An energy cogeneration system of the type employed in industrial plants, such as paper mills, is described. The system utilizes the energy of steam to generate electricity, as well as to operate various industrial processes in the plant. The requirements of the processes for steam are continuously monitored, and if the requirements at any given time are significantly less than the steam being delivered thereto, the delivered steam pressure and/or temperature is reduced to make more steam energy available for other purposes.
A method and apparatus for extracting steam from a steam turbine and adjusting the temperature and pressure for a process. Steam is extracted from the first section of the turbine and is throttled to a desired pressure for use in the process. After the extracted steam is throttled it is transmitted to a suction port of a jet pump. If the pressure of the extracted steam entering the jet pump suction port is less than the desired process pressure, high pressure steam is routed to an inlet port of the jet pump. Steam leaving the jet pump may be desuperheated. Regulation of the steam flow between the first and second section turbines increased extraction pressure. At some point total efficiency of turbine operation and process operation can be improved by extracting steam from a second, higher pressure extraction location. Such extracted steam is throttled to the desired pressure and transmitted from the second pressure reducing station to a second jet pump along with steam from the second extraction location, as the steam flow rate from the first to the second section turbine is increased.
An adaptive control system for controlling the temperature of desuperheated steam in a turbine bypass system. In one embodiment of the invention, redundant temperature sensors downstream of desuperheating water sprays provide an indication of the actual steam temperature after desuperheating has occurred. The highest value of temperature is automatically selected for control and to provide an error signal to a controller. The controller output, indicative of the deviation from a desired temperature, is multiplied by a factor proportional to steam flow in the bypass system. The multiplied signal is then utilized to proportionally position one or more water control valves to spray more or less water into the bypassed steam. The control system thus automatically adapts itself to variations in steam flow. Preferably, the steam flow is taken as the product of the position of a steam flow throttling valve in the bypass line and the steam supply pressure ahead of the valve. Additionally, operating parameters such as temperature and differential pressures are monitored and continuously compared against limiting values to provide automatic protection action if any of the conditions being monitored warrant such action.
A method of obtaining work (e.g. electrical energy) in a counterpressure steam system in which the steam is expanded to produce work, e.g. drive an electrical current generator, in which the steam, prior to the expansion, is passed into isobaric heat exchange at an elevated pressure with expanded steam and is then heated substantially isobarically by externally supplied heat. After expansion and at a relatively low pressure, the steam is substantially isobarically cooled.
In a steam and power cogeneration system optimization results for steam flow and power are calculated off-line recurrently based on actual demand and control is effected on a multiplane basis upon selection of a new plane of control defined by a new status and configuration of the system network, the optimization results for such particular plane being selected and control performed at the time of plane change. Pressure reducing valves are positioned initially at the time of plane change in accordance with the optimization results for the new plane. Pressure reducing valves are positioned for flow tuning about such initial valve positioning.
Energy recovery systems for cold storage warehouses refrigerated by mechanical refrigeration apparatus coacting with a energy recovery unit including a turbine driving an electromotive generator. The cogenerator turbine is driven by the kinetic energy extracted from refrigerant flowing through a first conduit system connecting the compressor, evaporators and condenser of the refrigeration or by the kinetic energy extracted from a coolant being pumped through a second conduit system independent of the first conduit system to cool the compressor as it becomes heated during compression of refrigerant from a vapor phase to a liquid phase during the refrigeration cycle. The extraction of the kinetic energy of the refrigerant flow or coolant flow and the heat generated by the compressor during the refrigerant compression phase represents useful work obtained from the energy recovery system from available surplus energy that otherwise would be wasted.
