Calorimeter with condensers, evaporaters and all HVAC systems with refrigerants R134a and R1234yf
The purpose of the device is measurement and calculation of condensation(evaporating) output of samples (automotive condenser/evaporater) at given parameters with the control of individual flaps, blower using by stepper motors or Local Interconnect Network (LIN) communication. The process can also be automated using a sequential automaton.
The device consists of two basic circuits. The coolant circuit – Freon module and the air part – aerodynamic tunnel (closed/open). These two circuits are regulatory independent , i.e. the aerodynamic tunnel may be operated without the Freon module run.
The device may be used for measurements of exchangers with the through flow surface from about 0.05m2 to 0.6 m2 at air weight flow rates from 150 m3/hr to 9,000 m3/hr.
The device is able to measure, with the required accuracy, outputs within the range from 1.5 to 29 kW. Relative error within this range does not exceed +/-2%, and from about 30% of the actual device range the error drops to about +/-1%.
Calorimeter for heat exchangers – glycol circuit
The device is designed and manufactured to allow for cooler(heating inserts) output measurement. The device works with heated water/glycol mixture. The whole circuit is automatic including filling and draining. Using the device, it is possible to change the flow rate, temperature and required pressure
Glycol circuit parameters:
Input temperature of liquid: +5 ÷ 120 °C ± 0.15 K
Pressure on sample feed side: 1 ÷ 4 Bar (relative) ± 0.2%
Liquid flow rate: 100 ÷18,000 l/hr ± 0,5 %
Air tunnel parameters:
Input temperature of air: -20 ÷ 60 °C ± 0.25 K
Air humidity 20 ÷ 90 % ± 1 %
Air flow rate @ 800 Pa: 500 ÷ 16,500 m3/hr ± 1.5 %
Calorimeter for measuring air-conditioning units
The air-conditioning unit connected to the chamber has the task of changing the flow rate through the sample and further adjusting the air temperature to the required parameters. It is also possible to change the required humidity in the chamber, using a steam generator located outside the chamber. A cold and warm module is further connected to the tested air conditioning unit via pipes and hoses, which can be used to control the flow rate and at the same time regulate to the required temperatures in the individual circuits.
The air part includes a measurement branch where the homogeneous (in planes perpendicular to the stream duct axis) gas stream with accurately defined properties (temperature, pressure, speed) hits the exchanger, passes through it and continues along a hermetic and heat insulated stream duct, again homogenising and passing through the measurement section where the exact stream characteristics are measured again. The whole stream duct is a closed circuit.
On the basis of specification an aerodynamic design of the measuring branch was prepared, the curves of the curved part of the stream duct were calculated and pressure loss calculation was implemented for empty space of heat exchangers for three different volume flows.
The design concept assumes certain unusual stream duct designs (adjustable feed and fixed entry to the balance chamber) with regard to the strict requirements for stream homogeneity, wide range of text modes and sizes of the tested heat exchangers and with regard to spatial layout and simplification of manufacture of the calorimeter measuring arm.
Cooler calorimeter, heating inserts
The device is designed and manufactured to allow for cooler output measurement. Adjustable water flow rate 40 to 420 l / min at maintained water temperature of + 40 to +125 C. Water transport pressure up to 5Bar. Adjustable air flow rate from 600 to 24,000 m 3 hr –1. External pressure in the air circuit max. 2,500 Pa. Air temperature may be increased by mixing with air after cooler pass and decreased by an external cooler to the required temperature.
Calorimeter for intercooler (turbocharger intercooler) measurement
The measuring track is designed for measurement of automobile intercooler outputs with pressurised air.
The device is connected into a single whole with its own control system and SW data collection. The device is conceived to allow for output measurements on both air sides.
The device may be used for measurements of exchangers with the through flow surface from about 0.05m2 to 0.6 m2 at air weight flow rates from 300 kg/hr to 25,000 kg/hr. The aerodynamic tunnel is designed as closed.
The regulation circuits are installed in specially constructed skeletons with technology entries into the workspace where the tested sample is connected (hereinafter SUT), which is placed in a separate cabin with controlled ambient temperature and defined air flow rate.
The measuring members for the actual temperature, flow rate and pressure measurement are placed in separate circuits. The electrical part and data collection are located in separate switchboards.
Hot compressed air module parameters:
Input temperature of air: +90 ÷ 300 °C ± 0.2 K
Pressure on sample feed side: 1.1 ÷ 3 Bar (relative) ± 0.15 Bar
Compressed air flow rate: 78 ÷ 780 kg/hr ± 0.5 %
Exchanger calorimeter for exhaust pipeline
Device for measurement of output characteristics of pipe exchangers (EGR – Exhaust Gas Recirculation – exchanger). This exchanger is used for heat transfer from the gas to the liquid side.
The direct purpose of this product is exhaust gas cooling in automobile diesel aggregates for potential re-suction of these gases to the workspace of the cylinder with fresh air mix.
The device consists of two basic circuits. Liquid (glycol) circuit and air part.
The liquid circuit is part of device for testing of EGR exchangers and for assurance of certain parameters such as liquid temperature, liquid flow through the sample, pressure in front of the sample (static overpressure).
The basic regulation task of the air circuit is to set and maintain accurate flow rate, temperature and pressure of the hot air.
The source is a turbocharger with constant speed and output (circa 3.8 kg/min at 1.6 Bar g) – this source is a module allowing for replacement.
Basic input data and values determining the exchanger work:
Gas feed temperature range……………………………130 – 700 °C ± 0.4 K
Pressure on the sample entry side, the air side: 0.6 ÷ 1.6 Bar (relative)± 0.02 Bar
Pressure on the sample entry side, the liquid side: 1 ÷ 5 Bar (relative)± 0.05 Bar
Gas flow volume………………………………….2 – 62 g/sec ± 1 % of the set value
depending on the turbocharger
Cooling liquid input temperature………………………………50 – 125 °C ± 0.5 K
Liquid flow volume ……………………………….2 – 65 l/min ± 0.7% of the set value
Typical output scope with regard to the abovementioned ranges 150 – 15,000 W.
The device for testing heat pumps and condensation units consists of several separate circuits:
Test chamber – The chamber concept is designed as a self-supporting structure of sandwich panels with inside insulation material.
Air circuit – heating + cooling
The air circuit is based on a set of axial ventilators controlled by a frequency exchanger. Behind the ventilator set there is an electric heater divided into sections. The heater output is extended to 36 kW for use by certain measurement modes (especially the low evaporation temperature). The heaters are arranged as final regulation members with the purpose to maintain the specified temperature +/-0.2 deg C.
A steam generator of circa 15 kW, representing water flow output 0.003 – 0.23 kg/min.
Cooling is designed as indirect, i.e. first the heat carrier substance is cooled (the mixture of water and mono-ethylene-glycol) and this substance then performs controlled cooling of the process air.
The cooler circuit is based on 3 hermetic compressors K01, K02, K03 Copeland with roughly the same output. The series with output regulation 10 – 100% is used.
The compressors are connected in parallel and the first stage is equipped with connected output regulation – the “digital scroll”.
Controlled evaporator circuit
The concept of the heat gains and losses is designed as a closed circuit, i.e. the heat generated at the SUT (tested) for example condensation unit is used for heating of the evaporators of the measured circuit and the supplied heat is only wasted by the difference between the two – the heat generated by the compressor work. The technical design of this heat exchange consists of a set of two liquid evaporators with electronic expansion valves to cover the output range of 1 – 30 kW.
Liquid circuit of heat pump
To measure heat pumps the cooling liquid circuit of the interior chamber is equipped with a proportionally closable branch to a flat rib exchanger where another circuit is connected with a separate pump and variable output and heating, used for accurate fine tuning of the required temperature.
The control system and the electrical part are installed in separate switchboard fields. The data switchboard including the distributed DAQ chassis for data collection and support circuits is installed in front of the chamber for the length of the sensors conductors to be minimised.