CN201973952U - Lithium bromide absorption evaporative condensation water chiller - Google Patents

Abstract

A lithium bromide absorption type evaporative condensation chiller, the equipment includes a generator 2 of the chiller, an evaporator 3, an absorber 4, an evaporative condenser 1 and a cooling tower body 7, and is characterized in that the generator 2, the evaporator 3 and the absorber 4 are arranged inside the chiller body 12, the upper part of the chiller body 12 is the generator 2, and the lower part is the evaporator 3 and the absorber 4, which is also characterized in that the evaporative condenser 1 and the absorber 4 The cooling water circulation part is arranged inside the overall cooling tower 7, and the cooling water is sprayed onto the cooling tower filler and the evaporative condenser in sequence to realize evaporative cooling. The utility model patent uses the evaporative condenser as the condenser of the lithium bromide absorption chiller. The evaporative cooling can reduce the condensation temperature of the condenser by about 5°C. Good conditions are provided, which is more conducive to the utilization of low-temperature waste heat and solar refrigeration and air conditioning.

Description

A lithium bromide absorption evaporative condensation chiller

technical field

The invention relates to a lithium bromide absorption type evaporative condensation chiller, more specifically, relates to a lithium bromide absorption type chiller equipment in which the condenser adopts the evaporation condensation mode.

Background technique

The LiBr absorption chiller differs from conventional compression chillers in that it uses heat as the driving energy, rather than electricity. It uses lithium bromide solution as absorbent, steam, hot water, heat generated by direct combustion of fuel oil/gas or other waste heat as heat source, and uses the principle of evaporation and absorption to realize refrigeration. Because CFCs and HCFCs refrigerants have a destructive effect on the atmospheric ozone layer , HFCs refrigerants also have a greenhouse effect. Under the current internal and external environmental conditions of tight power supply and climate change, lithium bromide absorption refrigerators have a high promotion value. my country has become a major producer of absorption refrigerators in the world. The development direction of lithium bromide absorption refrigerators in the near future is mainly to improve efficiency, popularize and apply them to cogeneration systems of heat, electricity and cooling, and recover waste heat and use solar energy, etc., to be energy-saving and environmentally friendly. The road of lithium bromide absorption refrigerator is an inevitable trend of development. The development of multi-energy comprehensive utilization lithium bromide absorption refrigerators can not only make full use of renewable resources, improve energy utilization efficiency, but also make full use of waste heat and waste heat resources in factories, reduce heat pollution while recycling energy, improve the environment, and relieve the supply and demand of the power grid Contradictions, saving investment in power industry capital construction, these have important practical significance for improving the country's energy utilization.

Lithium bromide absorption chillers can generally be divided into single-effect and double-effect. Single-effect lithium bromide consists of generator, condenser, absorber, evaporator and solution heat exchanger. The double-effect absorption lithium bromide chiller generally consists of a high-pressure generator, a low-pressure generator, a condenser, an absorber, an evaporator, a low-temperature solution heat exchanger, a high-temperature solution heat exchanger, and a condensate regenerator. Regardless of the single-effect absorption chiller or the double-effect absorption chiller, the condenser uses water as the cooling medium. The lithium bromide absorption chiller consumes a lot of cooling water during operation. In order to save water, the cooling water system of the unit Most of them adopt an open circulation system, and the water is evaporated and cooled in the cooling tower to take away the heat. In this way, the heat transfer temperature difference between the cooling water and the condensation temperature of the condenser is generally about 5°C.

The evaporative condenser is a kind of high-efficiency and energy-saving heat exchange equipment developed on the basis of absorbing the most advanced foreign heat exchange technology. The actual water consumption is about 5% to 10% of that of the water-cooled condenser, and the power consumption is reduced at the same time. This product integrates traditional condenser, cooling tower, circulating water pump, water pool and connecting water pipes as a whole. It has the advantages of small footprint, convenient installation, low noise, water and electricity saving, low investment, low operating cost, and no pollution to the environment. Long service life, easy maintenance and many other advantages. The United States, Canada and other countries have applied it to cold storage refrigeration devices since the 1970s. Since the 1980s in my country, chemical, pharmaceutical, industrial refrigeration and beer beverages, low-temperature processing and refrigeration of food, and building air-conditioning and refrigeration have also been applied. Started to use evaporative condensers. After more than 20 years of practice, it has been proved that evaporative condensers have obvious energy-saving effects.

The best working temperature of single-effect lithium bromide absorption refrigerator is 80-100℃, and its maximum COP value can reach 0.7 when the heat source temperature is 85℃. Since the solution is limited by crystallization conditions, the heat source temperature of the refrigerator cannot exceed 150 ℃. The COP of the double-effect lithium bromide absorption refrigeration unit is about 1.1 to 1.2, and the driving heat source can be high-temperature hot water above 150°C, or saturated steam at 0.25 to 0.8 MPa (gauge pressure), and its maximum COP value is at the temperature of the heat source. It can reach 1.2 at 130°C. The COP of the three-effect lithium bromide absorption refrigeration unit is about 1.65 to 1.75, and the temperature of the driving heat source needs to be above 200°C. The two-stage lithium bromide absorption refrigeration system has lower requirements on the temperature of the heat source than the single-effect lithium bromide absorption refrigeration system, and can be driven by hot water at 70-80°C. Therefore, the two-stage LiBr absorption refrigeration system is more suitable for utilizing low-grade energy than the single-effect LiBr absorption refrigeration system. However, the COP value of the two-stage lithium bromide absorption refrigeration system is lower, only about 0.3 to 0.4, the cooling water consumption is about twice that of the single-effect lithium bromide absorption refrigeration unit, and the initial investment is relatively large. For example, the solar-driven lithium bromide absorption refrigeration system uses flat plate or heat pipe vacuum tube collectors to collect solar energy and generates hot water at 80°C to 95°C to drive single-effect, double-effect or double-stage absorption refrigerators. The temperature of the heat source driven by the unit generator generally needs to be greater than 80°C, as shown in Table 1

Table 1 Comparison of solar lithium bromide absorption refrigeration systems per kW refrigeration power

The patent of this invention uses the evaporative condenser as the condenser of the lithium bromide absorption chiller, and the evaporative cooling can reduce the condensation temperature of the condenser by about 5°C, which not only improves the COP value of the absorption chiller, but also creates a great opportunity for reducing the temperature of the heat source Good conditions are more conducive to the utilization of low-temperature waste heat and solar refrigeration and air conditioning.

Contents of the invention

The patent of this invention uses the evaporative condenser as the condenser of the lithium bromide absorption chiller, and the evaporative cooling can reduce the condensation temperature of the condenser by about 5°C, which not only improves the thermal efficiency COP value of the absorption chiller, but also creates a great opportunity for reducing the temperature of the heat source Good conditions are more conducive to the utilization of low-temperature waste heat and solar refrigeration and air conditioning. In order to achieve the above object, the technical solution of the present invention provides lithium bromide absorption type evaporative condensation chiller equipment.

Technical scheme of the present invention is:

A lithium bromide absorption type evaporative condensation chiller, the equipment includes an evaporative condenser 1, a generator 2, an evaporator 3, an absorber 4 and a cooling tower body 7 of the chiller, and is characterized in that the generator 2, evaporator 3 and the absorber 4 are arranged inside the chiller body 12, the upper part of the chiller is the generator 2, and the lower part is the evaporator 3 and the absorber 4, which is also characterized in that the cooling water circulation of the evaporative condenser 1 and the absorber 4 Some are arranged inside the cooling tower body 7 to realize evaporative cooling.

In the above technical solution, the cooling tower body 7 is composed of an evaporative condenser 1, a nozzle 10, a filler 14, a cooling water circulating pump 8, a cooling tower water pan 9 and an axial flow fan 11, and is characterized in that the chiller The generator 2 of the body 12 and the evaporative condenser 1 inside the cooling tower body 7 are connected to the evaporative condenser 1 through refrigerant steam pipes to achieve the same condensation pressure, and the refrigerant vapor generated by the generator 2 flows into the evaporative condenser 1, condensed into refrigerant water and returned to the chiller body 12.

In the above technical solution, the lithium bromide absorption evaporative condensation chiller is characterized in that the evaporative condenser 1 is arranged on the upper part of the cooling tower packing 14, and is also characterized in that the evaporative condenser transmission of the evaporative condenser 1 The heat pipe group 13 is a finned cooling copper tube group. The inside of the copper tube group directly condenses the refrigerant water vapor into refrigerant water. The evaporative condenser 1 evaporates and discharges heat by directly contacting the cooling water and air.

In the above technical solution, in the cooling water circulation part of the evaporative condenser 1, the cooling water in the cooling tower water pan 9 is transported to the cooling tower nozzle 10 via the cooling water circulating water pump 8 and sprayed to the cooling tower filler 14 and the evaporative condenser. The condenser 1 realizes evaporative cooling. The refrigerant (water) in the condenser is cooled in the finned cooling copper tubes of the evaporative condenser heat transfer tube group 13, and enters the evaporator 3 in the chiller body 12 through the throttle valve. It is characterized in that the cooling water in the cooling tower water pan 9 at the bottom of the cooling tower body 7 is sent to the absorber 4 of the chiller body 12 through the cooling water pump 8 and one way out of the cooling water pump to cool the water produced by the generator 2. Lithium bromide concentrated solution, the cooling water is heated to the nozzle 10, sprayed on the cooling tower packing 14, and the other cooling water passes through the cooling tower nozzle 10, and sprayed on the finned cooling copper tube group 13.

In the above technical solution, the evaporative condenser 1 mainly adopts the air-cooled form to achieve cooling under the operating condition that the outdoor wet-bulb temperature meets the requirements. The air formed in the counter-flow, sequentially through the filler 14 and the evaporative condenser 1 to achieve air cooling, and is discharged by the cooling tower fan 12 installed on the upper part.

In the above technical solution, the lithium bromide absorption evaporative condensation chiller is characterized in that the driving cold and heat source of the generator 2 can be a low-temperature waste heat with a heat source temperature of 70°C to 85°C or a solar collector The hot water produced is also characterized in that the condensing temperature of the evaporative condenser 1 can be reduced by 5°C, and the cooling water inlet temperature is 25-32°C.

Beneficial effects of the present invention:

In this patent, the condenser of the unit adopts the evaporation and condensation method, that is, the cooling water is sprayed outside the copper tube of the condenser to meet the requirements of evaporation and condensation, and the refrigerant steam of the unit is condensed in the copper tube after being cooled by the cooling water outside the tube. Since the cooling water outside the copper tube absorbs the heat of condensation and continuously evaporates and releases heat outside the copper tube, the temperature of the cooling water is always at a relatively low temperature. Under the same external temperature conditions, the condensing temperature of the condenser using the evaporative condenser can be reduced by about 5°C, which creates good conditions for the absorption chiller to increase the COP and reduce the temperature of the heat source. According to the calculation of the performance of the lithium bromide absorption refrigeration unit, it can be known that under the condition of other external conditions remaining unchanged, within a certain range, every time the temperature of the cooling water entering the unit decreases by 1 °C, the cooling capacity increases by about 5% to 6% (but the cooling water enters the unit). The temperature of the machine should not be too low, otherwise it may cause solution crystallization and refrigerant water pollution. The temperature of the cooling water inlet should generally be controlled within the range of 25-32°C). At the same time, after using the evaporative condenser, the operating temperature of the heat source can be reduced by 7°C to 8°C. When the heat source temperature is 82°C, the thermal efficiency COP of the unit can reach 0.7, which is equivalent to the efficiency of the conventional absorption chiller when the heat source temperature is 90°C.

The invention solves the contradiction between the performance of the unit and the grade of the heat source in the traditional lithium bromide absorption chiller technology, improves the performance parameters of the unit while reducing the requirements on the grade of the driving heat source, expands the application range of the lithium bromide absorption chiller, and satisfies Energy conservation, emission reduction, water conservation and reliable environmental control requirements have created favorable conditions for the comprehensive utilization of low-temperature waste heat and the continuous application of solar refrigeration and air conditioning.

The invention also has the advantages of simple and reliable structure, and convenient manufacture and maintenance.

Description of drawings

Below in conjunction with the accompanying drawings, it will be described through specific experimental methods, so as to make the present invention more clear.

Fig. 1. is lithium bromide absorption type evaporative condensation chiller flow chart of the present invention

Figure 2. Flow chart of double-effect lithium bromide absorption evaporative condensation chiller

Numbers in the drawings: 1 is evaporative condenser, 2 is low generator, 3 is evaporator, 4 is absorber, 5 is low temperature heat exchanger, 6 is solution pump, 7 is cooling tower body, 8 is cooling water circulation Water pump, 9 is cooling tower water pan, 10 is cooling tower nozzle, 11 is cooling tower fan, 12 is chiller body, 13 is evaporative condenser heat transfer tube group, 14 is cooling tower packing, 15 is high temperature heat exchanger , 16 is the high voltage generator

Detailed ways

The content of the present invention will be described in detail below in conjunction with the drawings and specific embodiments. It should be understood that the present invention is not limited to the following preferred embodiments, which are only used as illustrations of the present invention.

As shown in Figure 1, the cooling water of the cooling tower water pan 9 at the bottom of the cooling tower body 7 of the present invention is sent into the absorber 4 of the chiller body 12 through the cooling water pump 8 and the cooling water pump one way to cool from the generation The lithium bromide concentrated solution produced by device 2, the cooling water is heated up to the nozzle 10, sprayed on the cooling tower filler 14, and the other cooling water passes through the cooling tower nozzle 10, and sprayed on the finned cooling copper of the evaporative condenser heat transfer tube group 13 The water film is formed on the filler layer and the outer surface of the copper pipe in turn, and the falling water film forms a countercurrent flow with the air entering from the air inlet grids on both sides of the cooling tower body 7, and a part of the water is directly turned into steam by the air when it is heated , the other part of the water is slowly dropped by the high-speed airflow or blown away to form small water droplets during the falling process, flying upwards, exchanging heat with the air, and reducing the temperature. The upper part is provided with a cooling tower blower fan 11 to take it away. In order to prevent the unevaporated water droplets from being taken away by the air, a water baffle is installed on the upper part of the water spray pipe, and the water droplets separated from the hot and humid air flow to the water storage tank. In this way, using air and water as the cooling medium, on the one hand, use part of the cooling water to evaporate and take away the heat medium in the gas phase, and the heat released during the condensation process includes part of the sensible heat of the gas phase and part of the liquid phase; on the other hand, with a temperature close to the wet bulb temperature The cold air cools the circulating water and achieves the purpose of condensation and cooling through the indirect heat exchange between the repeatedly cooled circulating water and the hot refrigerant (water) in the evaporative condenser 1 . The above two processes occur at the same time, and the respective proportions of the two parts of the heat load change with the change of the ambient temperature and the difference of the product structure.

As shown in Figure 2., the flow chart of the double-effect lithium bromide absorption evaporative-condensing chiller of the present invention. The double-effect unit adds a high-temperature heat exchanger 15 and a high-pressure generator 16 on the basis of the single-effect.

Claims (6)

1. suction-type lithium bromide evaporative condenser handpiece Water Chilling Units, this equipment comprises evaporative condenser 1, generator 2, evaporimeter 3, absorber 4 and the cooling tower body 7 of handpiece Water Chilling Units, it is characterized in that described generator 2, evaporimeter 3 and absorber 4 are arranged on handpiece Water Chilling Units body 12 inside, handpiece Water Chilling Units top is generator 2, the bottom is evaporimeter 3 and absorber 4, its feature is that also the cooling water cyclic part of described evaporative condenser 1 and absorber 4 is arranged on cooling tower body 7 inside, realizes evaporative cooling.

2. suction-type lithium bromide evaporative condenser handpiece Water Chilling Units according to claim 1, described cooling tower body 7 is made up of evaporative condenser 1, nozzle 10, filler 14, cooling water cycle water pump 8, cooling tower ponding dish 9 and axial flow blower 11, its feature is that also the generator 2 of handpiece Water Chilling Units body 12 and the evaporative condenser 1 of cooling tower body 7 inside are connected with evaporative condenser 1 by the refrigerant vapour pipeline, realize same condensing pressure, the refrigerant vapour that generator 2 goes out flows into evaporative condenser 1, is condensed into water as refrigerant and gets back in the handpiece Water Chilling Units body 12.

3. suction-type lithium bromide evaporative condenser handpiece Water Chilling Units according to claim 1, it is characterized in that described evaporative condenser 1 is arranged on cooling tower filler 14 tops, its feature is that also the evaporative condenser heat transfer tube group 13 of evaporative condenser 1 is finned cooling copper tube group, copper pipe group inside directly is condensed into water as refrigerant with water as refrigerant steam, evaporative condenser 1 is evaporated heat extraction by directly contacting with the cooling water and air.

4. suction-type lithium bromide evaporative condenser handpiece Water Chilling Units according to claim 1, the cooling water cyclic part of described evaporative condenser 1, the cooling water of cooling tower ponding dish 9 is delivered to cooling tower nozzle 10 respectively via cooling water cycle water pump 8 and sprays cooling tower filler 14 and evaporative condenser 1, realize evaporative cooling, condenser inner refrigerant (water) cools off in the finned cooling copper tube of evaporative condenser heat transfer tube group 13, enter evaporimeter 3 in the handpiece Water Chilling Units body 12 via choke valve, the cooling water of cooling tower ponding dish 9 that it is characterized in that described cooling tower body 7 bottoms is via cooling water pump 8, go out cooling water pump one road cooling water and send into the bromize lithium concentrated solution that cooling produces from generator 2 in the absorber 4 of handpiece Water Chilling Units body 12, cooling water is through being warming up to nozzle 10, be sprayed on the cooling tower filler 14, another road cooling water is sprayed on the finned cooling copper tube group 13 by cooling tower nozzle 10.

5. suction-type lithium bromide evaporative condenser handpiece Water Chilling Units according to claim 1, described evaporative condenser 1 is under the operating condition that outdoor wet-bulb temperature meets the demands, the air-cooled form of main employing is to realize cooling, it is characterized in that forming adverse current from the air that the air intake grid of cooling tower body 7 both sides enters, air-cooled via filler 14 and evaporative condenser 1 realization successively, discharge by the blower fan of cooling tower 12 that top is provided with.

6. suction-type lithium bromide evaporative condenser handpiece Water Chilling Units according to claim 1, described suction-type lithium bromide evaporative condenser handpiece Water Chilling Units, it is the hot water that 70 ℃～low temperature exhaust heat used heat more than 85 ℃ or solar thermal collector produce that the driving Cooling and Heat Source that it is characterized in that described generator 2 can be heat source temperature, its feature is that also the condensation temperature of described evaporative condenser 1 can reduce by 5 ℃, and cooling water inlet temperature is 25～32 ℃.

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