● High accuracy wet and dry bulb sensors before and after each process to determine air condition.
● All processes fully instrumented to allow energy and mass balances across each process of heating cooling and humidity change.
● Reaches stability rapidly after a change of operating conditions.
● May be upgraded at any time to reduce capital outlay.
● Upgrade options available include:
Digital Temperature,
Re-circulation,
Computer linking (with software),
PID control and Environmental Chamber.
● Two year Warranty.
Introduction
The range of temperature, humidity and air movement which the majority of individuals regard as comfortable is extremely narrow. It is therefore increasingly common for close controlled air conditioning to be applied to new and refurbished buildings and transport facilities.
This increasing use of air conditioning, if not carefully designed, installed and maintained could be a major contributor to the causes of global warming.
Therefore student engineers training for careers involved in the design, operation or servicing of air conditioning plant must be completely familiar with the processes occurring between air inlet and its discharge to the conditioned space.
The Hilton Air Conditioning Laboratory Unit A660 is an expandable teaching and experimental unit that enables students to investigate the basic air conditioning processes of heating, cooling, humidification, dehumidification and air movement that are of fundamental importance to undergraduate engineers.
The addition of optional upgrades, which may be added at any stage in the units extensive life, allow students to investigate air re-circulation and mixing, computer monitoring, dynamic humidity and temperature control and the environmental control of a test chamber.
The unit is applicable for the teaching of students in:
Refrigeration and air conditioning
Building services
Mechanical Engineering
Marine engineering
Plant and process engineering
Food processing
Chemical engineering
Mining engineering
Control engineering
Experimental Capabilities
Air conditioning laboratory Unit A660
● Demonstration of the processes and components used in heating, cooling, humidification, dehumidification of an airstream.
● Measurement of air psychrometric condition before and after humidification, heating, de-humidification / cooling using pairs of precision wet and dry bulb sensors.
● Determination of a heat and mass balance across each process resulting in heating, cooling and humidity change using the instrumentation fitted.
● Construction of a complete refrigeration cycle diagram for the air-cooling plant plus an energy balance between the refrigeration circuit and the change in air enthalpy and its mass flow across the evaporator.
● Investigation of the volumetirc efficiency of the refrigeration compressor under varying load.
● Determination of the specific heat capacity of air, by measurement of the change in psychrometric condition across a heating or cooling process.
Description
A complete, upgradeable, instrumented air conditioning laboratory unit mounted on a steel frame and castor wheels. Upgrades may be added at any stage in the unit’s long life to spread the investment costs.
The base unit comprises a variable speed radial acting axial flow fan discharging into a 250mm square duct with steam humidifier, electrical pre-heaters, direct expansion cooling coil/de-humidifier, electrical reheaters and orifice plate for airflow measurement. Aircooling is provided by vapour compression refrigeration system with pressure, temperature and refrigerant flow measurement. This allows the construction of a full cycle diagram and the balancing of refrigerant system energy balance against the airside energy transfer.
Air condition is recorded before and after each process using precision wet and dry bulb thermometers.
Instrumentation allows the electrical power to each resistive load to be measured and balanced against the air enthalpy change and mass flow.
Specification
An upgradeable fully instrumented air conditioning laboratory unit incorporating steam humidification, direct expansion refrigeration cooling and de-humidification, reheating, variable speed radial acting axial flow fan and airflow measurement.
All parts in corrosion proof plastic, stainless steel, galvanised steel, brass or copper.
Psychrometric condition measured before and after each process by high precision wet and dry bulb sensors with 0 to 100% RH measurement capability.
Airflow is adjustable to at least 0.14m3/s with switchable heating up to 4kW and switchable steam injection up to 5kW electrical equivalent. Cooling is by a fully instrumented vapour compression cycle with nominally 2kW capacity.
Optional upgrade paths include:
● Digital Temperature Upgrade A661A
● Recirculating Duct Upgrade A661B
● PID Control Upgrade A660C
● Environmental Chamber Upgrade A660D
● Computer Linked Upgrade AC661A
Supplied with a detailed experimental operating and maintenance manual giving example experimental results and sample calculations.
Accessories and spares for two years normal operation together with a full two-year warranty.
