster fans fit in the vents within a home, operating quietly on low power (2W) to augment HVAC systems and improve their performance. In this study, a prototype duct system is used to measure and evaluate the ability for smart booster fans and dampers to control airflow to different vents for the purpose of increasing the efficiency of HVAC systems. Four case studies were evaluated: an HVAC system (1) without any fans or dampers, (2) with a fan installed in one vent, but without any dampers, (3) with dampers installed at the vents, but without any fans, and (4) with both fan and dampers installed. The results from both the experimental and numerical evaluation show that the smart booster fan and dampers can significantly improve the airflow at a vent that is underperforming. For example, the airflow at the last vent in a ducting branch was increased from 17 to 37 CFM when a smart booster fan was installed at this vent. Results from the numerical analysis show that for the case of an underperforming vent during the winter season the HVAC running time may be reduced from 24 hr/day to 5.6 hr/day. Furthermore, results from the numerical analysis show the HVAC running time is further reduced to 4.5 hr/day for cases 3 and 4.

The Heat-Dissipation and Dehumidification System of the Hybrid Multi-Layer Gravity Heat Pipe Applied to Granary

Based on the basic working principle and heat transfer characteristics of gravity heat pipe in combination with the grain stack particle's stacking characteristics, this study changes the structure of traditional heat pipe to change the heat transfer mode between the grain stack and the gravity heat pipe so as to improve the grain's heat-dissipation rate and heat-dissipation efficiency. Generally, this system can satisfy the internal heat dissipation requirements of grain stack only under the action of a non-power fan driven by the air in the atmosphere and the temperature difference between inside and outside of the fan. When the internal temperature sensor of the grain stack detects that the internal temperature of the grain stack is high only under the action of the non-power fan, the pipeline booster fan will be started. At the same time, when the gas exchange occurs between the internal gas in grain stack and the external air, the dehumidification and drying of the grain stack can be realized through the gas drying device of the product. Through theory and simulation, this paper conducts a comparative analysis on the variation law of grain stack's temperatures under the action of gravity heat pipe and no gravity heat pipe so as to explore the heat-dissipation system's working efficiency of the new structure gravity heat pipe. The gravity heat pipe and the non-power fan in the system are all green products, which makes this design product have better heat-dissipation effect and less energy consumption.

Perancangan Pengkondisian Udara pada Ruangan Steril Rumah Sakit Mitra Medika dengan Standard Cleanroom Menggunakan Instalasi Ducting

Desain penyejuk udara juga dapat diterapkan di bidang kesehatan, dengan standar Cleanroom dapat diperoleh suhu, kelembaban, kenyamanan dan kebersihan yang dibutuhkan untuk ruang steril (ruang bedah). Perancangan pendingin udara dalam hal ini dilakukan dengan menentukan beban pendinginan yang diperlukan untuk ruang steril (ruang bedah), kemudian menentukan ukuran ducting, jalur ducting, dan jumlah penggunaan ducting. Desain ini menggabungkan unit split saluran yang dimodifikasi, kipas booster, filter pra, filter medium, dan filter HEPA dengan menggunakan saluran aluminium preinsulated sebagai saluran udara. Desain dilakukan dengan menggunakan perangkat lunak AutoCAD 2012, Design Tools Duct Sizer, dan Microsoft Excel. Dari hasil perhitungan dan desain didapatkan kebutuhan kapasitas 3 ruang bedah yaitu ducted ducted 100.000 BTUH sebanyak 3 unit, booster fan 3.3 - 4 Di WG sebanyak 3 unit, pre filter 24 "x 24" x 2 "6 set, filter menengah 610 x 610 x 290 mm 6 set, dan filter HEPA 1220 x 610 x 70 mm 12. Untuk ruang steril, tekanan statis yang dihasilkan oleh unit pendingin harus lebih besar daripada tekanan statis yang dihasilkan dari unit yang ada. di ruang semi steril. Dengan kata lain, ruang steril harus memiliki tekanan positif terhadap ruang semi steril. Hal ini dimaksudkan agar udara di ruang semi steril tidak masuk ke ruang steril ketika pintu antar ruangan dibuka. Desain dan perhitungan ruang bedah, suhu nyata yang diperoleh adalah 23 ° C ± 2 ° C dan kelembaban relatif yang diperoleh adalah 60% ± 2%. Air conditioning design can also be applied in the health field, with cleanroom standard can be obtained temperature, humidity, comfort and hygiene needed for sterile room (surgical room). The design of air conditioning in this case is done by determining the cooling load required for the sterile room (surgical room), then determining the ducting size, ducting path, and the amount of ducting usage. This design combines modified ducted split unit, booster fan, pre filter, medium filter, and HEPA filter by using preinsulated aluminum duct as an air passage. The design is done by using AutoCAD 2012 software, Design Tools Duct Sizer, and Microsoft Excel. From the calculation and design result obtained the capacity requirement of 3 surgical room that is split ducted 100.000 BTUH as many as 3 units, booster fan 3.3 - 4 In WG as many as 3 units, pre filter 24"x 24" x 2" 6 sets, medium filter 610 x 610 x 290 mm 6 sets, and HEPA filter 1220 x 610 x 70 mm 12 sets. For the sterile room, the static pressure generated by the cooling unit shall be larger than the static pressure generated from the unit present in the semi sterile room. In other words, the sterile room must have positive pressure to the semi sterile room. It is intended that the air in the semi sterile room does not enter into the sterile room when the door between room opened. In this surgical room design and calculation, real temperature obtained is 23 °C ± 2 °C and the relative moisture obtained is 60% ± 2%.

The Energy-Saving Retrofit of Axial Fan Based on Performances Test in a 300MW Unit

In a power plant of 300MW, the power consumption of its axial Induced Draft Fan (IDF) and Flue Gas Desulfurization (FGD) booster fan was high on the whole. So it is necessary to take measures to reduce the power consumption by energy-saving retrofit. Firstly, a series of test and optimization are carried out on its operational performances. Furthermore, several retrofit schemes are worked out. Then, based on a series of test about its operational characters, an evaluation on potential to save energy is carried out for the IDF and the FGD booster fan. Finally, according to the comprehensive analysis including technical economic, difficulty and reliability, it is of the best scheme to carry out the frequency conversion retrofit for IDF. In fact, its effect is good after the retrofit is conducted, namely, the energy-saving index is almost the same as from evaluation. Obviously, the evaluation as for performance test is quite accurate and can avoid several problems likely to occur in frequency conversion retrofit.

Problem and Solution of Frequency Conversion Transformation on Axial FGD Booster Fan in 600MW Unit

in 600 MW unit of a certain power company, the frequency conversion transformation on an axial FGD booster fan had been done, but it was found that have only little energy-saving effect and the investment recovery period would be very long. Based on performance characteristics test, the reason of this problem was analyzed. It shows that the transformation scheme in effect is unsuitable. The optimized scheme was proposed and suggesting good effect through energy-saving estimate. The company implemented optimization and then found the energy-saving index is almost the same as estimate. This problem is representative for frequency conversion transformation of fans, it can be avoided through performance characteristics test and energy-saving estimate before transformation.

Diagnosis and Treatment of Misalignment for a Desulfurization

After changing the bearing box on a desulfurization booster fan, its horizontal vibration value is over 185μm beyond the standard. Through the test, it is decided that fan diaphragm coupling misalignment is the main reason for vibration. The vibration eliminates after readjusting the center.