Combined solar collector and energy storage system

A combined solar energy collector, fluid chiller and energy storage system is disclosed. A movable interior insulated panel in a storage tank is positionable flush against the storage tank wall to insulate the tank for energy storage. The movable interior insulated panel is alternately positionable to form a solar collector or fluid chiller through which the fluid flows by natural circulation

Cooling load forecasting-based predictive optimisation for chiller plants

Extensive electric power is required to maintain indoor thermal comfort using heating, ventilation and air conditioning (HVAC) systems, of which, water-cooled chiller plants consume more than 50% of the total electric power. To improve energy efficiency, supervisory optimisation control can be adopted. The controlled variables are usually optimised according to instant building cooling load and ambient wet bulb air temperature at regular time intervals. In this way, the energy efficiency of chiller plants has been improved. However, with an inherent assumption that the instant building cooling load and ambient wet bulb temperature remain constant in the coming time interval, the energy efficiency potential has not been fully realised, especially when cooling loads vary suddenly and extremely. To solve this problem, a cooling load forecasting-based predictive optimisation method is proposed. Instead of minimising the instant system power according to the instant building cooling load and ambient wet bulb temperature, the controlled variables are derived to minimise the sum of the instant system power and one-time-step-ahead future system power according to both instant and forecasted future building cooling loads. With this method, the energy efficiency potential of a chiller plant can be further improved without shortening the operation time interval. 80% redundant energy consumption has been reduced for the sample chiller plant; energy can be saved for chiller plants that work for years. The evaluation on the effect of cooling load forecasting accuracy turns out that the more accurate the forecasts are, the more redundant energy consumption can be reduced

Modification of air flows within an industrial carcass chiller using delta wing vortex generators

The chilling of carcasses after slaughter has a considerable bearing on process costs and quality of the meat. Uniform air distribution is essential for the optimal operation of carcass chillers, yet many existing chillers have highly variable and ineffective air flow. This directly affects the uniformity of evaporative weight loss and carcass cooling rates within the chiller. Delta plan aerofoils are known to convert a unidirectional air stream, progressively into a rotational and then turbulent multidirectional fragments of moving air. The aim of this research was to evaluate the use of delta wings to improve air flows inside a venison carcass chiller of typical design used in the New Zealand meat industry. Air flow patterns within the chiller were characterised by measuring mean air speeds with a hot-wire anemometer over 61 grid points at 4 levels in height. Air speeds were found to be highly time-variable so the mean, standard deviation and range of 60 one second air speed measurements were used to represent the air flow at each point on the grid. The measurement of air velocity (speed and direction) using three othoganally mounted propeller anemometers had limited success, as air speeds within the chiller were often below the threshold of the anemometer. Measurements before the installation of the delta wings indicated that a poor air flow distribution existed within the chiller as the majority of air was found to circulate around the walls and floor, producing near stagnant conditions between the carcasses. Delta wings were constructed in two sizes from thin aluminium sheets. Wings were installed into the chiller by suspending them from the ceiling within the evaporator fan delivery air stream. Two wing configurations were trialed: The first wing configuration utilised 3 large delta wings mounted in front of the evaporator fans followed by a row of 6 small wings then a row of 7 small wings (3,6,7). The second delta wing configuration utilised a row of 6 large wings closest to the evaporator fans followed by a row of 9 small wings then a row of 13 small wings (6,9,13). The second delta wing configuration showed superior performance over the first. In comparison to the unmodified chiller without wings, the mean air speeds in the critical region amongst the carcasses increased from 0.4 m/s to 0.6 m/s; the standard deviation of mean air speeds decreased from 0.33 m/s to 0.22 m/s and the percentage of mean air speeds between half and twice the mean increased from 84% to 95%. The second configuration of delta wings also produced a 14% increase in the mean air turbulence intensity (measure of the time-variability in air speed) and reduced the variability of evaporative weight loss within the chiller. Overall, the delta wings were found to be an economic way to improve the performance of a chiller by providing a more uniform and effective air distribution without increasing fan power. This can result in a reduction in chilling times and less potential for weight loss. Their use in both new and existing chillers is recommended

Measured performance of a 3 ton LiBr absorption water chiller and its effect on cooling system operation

A three ton lithium bromide absorption water chiller was tested for a number of conditions involving hot water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It was concluded that a three-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions

Experimental Testing and modeling of a Dual-Fired LiBr-H2O Absorption Chiller

An LiBr-H2O chiller was modified to utilize heat sources from natural gas combustion and/or from hot fluid. This was achieved by replacing the original gas-fired generator with a dual-fired generator. Steam was used as the hot fluid. The generator of the chiller can be powered by each source separately or both sources simultaneously. Experimental investigation was performed to obtain capacity and coefficient of performance (COP) of the original chiller and the modified chiller. During the experiments, the modified chiller was powered solely by steam, natural gas, or both. There was a significant increase in COP and capacity when steam was used as a heat source. The tests using natural gas resulted in performance similar to the original chiller. The experimental conditions were closely modeled by a numerical program

ANALISA PERFORMANSI TIPE WATER COOLED CHILLER CENTRIFUGAL KAPASITAS 2000 TR PADA GEDUNG CENTRAL PARK MALL JAKARTA BARAT

Analisa Performansi tipe Water Cooled Chiller Centrifugal Kapasitas 2000 TR. Water Cooled Chiller Centrifugal adalah salah satu tipe AC sentral dengan pendinginan refrigeran menggunakan air dimana pendinginan air melalui menara air (cooling tower), mesin pengkondisian udara ruangan yang digunakan di Central Park Mall Jakartaadalah  water cooled chiller dimana chiller ini menggunakan hampir 30%-40% penggunaan energi listrik dari Central Park Mall Jakarta Barat, Pada proyek akhir ini penulis ingin menganalisis performansi chiller di Central Park Mall Jakarta Barat dengan cara menghitung COP nya dan menghitung emisi CO2 yang dihasilkan dari penggunaan energi listrik tersebut. Hasil dari Tugas akhir ini bertujuan untuk mengetahui performansi dan emisi CO2 yang dihasilkan guna mengidentifikasi kemungkinan untuk dilakukan effisien energi dan juga mengurangi efek pemanasan global.Kata kunci: Chiller, COP, Emisi CO2,Performansi, Efek pemanasan globalPERFORMANCE ANALYSIS OF WATER COOLED CHILLER CENTRIFUGAL WITH 2000 TR CAPACITY AT CENTRAL PARK MALL JAKARTA BARATAnalyze Permance Water Cooled Chiller Centrifugal type Capacity 2000 TR. Water Cooled Chiller Centrifugal is one type of central air conditioner with refrigerant cooling using water where cooling water through a water tower cooling tower, the room air conditioning machine used at Central Park Mall Jakarta is a water cooled chiller where this chiller uses almost 30% - 40% the use of electrical energy from Central Park Mall West Jakarta. In this final project, the writer wanted to analyze chiller performance at Central Park Mall Jakarta by calculating its COP and calculating CO2 emissions resulting from the use of electric energy. The results of this final project aims to determine the performance and emissions of CO2 generated to identify the possibility to be carried out energy efficiency and also reduce the effects of global warming.Keywords: Chiller, COP, CO2 Emissions, Performance, Effects of global warmin

The development and calibration of a generic dynamic absorption chiller model

Although absorption cooling has been available for many years, the technology has typically been viewed as a poorly performing alternative to vapour compression refrigeration. Rising energy prices and the requirement to improve energy efficiency is however driving renewed interest in the technology, particularly within the context of combined cooling, heat and power systems (CCHP) for buildings. In order to understand the performance of absorption cooling, numerous models are available in the literature. However, the complexities involved in the thermodynamics of absorption chillers have so far restricted researchers to creating steady state or dynamic models reliant on data measurements of the internal chiller state, which require difficult-to-obtain, intrusive measurements. The pragmatic, yet fully-dynamic model described in this paper is designed to be easily calibrated using data obtained from the measurements of inflows and outflows to a chiller, without resorting to intrusive measurements. The model comprises a series of linked control volumes featuring both performance maps and lumped mass volumes, which reflect the underlying physical structure of the device. The model was developed for the ESP-r building simulation tool. This paper describes the modelling approach, theory and limitations, along with its calibration and the application of the model to a specific example

Pengaruh Kegagalan terhadap Kinerja Chiller

Dalam artikel ini kami melakukan analisa pengaruh delapan jenis kegagalan terhadap kW/Ton chiller dengan menggunakan regresi satu variabel. Kemudian hasil ini kami bandingkan dengan yangdiperoleh dalam penelitian lain. Hasilnya adalah bahwa tidak semua kegagalan dapat dideteksi dengan Perubahan nilai kW/Ton chiller dan tidak semua kegagalan menyebabkan naiknya konsumsikW/Ton chiller. Selain hal ini, jenis metode regresi dan satuan yang digunakan juga berpengaruh terhadap hasil kW/Ton chiller

Transient thermal analysis of a data centre cooling system under fault conditions

Data centres housing the IT infrastructure of large organisations constitute a considerable technical challenge to ensure 100% operational availability for mission critical IT systems. Specifying plant cooling systems to maintain suitable temperature levels and dissipate the heat generated can be carried out using industry standard design methods. However, accounting for perturbations in cooling due to failure of plant and restart of backup systems requires for faster thermal transients to be addressed than would normally be encountered in building system analysis. It is in this context that this paper describes the modelling and analysis of a 5 MW chilled water cooling system used for the cooling of a recently constructed UK data centre. The model has been developed using the TRNSYS software and includes a full model of the energy transfers for the data centre including chillers, hydraulic network, valve models and each of the 70 Room Air Conditioning Units. The coupling between the data centre air temperature levels and the cooler system has enabled a full assessment of the cooling system design in response to system perturbations. A number of scenarios are examined involving the failure of the chillers and how the inherent thermal inertia of the system plus additional inertia achieved through buffer vessels allowed a suitable design to be achieved. The detailed transient analysis model allowed the sizing of these vessels effectively and to gain a better understanding of the chilled water plant operation, both in normal conditions and in the case of failure