Micro Cooling, Heating, and Power (Micro-CHP) and Bio-Fuel Center, Mississippi State University

Technical Report · Fri Sep 26 00:00:00 EDT 2008

DOI:https://doi.org/10.2172/949763· OSTI ID:949763

Chamra, Louay

Initially, most micro-CHP systems will likely be designed as constant-power output or base-load systems. This implies that at some point the power requirement will not be met, or that the requirement will be exceeded. Realistically, both cases will occur within a 24-hour period. For example, in the United States, the base electrical load for the average home is approximately 2 kW while the peak electrical demand is slightly over 4 kW. If a 3 kWe micro- CHP system were installed in this situation, part of the time more energy will be provided than could be used and for a portion of the time more energy will be required than could be provided. Jalalzadeh-Azar [6] investigated this situation and presented a comparison of electrical- and thermal-load-following CHP systems. In his investigation he included in a parametric analysis addressing the influence of the subsystem efficiencies on the total primary energy consumption as well as an economic analysis of these systems. He found that an increase in the efficiencies of the on-site power generation and electrical equipment reduced the total monthly import of electricity. A methodology for calculating performance characteristics of different micro-CHP system components will be introduced in this article. Thermodynamic cycles are used to model each individual prime mover. The prime movers modeled in this article are a spark-ignition internal combustion engine (Otto cycle) and a diesel engine (Diesel cycle). Calculations for heat exchanger, absorption chiller, and boiler modeling are also presented. The individual component models are then linked together to calculate total system performance values. Performance characteristics that will be observed for each system include maximum fuel flow rate, total monthly fuel consumption, and system energy (electrical, thermal, and total) efficiencies. Also, whether or not both the required electrical and thermal loads can sufficiently be accounted for within the system specifications is observed. Case study data for various micro-CHP system configurations have been discussed and compared. Comparisons are made of the different prime mover/fuel combinations. Also, micro- CHP monthly energy cost results are compared for each system configuration to conventional monthly utility costs for equivalent monthly building power, heating, and cooling requirements.

• Research Organization: Mississippi State Univ., Starkville, MS (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: FG02-04ER63842
• OSTI ID: 949763
• Report Number(s): DOE/ER/63842-1; TRN: US200917%%400
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ABSORPTION
BOILERS
CONFIGURATION
DIESEL ENGINES
ECONOMIC ANALYSIS
ELECTRICAL EQUIPMENT
ELECTRICITY
ENERGY ACCOUNTING
ENERGY CONSUMPTION
FLOW RATE
FUEL CONSUMPTION
HEAT EXCHANGERS
HEATING
IMPORTS
INTERNAL COMBUSTION ENGINES
ON-SITE POWER GENERATION
PARAMETRIC ANALYSIS
THERMODYNAMIC CYCLES
cooling, heating, and power
energy efficiency
bio-fuel