热泵供暖的经济性分析

该文对利用低品位的浅层地下水作为水源热泵的热源，冬季向建筑物供暖的经济性进行了分析研究，结果表明用低品位的地热资源利用热泵技术进行供暖具有很好的节能和环保效益。     

回收循环水余热的热泵供热系统经济性分析

利用热泵技术回收电厂循环水余热,能够提高机组的热效率和供热能力,降低机组的冷源损失。从热泵制热性能系数COP出发,分析压缩式和溴化锂吸收式热泵的节能机理,并以300MW机组为例,在保证供热负荷不变的情况下,计算分析2种热泵供热系统的经济性。计算结果表明:溴化锂吸收式热泵供热机组的经济性优于压缩式热泵机组,整个供暖期间,获得的总节能收益比压缩式热泵供热机组高785.8万元。在乏汽利用方面,压缩式热泵供热机组的节水量要远高于溴化锂吸收式热泵供热机组,这对于某些缺水地区有重要意义。     

低温地热运用热泵供热的技术经济性

结合某工程可行性研究,分析了低温地热运用热泵供暖,供生活热水的技术经济性,并与传统锅炉供热方式进行比较,讨论了地热热泵应用的可行性。     

热泵供热技术应用分析——石家庄案例

石家庄市是我国首批清洁取暖示范城市之一,在采用热泵技术供热方面做出了积极探索。本文介绍了石家庄市应用各类热泵的技术特点和适用场景,梳理了典型案例,对集中热源和分散热源热泵的供热技术进行了对比分析,为热泵供热在其他城市应用推广提供了参考。     

水源热泵在空调系统中应用的经济性分析

本文对水源热泵的能耗进行了分析,表明水源热泵机组的性能系数与水源的温度直接相关,讨论了水源热泵在嵊州市空调系统集中供冷供热的可行性,对集中冷热水供水系统夏季空调工况与冬季热泵工况的经济性进行了计算与分析,结果表明,嵊州市利用水源热泵建立集中冷热水供水系统的社会经济效益显著,具有重要的节能与环保意义。     

抚顺地区水源热泵的经济性分析及应用

抚顺地区具有丰富的水资源,根据水源热泵系统的工作原理,提出在该地区采用水源热泵替代燃煤集中供热的采暖方案。以抚顺地区的工程为例,把地下水水源热泵机组与燃煤集中供热锅炉进行经济性和环保性分析比较。结果表明:水源热泵方案是可行、经济、而且更加环保,应在抚顺地区大力推广。     

地源热泵及其应用分析

介绍了地源热泵的类型、原理及特点，并对水平埋管和竖直埋管的地源热泵与空气源热泵的经济性进行了比较。结果表明，对小型住宅，采用水平埋管的地源热泵经济性最好。     

Performance of ejector heat pumps

An ejector-compression heat pump can use low-grade thermal energy in the neighbourhood of 93.3°C (200°F) to provide space cooling and heating. This paper applies the existing ejector theory to estimate the performance of an ejector heat pump system at various operating conditions. The study includes parametric, sensitivity and off-design analyses of the heat pump performance. The performance enhancement options and desired ejector geometry are also examined. Refrigerants 11, 113 and 114 are three of the halocarbons most suitable for the ejector heat pump system. The estimated coefficients of performance for a simple ejector heat pump are 0.3 for the cooling mode and 1.3 for the heating mode at a sample operating condition in which the refrigerant (R-11) boiling temperature is 93.3°C (200°F), condensing temperature 43.3°C (110°F) and evaporating temperature 10°C (50°F). A 24 per cent performance improvement is predicted for a heat pump with two-stage ejectors and regenerative heat exchangers. The off-design performance is relatively insensitive to the evaporator temperature variations.     

Heat pumps and combined heat and power a technology assessment

This paper utilizes a novel system boundary and methodological framework for comparing the technical, economic and institutional factors affecting the development of advanced heating technologies. The focus is on the USA where electric heat pump technology has recently gained widespread acceptance; parts of the centralized combined heat and power (CHP) industry are in a state of decline; and a rapidly changing regulatory environment is stimulating development of small decentralized gas-fired CHP systems.     

Metal hydride heat pumps

Heat pumps have been known for a long time, but, until the energy crisis of 1973, there were only a few studies covering them. Since that time, in addition to alternative energy sources, scientists and engineers have started studying heat pumps more earnestly. There are several kinds of heat pump and utilizations of them, but the most common one is the vapour-compression heat pump. In recent years researchers have started to study metal hydride heat pumps. The paper considers the metal hydride bed, its thermodynamics, and its utilization as a heat pump. It is also compared with conventional heat pumps. The results indicate that the metal hydride heat pump has several advantages, and its utilization in the industrial, commercial and residential fields is foreseen.     

Value of electric heat boilers and heat pumps for wind power integration

The paper analyses the economic value of using electric heat boilers and heat pumps as wind power integration measures relieving the link between the heat and power production in combined heat and power plants. Both measures have different technical and economic characteristics, making a comparison of the value of these measures relevant. A stochastic, fundamental bottom‐up model, taking the stochastic nature of wind power production explicitly into account when making dispatch decisions, is used to analyse the technical and economical performance of these measures in a North European power system covering Denmark, Finland, Germany, Norway and Sweden. Introduction of heat pumps or electric boilers is beneficial for the integration of wind power, because the curtailment of wind power production is reduced, the price of regulating power is reduced and the number of hours with very low power prices is reduced, making the wind power production more valuable. The system benefits of heat pumps and electric boilers are connected to replacing heat production on fuel oil heat boilers and combined heat and power (CHP) plants using various fuels with heat production using electricity and thereby saving fuel. The benefits of the measures depend highly on the underlying structure of heat production. The integration measures are economical, especially in systems where the marginal heat production costs before the introduction of the heat measures are high, e.g. heat production on heat boilers using fuel oil. Copyright © 2007 John Wiley & Sons, Ltd.     

Extended mechanical efficiency theorems for engines and heat pumps

Prior work by the author established basic theorems relating the mechanical efficiency of an engine to its thermodynamic cycle, external pressure, and the effectiveness of its mechanism. That work treated the elementary single‐workspace reciprocating piston heat engine. This paper extends the analysis to cover more complex engine types and heat pumps, including double‐acting and split‐workspace devices. Theorems are derived which allow best‐possible estimates and broad comparisons of the overall performance of a large variety of thermomechanical machines. Examples from the field of Stirling engines illustrate the application of the main results. Copyright © 2000 John Wiley & Sons, Ltd.     

Optimum arrangement and use of heat pumps in recovering waste heat

Relations are derived for the coefficient of performance of heat pump systems used to transfer heat from a low temperature heat source stream to a high temperature heat sink stream. The manner of use and operation of a number of heat pumps in such a system has been determined for the thermodynamic optimum for reversible and irreversible heat pumps.     

A comparative thermodynamic study of fluorocarbon refrigerant based vapour absorption heat pumps

A thermodynamic analysis of the vapour absorption heat pump (VAHP) cycle is made to study the performance of four fluorocarbon based working fluid pairs namely, R21-DMETEG, R21-DMF, R22-DMETEG and R22-DMF. The performance characteristics compared are total heat output per unit solution flow rate; heating coefficient of performance; second law efficiency and circulation ratio. Among the four combinations, R21-DMETEG stands out as the most suitable solution for low temperature VAHP applications. Correlations are given for quick estimation of COP and limiting generator temperature. The effects of mass transfer effectiveness at generator and absorber on the performance are also investigated.     

The drying of grain with heat pumps in South Africa: A techno-economic analysis

The economic viability of air heating for grain drying with the aid of heat pumps and the viability of replacing existing heating methods (i.e. direct electrical heaters and diesel burners) with heat pumps are investigated. The energy costs of different types of heating apparatus to dry grain are calculated and, taking the different capital costs into account, the life cycle costs of the heating methods can be predicted. On comparing the life cycle costs of the different heating methods, it is concluded that heat pumps are more economical than other methods of heating provided that the apparatus is used for more than a minimum period per year. Drying of grain is usually done for periods shorter than this minimum; the result is that the use of heat pumps cannot be economically justified for the drying of grain only.     

Opportunities for the integration of absorption heat pumps in the pulp and paper process

Implementation of absorption heat pumps (AHPs) in a Kraft pulping process was studied using a new methodology for the optimal integration of those devices in a process. Two generic opportunities were identified for an energy and water optimized mill: (i) integration of a double lift chiller in the bleaching chemical making plant to produce chilled and hot water simultaneously, using MP steam as the driving energy and, (ii) installation of a single stage heat pump to concentrate the black liquor and produce useful hot water by upgrading heat from the bleaching effluent and using MP steam as driving energy. The principles of AHPs operation and their efficient integration into a process are described. The simple payback time (SPB) and net present value (NPV) were used to evaluate the interest of such implementations. Considering 63 $/MWh for the steam price, SPB of 2.7 and 1.7 years have been estimated for the two cases.