Energy saving analysis of a hybrid ground-coupled heat pump project

A hybrid ground-coupled heat pump（HGCHP）project in Nanjing,China is chosen to analyze the building energy-consumption properties in terms of different control strategies,building envelope and the terminal air-conditioning system.The HGCHP uses a supplemental heat rejecter to dissipate extra thermal energy to guarantee underground soil heat balance.The software EnergyPlus is employed to simulate the project and design the heat flow of the cooling tower and the borehole heat exchanger（BHE）.Then two feasible control strategies for the cooling tower and the borehole heat exchanger are proposed.The energy-saving potential of the building envelope is analyzed in terms of the surface color of the wall/roof.With the same terminal system,it is found that in the cooling season the heat flow of the insulated building with black wall/roof is 1.2 times more than that with white wall/roof.With the same insulated building and gray wall/roof,it is concluded that the heat pump units for a primary air fan-coil system show an annual energy consumption increase of 44.7 GJ compared with a radiant floor system.

Energy savings and CO_2 emission reduction by using geothermal heat pumps

The renewable energy will play significant role in the world primary energy consumption in the future. Geothermal energy is immense with 5 000 EJ/a of technical potential, and geothermal heat pumps (GHPs) are one of the fastest growing applications of renewable energy in the world with annual increases of 10 % and much faster in China. With high coefficient of performance (COP) up to 6, GHPs make efficiency of primary energy more than 240 % with assumed a 40 % of electricity generation efficiency, which means energy savings and CO2 emission reduction. In this paper,the geothermal resources and its utilization are talked about, and GHPs technology was introduced. Due to its high efficiency, there will be energy savings by using GHPs. There is also CO2 emission reduction because of using geothermal heat pumps, which is analyzed in the end.

Case Studies of Energy Saving and CO₂Reduction by Cogeneration and Heat Pump Systems

This paper describes two case studies: 1) a cogeneration system of a hospital and 2) a heat pump system installed in an aquarium that uses seawater for latent heat storage. The cogeneration system is an autonomous system that combines the generation of electrical, heating, and cooling energies in a hospital. Cogeneration systems can provide simultaneous heating and cooling. No technical obstacles were identified for implementing the cogeneration system. The average ratio between electric and thermal loads in the hospital was suitable for the cogeneration system operation. An analysis performed for a non-optimized cogeneration system predicted large potential for energy savings and CO2 reduction. The heat pump system using a low-temperature unutilized heat source is introduced on a heat source load responsive heat pump system, which combines a load variation responsive heat pump utilizing seawater with a latent heat-storage system (ice and water slurry), using nighttime electric power to level the electric power load. The experimental coefficient of performance (COP) of the proposed heat exchanger from the heat pump system, assisted by using seawater as latent heat storage for cooling, is discussed in detail.

Possibilities of Reducing Energy Consumption by Optimization of Ground Source Heat Pump Systems in Babylon, Iraq

Iraq is located in the Middle East with an area that reaches 437,072 km2 and a population of about 36 million. This country is suffering from severe electricity shortage problems which are expected to increase with time. In this research, an attempt is made to minimize this problem by combining the borehole thermal energy storage (BTES) with a heat pump, the indoor temperature of a residential building or other facility may be increased or reduced beyond the temperature interval of the heat carrier fluid. Due to the relatively high ground temperature in Middle Eastern countries, the seasonal thermal energy storages (STES) and ground source heat pump (GSHP) systems have a remarkable potential, partly because the reduced thermal losses from the underground storage and the expected high COP (ratio of thermal energy gain to required driving energy (electricity)) of a heat pump, partly because of the potential for using STES directly for heating and cooling. In this research, groundwater conditions of Babylon city in Iraq were investigated to evaluate the possibility of using GSHP to reduce energy consumption. It is believed that such system will reduce consumed energy by about 60%.

Multi-Effect Evaporation Coupled with MVR Heat Pump Thermal Integration Distillation for Separating Salt Containing Methanol Wastewater

Due to the high energy consumption for separation of salt containing methanol wastewater, in this work, the multi-effect evaporation coupled with mechanical vapor recompression (MVR) heat pump and thermal integration technologies were raised for the first time. The ELECNRTL thermodynamic model is used to simulate and optimize the evaporation rectification process. Energy consumption and total annual cost (TAC) are taken as objective functions. The results show that multi-effect evaporation coupled with conventional distillation process can save energy consumption and TAC by 44.12% and 39.14%. The multi-effect evaporation coupled with distillation process based on MVR heat pump technology can save energy consumption and TAC by 55.27% and 47.49%, which is super to three-effect evaporation coupled with conventional distillation process. The three-effect evaporation coupled with MVR heat integration process can save energy consumption and TAC by 81.32% and 58.55%, which is more economical than other processes. It can be clearly seen that three-effect evaporation coupled with MVR heat integration process is more competitive to deal with the salt containing methanol wastewater.

Synthesis and Design of Distillation Columns for Wide-Boiling Binary Mixtures with Vapor Recompression Heat Pumps

The vapor recompression heat pump(VRHP) distillation technology offers significant improvements in energy efficiency for distillation systems with small temperature differences between the top and bottom of the column. However, the separation of wide-boiling binary mixtures leads to substantial temperature differences between the top and bottom of the column. This limits the applicability of conventional VRHP due to high capital costs and strict performance requirements of the compressor. To overcome these challenges and to accommodate compressor operating conditions, a novel synthesis and design method is introduced to integrate VRHPs with wide-boiling binary mixture distillation columns(WBMDCs). This method enables quick determination of an initial configuration for the integrated WBMDC-VRHP system and helps identify the optimum configuration with the minimum total annual cost. Two examples, namely the separation of benzene/toluene and isopropanol/chlorobenzene, are employed to derive optimum configurations of the WBMDC-VRHP and compare them with the WBMDC. A systematic comparison between the WBMDC-VRHP and WBMDC demonstrates the superior steady-state performance and economic efficiency of the WBMDC-VRHP.

Design and Analysis of a Small Sewage Source Heat Pump Triple Supply System

Based on the characteristics of sewage from beauty salons,a simulation model of a small sewage source heat pump triple supply system that can be applied to such places is established to optimize the operating conditions of the system.The results show that with the increase of sewage temperature and flow,the performance of the system also increases.In summer conditions,the system provides cooling,recovers waste heat and condensed heat from sewage,with a COP value of 8.97;in winter conditions,the system heats and produces hot water,with a COP value of 2.44;in transitional seasons,only hot water is produced.The COP value is 2.75.Compared with the traditional systems which refers to the air source heat pump and hot water boiler system currently used in beauty salons,this system can save energy by 50.9%.

Recent Development and Application of Geothermal Heat Pump Systems in Cold-Climate Regions of the US: A Further Investigation

A Geothermal Heat Pump (GHP) system is known to have enormous potential for building energy savings and the reduction of associated greenhouse gas emissions, due to its high Coefficient Of Performance (COP). The use of a GHP system in cold-climate regions is more attractive owing to its higher COP for heating compared to conventional heating devices, such as furnaces or boilers. Many factors, however, determine the operational performance of an existing GHP system, such as control strategy, part/full-load efficiency, the age of the system, defective parts, and whether or not regular maintenance services are provided. The omitting of any of these factors in design and operation stages could have significant impacts on the normal operation of GHP systems. Therefore, the objectives of this paper are to further investigate and study the existing GHP systems currently used in buildings located in cold-climate regions of the US, in terms of system operational performance, potential energy and energy cost savings, system cost information, the reasons for installing geothermal systems, current operating difficulties, and owner satisfaction to date. After the comprehensive investigation and in-depth analysis of 24 buildings, the results indicate that for these buildings, about 75% of the building owners are very satisfied with their GHP systems in terms of noise, cost, and indoor comfort. About 71% of the investigated GHP systems have not had serious operating difficulties, and about 85% of the respondents (building owners) would suggest this type of system to other people. Compared to the national median of energy use and energy cost of typical buildings of the same type nationwide, the overall performance of the actual GHP systems used in the cold-climate regions is slightly better, i.e. about 7.2% energy savings and 6.1% energy cost savings on average.

Research on Energy Saving Optimization of MVR Distilled Water Machine

Compared with the multi-effect distilled water machine,the mechanical vapor recompression(MVR)distilled water machine has many advantages,and has been a trend to replace the traditional distilled water machine.Based on the conservation equations of mass and energy,this paper designs an MVR distilled water production process and establishes the corresponding thermodynamic model.Effects of the produced water temperature,heat exchange temperature difference,compressor adiabatic efficiency,and pipeline loss to the produced water energy consumption,energy saving rate and coefficient of performance(COP)were studied.Research shows that the MVR distilled water machine is more suitable for occasions with low water production temperature.Appropriate heat exchangers and compressors should be selected to improve comprehensive performance through heat exchange temperature differences and improving adiabatic efficiency.

VRV多联机地源热泵系统的技术经济案例分析

VRV多联机地源热泵是由VRV多联机和地源热泵两种技术组合而成的一种新的节能技术。这里以上海某办公楼的VRV多联机地源热泵系统为研究对象,与其他三种常规空调系统进行比较,对VRV多联机地源热泵系统的经济性进行分析。利用BIN法对该办公楼各空调方案的能耗进行计算,并结合上海市的公共事业费率,通过对比分析各方案的一次能耗、初投资、运行费用、费用年值,得到VRV多联机地源热泵系统的经济性。

多元VRV空调系统性能研究

提高舒适性与降低能耗是空调系统的发展方向。在现代建筑中，在同一时刻，有的房间需要制冷，有的房间需要制热，甚至有的房间既不需要制冷也不需要制热，传统的空调系统只能所有房间同时供热或同时制冷，本文提出了一种新型的多元热回收ＶＲＶ空调系统。此系统由一个室外机和多个室内机构成。系统通过变频压缩机和电子膨胀阀自动调节各室内机的制冷剂流量以满足各个房间的负荷的需要，通过电子膨胀阀与电磁三通阀的切换实现多个房间同时制冷和制热的要求。制热房间的室内机作为冷凝器，制冷房间的室内机作为蒸发器，而室外机可能是冷凝器也可能是蒸发器。这样，由于冷凝热与蒸发热同时被利用，系统能效比大大提高，与得到相同冷热量的分散机组相比，室外机的容量和能耗都大大降低。与传统的空调系统相比，此系统用较低的能耗提供有较高的舒适性，适用于住宅或商业建筑使用，有制冷、热泵和热回收等五种运行模式，可在全年内运行。

VRV空调系统的节能因素分析

扼要地介绍了VRV空调系统的特点及发展状况 ,从机械制造、传热介质、设计理念、自动控制以及新风处理等角度分析了该系统的运行节能因素 ,提出了该系统有待解决的一些问题 。

大金变频控制热泵式VRV空调机组制冷运行特性的实验研究

本文对大金变频控制热泵式ＶＲＶ空调系统夏季制冷运行时的节能性作了一系列实验研究，得到了ＶＲＶ空调系统的夏季部分负荷运转特性，并在节能方面与普通风冷热泵冷热水机组作了比较，证明该空调机组比普通风冷热水机组节能。

变频控制VRV空调系统热回收系列及其节能性分析

本文主要介绍了变频控制VRV空调系统热回收系列空调器的形式、运行方式和特点，并对其节能性作了分析。

VRV(变制冷剂流量)空调系统热回收型在建筑内区的应用及节能性分析

为了降低空调系统的能耗,对于建筑内区的房间在冬季需要供冷的情况下,可以用变频技术中的热回收型VRV(变制冷剂流量)空调系统,充分利用室内的冷量和热量,实现冷热能量在建筑物内的最佳平衡从而达到节能效果。通过对热回收型VRV中央空调系统的结构和运行原理及具体工程实例的分析,对热回收型VRV(变制冷剂流量)空调系统在建筑内区的应用及其节能性进行了探讨。

变频控制热泵式VRV空调机组运行特性与节能性能实验研究

本文对变频控制热泵式VRV空调系统冬夏季运行特性和节能性能作了一系列实验研究 ,分析了影响室内机制冷 (热 )量、机组功率的因素 ,得到了VRV空调系统的部分负荷运转特性 ,并在节能性能方面与普通风冷热泵冷热水机组作了比较 。

VRV空调系统与螺杆式风冷热泵空调系统全年能耗比较

本文针对某一实际建筑,分别进行VRV空调系统和螺杆式风冷热泵空调系统设计,并利用动态负荷计算软件,对VRV空调系统和螺杆式风冷热泵空调系统进行了全年运行季节动态能耗计算,并利用季节能效比SEER分析比较了两种空调系统在冬、夏季运行季节内的能耗利用情况。

无锡某SOHO办公楼水源热泵VRV空调系统设计及分析

对某办公楼空调系统的设计做了多方案比选,最终确定为水源热泵VRV系统方案。对水源热泵VRV系统的设备做了设计选型,对水源热泵VRV的建设模式、节能运行做了讨论,为地产开发商、设计咨询公司、施工企业等提供参考。

多功能VRV空调系统在别墅中的应用

通过具体的项目设计实例,介绍多功能VRV空调系统整合了家用中央空调、地面辐射采暖和生活热水三大系统的原理和特点,总结其应用于别墅项目中的一些设计经验,分析该系统与传统暖通系统的区别与不同。

多联式智能化中央空调系统——大金VRVⅢ空调系统

随着空调行业的不断发展,空调系统的种类逐日增多,如螺杆机、离心机、溴化锂、多联机、水地源热泵等。近年来,多联机以其节能性、舒适性、便利性以及可靠性等诸多特点,在国内得到广泛的应用。文章将以多联机行业的开拓者及领头羊——大金为例,介绍多联机的发展情况及特点。