Cold-start tests

Cold-start tests are also important in order to observe how freezing temperatures affect the material properties of the diffusion layers. Oszcipok et al. [262] dried a fuel cell through purging with N2 prior to cooling it down to -10°C. At this point, the cell was started and operated at different voltages. After more than 10 tests, the cell was disassembled and it was observed that the FF channel pattern was visible on the cathode DL. 

System sampling Equipment cold-start tests System-invasive tests... 

It was shown that future legislative requirements can be fulfilled with this EHC. Figure 2 shows temperature and concentration profiles of CO, propene and propane at different times of the cold-start test cycle. Because of the time dependent conditions at the inlet of the converter, the concentration profiles are always normalized with respect to the inlet concentrations at each... 

The catalytic species of current automotive catalysts are balanced mixtures of precious metals and promoters selected, as discussed previously, on the basis of application. Precious metals are favoured due to high catalytic activity and selectivity, particularly at low temperatures (as experienced with cold start tests). Additionally their supported dispersions are relatively stable at high temperatures and exhibit good resistance to poisoning. 

Cold start testing of the reformer using ethanol was completed at half power and operability of the reformer using new sensors and controllers was demonstrated at full power, resulting in reformate with less than 20 parts per million CO and with 37% of hydrogen (H2) under stable condition. (See Figures 2 and 3.)... 

Except for preconditioning the evaporative emission control canister, the emission tests were performed as prescribed (3, 4, 5, 6). As an expedient, test variability attributable to variable HC loading on the evaporative control canister was eliminated by using a purged canister for all tests. All cold start tests were performed after a minimum 12-hr vehicle soak time. 

Rapid cold-start testing ofthe device vas carried out. The duration of the whole test was as short as 60 s. After 5 s ofheating and dosing water, the fuel pump was switched on and after 15 s the excess water flow was reduced to the level of stationary operation. 

One way to solve this problem, and thereby control emissions directly from the start, is to use a sensor based on a material more resistant to thermal shock as a cold-start sensor [128]. SiC, as the second hardest material in existence only surpassed by diamond, is such a material and has therefore been tested for its suitability as a cold-start sensor. The water-splash resistance of SiC is still not verified because these experiments are complicated to perform in a laboratory engine test bench. 

After completion of visual inspection by manufacturing, QAI will perform (a) the review of printout of cold leak test carried out by production and (b) the visual inspection. See SOP (provide number). He gives the release for packing if the results are satisfactory. QAI will fill the optical inspection report attachment no. 1700.30(G) and 1700.30(H) for each batch optically inspected and for leakage. When packaging of the batch starts, the production supervisor will request the area QAI for line clearance. The QAI will check the area and countersign the line clearance given by the supervisor. See attachment no. 1700.30(B). 

The col was filled with a bottom hole crude sample and immersed in a thermostatted bath. After one hour at 46°C, the temperature of the bath was gradually decreased at 1.5°C/hr to 4°C and maintained at this temperature for two weeks. After the test period, flow was obtained by applying 0.04 bar (equivalent to 30 psi In field with 5" flowline), indicating that cold start-up would not be a problem ir the field. 

To study the possibility of application in the reduction of cold start emission, Pitchon et al. tested the reaction of total oxidation of a mixture of light hydrocarbons... 

From new sequences under more severe test conditions, which include measurements from a cold start. 

The cold crank simulator test, ASTM D2602/IP 383, measures the apparent viscosity of an oil sample at low temperatures and high shear rates, related to the cold starting characteristics of engine oils, which should be as low as possible. The oil sample fills the space between the rotor and the stator of an electric motor, and when the equipment has been cooled to the test temperature, the motor is started. The increased viscosity of the oil will reduce the speed of rotation of the motor and indicates the apparent viscosity of the oil. The test is comparative for different oil samples rather than an accurate prediction of the absolute performance of an oil in a specific engine. 

Three-way catalyses (TWC) require a minimum temperature of approx. 3500C for proper catalytic combustion. Due to the heat capacity of the exhaust system it takes about 1 min after engine start until this temperature level is reached if the catalyst is only heated by the exhaust gas. The amount of toxics produced during this cold-start period presents a considerable fraction of the total amount during one test cycle [1]. Due to more stringent legal purification requirements several concepts were developed to reduce the catalyst heat up time. Presently the main approaches to lower the cold-start emissions are the use of an electrically heated catalyst (EHC) [2], a burner heated catalyst (BHC) [3, 4] and hydrocarbon adsorber systems [5, 61. 

This cold-start concept was tested in a Volkswagen vehicle (engine 2.0 1 catalyst 1.9 1, Pt/Rh (5 1) 50 ). Since the experimental setup could not be placed in normal underbody position the catalyst in the experiments was positioned at the end of the exhaust tail pipe behind the mufflers. In spite of these unfavourable conditions very good conversion behavior of the CHC-concept can be observed in the experiments. 

---