發(fā)布時(shí)間：2018-01-09 12:14

  本文關(guān)鍵詞：基于太陽能熱泵的LPG氣化系統(tǒng)研究　出處：《華北電力大學(xué)》2015年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 太陽能熱泵 液化石油氣 直膨式 氣化 優(yōu)化設(shè)計(jì) 運(yùn)行特性

【摘要】：隨著常規(guī)能源的日漸枯竭和環(huán)境問題的日益嚴(yán)峻,作為清潔能源的液化石油氣(LPG)和可再生能源的太陽能受到中國政府的日益重視和青睞。LPG管道集中供應(yīng)作為天然氣管網(wǎng)的補(bǔ)充在國內(nèi)有著大量應(yīng)用,而太陽能熱泵技術(shù)作為太陽能利用的一種較成熟的應(yīng)用方式,近幾十年來得到了迅速發(fā)展。在LPG管道集中供應(yīng)系統(tǒng)中,傳統(tǒng)的LPG氣化方式能耗高,而太陽能熱泵技術(shù)能夠高效地制取中高溫?zé)崴?可作為液態(tài)LPG的氣化熱源。基于解決LPG氣化高能耗問題和拓寬太陽能熱泵技術(shù)應(yīng)用領(lǐng)域的思想,我們提出了一種新型的基于太陽能熱泵的LPG氣化(Direct Expansion Solar Assisted Heat Pump Vaporization, DX-SAHPV)系統(tǒng),該系統(tǒng)主要由直膨式太陽能熱泵(DX-SAHP)、蓄熱水箱、輔助熱源及氣化器組成,將太陽能熱泵技術(shù)應(yīng)用到城市燃?xì)忸I(lǐng)域,提高了太陽能熱泵的全年利用率。本文利用熱量守恒定律、質(zhì)量守恒定律、氣液相平衡原理和SRK狀態(tài)方程建立了鋼瓶內(nèi)LPG自然氣化模型。將鋼瓶內(nèi)的氣相LPG和液相LPG分別視為實(shí)際氣體和實(shí)際溶液,在模型中考慮了由于非共沸混合物的特性導(dǎo)致的LPG成分變化及其對LPG溫度、壓力、氣化潛熱、密度等物性參數(shù)的影響。以此為基礎(chǔ),在給定初始液相LPG成分和外界參數(shù)的條件下,對充裝LPG的ysp-50型鋼瓶內(nèi)的LPG自然氣化特性進(jìn)行了數(shù)值模擬,并通過已有的實(shí)驗(yàn)結(jié)果進(jìn)行驗(yàn)證。研究發(fā)現(xiàn),自然氣化過程中,氣、液兩相LPG的成分瞬時(shí)變化,LPG溫度急劇下降后基本維持在一定值,氣相中低沸點(diǎn)成分的減少和溫度的降低導(dǎo)致了LPG壓力的下降。對比模擬結(jié)果和實(shí)驗(yàn)結(jié)果及實(shí)際現(xiàn)象,建立的LPG自然氣化模型具備較高的數(shù)值計(jì)算精度。在自然氣化模擬的基礎(chǔ)上確定了定用氣量和變用氣量時(shí)單個(gè)鋼瓶的自然氣化能力。同時(shí),進(jìn)行了居民燃?xì)庥脩粲脷饬亢陀脷庳?fù)荷波動(dòng)性的分析和計(jì)算。該部分工作可以為DX-SAHPV系統(tǒng)的合理設(shè)計(jì)與性能研究提供客觀依據(jù)。為了使DX-SAHP具有良好的熱經(jīng)濟(jì)性,利用有限時(shí)間熱力學(xué)理論建立了DX-SAHP的熱力學(xué)模型。以單位成本熱負(fù)荷最大為目標(biāo)函數(shù),推導(dǎo)出了最佳設(shè)計(jì)參數(shù)(如蒸發(fā)溫度、冷凝溫度、換熱器面積比等)的理論表達(dá)式。同時(shí),考察了環(huán)境參數(shù)、換熱器性能參數(shù)、經(jīng)濟(jì)性參數(shù)等對DX-SAHP優(yōu)化特性和最優(yōu)設(shè)計(jì)參數(shù)的影響。研究結(jié)果表明,DX-SAHP運(yùn)行時(shí),比供熱率應(yīng)小于單位成本熱負(fù)荷最大時(shí)對應(yīng)的比供熱率值,以避免DX-SAHP的供熱性能系數(shù)和熱經(jīng)濟(jì)性出現(xiàn)惡化；內(nèi)不可逆性、單位面積換熱器投資成本、壓縮機(jī)投資和運(yùn)行成本、集熱面太陽輻射強(qiáng)度、集熱／蒸發(fā)器吸收率和透過率的乘積、負(fù)載水溫對DX-SAHP的優(yōu)化特性影響較大,當(dāng)其它參數(shù)不變,這些參數(shù)分別變化10%時(shí),最佳熱經(jīng)濟(jì)性的變化超過2%。根據(jù)LPG自然氣化特性、用戶用氣負(fù)荷和氣象條件波動(dòng)特性,研究了DX-SAHPV系統(tǒng)的六種運(yùn)行模式和運(yùn)行原理。以DX-SAHP熱經(jīng)濟(jì)性優(yōu)化為基礎(chǔ),采用年費(fèi)用最小、一次能源節(jié)省率最大和全球變暖影響指數(shù)最小作為優(yōu)化目標(biāo),針對DX-SAHPV系統(tǒng)的供氣要求,建立了系統(tǒng)的多目標(biāo)優(yōu)化設(shè)計(jì)模型。利用該模型分析了系統(tǒng)中DX-SAHP和輔助熱源的最優(yōu)氣化負(fù)荷分配、各部分最優(yōu)設(shè)計(jì)參數(shù)和最優(yōu)輔助熱源形式,制定了DX-SAHPV系統(tǒng)的優(yōu)化設(shè)計(jì)方法。建立了DX-SAHPV系統(tǒng)的動(dòng)態(tài)仿真數(shù)學(xué)模型,制定了系統(tǒng)中DX-SAHP、輔助熱源和氣化器的啟／停條件,得出各運(yùn)行模式的控制策略,進(jìn)而得出不同運(yùn)行工況下蓄熱水箱數(shù)學(xué)模型的具體表達(dá)形式。在所建立的LPG自然氣化模型、多目標(biāo)優(yōu)化設(shè)計(jì)、系統(tǒng)仿真模型及控制策略基礎(chǔ)上,以規(guī)模為1000戶居民的住宅小區(qū)為供氣對象,深入研究了DX-SAHPV系統(tǒng)在北京地區(qū)的全年動(dòng)態(tài)運(yùn)行性能。此外,改變應(yīng)用地區(qū)的地理參數(shù)和氣象條件,模擬預(yù)測分析了系統(tǒng)在全國幾個(gè)不同太陽能資源等級典型地區(qū)的運(yùn)行性能。
[Abstract]:With the gradual depletion of conventional energy and the increasingly serious environmental problems, as liquefied petroleum gas (LPG) clean energy and renewable energy solar China government pay more and more attention and favor.LPG pipeline as a supplement to focus on the supply of natural gas pipeline network in the country has a large number of applications, and the solar heat pump technology as a kind of solar energy utilization. The mature application, in recent decades has been developing rapidly. Focus on LPG pipeline supply system, the traditional way of high energy consumption of LPG gasification, and solar heat pump technology can efficiently produce high temperature hot water, can be used as heat source for gasification of liquid LPG. To solve the LPG gasification of high energy consumption problem and broaden the field of application of solar heat pump technology based on the idea, we propose a new type of solar heat pump based on LPG gasification (Direct Expansion Solar Assisted Heat Pump Vaporization, DX-SA HPV) system, the system is mainly composed of DX-SAHP (DX-SAHP), storage tank, auxiliary heat source and gasification device, the application of solar heat pump technology to city gas field, improve the utilization rate of the solar heat pump. Based on the law of conservation of energy, the law of mass conservation principle and SRK state equation of cylinder LPG gasification model was established for gas-liquid equilibrium. The cylinder gas phase and liquid phase LPG LPG are regarded as the actual gases and solutions, in the model of senior high school entrance examination considered due to the non azeotropic mixture characteristics lead to LPG component changes and the LPG temperature, pressure, latent heat of vaporization, density and other physical parameters on the basis, given the initial liquid phase LPG components and external parameters under the condition of natural LPG gasification characteristics of ysp-50 type cylinder for filling in LPG was simulated, and the existing experimental results are tested Card. The study found that the natural process of gasification, gas, liquid component instantaneous change of LPG, LPG after a sharp drop in temperature is maintained at a certain value, reduce the low boiling point components in gas phase and temperature led to decreased LPG pressure. Comparing the simulation results and the experimental results and the actual phenomenon, the natural LPG gasification model the establishment of a higher numerical accuracy. On the basis of natural gasification simulation is determined on the fixed gas and natural gas gasification ability of single cylinder. At the same time, the residents of gas users and gas analysis and calculation of gas load fluctuates. This work can provide the objective basis for the study of rational design DX-SAHPV system and performance. In order to make the DX-SAHP has good thermal economy, the thermodynamic theory of a thermodynamic model of DX-SAHP using finite time. The unit cost of heat load as the goal The function, deduced the optimum design parameters (such as evaporation temperature, condensation temperature, heat exchanger area ratio) the theoretical expression. At the same time, effects of environmental parameters, change the performance parameter of heat exchanger, the economic impact of parameters on the optimization characteristics and the optimal design parameters of DX-SAHP. The results show that DX-SAHP is running the heating rate should be less than the unit cost of heat load corresponds to the maximum ratio of heating rate, to avoid heating performance coefficient and thermal economy of DX-SAHP deteriorated; internal irreversibility, unit area heat exchanger compressor investment cost, investment and operation cost, heat collecting surface solar radiation, heat collector / evaporator absorption rate and the transmittance of the product, greater impact load optimization characteristics on DX-SAHP constant temperature, when the other parameters, these parameters were changed in 10% when the economy changes the best heat more than 2%. LPG according to the characteristics of natural gas, gas users with negative Load and meteorological conditions on the wave characteristics of six kinds of operation mode and operation principle of the DX-SAHPV system. The DX-SAHP thermal efficiency optimization as the foundation, the minimum annual cost, an energy saving rate and the impact of global warming index minimum as the optimization goal, according to the requirements of the DX-SAHPV system of the gas supply, a multi-objective optimization model analysis of the gasification system. Optimal load allocation DX-SAHP and auxiliary heat source system by using the model, the optimal design parameters and the optimum auxiliary heat source form, the optimal design method for the DX-SAHPV system. A dynamic simulation model of DX-SAHPV system, developed a system of DX-SAHP, start / stop condition and auxiliary heat source the gasifier, the control strategy for each operation mode, then obtains the specific forms of expression of the mathematical model of the heat storage tank under different operating conditions in the establishment of the LPG. Vaporization model, multi-objective optimization design, model and control strategy based on system simulation, with the scale of 1000 households in the residential supply object, in-depth study of the dynamic performance of DX-SAHPV system in the Beijing area. In addition, change the application areas of the physical parameters and meteorological conditions, simulation and prediction of performance analysis the system in several typical regions of different levels of solar energy resources.

【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TU83

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本文編號：1401350