CN100427851C - Energy-saving air conditioner driven by combined solar energy and natural gas - Google Patents

Abstract

The invention discloses a solar energy-natural gas combined driven energy saving air-conditioner, where the outdoor machine set comprises solar heat collector, solar heat storer and natural gas heater; a heat exchanger pipe coil in the solar heat collector is connected with the two ends of the other heat exchanger in the high pressure generator through the natural heater and circulating pump to drive indoor machine set to work. And it uses heat source as drive energy, integrating refrigeration, heating and living hot water supply; the condenser and absorber in the machine set adopt wind cooling, omitting the cooling water circulating system so as to be used at home and in medium- and small-sized buildings; and its performance coefficient can be up to above 1.5, reducing energy consumption and making full use of renewable energy source. In addition, it has characters of environmental protection, saving energy, and safety.

Description

Energy-saving air conditioner driven by combined solar energy and natural gas

1. Technical field

The invention relates to a refrigeration air conditioner, in particular to a high-efficiency energy-saving air conditioner driven by combined solar energy and natural gas.

2. Background technology

Since the reform and opening up, my country's comprehensive national strength and people's living standards have been greatly improved. As one of the basic industries of the national economy, the energy industry has achieved considerable development. However, the development of the energy industry still cannot meet the needs of the rapid development of the national economy and the rapid growth of people's daily energy consumption, and the national energy shortage situation still exists.

To solve the current energy shortage problem, it is necessary to develop renewable energy, such as solar energy, geothermal energy, biomass energy, wind energy, ocean energy and so on. Among various renewable energy sources, solar energy is the most important basic energy source. In a broad sense, geothermal energy, biomass energy, wind energy, ocean energy, etc. all come from solar energy. Solar energy is not only "inexhaustible and inexhaustible", but also does not produce greenhouse gases and is pollution-free, which is conducive to protecting the environment. clean energy. my country has taken solar energy utilization as an important part of renewable energy in the follow-up energy strategy, and introduced a series of policies to encourage and support the development of solar energy conversion research and application. The "Renewable Energy Law" implemented in 2006 has further promoted the research, development and application of solar energy utilization.

As a clean energy source, solar energy is both a primary energy source and a renewable energy source, and has incomparable advantages over fossil energy sources. According to calculations, the sun can release 391×10 ²¹ kW of energy per second, and although the energy radiated to the surface of the earth is only 1/2.2 billion, it is equivalent to 80,000 times the current total power generation in the world . Therefore, solar energy resources are very rich, and it is the most eye-catching, most developed and most widely used clean energy among renewable energy sources. At present, the utilization of solar energy is mainly the utilization of light and heat, such as solar water heaters, and the utilization of photovoltaics, such as solar cells. Considering the cost of use and wide application, the use of solar heat and light is more common, and now solar water heaters have entered thousands of households. However, because the supply and demand of solar energy cannot be well matched and coordinated in terms of quantity and time, a large amount of energy is wasted. Excessive solar energy causes solar energy to be wasted in vain as daytime, and solar energy is not enough at night and cloudy and rainy day. Moreover, in solar water heaters, the energy storage density of water heat storage is low, the volume is large, and the energy storage efficiency is poor.

In addition, a key project of my country's energy construction - "West-to-East Gas Pipeline" has been implemented, which will cause major changes in the energy structure of cities and towns along the gas pipeline from Xinjiang to Shanghai in the next few years.

The development of natural gas air conditioners not only improves the environment, but also optimizes national energy investment. With the improvement of people's material living standards, the demand for air conditioners will further increase. This makes large-scale transformation of urban and rural power grids and the construction of a large number of new power plants inevitable. The construction investment of China's thermal power plants is about 6,000 yuan per kilowatt, and the desulfurization facilities need to be increased by 900 yuan per kilowatt. In addition, the construction of power grids is about 2,000 yuan per kilowatt, and the total investment in power supply is nearly 9,000 yuan per kilowatt. 3 to 6 times higher. If the air-conditioning load is increased by 15 million kilowatts, the state will need to spend 135 billion yuan in power construction funds. If the huge construction costs are apportioned to users, it will be 2 to 10 times more than users buying household air conditioners or central air-conditioning equipment itself. At present, although this investment has not been apportioned to air-conditioning users for the time being, it has caused a great investment burden on the national power construction.

The development of natural gas gas-fired air conditioners is an important way to "demand-side management" of energy. The peak and valley of city gas and the peak and valley of electricity have great complementarity. Analysis of the reasons for the peak-to-valley difference in gas shows that: city gas has a single purpose, and was mainly used for heating and heat in the past, and was rarely used for refrigeration. If natural gas gas-fired air conditioners are vigorously promoted, the serious seasonal imbalance between urban gas and electric power peaks and valleys will be easily resolved, and the effect of mutual promotion of gas and electric power enterprises will be achieved.

Producing and supplying clean energy, establishing a stable clean energy terminal consumption market, and realizing sustainable development have become the most urgent tasks to ensure the prosperity of human beings and the health of the earth. Therefore, people are now beginning to seriously study the optimal allocation of energy, and comprehensively measure the energy efficiency and safety of coal, oil, natural gas, nuclear energy, water energy, solar energy and new energy sources that may be discovered. Our government has been keenly aware of the key to the problem - vigorously develop and utilize natural gas. Since 2000, energy utilization strategies such as "West-East Gas Transmission", "Imported LNG", "Offshore Natural Gas Landing", and "Coalbed Methane Development" have been formulated.

To sum up, the development of solar-natural gas combined air conditioners is in line with the national energy and environmental protection policies. The country encourages users to use solar energy and natural gas without policy restrictions.

A pursuit or symbol of people's living standard improvement is the significant improvement of living conditions, in which the specific requirements for the indoor environment are comfortable temperature and humidity conditions and convenient hot water supply.

At present, vapor compression air conditioners are commonly used for indoor temperature regulation, which use electricity as the driving energy. The traditional working fluids Freon CFC and HCFC used in the machine have a great destructive effect on the atmospheric ozone layer on which the earth's biosphere depends. Alternative situations: There are still many problems in some newly developed alternative working fluids, such as HFC134a, which has been widely used, has the potential danger of forming acid rain. In addition, the work of the vapor compression air conditioner is also limited by the ambient temperature, that is, when the temperature is low (such as below -5°C), it will not work properly (such as frosting on the evaporator, low heating efficiency, or even failure to start. etc.) situation.

3. Contents of the invention

The object of the present invention is to provide a high-efficiency energy-saving air conditioner driven by solar energy and natural gas. The air conditioner uses a heat source as the driving energy, and the working medium used is lithium bromide aqueous solution, which will not damage the atmospheric ozone layer; and it can still operate normally when the temperature is low; due to the use of few moving parts, the air conditioner has almost no noise during operation .

The purpose of the present invention is achieved through the following technical solutions:

An energy-saving air conditioner driven jointly by solar energy and natural gas, including an outdoor unit and an indoor unit, the indoor unit is composed of a fan and a heat exchange coil; Flow devices, evaporators, air-cooled absorbers, solution pumps, heat exchangers, refrigeration control valves, heating control valves, solar collectors, solar thermal storage and natural gas heaters; There is lithium bromide working medium solution in both the condenser and the air-cooled absorber, and the refrigerant medium in the air-cooled condenser and evaporator; there is a natural gas burner in the natural gas heater, and a heater in the high-pressure generator. There are heat exchanger coils in the low-pressure generator, evaporator and solar thermal storage; the solar thermal collector is connected to the solar thermal storage through a circulation pump, and the heat exchanger coils in the solar thermal storage are heated by natural gas The generator and circulation pump are connected to both ends of the heater in the high-pressure generator; the outlet of the high-pressure generator is connected to the heat exchanger coil in the low-pressure generator through a refrigeration control regulating valve, and after passing through the air-cooled condenser and throttling device It is connected to the evaporator, and the outlet of the high-pressure generator is connected to the evaporator through the heating control regulating valve; the heat exchanger coil in the evaporator is connected to the indoor unit through the circulation pump; and the evaporator is connected to the air-cooled absorber through the control regulating valve Connection; the inlet of the air-cooled absorber is connected to the low-pressure generator, and the outlet is connected to the high-pressure generator through the solution pump and heat exchanger; the high-pressure generator is connected to the low-pressure generator through the heat exchanger.

In the present invention, multiple sets of indoor units can be connected in parallel as required.

For rational utilization of energy, the present invention can be an energy storage type air conditioner, the evaporator is connected to the energy storage device; the left inlet of the energy storage device is connected to the outlet of the evaporator through a regulating valve, and the left outlet is connected to the inlet of the evaporator through a regulating valve Connection; the right outlet of the energy storage device is connected to the inlet of the indoor unit through the energy storage circulation pump and the regulating valve, and the right inlet is connected to the outlet of the indoor unit through the regulating valve.

In order to facilitate the use of hot water, the present invention is equipped with a hot water utilization device. The high-pressure generator is connected to the water heater through a water heater regulating valve. The water heater is equipped with a refrigerant medium, and the cold water inlet passes through the heat exchanger coil installed in the water heater. Connect with hot water outlet.

The cooling capacity range of the air conditioner of the present invention is 5-40kW, the heating capacity range is 5-40kW, and the hot water capacity can be adjusted as required.

The solar-natural gas combined air conditioner adopts the priority of using solar energy, and the insufficient part is supplemented by natural gas, which has the characteristics of environmental protection, energy saving and safety.

The solar-natural gas combined air conditioner integrates refrigeration, heating and domestic hot water supply, and has a compact structure and a miniaturized unit.

The condenser and the absorber in the air conditioner driven by solar energy and natural gas are air-cooled, and the cooling water circulation system is omitted, so that it can be used in households and small and medium-sized buildings.

The solar heat collector adopts a heat pipe heat collector or a vacuum pipe heat collector. The heat storage medium water is filled in the solar heat storage device.

The air-cooled condenser and the air-cooled absorber are tube-sheet type, tube-belt type or stacked type.

The throttling device adopts a "U"-shaped tube or a capillary tube.

The energy storage device is filled with energy storage balls or energy storage plates. The energy storage ball or the energy storage plate is encapsulated with a phase change energy storage material.

The working medium of the system is lithium bromide solution, the concentration of the dilute solution is 58%-60%, and the concentration of the concentrated solution is 62%-64%.

The heat exchanger coil adopts spiral coil or serpentine coil or "U" coil, smooth or threaded tube or finned tube, copper tube or steel tube.

The heat exchanger can recover energy and improve the thermal coefficient of the whole system.

The invention overcomes the shortcomings of the existing air conditioners and provides an air conditioner driven jointly by solar energy and natural gas. The air conditioner integrates refrigeration, heating and domestic hot water supply, with compact structure and miniaturized unit; the condenser and absorber in the unit are air-cooled, eliminating the need for a cooling water circulation system, so that it can be used in households and small and medium-sized Building use; when heating, it solves the problems of frequent defrosting and poor heating effect of existing compression heat pump air conditioners. Heating, heating temperature is uniform. Since the air conditioning system is driven by solar energy and natural gas, its performance coefficient can reach more than 1.5, reducing energy consumption and making full use of renewable energy. In addition, it also has the characteristics of environmental protection, energy saving and safety.

Compared with the prior art, the present invention has the remarkable advantages of:

(1) Combined drive of solar energy and natural gas energy is adopted, which is environmentally friendly, energy-saving, safe, reduces energy consumption, makes full use of renewable energy, and balances power loads.

(2) Integrate refrigeration, heating and supply of domestic hot water, with compact structure and miniaturized unit.

(3) The condenser and absorber in the unit are air-cooled, which saves the cooling water circulation system, so that it can be used in households and small and medium-sized buildings.

(4) The air-conditioning system is equipped with energy storage devices and solar heat storage devices, so that the supply and demand of solar energy can be well matched and coordinated in terms of quantity and time. Make full use of solar energy during the day, and use energy storage devices for cooling at night and rainy days.

(4) Solve the problems of frequent defrosting and poor heating effect of existing compression heat pump air conditioners, and can still supply heat to the room normally when the outdoor ambient temperature is lower than -30°C.

4. Description of drawings

Accompanying drawing is the structural representation of the present invention.

Explanation of marks in the drawings

1-High pressure generator 2-Low pressure generator 3-Air-cooled condenser 4-Throttling device 5-Evaporator 6-Air-cooled absorber 7-Solution pump 8-Heat exchanger 9-Heater 10-Water heater 11, 12, 13, 14-control valve 16-heat exchanger coil 18-circulation pump 19-regulation valve 20a, 20b, 21a, 21b-regulation valve 22-energy storage device 23-circulation pump 24-energy storage ball (plate) 25 -Solar heat collector 26-Solar heat storage 27-Heat exchanger coil 28-Solar circulation pump 29-Burner 30-Natural gas heating 31-Natural gas circulation pump

5. Specific implementation

A solar-natural gas combined air conditioner of the present invention comprises an outdoor unit and an indoor unit, the indoor unit is composed of a fan and a heat exchange coil; in the outdoor unit, the high-pressure generator, the low-pressure generator and the air-cooled There is a lithium bromide working medium solution inside, and there is a refrigerant medium in the air-cooled condenser 3 and the evaporator 5; a natural gas burner 29 is provided in the natural gas heater 30, and a heater 9 is provided in the high-pressure generator 1, A heat exchanger coil 16 is arranged in the low pressure generator 2, the evaporator 5 and the solar thermal storage 26; the solar thermal collector 25 is connected with the solar thermal storage 26 by a circulating pump 28, and the heat in the solar thermal storage 26 The exchanger coil is connected to both ends of the heater 9 in the high-pressure generator 1 through a natural gas heater 30 and a circulation pump 31; The pipe 16 is connected to the evaporator 5 through the air-cooled condenser 3 and the throttling device 4, and the outlet of the high-pressure generator 1 is connected to the evaporator 5 through the heating control regulating valve 12; the heat exchanger in the evaporator 5 The coil 16 is connected to the indoor unit through the circulating pump 18; and the evaporator 5 is connected to the air-cooled absorber 6 through the control valve 14; The exchanger 8 is connected with the high-pressure generator 1; the high-pressure generator 1 is connected with the low-pressure generator 2 through the heat exchanger 8.

The evaporator 5 is also connected with the energy storage device 22; the left side inlet of the energy storage device 22 is connected with the outlet of the evaporator 5 through the regulating valve 20a, and the left side outlet is connected with the inlet of the evaporator 5 through the regulating valve 20b; the energy storage device 22 The outlet on the right side is connected to the inlet of the indoor unit through the accumulator circulating pump 23 and the regulating valve 21a, and the inlet on the right side is connected to the outlet of the indoor unit through the regulating valve 21b.

The high-pressure generator 1 is connected with the water heater 10 through the water heater regulating valve 11, and the water heater 10 is equipped with refrigerant medium, and the cold water inlet is connected with the hot water outlet after passing through the heat exchanger coil 15 arranged in the water heater 10.

Its working principle is described as follows, see attached drawing:

The electronic control part and the fans of the indoor unit and the outdoor unit are omitted in the drawings. The indoor units can be connected in parallel in multiple groups as required, and only one group of indoor units is shown in the figure.

When performing the system (storage) cooling cycle, the refrigeration control regulating valve 13 is opened, the heating control regulating valve 12, and the control regulating valve 14 are closed, the heater 9 heats the high-pressure generator 1, and the heat energy of the heater 9 is supplied by the solar thermal storage device 26 Provided with the natural gas heater 30, the circulating medium in the heater 9 is first heated to 60-80°C by the solar heat storage device 26, and then heated to about 150°C by the natural gas heater 30, and the thermal energy in the solar heat storage device 26 is provided by the solar heat storage device 26. Collector 25 supply. The dilute lithium bromide solution coming out of the air-cooled absorber 6 is transported by the solution pump 7 through the heat exchanger 8, and then enters the high-pressure generator 1 and is heated by the heater 9 to generate part of the refrigerant vapor, so that the concentration of the lithium bromide solution increases and leaves the high-pressure generator 1. After being cooled by the heat exchanger 8, it enters the low-pressure generator 2 and is heated by the refrigerant vapor introduced from the high-pressure generator 1. The concentration of the lithium bromide solution increases again, and new refrigerant vapor is generated and sent to the air-cooled condenser 3 for cooling and condensed into refrigerant water, mixed with the refrigerant water coming out of the high-pressure generator 1, cooled and condensed in the low-pressure generator 2, entering the air-cooled condenser 3, and then entering the evaporator 5 for evaporation and refrigeration after being depressurized by the throttling device 4 , and then turn into refrigerant vapor, which is absorbed by the lithium bromide concentrated solution sent by the low-pressure generator 2 in the air-cooled absorber 6 and becomes a dilute solution, and the process of cold storage (storage) is completed in a cycle like this. When making (storing) cold, the refrigerant water in the evaporator 5 absorbs the water in the heat exchanger coil 17

The heat of the refrigerant water turns into refrigerant vapor, and the temperature of the refrigerant water in the heat exchanger coil 17 drops accordingly. The air-cooled condenser 3 and the air-cooled absorber 6 of the outdoor unit dissipate heat to the environment. When only supplying cooling to the indoor unit, the regulating valves 20a, 20b, 21a, 21b are closed, and the refrigerant water in the heat exchanger coil 17 provides cooling capacity to the indoor unit through the circulating pump 18; When the energy device 22 is charging cold, the regulating valves 20a, 20b are opened, and the regulating valves 21a, 21b are closed. The refrigerant water in the heat exchanger coil 17 supplies cooling to the indoor unit and charges the energy storage device 22 through the circulation pump 18 at the same time. The energy storage ball (plate) 24 in the energy storage device 22 stores cold energy, and the energy storage material therein undergoes a solidification phase transition when the energy storage ball (plate) 24 stores cold; when only the energy storage device 22 supplies cooling to the indoor unit , the heater 9 stops working, the regulating valves 20a, 20b are closed, and the regulating valves 21a, 21b are opened. The refrigerant water in the energy storage device 22 is cooled to the indoor unit through the circulation pump 23. When the energy storage ball (plate) 24 is cooled, it will The energy storage material inside undergoes a melting phase transition.

When the heating (storage) cycle is executed, the heating control regulating valve 12 and the control regulating valve 14 are opened, the cooling control regulating valve 13 is closed, and the refrigerant vapor flowing out from the high-pressure generator 1 passes through the heat exchange coil in the evaporator 5 17 condenses and releases heat, and the hot water in the heat exchange coil 17 is heated to increase in temperature. The refrigerant water condensed in the evaporator 5 flows into the air-cooled absorber 6 to dilute the lithium bromide concentrated solution into a dilute solution, and the lithium bromide dilute solution in the air-cooled absorber 6 is transported by the solution pump 7 through the heat exchanger 8, and then enters the high pressure The generator 1 is heated by the heater 9 to generate refrigerant vapor. The thermal energy of the heater 9 is provided by the solar heat storage device 26 and the natural gas heater 30, and the circulating medium in the heater 9 is first heated to 60-80°C by the solar heat storage device 26, and then heated to about 150°C by the natural gas heater 30 , the thermal energy in the solar thermal storage 26 is supplied by the solar thermal collector 25 . When producing (storing) heat, the heat medium water in the heat exchanger coil 17 heats up due to absorbing the heat of the refrigerant vapor in the evaporator 5 . When only heat is supplied to the indoor unit, the regulating valves 20a, 20b, 21a, 21b are closed, and the heat medium water in the heat exchanger coil 17 provides heat to the indoor unit through the circulation pump 18; When the energy device 22 is storing heat, the regulating valves 20a and 20b are opened, and the regulating valves 21a and 21b are closed. The heat medium water in the heat exchanger coil 17 supplies heat to the indoor unit and stores heat in the energy storage device 22 through the circulation pump 18 at the same time. The energy storage ball (plate) 24 in the energy storage device 22 stores heat, and when the energy storage ball (plate) 24 heat storage, the energy storage material in it stores sensible heat and does not undergo solidification phase transition; When the indoor unit is heating, the heater 9 stops working, the regulating valves 20a and 20b are closed, and the regulating valves 21a and 21b are opened. ) 24 When the heat is released, the energy storage material in it releases sensible heat, and no melting phase transition occurs.

In order to supply domestic hot water, the unit is provided with a water heater 10 circulation loop. When domestic hot water is needed, the control valve 11 is opened. The unit can simultaneously produce hot water for domestic use and produce (storage) cold or heat (storage). , its working process is the same as the above-mentioned system (storage) cold or system (storage) heat cycle; the other way is used to make hot water for domestic use, and the refrigerant steam from the high-pressure generator 1 is in the heat exchanger in the water heater 10 Condensation on the coil 15 releases heat, and the hot water in the heat exchanger coil 15 is heated to raise the temperature, so that domestic hot water can be supplied to the room. The condensed refrigerant water automatically returns to the high-pressure generator 1 depending on the potential difference, so as to maintain a constant solution concentration in the high-pressure generator 1.

Claims (7)

1. An energy-saving air conditioner driven jointly by solar energy and natural gas, comprising an outdoor unit and an indoor unit, and the indoor unit is composed of a fan and a heat exchange coil; it is characterized in that: the outdoor unit includes a high-voltage generator (1), a low-voltage generator (2 ), air-cooled condenser (3), throttling device (4), evaporator (5), air-cooled absorber (6), solution pump (7), heat exchanger (8), refrigeration control regulating valve (13 ), heating control valve (12), solar thermal collector (25), solar thermal storage (26) and natural gas heater (30); There is a lithium bromide working medium solution in the cold absorber (6), and there is a refrigerant in the air-cooled condenser (3) and the evaporator (5); a natural gas burner (29) is provided in the natural gas heater (30) , a heater (9) is provided in the high-pressure generator (1), and a heat exchanger coil (16) is provided in the low-pressure generator (2), the evaporator (5) and the solar heat storage device (26); The solar heat collector (25) is connected with the solar thermal storage (26) through the solar circulation pump (28), and the heat exchanger coil (16) in the solar thermal storage (26) passes through the natural gas heater (30) and the natural gas The circulating pump (31) is connected to both ends of the heater (9) in the high-pressure generator (1); the outlet of the high-pressure generator (1) is connected to the heat in the low-pressure generator (2) through the refrigeration control regulating valve (13). The exchanger coil (16) is connected to the evaporator (5) after passing through the air-cooled condenser (3) and throttling device (4), and the outlet of the high-pressure generator (1) passes through the heating control regulating valve (12 ) is connected to the evaporator (5); the heat exchanger coil (16) in the evaporator (5) is connected to the indoor unit through a circulating pump (18); and the evaporator (5) is connected to the air conditioning valve (14) The cold absorber (6) is connected; the inlet of the air-cooled absorber (6) is connected to the low-pressure generator (2), and the outlet is connected to the high-pressure generator (1) through the solution pump (7) and heat exchanger (8); the high-pressure The generator (1) is connected to the low-pressure generator (2) through the heat exchanger (8); the evaporator (5) is connected to the energy storage device (22); the left inlet of the energy storage device (22) passes through the regulating valve (20a ) is connected with the outlet of the evaporator (5), and the left outlet is connected with the inlet of the evaporator (5) through a regulating valve (20b); The valve (21a) is connected to the inlet of the indoor unit, and the right inlet is connected to the outlet of the indoor unit through a regulating valve (21b). 2. The energy-saving air conditioner driven by combined solar energy and natural gas according to claim 1, characterized in that: the energy storage device (22) is filled with energy storage balls or energy storage plates. 3. The energy-saving air conditioner driven by combined solar energy and natural gas according to claim 2, characterized in that: phase change energy storage materials are encapsulated in the energy storage ball or the energy storage plate. 4. The energy-saving air conditioner driven by combined solar energy and natural gas according to claim 1, characterized in that: the high-pressure generator (1) is connected to the water heater (10) through the water heater regulating valve (11), and is installed in the water heater (10) There is a refrigerant medium, and the cold water inlet is connected with the hot water outlet after passing through the heat exchanger coil (15) arranged in the water heater (10). 5. The energy-saving air conditioner driven by combined solar energy and natural gas according to claim 1, characterized in that: the solar heat collector (25) adopts a heat pipe heat collector or a vacuum pipe heat collector. 6. The energy-saving air conditioner driven by combined solar energy and natural gas according to claim 1, characterized in that: the working medium is lithium bromide dilute solution or lithium bromide concentrated solution, the concentration of the dilute solution is 58%-60%, and the concentration of the concentrated solution is 62%-64%. 7. The energy-saving air conditioner driven by combined solar energy and natural gas according to claim 1, characterized in that: the heat exchanger coil (16) adopts a spiral coil or a serpentine coil or a "U"-shaped coil.

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