Andrey V. Mityakov

Local Heat Flux Measurement in a Permanent Magnet Motor at No Load

Heat transfer is a limiting factor in the performance of electrical machines. Measuring the heat flux in an electrical machine is traditionally carried out indirectly with temperature measurements as there are only a few sensors for heat flux measurements. This paper describes a new experimental method to measure the local heat flux inside an electrical machine. The measurement was proven successful in the air gap of the permanent magnet machine, 37 kW 2400 min-1, under an influence of the air gap magnetic flux. The heat flux was measured by using sensors based on the transverse Seebeck effect. The test machine was an axial flux permanent magnet machine with two stator stacks and one internal, ironless rotor disc. A gradient heat flux sensor was installed in the air gap on the stator side. Local Nusselt and Reynolds numbers were calculated according to the measured heat flux results and compared with the results given by traditional methods to verify the new measurement method.

Oil flow control system based on gradient heat flux sensors for industrial application as industrial forklift

Paper researches application of the gradient heat flux sensor (GHFS) as oil flow control unit for industrial application. The results as presented here show that the usage of GHFSs for fluid flow indication in comparison with the available temperature devices is quite competitive.

High-Temperature Heat Transfer Investigations Using Heterogeneous Gradient Sensors

The local heat flux measurements are limited by low working temperature of the gradient heat flux sensors (GHFS) [1–3]. The novel heterogeneous sensors (HGHFS) made from metal-metal or metal-semiconductor layered composites (so-called anisotropic thermoelements) have high temperature level of 1300 K and more. Theory of the HGHFS allows to choose thickness and angle of inclination for the layers of composite, and to forecast volt-watt sensitivity. The sensitivity of metal-metal sensors is typically on the order of 0.02 to 0.5 mV/W, and it is much beyond when semiconductors are used. HGHFS are used for a first time for heat flux measurements in the furnace of the industrial boiler which is in operating of the Thermal Power Plant (fossil fuel power plant) in the city of Kirov (Russia). The local heat flux at the surface of refractory-faced water wall is measured in different regimes of operating. It is also shown that HGHFS may be used as indicator of furnace slugging. Small sizes (minimally 2×2×0.1 mm) and high working temperature of the HGHFS are useful for heat transfer investigations.© 2010 ASME