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Comparison of elementary geothermal-brine power-production processes

Description: From applied technology geothermal committee meeting; Idaho Falls, Idaho, USA (7 Aug 1973). A comparison of three simple geothermal power- production systems shows that the flashed steam and the compound systems are favored for use with high-temperature brines. The binary system becomes economically competitive only when used on low-temperature brines (enthalpies less than 350 Btu/lb). Geothermal power appears to be economically attractive even when low-temperature brines are used. (auth)
Date: August 1, 1973
Creator: Green, M.A. & Laird, A.D.K.
Partner: UNT Libraries Government Documents Department

Program Geothm: A thermodynamic process program for geothermal power plant cycles

Description: Program GEOTHM is a thermodynamic process program now under development for the LBL Geothermal Energy Program. To date, the program development has centered upon the modeling of working fluid properties, developing thermodynamic process models, and modeling the design performance of geothermal power plants. When the program is completed, it will be able to optimize a power plant or refrigeration plant for minimum cost power or refrigeration. Furthermore, operation of the thermodynamic cycles at off design conditions will be able to be simulated. Program GEOTHM is currently able to calculate several types of geothermal power cycles using a wide variety of working fluids.
Date: October 1, 1974
Creator: Green, M.A. & Pines, H.S.
Partner: UNT Libraries Government Documents Department

Large superconducting detector magnets with ultra thin coils for use in high energy accelerators and storage rings

Description: The development of a new class of large superconducting solenoid magnets is described. High energy physics on colliding beam machines sometimes require the use of thin coil solenoid magnets. The development of these magnets has proceeded with the substitution of light materials for heavy materials and by increasing the current density in the coils. The Lawrence Berkeley Laboratory has developed a radical approach to the problem by having the coil operate at very high current densities. This approach and its implications are described in detail.
Date: August 1, 1977
Creator: Green, M.A.
Partner: UNT Libraries Government Documents Department

Multiparameter Optimization Studies on Geothermal Energy Cycles

Description: Various standard geothermal power cycles are modeled and optimized with program GEOTHM. The results are displayed in 3-D isometric form. These graphical plots vividly display the sensitivity of energy cost and other performance criteria as a result of departures from the design operating point. For example, we will present the mutual interaction of energy cost, resource utilization efficiency, and resource temperature as an EC-RUE-RT surface for a range of temperatures between 100 C and 300 C. Calculation results will be presented for subcritical and supercritical binary cycles with several pure fluids, and on two stage flashed steam cycles for practical non-condensable gas levels.
Date: August 1, 1977
Creator: Pope, W.L.; Pines, H.S.; Silvester, L.F.; Green, M.A. & Williams, J.D.
Partner: UNT Libraries Government Documents Department

Quenches in large superconducting magnets

Description: The development of large high current density superconducting magnets requires an understanding of the quench process by which the magnet goes normal. A theory which describes the quench process in large superconducting magnets is presented and compared with experimental measurements. The use of a quench theory to improve the design of large high current density superconducting magnets is discussed.
Date: August 1, 1977
Creator: Eberhard, P.H.; Alston-Garnjost, M.; Green, M.A.; Lecomte, P.; Smits, R.G.; Taylor, J.D. et al.
Partner: UNT Libraries Government Documents Department

Optimizations of geothermal cycle shell and tube exchangers of various configurations with variable fluid properties and site specific fouling. [SIZEHX]

Description: A new heat exchanger program, SIZEHX, is described. This program allows single step multiparameter cost optimizations on single phase or supercritical exchanger arrays with variable properties and arbitrary fouling for a multitude of matrix configurations and fluids. SIZEHX uses a simplified form of Tinker's method for characterization of shell side performance; the Starling modified BWR equation for thermodynamic properties of hydrocarbons; and transport properties developed by NBS. Results of four parameter cost optimizations on exchangers for specific geothermal applications are included. The relative mix of capital cost, pumping cost, and brine cost ($/Btu) is determined for geothermal exchangers illustrating the invariant nature of the optimal cost distribution for fixed unit costs.
Date: March 1, 1978
Creator: Pope, W.L.; Pines, H.S.; Silvester, L.F.; Doyle, P.A.; Fulton, R.L. & Green, M.A.
Partner: UNT Libraries Government Documents Department

Thermodynamic and cost benefits of a floating cooling geothermal binary cycle power plant at Heber, California

Description: The application of the floating cooling concept to evaporative heat rejection systems was studied as a method of improving the performance of geothermal power plants operating upon medium temperature hydrothermal resources. The LBL thermodynamic process computer code GEOTHM was used in the case study of a 50 MWe isobutane binary cycle power plant at Heber, California. It was found that operating a fixed capacity plant in the floating cooling mode can generate significantly more electrical energy at a higher thermodynamic efficiency and reduced bus bar cost for approximately the same capital investment. Floating cooling was also found to minimize the adverse influence on plant performance due to a declining resource temperature.
Date: April 1, 1978
Creator: Pines, H.S.; Pope, W.L.; Green, M.A.; Doyle, P.A.; Silvester, L.F. & Fulton, R.L.
Partner: UNT Libraries Government Documents Department

Large high current density superconducting solenoid for the time projection chamber experiment

Description: One of the experiments for the PEP storage rings at the Stanford Linear Accelerator Center uses a superconducting magnet to provide the magnetic field for the Time Projection Chamber detector. This magnet has an inside diameter of 2.04 m and a gap of 3.26 m. The magnet central induction is 1.5 T. This magnetic induction is supplied by a thin high current density superconducting coil which is less than 0.4 radiation lengths thick. The magnet stored energy will be 10.9 MJ; the coil superconductor matrix current density will be about 7.0 x 10/sup 8/ Am/sup -2/. The TPC magnet uses a two-phase forced flow tubular cooling system which combines many of the advantages of single-phase supercritical helium cooling with those of boiling helium bath cooling.
Date: June 1, 1978
Creator: Green, M.A.; Burns, W.A.; Eberhard, P.H.; Gibson, G.H.; Miller, P.B.; Ross, R.R. et al.
Partner: UNT Libraries Government Documents Department

Vacuum impregnation with epoxy of large superconducting magnet structures

Description: The Lawrence Berkeley Laboratory (LBL) has been developing a new generation of superconducting magnets which have the helium cooling system as an integral part of the magnet structure. The LBL technique calls for large sections of the magnet structure to be vacuum impregnated with epoxy. The epoxy was chosen for its impregnation properties. Epoxies which have good impregnation characteristics are often subject to cracking when they are cooled to cryogenic temperatures. The cracking of such an epoxy can be controlled by: (1) minimizing the amount of epoxy in the structure; (2) reducing the size of unfilled epoxy spaces; and (3) keeping the epoxy in compression. The technique for using the epoxy is often more important than the formulation of the epoxy. The LBL vacuum impregnation and curing technique is described. Experimental measurements on small samples of coil sections are presented. Practical experience with large vacuum impregnation superconducting coils (up to two meters in dia) is also discussed.
Date: June 1, 1978
Creator: Green, M.A.; Coyle, D.E.; Miller, P.B. & Wenzel, W.F.
Partner: UNT Libraries Government Documents Department

Floating dry cooling: a competitive alternative to evaporative cooling in a binary cycle geothermal power plant

Description: The application of the floating cooling concept to non-evaporative and evaporative atmospheric heat rejection systems was studied as a method of improving the performance of geothermal powerplants operating upon medium temperature hydrothermal resources. The LBL thermodynamic process computer code GEOTHM is used in the case study of a 50 MWe isobutane binary cycle power plant at Heber, California. It is shown that operating a fixed capacity plant in the floating cooling mode can generate significantly more electrical energy at a higher thermodynamic efficiency and reduced but bar cost for approximately the same capital investment. Floating cooling is shown to benefit a plant which is dry cooled to an even greater extent than the same plant operating with an evaporative heat rejection system. Results of the Heber case study indicate that a dry floating cooling geothermal binary cycle plant can produce energy at a bus bar cost which is competitive with the cost of energy associated with evaporatively cooled systems.
Date: July 1, 1978
Creator: Pines, H.S.; Green, M.A.; Pope, W.L. & Doyle, P.A.
Partner: UNT Libraries Government Documents Department

Magnet system for the time projection chamber at PEP

Description: A superconducting solenoid with a conductive bore tube is under construction for use with the time projection chamber (TPC) detector at PEP. It will be a uniform induction of 1.5 T over a 6.3 m/sup 3/ volume. Its stored energy will be 11 MJ while maintaining a radiation thickness of 0.3 radiation lengths for the coil package. The coil will operate at a current density of 7 x 10/sup 8/ Am/sup -2/ and it will be cooled by force flow two phase helium in a tube. The final design details are given here.
Date: August 1, 1978
Creator: Green, M.A.; Eberhard, P.H.; Taylor, J.D.; Burns, W.A.; Garfinkel, B.; Gibson, G.H. et al.
Partner: UNT Libraries Government Documents Department

Quench protection for a 2-MJ magnet

Description: A superconducting solenoid with conductive bore tube has been used at energies up to 1.9-MJ to test various methods of quench protection. The methods all involve shifting the main coil current to the conductive bore tube and include (1) allowing the quench to evolve naturally, (2) interrupting the primary circuit while providing a varistor used as a shunt across the coil, and (3) turning the entire magnet normal by dumping a short pulse of current from a capacitor bank through the windings.
Date: September 1, 1978
Creator: Taylor, J.A.; Alston-Garnjost, M.; Eberhard, P.E.; Gibson, G.H.; Green, M.A.; Pardoe, B. et al.
Partner: UNT Libraries Government Documents Department

Construction and testing of the two meter diameter TPC thin superconducting solenoid

Description: High energy colliding beam physics often requires large detectors which contain large volumes of magnetic field. The TPC (Time Projection Chamber) experiment at PEP will use a 1.5T magnetic field within a cylindrical volume which is 2.04m in diameter bounded by iron poles which are separated by a gap of 3.25m. The TPC magnet, built in 1979 by the Lawrence Berkeley Laboratory (LBL), is the largest high current density superconducting magnet built to date. It is designed to operate at a current density of 7 x 10/sup 8/Am/sup -2/ and a stored energy of 11MJ, and it is protected by shorted secondary windings during a quench. The paper describes the basic parameters of the TPC magnet and the results of the first subassembly tests at LBL.
Date: August 1, 1979
Creator: Green, M.A.; Eberhard, P.H.; Ross, R.R. & Taylor, J.D.
Partner: UNT Libraries Government Documents Department

Forced two phase helium cooling of large superconducting magnets

Description: A major problem shared by all large superconducting magnets is the cryogenic cooling system. Most large magnets are cooled by some variation of the helium bath. Helium bath cooling becomes more and more troublesome as the size of the magnet grows and as geometric constraints come into play. An alternative approach to cooling large magnet systems is the forced flow, two phase helium system. The advantages of two phase cooling in many magnet systems are shown. The design of a two phase helium system, with its control dewar, is presented. The paper discusses pressure drop of a two phase system, stability of a two phase system and the method of cool down of a two phase system. The results of experimental measurements at LBL are discussed. Included are the results of cool down and operation of superconducting solenoids.
Date: August 1, 1979
Creator: Green, M.A.; Burns, W.A. & Taylor, J.D.
Partner: UNT Libraries Government Documents Department

Superconducting magnet system for the SPIRIT cosmic ray space telescope

Description: The SPIRIT (A Superconducting Passive Iron Isotope Telescope) experiment requires a large volume (1m/sup 3/) of 2T field in order to achieve enough resolution to study heavy primary cosmic rays. It is proposed that the SPIRIT superconducting magnet system and its experimental package would be used in one of the space shuttles. The superconducting magnet design is based on Lawrence Berkeley Laboratory thin high current density solenoid technology. The superconducting magnet system consists of a number of coils which generate a 2T induction within the experiment, and at the same time allow free access to the package by cosmic rays. The superconducting magnet system uses high current density conductor which is protected by a shorted secondary circuit. The magnet coils are to be cooled by pumped two phase helium which is circulated through tubes. Refrigeration is supplied from a large liquid helium dewar.
Date: August 1, 1979
Creator: Green, M.A.; DeOlivares, J.M.; Tarle, G.; Price, P.B. & Shirk, E.K.
Partner: UNT Libraries Government Documents Department

Combining magnetic shielding and cryopumping for a neutral beam source

Description: This paper describes a feasible geometry for the shield/cryopump for a TFTR/Doublet type of neutral beam source, summarizes some of the design parameters, and compares the performance, fabrication, and operating cost of such a system with a more conventional system.
Date: October 1, 1979
Creator: Tanabe, J. & Green, M.A.
Partner: UNT Libraries Government Documents Department

2 meg-ampere prototype levitated coil for multipole fusion

Description: The coils major diameter is 1.0 meter and it occupies a cross-section which is about 0.2 meter minor in diameter. The prototype coil will carry four times the current of the largest such magnet built to date. As a result, the peak induction in the coil is about 8 T and the stored magnetic energy will be around 3 MJ. The paper describes the proposed Nb/sub 3/SN superconductor, the quench protection system which is based on the LBL shorted secondary concept, the isochroic refrigeration storage system which stores about 5 kJ of refrigeration between 4.5/sup 0/K and 7/sup 0/K, and the persistent switch.
Date: November 1, 1979
Creator: Green, M.A. & Glueck, R.
Partner: UNT Libraries Government Documents Department

Use of high current density superconducting coils in fusion devices

Description: Superconducting magnets will play an important role in fusion research in years to come. The magnets which are currently proposed for fusion research use the concept of cryostability to insure stable operation of the superconducting coils. This paper proposes the use of adiabatically stable high current density superconducting coils in some types of fusion devices. The advantages of this approach are much lower system cold mass, enhanced cryogenic safety, increased access to the plasma and lower cost. (MOW)
Date: November 1, 1979
Creator: Green, M.A.
Partner: UNT Libraries Government Documents Department

Progress on the superconducting magnet for the time projection chamber experiment (TPC) at PEP

Description: The TPC (Time Projection Chamber) experiment at PEP will have a two meter inside diameter superconducting magnet which creatests a 1.5 T uniform solenoidal field for the TPC. The superconducting magnet coil, cryostat, cooling system, and the TPC gas pressure vessel (which operatests at 11 atm) were designed to be about two thirds of a radiation length thick. As a result, a high current density coil design was chosen. The magnet is cooled by forced flow two phase helium. The TPC magnet is the largest adiabatically stable superconducting magnet built to date. The paper presents the parameters of the TPC thin solenoid and its subsystems. Tests results from the Spring 1980 cryogenic tes are presented. The topics to be dealt with in the paper are cryogenic services and the tests of magnet subsystems such as the folded current leads. Large thin superconducting magnet technology will be important to large detectors to be used on LEP.
Date: January 1, 1980
Creator: Green, M.A.; Eberhard, P.H. & Burns, W.A.
Partner: UNT Libraries Government Documents Department

TPC magnet cryogenic system

Description: The Time Projection Chamber (TPC) magnet at LBL and its compensation solenoids are adiabatically stable superconducting solenoid magnets. The cryogenic system developed for the TPC magnet is discussed. This system uses forced two-phase tubular cooling with the two cryogens in the system. The liquid helium and liquid nitrogen are delivered through the cooled load by forced tubular flow. The only reservoirs of liquid cryogen exist in the control dewar (for liquid helium) and the conditioner dewar (for liquid nitrogen). The operation o these systems during virtually all phases of system operation are described. Photographs and diagrams of various system components are shown, and cryogenic system data are presented in the following sections: (1) heat leaks into the TPC coil package and the compensation solenoids; (2) heat leaks to various components of the TPC magnet cryogenics system besides the magnets and control dewar; (3) the control dewar and its relationship to the rest of the system; (4) the conditioner system and its role in cooling down the TPC magnet; (5) gas-cooled electrical leads and charging losses; and (6) a summation of the liquid helium and liquid nitrogen requirements for the TPC superconducting magnet system.
Date: March 1, 1980
Creator: Green, M.A.; Burns, W.A.; Taylor, J.D. & Van Slyke, H.W.
Partner: UNT Libraries Government Documents Department