Just pair an MFI or Steam controller to your Mac, connect to a computer running Steam on the same local network, and start playing your existing Steam games. Emulators and Steam both work similarly (to customize how your controller works with Steam, go to Big Picture Mode and access the settings as detailed above).Before discussing the sizing of control valves for steam systems, it is useful to review the characteristics of steam in a heat transfer application.The Steam Link app allows you to play your Steam games across all your computers. With your Steam controller, configure the desktop configuration for it as a generic XBOX controller.As with the Mac, once you have the controller paired, you can use it for a wide variety of games. For that, while the Steam client is running it will maintain a 'desktop configuration'. In non-Steam native Linux games however the overlay may not be practical. Normally a Steam controller requires the use of the Steam-overlay.The volume of condensate is very much less than steam. Steam condenses on the heat transfer surfaces, creating condensate. Steam passes through the control valve and into the steam space of the equipment where it comes into contact with the heat transfer surfaces. Controller to your computer, and use it with the Dolphin Emulator, on Mac or PC. Steam is supplied at a specific pressure to the upstream side of the control valve through which it passes to a heat exchanger, also operating at a specific pressure.If a controller is not listed, it is not compatible with Steam Link. Computer running Steam - Windows, Mac, or Linux.If a modulating control system is used, as the temperature of the process approaches the controller set point, the controller will close the valve by a related amount, thereby reducing the steam flowrate to maintain the lower pressure required to sustain a lower heat load. Should, at any time, the flowrate of steam through the valve be less than the condensing rate (perhaps the valve is too small), the steam pressure and the heat transfer rate in the heat exchanger will fall below that which is required the heat exchanger will not be able to satisfy the heat load. The rate of steam flow into the equipment is governed by this pressure difference and the valve orifice size. The reduced pressure in the steam space means that a pressure difference exists across the control valve, and steam will flow from the high-pressure zone (upstream of the control valve) to the lower pressure zone (the steam space in the equipment) in some proportion to the pressure difference and, ideally, balancing the rate at which steam is condensing.
To achieve this heat output, a certain saturated steam temperature will be required at the heat transfer surface (such as the inside of a heating coil in a shell and tube heat exchanger). This means that a smaller difference in temperature exists between the steam and the process, so the rate of heat transfer is reduced, in accordance with Equation 2.5.3.The overall heat transfer coefficient (U) does not change very much during the process, and the area (A) is fixed, so if the mean temperature differenceΔTm is reduced, then the heat transfer from the steam to the secondary fluid is also reduced.Saturated steam flow through a control valveA heat exchanger manufacturer will design equipment to give a certain heat output. The steam pressure falls in the steam space and so too the steam temperature. Closing the valve reduces the mass flow. ![]() Further reduction of the valve size will require more pressure drop across the control valve for the same mass flow, and the need for an increased heat transfer surface area to maintain the same heat output.Whatever the size of the control valve, if the process demand is reduced, the valve must modulate from the fully open position towards closed. In other words, a larger heating coil or heat exchanger will be required. Because of this, the heat transfer area required to achieve the same heat load must be increased. Ms vcs3 emulator for mac book proIts shape, if designed correctly to match the upstream and downstream pressure conditions and the condition of the supplied steam, will allow it to operate at high efficiency.Such a nozzle can be thought of as a type of heat engine, changing heat energy into mechanical (kinetic) energy. The principle can be explained by looking at how nozzles work and how they compare to control valves.Consider an almost perfect orifice, such as a convergent-divergent nozzle shown in Figure 6.4.2. Critical pressure is explained in the Section below.Further, if a larger control valve is selected, the greater size of the valve orifice means that a given change in flowrate is achieved with a smaller percentage change in lift than is needed with a smaller control valve.This can often make the control unstable, increasing the possibility of ‘hunting’, especially on reduced loads.The mass flow of steam passing through the valve will increase in line with differential pressure until a condition known as ‘critical pressure’ is reached. When the control valve chosen is small enough to require a ‘critical pressure drop’ at full load the effect disappears. With further travel, as the valve plug approaches the seat, this effect reverses such that perhaps a 5% change in lift might produce a 10% change in flowrate, and better regulation is achieved.The initial part of the control valve travel, during which this lowered control effect is seen, is greater with the selection of the larger control valves and the accompanying small pressure drop at full load. Typically, a 10% change in lift might produce only a 5% change in flowrate. ![]() See Figure 6.4.4.Nozzles and control valves have different purposes. The vena contracta effect is discussed in more detail in Module 4.2 ‘Principles of Flowmetering’).Control valves can be compared to convergent-divergent nozzles, in that each has a high-pressure region (the valve inlet), a convergent area (the inlet between the valve plug and its seat), a throat (the narrowest gap between the valve plug and its seat), a divergent area (the outlet from the valve plug and its seat, and a low-pressure region (the downstream valve body). (This is in contrast to a sharp-edged orifice, where a vena contracta occurs downstream of the orifice. If the nozzle outlet is too large, the steam will expand too far in the nozzle and the steam pressure in the nozzle outlet will be lower than the required pressure, causing the steam to recompress outside the outlet in the low pressure region.The shape of the nozzle (Figure 6.4.3) is gently contoured such that the vena contracta occurs at the nozzle throat. If the nozzle outlet is too small, the steam has not expanded enough, and has to continue expanding outside the nozzle until it reaches the required downstream pressure in the low pressure region. The steam will expand after passing the throat such that, if the outlet area has been correctly sized, the required downstream pressure is achieved at the nozzle outlet, and little turbulence is produced as the steam exits the nozzle at high velocity.Should the nozzle outlet be too big or too small, turbulence will occur at the nozzle outlet, reducing capacity and increasing noise:
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