Testing and Optimization

Testing and Optimization

Company The EGELHOF Group Into the future with the right climate. As professionals in the sector of controls, the EGELHOF group has developed and produced expansion valves and control elements for refrigeration and heat technology according to the highest technical quality requirements since 1938. All famous producers worldwide within the automotive and heat industry use EGELHOF products. All EGELHOF activities are based on a vision of the future, a tradition of competence and a high degree of willingness to invest. At the company s core - the production - modern production lines, their own tool shop and machine building make for great flexibility mean meeting clients needs in a timely manner. About 500 competent and experienced EGELHOF staff members from Development, Design, QA, Production and Sales guarantee optimum production flows and a consistently high series-production quality. Modern production plants in Europe, the USA and Asia not only assure their own competitiveness, but that of all EGELHOF clients. Manufacturing in the Sixties 2/3

EGELHOF A/C System Test Bench As a special service, EGELHOF offers clients and partners the calibration of A/C systems with one or two evaporators at its own A/C system test bench. In cooperation with clients and partners, a complete A/C system design can be carried out. Refrigeration circuit components and tubes are installed as close as possible to their original assembly position, i.e. in the same way they are installed in the vehicle. Systematic Testing Increasing Standards with regard to the Environment Increasing requirements so as to reduce direct CO 2 emissions from vehicles can be directly fulfilled by optimizing drive systems. Increasing the efficiency of auxiliary equipment means other indirect decisive enhancements as well. A vehicle s A/C system offers a wide field for optimization, however for the user s comfort, refrigeration capacity ought to be at least maintained, and as for circuits with two evaporators it ought to even be increased. In addition to the discussion regarding direct CO 2 emissions, we are faced with the legal requirement to replace the refrigerant and greenhouse gas R134a with alternative refrigerants. This basically requires an adaptation or even the design of a completely new refrigeration circuit for the A/C system. While doing so, our target is to increase efficiency and to reduce the weight of the system and of charge quantity. The functions of individual components have a growing impact on each other; hence optimization of a single component does not always result in a system enhancement. EGELHOF has therefore decided to merge its experience as a control valves producer with the experience of EGELHOF clients. Main focus of tests carried out on the system test bench: adapt and validate the selection in respect of thermostatic expansion valves (TXV) within system development for and in cooperation with clients metrological support with regard to further development of A/C systems with one or two evaporators operated with R134a metrological support with regard to new developments of A/C systems operated with R744 (CO 2 ) or alternative refrigerants metrological support with regard to the development and optimization of systems with an internal heat exchanger analysis so as to find weak points within refrigeration circuits benchmarking of various circuit components simulate or reproduce errors occurring in the field and development of corrective actions examine heat exchangers within the system in respect of air diffusion and oil transport examine condensation and condensation discharge evaluate capacity / performance of an A/C system related to refrigeration circuit 4/5

Climate Simulation Climate, Performance and Data Climate Choice Large-scale operating ranges allow for the simulation of nearly all applicable climate conditions. Capacity/Performance key figures of EGELHOF A/C system test bench: Utilizable inside dimensions of test bench: (l x w x h) 7.75 m x 2.75 m x 2.75 m The internal space is divided by a movable dividing wall into two zones thus enabling adaptation to different versions of test circuits. Maximum refrigeration capacity (test object): 18 kw, including up to 8 kw in case of a rear A/C system Extreme range 2 Extreme range 1 Maximum condenser capacity (test object): 27 kw Standard range Extreme range 3 Total temperature range of front -5 C to 60 C and rear system: Controlled humidity range: 10% to 90 % of rel. humidity Uncontrolled humidity range: up to -10 C dew point (dry) Total temperature range 5 C to 65 C of condenser: Compressor rpm, drive via electrical motor: Torque on compressor (0-3,000 rpm) 500 to 10,000 rpm min. 40 Nm Oil concentration in R134a test circuits is continuously measured. Refrigerant mass flow is measured according to Coriolis principle, 2 sensors are applied. 6/7

Instrumentation and Control Total Control Everything is considered Control functions are realized by graphic user interfaces of the InTouch -Software. Priority has been given to simple operation and clarity. Instrumentation data are transferred via Simatic Control made by Siemens and Profibus with a measurement range of up to 1Hz of the Kohlenberg MSR32 software. Approximately 150 measuring channels and up to 200 computational channels including relative formula are currently applied. The computation base for data around the refrigeration circuit is the chemical media data software REFLIB linked to the MSR32 of ILK Dresden. During a test run, a log p,h-diagram can be displayed online to follow up the circuit process. 8/9

Instrumentation and Control Everything done automatically Testing circuit channel assignment Safe and sure results Complete program-controlled measuring runs are carried out; if required, an optimum utilization of test bench running periods is possible. Each measuring task is handled in the form of a project. By doing so, settings of measuring and computational channels, channel groups, program control data, and protocol data are saved. They may therefore be loaded again at a later date. Measuring data are saved in MSR32 format and can be converted into ASCII text, in EXCEL - or in DasyLab format. For further evaluation, EGELHOF can make all of the project and measuring data on a data carrier (CD-ROM) available to the customer. 10/11

Testing is our Business We are ready to meet your demands EGELHOF offers its A/C system test bench as well as other test equipment for carrying out external tests, i.e. the helium leakage test system for carrying out leakage tests and the salt spray fog chamber according to DIN EN ISO 9227. 12/13

EGELHOF Test Equipment Other EGELHOF Test Equipment EGELHOF products: put to the acid test Helium leakage test system for carrying out leakage tests: Stricter environmental requirements with regard to emissions levels and longer maintenance intervals require that systems are no longer leaky. In particular, new A/C systems for vehicles applying CO 2 as a refrigerant make leak tightness a prerequisite since high internal pressures up to 130 bar are reached. In addition to test equipment (also offered as an external service), during product design, all EGELHOF products are submitted to additional high-quality simulations and test benches in their own Testing Department: Simulation of endurance: Operation reliability of EGELHOF products during their long life is ensured by applying load alternation tests. In pressure test benches, life up to wear is found in time lapse. Test pressures up to 200 bar can be set in the automated EGELHOF helium leakage test system. Parts charged with internal pressure as well as parts precharged with helium can be tested by applying integral or sniffer probe mode. Corrosion test in salt spray fog: The EC guideline concerning old vehicles which requires the use of chrom-6+-free corrosion protective coatings has resulted in new coating materials and coating processes. In many products a variety of different materials are combined. Consequently, the coaction of different metallic materials can result in a saliferous, humid environment causing considerable corrosion. In order to guarantee the longevity of components, EGELHOF carries out extensive tests for each new material combination and in connection with customer validations in their own salt spray fog chamber according to DIN EN ISO 9227. Environmental simulation of heat and cold with and without influence of humidity: Even the most extreme external temperature influences on EGELHOF products must not change guaranteed features. To assure this, several computer controlled climate chambers and temperature ovens, as well as a temperature shock chamber, are available to the Testing Department. Temperature range from -70 C to +250 C Humidity range from 10% to 98% of relative humidity Components test benches: Valves dynamic behavior can only be analyzed in a real refrigeration circuit. Precisely defined operating conditions allow for the testing and optimization of opening characteristics, oscillation behavior and performance. Due to the fact that passenger compartments are becoming more and more quiet, the development of low noise A/C systems is becoming increasingly important. By applying an acoustical measuring system, EGELHOF can detect flow noises and structure-borne noises on prototypes. This kind of information enables EGELHOF designers to continuously minimize the existence of disturbing noise emissions. 14/15

The competent EGELHOF team will be happy to assist you in carrying out your measuring tasks. Please send your inquiries to the following address: OTTO EGELHOF GmbH & Co. KG Stuttgarter Strasse 60 D - 70736 Fellbach +49 (0)711/575 47 0 e-mail: testing@egelhof.com Internet: www.egelhof.com 01-2008/01