摘要:

The organic Rankine cycle is one of the most promising techniques for production of mechanical power from low temperature sources such as solar heated fluids, geothermal brines and industrial waste heat. A series of cycle performance calculations has been carried out for a broad range of working fluids including Refrigerant 12, isobutane, isopentane, propone, and toluene as well as mixtures of isobutane and isopentane. For a source temperature range of 150°C to 170°C, current results show that the optimal cycle for some working fluids requires supercritical heat exchange while for others (the majority), heating is subcritical. Performance improvements available from exhaust fluid regeneration are shown to be more significant for an isobutane cycle (subcritical) than for a propane cycle (supercritical). For the foregoing cycles the amount of heat exchanger area per unit of output is compared; the isobutane cycle is found to require somewhat less area. The sensitivity of cycle output to changes in pump and turbine efficiencies is also illustrated.

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675403

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Future developments in direct-fired engine driven heat pumps utilizing various power cycles are discussed in the context of domestic heat pumps. The Rankine cycle is at present the most favoured on account of reliability, ease of control and low maintenance aspects but developments are progressing in Stirling cycles as well as others. In absorption systems no ideal working pairs have yet been identified, and their selection is based on compromise. Storage systems have been demonstrated, but their marketability depends very much on tariff structures and load matching.

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675404

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

In an attempt to improve the quality and reliability of methods used for long-term performance evaluation of solar systems, detailed information is provided about the long-term (typically 2 years) performance and stability of a relatively large number of instruments used in the performance monitoring of a well-instrumented solar heating project. The calibration methods are also described. The instruments include resistance temperature detectors, several types of flowmeters, wattmeters, pyranometers, wind anemometers, a humidity meter, a barometer, differential temperature solar system controllers, and an automatic data acquisition system used to scan, convert and store the data. Recommendations for good instrumentation of solar systems are also provided.

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675405

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

In this paper, equations have been developed to estimate diffuse fraction of the hourly, daily and monthly global insolation on a horizontal surface. These correlations are expressed in terms of Kd, the ratio of diffuse-to-total radiation, and KT, the clearness index. The hourly correlation equations, show a fairly similar trend to that of Orgill and Hollands (1) and Spencer (5) and support, their views on latitude dependence. The correlation equation for daily diffuse fraction of the global insolation agrees well with LIU and Jordan (6) and the latitude dependence is not very clear in this case. An equation has also been developed for monthly diffuse fraction of the global radiation. These correlation equations have been developed with limited data and apply to Singapore meteorological conditions.

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675406

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper describes work completed on behalf of the Commission of the European Community to develop a control device which may be used within air type solar collectors to regulate airflow. A prototype comprising of a temperature sensor/actuator, control cable and air damper was designed and tested within a simulated solar wall system. The operating characteristics of the complete system were optimised to obtain maximum energy recovery by adjusting the inlet and outlet configurations of the solar wall. In addition, a number of commercially available sensor actuators were tested and rated in order to obtain the best time/temperature response and actuator force development characteristics.

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675407

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675408

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675409

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675410

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-0750    

DOI:10.1080/01430750.1984.9675402

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor