Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including b...

Background: Due to the lack of a proper waste management system, Tehran Municipality Region 20 is facing economic and environmental problems such as the high costs of a disposal system and source pollution. Life cycle assessment (LCA) is a method for collecting and evaluating the inputs, outputs, and potential environmental impacts of a product system throughout its life cycle. The current stud...

Confined aquifers are formations surrounded by impermeable layers called cap rocks and bed rocks. These aquifers are suitable for the seasonal storage of thermal energy. A confined aquifer was designed to meet the cooling and heating energy needs of a residential building complex located in Tehran, Iran. The annual cooling and heating energy needs of the buildings were estimated to be 8.7...

Micro grid technology brings the opportunity to integrate renewable energies with a traditional energy mix on a regional level and to achieve specific local goals. To obtain an optimal energy mix plan, different scenarios need to be simulated and analyzed. However, effective tools for analyzing such simulation results are lacking. Here we present an interactive visual query analysis tool design...

Four methods for determining substrate recoveries in studies concerned with the partition of substrate between sludge synthesis and respiration were investigated. An energy balance comparing chemical oxygen demand (COD) removed with the summation of oxygen uptake and the COD of the cells produced yielded average recoveries closer to 100% than any of the other three methods tested. The standard ...

Significant waste heat recovery technologies have been developed to recover exhaust heat and turn it into useful energy such as in downsizing the engine or to regain the auto-electricity. Extensive work and research in energy recovery have been identified in the automotive sector; therefore the main objective of this paper is to assess each waste heat recovery technology based on current develo...