Abstract: The application of high temperature water source heat pump to Dagang Oilfield is analyzed in this paper. It has great advantages over alternatives in many aspects such as economy. The applied analysis of high temperature heat pump using at DaGang Oil Field Fuchun Meng Jing You (Beijing Qingyuanshiji Scientific & technical Ltd.) Abstract: This essay make a analysis of high temperature heat pump use at DaGang Oil Field, at several respects such as economy, have a huge advantage. Keyword: High temperature heat pump; Geo-heating; Tail water; Energy-saving; Environmental protecting I. Project Overview Dagang Oilfield Group Drilling Engineering Co., A drilling company located in Dagang, Tianjin, the existing geothermal wells, geothermal water outlet water temperature is 55 ℃, the water volume is 25t / h, 2003-2004 heating season using Beijing Qingyuan Century Technology Co., a high-temperature water source heat pump, total Heating area of ​​8500 square meters, of which 5500 square meters for the cottage area, office building area of ​​3000 square meters. Before 2003, the use of geothermal water for direct heating, poor heating effect; using high-temperature water source heat pump, after a heating season of the actual operation, the heating effect is good, exceeding the original design requirements. Second, the load calculation After checking the relevant norms, outdoor heating temperature calculation in winter in this region is -9 ℃, indoor calculation temperature is 18 ℃. Load index office building in accordance with 60W / ㎡ to calculate; cottage in accordance with 100W / ㎡ to calculate. Total heating area of ​​office building: F = 3000㎡ Total heat load of office building: Q = q × F = 60 × 3000 = 180kW Total heating area of ​​bungalow: F = 5500㎡ Total heat load of bungalow: Q = q × F = 100 × 5500 = 550kW Third, the status quo analysis Dagang Oilfield Group Drilling Engineering Company First Drilling Company total heating area of ​​8500 square meters, the heating season in 2003 before the use of geothermal water for direct heating, geothermal water for direct heating of hot water available temperature drop is limited According to the experience of geothermal heating in Tianjin, the minimum discharge temperature of the geothermal water in the heating system with the radiator at the end should not be lower than 35 ℃. According to this calculation, the heat that can be released when the geothermal water is heated is: Q = 25 × ( 55-35) × 1.163 = 582kw, which is 20% less than the maximum heat load of the system of 730kw. In the actual heating system, the heating users are more dispersed and the main pipes for heating and water supply are outdoors overhead laying with greater heat loss, At the same time the system has not made big changes over the years, there is leaking and more serious scaling phenomenon, cooling effect is not good, heating system is not here for low supply, return water temperature operating conditions design, radiator cooling area is insufficient, These are the reasons Thermal less than 40%, when heating the indoor temperature more in the following 12 ℃, seriously affected the normal work. Fourth, the heating program 55 ℃ geothermal water through the first system of supply to the cottage, as much as possible after the release of heat into the heat pump, the plate heat exchanger and circulating water for heat exchange, complete the heat exchange cycle water into the high temperature water source heat pump unit by the heat After the upgrade, the output of 75 ℃ high temperature hot water supply to the end of the radiator plate 3000 ㎡ office building heating. Geothermal water supply bungalow temperature decreases, into the plate before the temperature dropped to less than 36 ℃. A total of 118 rooms in the office building, the majority of the company's workers in the building office, the higher requirements of the environment, most of the bungalow at night were mostly uninhabited and therefore relatively less effect on the heating effect, so the key to this project is : Completely solve the heating problems in office buildings at the same time very good to improve the heating system cottage effect. The implementation of the renovation program mainly includes the following: 1. The original heating system is divided into two systems, namely office building system and bungalow heating system, the original bungalow heating system follows the method of direct heating of geothermal water unchanged, re-laying Supply and return to the main channel, to make the pipeline external insulation, through the calculation to increase the area of ​​the radiator at the end of the cottage heating system, all the hot water first for the cottage system heating, hot water can exotherm 582kw, consider the tube Network heat loss, the basic can meet the 550kw cottage system maximum heat load requirements. 2. In order to prevent the geothermal tail water from damaging the evaporator of the heat pump unit, the office heating system is equipped with a titanium alloy plate heat exchanger, and the geothermal tail water after the heating of the bungalow system enters the plate exchange and circulating water on the heat pump evaporator side Heat exchange, the heat pump compressor work in the condenser heat while outputting 75 ℃ high temperature hot water for the office heating, heat pump evaporator side of the circulating water and office heating system circulating water are used to soften the water, to avoid the heat Water corrosion and heat pump units, system pipe network scaling. 3. In the office building heating system to add replenishment pressure system, the circulatory system; The main equipment of electric power: QYHP-220H high temperature water source heat pump: 66kW circulating pump (one with a backup): 1.5kW heat source water circulation pump : 1.5kW Replenishment pump (one with a prepared): 1.1kW Actual conditions checking: 25t / h, 55 ℃ geothermal water through the bungalow, the temperature dropped to 36 ℃, the release of energy: Q = 582kW, consider Pipe network heat loss, basic to meet the 550kw cottage system maximum heat load requirements. QYHP-220H high temperature water source heat pump unit in this design conditions, the actual heating capacity of 193kW, fully able to meet the office building in the coldest weather heating needs. Economic Analysis According to a heating season analysis of operating conditions, high-temperature water source heat pump unit works well, because the heat pump itself has a complete automatic control function, operation and management personnel according to the weather, set the heat pump water temperature so that the heat pump Average COP has been greatly improved, for example, the weather is not too cold, the heat pump outlet temperature is set to 55 ℃, then the heat pump COP reached 5 or more, energy saving is very good. In the following calculation, we consider the average COP of the heating season of the heat pump system (considering the power consumption of the water pump); 3.8 Price: The electricity price of the project adopts the large industrial electricity price: 0.45 yuan / kWh; the heating time is 120 days / Average annual heat index: consider the 24-hour uninterrupted heating average thermal index of 32w / ㎡. The annual running cost of the project is (excluding geothermal water fee): 32740 Average per square meter: 10.91 yuan / ㎡ If you do not use high-temperature water source heat pump, the region will use oil-fired boiler (90% efficiency), then The annual running cost is: 108,336 yuan, equivalent to the unit heating area: 36.11 yuan / ㎡, the operating cost is 330% of the heat pump. The following table shows the investment income analysis of high-temperature water source heat pump and oil-fired boiler (for 3000 ㎡): High-temperature water source heat pump system Oil-fired boiler system Energy mode Electric fuel + circulating pump Electricity consumption Average daily energy consumption 606kW.h 72kW.h + 256kg Oil average Daily operation cost 273 yuan 903 yuan Energy consumption throughout the heating season 72720kW.h 8640kW.h +30720kg Oil throughout the heating season operating costs 32724 yuan 108336 yuan per square meter operating costs 10.91 yuan / ㎡ 36.11 yuan / ㎡ initial investment 260,000 yuan 100,000 yuan Static investment recovery period of 2.2 years It can be seen from the above table, the use of high-temperature water source heat pump system, has an excellent return on investment advantages. VI. Project Features 1. Waste Heat Utilization, Economic and Energy Saving The project makes full use of the thermal energy in the geothermal tail water to make one well serve the two wells and not only meets the demand for heating, but also significantly reduces the temperature of the tail water of the geothermal water , Is conducive to the oil field on the further utilization of these geothermal water. 2.Green environmental protection, significant benefits Geothermal water with high temperature water source heat pump to replace the oil-fired boiler can achieve good environmental effects and economic effects, to avoid the oil-fired boiler on the environment pollution. There are no safety issues at the same time. 3. Optimize the system to save pump consumption The original plan is to use direct supply of geothermal water, geothermal water on the system there is a serious corrosion, according to the actual situation in the field, only about two years, all external pipe corrosion . The most important office building system in the heating system is now replaced by a mezzanine, greatly reducing the cost of overhauling the heating system. At the same time, the supply and demand of direct supply will also bring about a great reduction in the power consumption of the pump. The circulating pump power consumption in this project is only 1.5kW. 4. Focus on the outstanding, taking into account the rest of the transformation, not only to achieve the heating needs of the office building, the original part of the cottage as a secondary heating issues have been well resolved, optimizing the working environment, all employees receive the praise . 5. Multi-purpose machine, save money In this project, the use of high-temperature water source heat pump to provide winter heating at the same time, but also to provide summer cooling, there are 100KW of cooling capacity can be about 1000 ㎡ ordinary buildings for summer cooling, Multi-purpose machine, thus avoiding the duplication of central air-conditioning investment and improve the utilization of equipment. 6 stable performance, high degree of self-control High-temperature water source heat pump running a high degree of automation, easy to control, less operating personnel, field personnel reflect, just set the water temperature, heat pump compressor will be automatically based on the backwater temperature to upload and Download, energy saving is very good.
