CN201203297Y - Solar-assisted direct-fired hot and cold water unit - Google Patents

Abstract

The utility model relates to a solar-assisted direct-fired hot and cold water unit. The system consists of a high-voltage generator (1), an air-water heat exchanger (2), a waste heat generator (3), a flue gas pipe (4), and a solar collector. Heater (5), low pressure generator (6), condenser (7), absorber (8), evaporator (9), cooling tower (10), cooling (heating) coil (11), low temperature solution heat It consists of an exchanger (12), a high-temperature solution heat exchanger (13), valves and pumps. On the basis of the original double-effect direct-fired hot and cold water machine, the unit introduces a single-effect cycle composed of solar collectors, steam-water heat exchangers and waste heat generators to form a new cycle. Use the solar heat collector (5) to heat the circulating water and make the temperature rise initially, then pass it into the air-water heat exchanger (2) to further increase the temperature, and the high-temperature hot water flowing out from the air-water heat exchanger (2) Entering the waste heat generator, when cooling water and heating water, it is used as an auxiliary driving heat source to heat the solution to provide cooling and heat respectively, while reducing fuel consumption. The utility model optimizes the circulation system by making full use of the low-grade solar heat source and the high-temperature flue gas generated by combustion in the high-pressure generator of the direct-fired engine, so that the energy utilization efficiency is improved compared with the double-effect direct-fired hot and cold water unit, and the energy-saving effect is remarkable. , the primary energy efficiency PER can be increased by 9%.

Description

Solar-assisted direct-fired hot and cold water unit

technical field

The utility model relates to a direct-fired cold and hot water unit, in particular to a solar-assisted direct-fired cold and hot water unit for air conditioning.

Background technique

Estimates made by the International Institute of Refrigeration (IIR) show that 15% of the world's electrical energy is consumed in various refrigeration and air-conditioning industries, and air-conditioning consumes 45% of the energy consumed by homes and commercial buildings. The proportion of my country's building energy consumption to the total energy consumption of all end users will reach 35% in recent years. The research on building energy consumption shows that the energy consumption of air-conditioning accounts for up to 60% of the total energy consumption of office buildings. With the improvement of economic conditions in my country, the energy consumption of building air-conditioning continues to rise. The environment brings a lot of pressure. Therefore, energy saving is a major issue related to the national economy and the people's livelihood. The two main ways to save energy are: improving energy utilization efficiency and using renewable energy.

The direct-fired absorption chiller is an air-conditioning cold and heat source equipment driven by natural gas and other fuels. Its working fluid does not damage the ozone layer and effectively reduces the peak-valley difference in power supply caused by electric air-conditioning, which is conducive to balancing the increase in gas consumption in winter and summer. Features such as the utilization rate of natural gas pipelines and the reduction of natural gas transmission costs are increasingly popularized. In order to alleviate the contradictions of energy demand, environmental protection, and load balance, direct-fired absorption chillers that directly use natural gas as power have been applied in areas with sufficient natural gas sources, which can replace the electric chillers of central air conditioners. However, both theoretical analysis and actual operation show that absorption chillers are worse than electric chillers in terms of energy consumption, economy, maintenance management and operating life. How to make the direct combustion engine play its advantages better, the industry has done and is doing a lot of research, such as: the cycle research of the direct combustion engine, such as the research of the cycle of the three-effect engine and the four-effect engine; the research of the absorption heat pump; the absorber Research on the enhanced heat and mass transfer of surfactants and generators; research on corrosion inhibitors; research on combustion efficiency, etc. Among them, the temperature of the solution in the three-effect lithium bromide absorption refrigeration cycle has been greatly improved compared with the single-effect machine and the double-effect machine. However, the corrosion inhibitors commonly used in double-effect lithium bromide units can no longer meet the requirements. In addition, the physical properties of lithium bromide solutions in high temperature areas lack standard data, and there are many difficulties in carrying out experimental research. The current research is mainly theoretical analysis, which is not relatively mature in China. Some foreign research institutions and companies are also in the experimental research stage. The temperature generated in the high-pressure generator of a double-effect direct-fired engine commonly used in the market reaches about 160°C. During actual operation, the exhaust gas temperature is generally above 190-200°C. Such a high exhaust gas temperature is not only a waste of energy, but also harmful to the environment. Also cause thermal pollution. Some people in China have done research and proposed a direct-fired hot and cold water machine with flue gas waste heat recovery. However, due to the limited recovery of flue gas, its economy cannot be fully reflected. On the other hand, solar energy is a kind of radiant energy without any chemical substances. It is the cleanest and most reliable huge energy treasure house. In recent years, solar thermal technology has been greatly developed. Based on this, the solar absorption air conditioner was once valued by the industry. Many solar air conditioners have emerged one after another at home and abroad. However, due to the low density of solar energy, most solar thermal technologies The grade of the heat source obtained is lower. Simultaneously because the instability of solar energy has limited the popularization of pure solar air conditioner.

Contents of the invention

The technical problem to be solved by this utility is to provide a solar-assisted direct-fired hot and cold water unit to alleviate the defects of low energy utilization efficiency and high fuel consumption in the existing direct-fired hot and cold water technology.

Technical solutions

The utility model provides a solar-assisted direct-fired hot and cold water unit, including a high-pressure generator, an air-water heat exchanger, a waste heat generator, a flue gas pipe, a solar heat collector, a low-pressure generator, a condenser, an absorber, Evaporators, cooling towers, cooling (heating) coils, low temperature solution heat exchangers, high temperature solution heat exchangers, and valves and pumps. On the basis of the traditional double-effect absorption cycle, the unit adds a waste heat circuit composed of waste heat generator, steam-water heat exchanger and solar collector. The whole cycle is equivalent to a double-effect cycle plus a waste heat circuit driven Single effect cycle. Use the solar heat collector to heat the circulating water and make the temperature rise initially, and then pass it into the air-water heat exchanger to further increase the temperature. The high-temperature hot water flowing out of the air-water heat exchanger enters the waste heat generator to generate refrigerant steam. condenser.

The solar-assisted direct-fired hot and cold water unit is characterized in that: the dilute solution from the absorber passes through the low-temperature solution heat exchanger and is divided into three paths, one path goes through the high-temperature solution heat exchanger to the high-pressure generator, and the other two paths Enter the low pressure generator and waste heat generator respectively. Finally, the three-way concentrated solutions are combined in front of the low-temperature solution heat exchanger, and then enter the absorber through the heat exchanger, and start a new round of circulation after being diluted.

Beneficial effect

Due to the use of a more optimized circulation system in this practical solar-assisted direct-fired hot and cold water unit, on the one hand, it can make full use of low-grade solar energy to apply low-temperature heat sources to absorption air-conditioning cold and hot water units; on the other hand, the waste heat generator and The simultaneous use of solar thermal collectors can reduce fuel consumption while increasing energy efficiency. It not only reduces the exhaust gas temperature of the conventional double-effect direct-fired cycle, but also overcomes the instability of the absorption air conditioner that only uses solar collectors and is easily affected by the weather. The primary energy efficiency PER is improved, thereby reducing operating costs and having a wide range of applications.

Description of drawings

Fig. 1 Schematic diagram of solar-assisted direct-fired hot and cold water unit.

Detailed ways

Below in conjunction with specific embodiment, further set forth the utility model. It should be understood that these embodiments are only used to illustrate the present invention but not to limit the scope of the present invention. In addition, it should be understood that after reading the contents of this practical teaching, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Example 1

As shown in Figure 1, the solar-assisted direct-fired hot and cold water unit is mainly composed of: high-pressure generator 1, air-water heat exchanger 2, waste heat generator 3, flue gas pipe 4, solar collector 5, and low-pressure generator 6 , condenser 7, absorber 8, evaporator 9, cooling tower 10, cooling (heating) coil 11, low temperature solution heat exchanger 12, high temperature solution heat exchanger 13, valves and pumps.

Utilize the solar heat collector 5 to preliminarily heat and circulate solar water, and pass the heated solar hot water into the air-water heat exchanger 2, so that the solar hot water and flue gas are fully exchanged and then passed into the waste heat generator 3, The cooled hot water in the waste heat circuit returns to the solar heat collector for repeated circulation, and the exhaust gas is discharged from the flue gas pipe 4. The dilute solution from the absorber 8 passes through the low-temperature solution heat exchanger 12 and is divided into three paths, one path goes through the high-temperature solution heat exchanger 13 to the high-pressure generator 1, and the other two paths enter the low-pressure generator 6 and the waste heat generator 3 respectively. The solution is heated and concentrated in the high-pressure generator 1. The steam generated by the high-pressure generator 1 enters the low-pressure generator 6 as a low-temperature heat source. After heating the solution, it enters the condenser 7 to condense. The steam generated by the low-pressure generator 6 directly enters the condenser 7 to condense. , the third solution enters the waste heat generator 3 to further utilize the heat in the flue gas and solar energy, and the generated steam also enters the condenser 7. Finally, the three-way concentrated solutions are combined before the low-temperature solution heat exchanger 12 and then exchanged heat through the heat exchanger: when cooling, the valve 14 is closed and valve 15 is opened, and the concentrated solution flowing out from the low-temperature solution heat exchanger 12 enters the absorber 8 Absorb the refrigerant vapor from the evaporator 9 and start a new cycle after being diluted. At the same time, the cooling water circuit composed of the cooling tower 10, the condenser 7 and the absorber 8 will discharge the air-conditioning heat load and absorption refrigeration to the atmosphere Circulating compensation heat energy, the cold water circuit formed by the evaporator 9 and the cooling coil is completed to provide cooling capacity for the cooling (heating) coil 11. When heating, the valve 14 is opened and the valve 15 is closed, the concentrated solution flowing out from the low-temperature solution heat exchanger 12 is directly diluted by the refrigerant water from the condenser 7, and the condenser 7 and the absorber 8 are separated from the cooling tower 10 and the heating plate The pipes are connected to form a hot water circuit, that is, the cooling water circuit is switched to a hot water circuit to provide heat for the cooling (heating) coil 11 .

The solar-assisted direct-fired hot and cold water unit uses a double-effect cycle plus a single-effect cycle driven by a waste heat circuit to improve energy utilization efficiency. At the same time, due to the use of clean energy solar energy, energy consumption is further reduced. Calculation data show that the cycle system can Compared with the conventional double-effect direct-fired engine, the primary energy efficiency PER is increased by 9%, and at the same time, the flue gas discharge temperature can be reduced to 120°C, and the energy-saving effect is obvious.

Claims (3)

1. the auxiliary direct-fired hot and cold water unit of solar energy is by high pressure generator (1), air-water heat exchanger (2), waste heat generator (3), fume pipe (4), solar thermal collector (5), low pressure generator (6), condenser (7), absorber (8), evaporimeter (9), cooling tower (10), cooling (heating) coil pipe (11), cryogenic fluid heat exchanger (12), high-temperature solution heat exchanger (13) and valve and pump are formed, it is characterized in that: absorbing on the basis of circulating in traditional economic benefits and social benefits has increased by one by waste heat generator (3), the waste heat loop that vapor-water heat exchanger (2) and solar thermal collector (5) are formed, whole circulation are equivalent to an economic benefits and social benefits circulation and add a single-action circulation by the waste heat drive circuit.

2. solar energy as claimed in claim 1 is assisted direct-fired hot and cold water unit, it is characterized in that: the weak solution of coming out from absorber (8) is divided into after through cryogenic fluid heat exchanger (12) the three tunnel, the one tunnel through high-temperature solution heat exchanger (13) whereabouts high pressure generator (1), two-way enters low pressure generator (6) and waste heat generator (3) respectively in addition.At last, three tunnel solution after concentrating converge after heat exchanger enters absorber (8) in that cryogenic fluid heat exchanger (12) is preceding, begin the circulation of a new round after diluted.

3. as claim 1, the auxiliary direct-fired hot and cold water unit of 2 described solar energy, it is characterized in that: described air-water heat exchanger (2) can be dividing wall type heat exchanger, direct-contact heat exchanger, heat regenerator or heat-pipe heat exchanger.

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