LAHU Heat Recovery System Optimal Operation and Control Schedules

2005 ◽  
Vol 128 (3) ◽  
pp. 360-366 ◽  
Author(s):  
Yujie Cui ◽  
Mingsheng Liu
Keyword(s):  
Thermal Energy ◽  
Heat Recovery ◽  
Energy Savings ◽  
Pump Energy ◽  
Weather Conditions ◽  
Optimal Operation ◽  
Air Handling Unit ◽  
Recovery System ◽  
Heat Recovery System ◽  
And Control

Optimal operation and control of heat recovery in an integrated Laboratory Air Handling Unit (LAHU) system differs substantially from that in conventional dedicated AHUs for laboratory buildings with a 100% outside air AHU for laboratory spaces, since the LAHU allows economizer operation for both offices and laboratories. Optimal operation and control schedules of the heat recovery systems in the LAHU have been developed to minimize the total thermal energy cost. This paper presents the procedure, methodology, and results of generic optimal heat recovery control schedules for the LAHU and investigates its impact on the LAHU potential thermal and pump energy savings. The optimal control schedule can potentially save 14% to 27% thermal energy and 17% to 100% pump energy during the winter under weather conditions that prevail in Omaha, Nebraska. The findings discussed in this paper also apply to any heat recovery system, where AHU has an economizer function.

Optimal Operation and Control of Heat Recovery System in the Laboratory Air Handling Unit (LAHU) System

Solar Energy ◽  
2004 ◽  
Author(s):  
Yujie Cui ◽  
Mingsheng Liu
Keyword(s):  
Air Temperature ◽  
Heat Recovery ◽  
Extreme Values ◽  
Optimal Schedule ◽  
Electricity Consumption ◽  
Optimal Operation ◽  
Air Handling Unit ◽  
Recovery System ◽  
Heat Recovery System ◽  
And Control

Optimal operation and control of heat recovery in the Laboratory Air Handling Unit (LAHU) system differs from the optimal control and operation schedule used in 100% outside air AHU. In the LAHU system, economizers can be used in both the office section and the laboratory section. An optimal operation and control schedule for the heat recovery systems has been developed by using the first derivative test for local extreme values to minimize the total thermal energy consumption. The schedule turns off the heat recovery system when the outside air temperature is higher than the LAHU free cooling temperature, which is much lower than the AHU discharge air temperature. The optimal schedule actually also reduces the electricity consumption of heat recovery water circulation pump and improves room relative humidity condition. The optimal operation and control schedule developed in the paper also applies to AHUs where economizer is used. The study also found that a heat recovery system may not be necessary for LAHUs under certain conditions.

scholarly journals Primary energy efficiency assessment of a coil heat recovery system within the air handling unit of an operating room

2021 ◽  
Vol 2069 (1) ◽  
pp. 012113
Author(s):  
F J Rey-Martínez ◽  
J F San José-Alonso ◽  
E Velasco-Gómez ◽  
A Tejero-González ◽  
P M Esquivias
Keyword(s):  
Energy Consumption ◽  
Energy Balance ◽  
Thermal Energy ◽  
Heat Recovery ◽  
Energy Savings ◽  
Electric Energy ◽  
Primary Energy ◽  
Recovery System ◽  
Heat Recovery System ◽  
Coil Heat

Abstract Heat recovery systems installed in Air Handling Units (AHUs) are energy efficient solutions during disparate outdoor-to-indoor temperatures. However, they may be detrimental in terms of a primary energy balance when these temperatures get closer, due to the decrease in the thermal energy recovered compared to the global energy consumption required for their operation. AHUs in surgical areas have certain particularities such as their continuous operation throughout the year, the large airflows supplied and the strict exigencies on the supply air quality, avoiding any cross contamination. This work presents the measurements and analysis performed on a coil heat recovery (run-around) loop system installed in the AHU that serves a mixed-air ventilation operating room in a Hospital Complex. A primary energy balance is studied, including the thermal and electric energy savings achieved, considering the electric energy consumption by the recirculation pump and the additional power requirements of fans due to the pressure drop introduced. The obtained value is then used to predict the thermal energy savings achieved by the heat recovery system. Results are extrapolated to the Typical Meteorological Year to provide an order of magnitude of the primary energy and CO2 emissions saved through the operation of the coil heat recovery system.

Effect of the Heat Recovery System to the Performance of Air Handling Unit of a Shopping Centre

2012 ◽  
Author(s):  
Furkan Kelasovali ◽  
Ali Celen ◽  
Nurullah Kayaci ◽  
Ahmet Selim Dalkilic ◽  
Somchai Wongwises
Keyword(s):  
Heat Exchanger ◽  
Energy Saving ◽  
Heat Recovery ◽  
Cooling Capacity ◽  
Capital City ◽  
Shopping Centre ◽  
Air Handling Unit ◽  
Battery Power ◽  
Recovery System ◽  
Heat Recovery System

In today’s world, the efficient use of energy is very important due to short of energy sources. In order to use energy efficiently, some methods/devices have been developed recently. One of them is heat recovery systems which are used for energy saving in the Heating Ventilating and Air Conditioning applications. Air handling units (AHUs) equipped with heat recovery system can be used applications for energy saving. Not only this paper presents information about rotary heat exchangers which is one of the air to air heat recovery systems but also it investigates their effects to system when they are used in an application. In the study, a shopping centre, which is located in the capital city of Turkey, is taken consideration. The shopping centre has an air handling unit having 54567 m3/h fresh air flow rate, 640 kW heating and 41 kW cooling capacity. Calculations are performed for AHU of the shopping centre both equipped with rotary heat exchanger and without rotary heat exchanger. In order to compare performance of AHUs, annual energy saving, initial investment cost, annual operating expenses, payback time and profit parameters are calculated for each month. According to the results, heating battery power in the heating season and cooling battery power in the cooling season is significantly decreased by using heat recovery system and total annual energy saving is calculated as $83,444. Consequently, it is found that the use of rotary heat exchanger improves performance of system in terms of the reduction in required powers and costs.

scholarly journals CFD analysis of a dual heat recovery system

2019 ◽  
Vol 85 ◽  
pp. 02007
Author(s):  
Robert Ştefan Vizitiu ◽  
Gavril Sosoi ◽  
Andrei Burlacu ◽  
Florin Emilian Ţurcanu
Keyword(s):  
Heat Exchanger ◽  
Thermal Energy ◽  
Heat Recovery ◽  
Hot Water ◽  
Heat Transfer Analysis ◽  
Cfd Analysis ◽  
Pipe System ◽  
Recovery System ◽  
Heat Recovery System

This paper presents a CFD Heat Transfer Analysis of an originally designed system for heat recovery in the building sector. The heat exchanger has a dual role, which means it will produce simultaneously hot water and warm air. The key to the efficiency of the heat exchanger is the heat pipe system which recovers thermal energy from residual hot water and transfers it to the secondary agents. The paper includes a case study structured by different mesh distributions and flow regimes. The purpose of the heat exchanger is to reduce the costs of producing thermal energy and to increase the overall energy efficiency of buildings.

Effect of the Heat Recovery System to the Performance of Air Handling Unit of a Workplace

2014 ◽  
Author(s):  
Onur Ali Şenlen ◽  
Ali Celen ◽  
Alican Çebi ◽  
Ahmet Selim Dalkilic ◽  
Somchai Wongwises
Keyword(s):  
Heat Exchanger ◽  
Energy Saving ◽  
Heat Recovery ◽  
Air Handling Unit ◽  
Battery Power ◽  
Payback Time ◽  
Air Handling Units ◽  
Recovery System ◽  
Heat Recovery System ◽  
Rotary Type

This study investigated heat recovery systems and its effects on energy saving. Heat recovery systems are used for energy saving in heating, ventilating and air conditioning applications. In the study, a workplace equipped with and without heat recovery system was taken into consideration. The workplace has an air handling unit (AHU) which has 25,000 m3/h fresh air flow rate, 414 kW heating and 356 kW cooling capacities. AHU uses mixture air including %50 rooms air and mixes in mixing filter section. As a heat recovery system, rotary type heat exchanger was selected and its performance was investigated. Annual energy saving, initial investment cost, annual operating expenses, payback time and profit parameters were calculated to compare two air handling units for each month. According to the results, cooling battery power in the cooling season and heating battery power is reduced with the usage of rotary type heat exchanger. It is obvious that presence of the heat recovery systems enhances performance of the air handling units.

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