CN104930745A - Concentrated cold and heat supply system based on steam compressing heat pump technology of mess hall - Google Patents

Abstract

The invention relates to a centralized cooling and heating system for canteens based on vapor compression heat pump technology, which mainly includes compressors, outdoor heat exchangers, indoor condensers, canteen heating equipment, canteen cooling equipment, oil fume purifiers, casing type Heat exchangers, evaporators in refrigerators, evaporators in air conditioners, etc. Compared with the prior art, the invention can significantly increase the heat output of the system and meet the heating demand of the canteen in winter. In winter, the central heating system is adopted, and the vapor compression heat pump technology is used to recover the waste heat from kitchen exhaust, which greatly improves the heating efficiency. At the same time, the capillary heat exchanger is used to improve the heat utilization efficiency of the terminal. In summer, a central cooling system is adopted to meet the cooling demand of the canteen and avoid heat dissipation from the refrigerator in the storage room to the room. The system has high efficiency, remarkable energy-saving effect, and fully considers the heating and cooling requirements of the cafeteria. It has many functions, flexible configuration, and strong practicability.

Description

A Central Cooling and Heating System for Canteens Based on Vapor Compression Heat Pump Technology

technical field

The invention relates to a cooling and heating system, in particular to a canteen centralized cooling and heating system based on vapor compression heat pump technology.

Background technique

Large canteens are important places where energy is intensively consumed. In addition to cooking, a large amount of gas is required. In order to maintain the freshness and taste of ingredients and ensure a comfortable dining environment, heating and cooling consume a lot of energy, but the energy utilization efficiency of canteens is not high.

In winter, there are many places in the canteen that need heating. First of all, it is the heat preservation of meals. In order to maintain the taste and health requirements of the meals sold in the canteen, it is necessary to continuously heat and keep them warm. The existing heat preservation devices are electric heating food insulation boards and incubators. Because the food requires a long time to keep warm (the running time of the heat preservation system in the university canteen From 6:00 am to 6:00 pm), the power consumption is very huge. According to survey statistics, it accounts for 25-30% of the entire kitchen's power consumption. Secondly, the external ambient temperature is too low in winter. In order to create a comfortable dining environment for diners, the canteen also needs heating.

The cooling of the restaurant in summer is mainly composed of three parts. First of all, the ambient temperature is high in summer. In order to maintain the freshness of the ingredients and prevent them from spoiling, the ingredients need to be refrigerated or even frozen to keep them fresh. Traditional decentralized refrigerators and freezers have low efficiency and consume a lot of power. According to survey statistics, summer refrigeration accounts for 30-40% of the electricity consumption of the entire kitchen. Secondly, in order to create a comfortable dining environment for diners, it is necessary to adjust the temperature and humidity of the restaurant. In addition, the kitchen operation room is in a high-temperature environment for a long time due to cooking heat dissipation, and the heat dissipation equipment of the distributed refrigerator freezer is often unable to be separated from the refrigerator. In summer, a large amount of heat is discharged in the kitchen, which deteriorates the thermal environment in the operation room. Considering the kitchen staff, kitchen cooling is essential.

It can be seen from this that the canteen kitchen consumes a lot of energy, but on the other hand, there is a large amount of waste heat in the kitchen that is not used. For example, the temperature of cooking fume is as high as 65 to 80°C, which has a good potential for waste heat utilization.

Chinese patent CN 102840711A discloses that the air conditioning system with heat recovery function is composed of an exhaust heat absorber, a drainage heat absorber, a water storage device, a refrigeration refrigerator, an indoor air conditioner, an outdoor heat exchanger, a compressor, and an expansion restrictor. , Auxiliary refrigeration device, power distribution control system. The exhaust heat absorber is installed in the range hood, exhaust hood and other equipment that removes high-temperature exhaust gas, and exchanges heat with high-temperature exhaust gas such as oil fume. The drain heat absorber is installed at the position where high-temperature wastewater such as kitchen washing passes through, and performs heat exchange with high-temperature wastewater. The exhaust heat absorber and the drain heat absorber are filled with water or refrigerant, and through the circulation of the circulating water pump or the refrigeration system, the heat energy discharged from the life, production and refrigeration refrigerators is collected into the water storage and the indoor air conditioner. Users provide domestic hot water and hot water for air conditioning, while saving fuel. The exhaust heat absorber and drainage heat absorber can not only serve as evaporators of the refrigeration system to absorb the heat energy of high-temperature waste gas and waste water, but also can be converted into condensers of the refrigeration system Absorb the cooling capacity of low-temperature exhaust gas and waste water, and improve the refrigeration efficiency of air conditioners. Compared with this patent, the present invention has the following significant differences:

1. The present invention is a centralized cooling and heating system for kitchens, which focuses on the high-efficiency comprehensive thermal management of canteens. Chinese patent CN 102840711A proposes an air-conditioning system that focuses on improving the efficiency of air-conditioning through heat recovery devices.

2. Heat recovery device: Chinese patent CN 102840711A installs the exhaust heat absorber in the range hood and exhaust hood, installs it on the panel, or in the air duct or bellows, and installs the drain heat absorber directly under the stove , in the kitchen drain, in the grease trap, or buried in the kitchen floor. Since the smoke exhaust heat absorber and the drainage heat absorber are essentially evaporators, they have a strong condensation and adsorption effect on oil pollution. The oil stain attached to the heat exchange tube will greatly reduce the heat exchange efficiency. After the system is used for a long time, a large amount of oil stain will block the flue or water channel, causing the system to shut down. Considering the existence of the above problems, the present invention specially designs a casing heat exchanger for the smoke exhaust system, which fundamentally prevents the oil fume from directly passing through the evaporator and avoids the above problems. In actual use, the amount of high-temperature wastewater in the kitchen is unstable, which will cause large fluctuations in the evaporation temperature. If a drainage heat absorber is used, the stability and applicability of the system will be greatly reduced. In order to ensure the stable operation of the system, this heat absorber is not used in the present invention. Chinese patent CN102840711A proposes to use a large amount of low-temperature washing wastewater in work and life to improve cooling efficiency in summer. However, due to unstable water volume and more sewage impurities, it will cause corrosion and other damage to heat extraction equipment, and there is less low-temperature wastewater in canteens in summer. In order to ensure the stability of the system, the present invention does not use waste water as a low-temperature cold source, but directly exchanges heat with the atmospheric environment.

3. Use of hot water: After the tap water is heated in the Chinese patent CN 102840711A, it is only proposed to be used as domestic water and air-conditioning water, and no special purpose is specified. A large water storage tank is required to store hot water that cannot be used in time, which takes up space. There is also the problem of heat loss in the actual application process. The invention fully considers that the temperature and time of hot water produced by the heat pump match the needs of keeping food warm and heating the canteen, so it is pointedly proposed to use the hot water produced by the heat pump to realize the above two functions. In order to cooperate with the realization of the above two functions, the food insulation table and insulation box with capillary heat exchangers are specially designed. The preferred layered hot water storage tank of the present invention only plays the role of regulating and storing water volume, and occupies less space.

4. Cooling supply: In the Chinese patent CN 102840711A, a freezer is used to freeze or refrigerate items, but the freezing function will greatly reduce the evaporation temperature of the system, causing system performance attenuation, and refrigeration means that there are multiple evaporation temperatures in a system, the system The difficulty of control is greatly improved, which is not conducive to the implementation of the plan. In the present invention, in order to ensure the efficiency of the heat pump system and simplify the system control, the short-term cold food preservation function of food is only realized through the refrigerator, and the freezing function is not involved.

In summary, compared with the Chinese patent CN 102840711A, the centralized cooling and heating system for canteens proposed by the present invention based on the principle of vapor compression heat pumps has a highly targeted application object, which is fully based on the actual conditions of canteens and restaurants. Considering the temperature range and timeliness of the heating and cooling requirements of the canteen, the stability of waste heat and waste cooling, and the oil fume pollution of the canteen, it has good stability and strong practicability.

Contents of the invention

The object of the present invention is to provide a canteen centralized cooling and heating system based on vapor compression heat pump technology that saves energy, reduces energy consumption, and improves heating and cooling efficiency in order to overcome the above-mentioned defects in the prior art.

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

A centralized cooling and heating system for canteens based on vapor compression heat pump technology, including:

Compressor: the inlet and outlet are respectively connected to the outdoor heat exchanger and the indoor condenser through the connecting pipe and the refrigerant three-way reversing valve;

Outdoor heat exchanger: There are two parts of connecting channels, one part is connected with the throttling device and compressor through the connecting pipe and the refrigerant three-way reversing valve, and the other part is connected with the DC fan and the exhaust port through the air connecting pipe;

Indoor condenser: There are two connecting channels, one part communicates with the compressor and the throttling device through the connecting pipe and the refrigerant three-way reversing valve, and the other part communicates with the water pump and the stratified hot water storage tank through the connecting pipe;

Canteen heating equipment: communicate with the outlet of the stratified hot water storage tank;

Canteen cooling equipment: connected with throttling device;

Oil fume purifier: through the flue gas connecting pipe, it is connected with the fume collecting hood and the casing heat exchanger;

Sleeve heat exchanger: There are two parts of connecting channels, one part is connected with the oil fume purifier and the smoke outlet through the flue gas connecting pipe, the other part is connected with the winter air inlet through the air connecting pipe, and the outlet is exchanged through the air tee. Directional valve and DC fan communicate with outdoor heat exchanger;

Refrigerator indoor evaporator: the inlet is connected to the indoor condenser through the refrigerant connecting pipe, throttling device, solenoid valve, refrigerant three-way reversing valve, and the outlet is connected to the compressor through the refrigerant connecting pipe, refrigerant three-way reversing valve Unicom;

Air conditioner indoor evaporator: There are two connecting channels, one part is connected with the throttling device and compressor respectively through the refrigerant connecting pipe and the refrigerant three-way reversing valve, and the other part is connected with the DC fan and the air outlet of the air conditioner through the air connecting pipe .

Preferably, the throttling device is an electronic expansion valve, the inlet is connected to the indoor condenser through the connecting pipe, and the outlet is respectively connected to the outdoor heat exchanger and the canteen cooling equipment through the connecting pipe and the refrigerant three-way reversing valve.

Preferably, the inlet of the stratified hot water storage tank is communicated with the indoor condenser through the hot water connecting pipe, and the outlet is communicated with the heating equipment of the canteen through the stratifier, floating water collector, electromagnetic valve, and water pump.

Preferably, the outdoor heat exchanger communicates with the summer air inlet through an air connecting pipe and an air three-way reversing valve.

Preferably, the DC blower communicates with the fresh air outlet of the air conditioner and the air supply outlet of the air conditioner through the air connecting pipe.

Preferably, the heating equipment in the canteen includes a food insulation platform, a food insulation box or floor heating.

More preferably, the main structure of the meal warming table includes a manual regulating valve, capillary heat pipe, check valve, table legs, heat preservation material, metal table plate, metal meal tray, electronic meter, and hot water connecting pipe. The manual regulating valve communicates with the water pump and the capillary heat pipe through the hot water connecting pipe; The connecting pipe is in communication with the check valve, and placed evenly under the metal table, and the parts that are not in contact with the metal table are wrapped with thermal insulation materials (such as foam materials); the inlet of the check valve is connected by hot water The tube communicates with the capillary heat pipe, and the outlet communicates with the layered hot water storage tank through the hot water connecting pipe; the metal meal tray and the electronic price counter are placed on the metal table.

More preferably, the main structure of the food incubator includes a hot water distribution pipe, a solenoid valve, a metal carrier plate, a number of capillary heat conducting pipes, an insulating material (such as a foam material), a check valve, a hot water collecting pipe, and a hot water connecting pipe. . The inlet of the electromagnetic valve communicates with the water pump and the layered hot water storage tank through the hot water connecting pipe, and the outlet communicates with the capillary heat conducting tube in the incubator through the hot water distribution pipe; The solenoid valve and the check valve are communicated and evenly placed under the metal carrier plate; the check valve is communicated with the water pump and the capillary heat pipe through the hot water connecting pipe; the inlet of the check valve is connected with the hot water connecting pipe The capillary heat pipe is connected, and the outlet is connected with the layered hot water storage tank after being collected by the hot water collection pipe.

Preferably, the casing heat exchanger recovers waste heat of high-temperature flue gas.

In the present invention, the temperature and pressure of the refrigerant rise after being compressed by the compressor to form high-temperature and high-pressure steam. When the high-temperature and high-pressure working medium vapor is condensed into a liquid through the condenser, a large amount of latent heat of liquefaction is released, which can be used for winter meal insulation and indoor heating. In order to ensure food safety and reduce the amount of refrigerant used, a heat transfer medium is used to transfer heat (water is used as an example in the present invention). Through the throttling effect of the throttling device, the refrigerant becomes a low-temperature and low-pressure liquid, which is vaporized in the evaporator and absorbs a large amount of latent heat of vaporization. In summer, it can be used for cooling and keeping fresh vegetables, fruits and meals, and for cooling in restaurants. Through such functional integration and collocation, one machine with multiple functions and effective operation throughout the year is realized, which shortens the system's return on investment cycle.

In order to improve the heating efficiency in winter, the system has been specially designed as follows. On the basis of the chimney, a casing heat exchanger is designed to recover the waste heat of the flue gas, recover the heat in the high-temperature flue gas, and preheat the outdoor air passing through the evaporator, so as to increase the evaporation temperature of the system and avoid oil pollution from blocking the outdoor heat exchange At the same time, during the heat exchange process of the high-temperature flue gas, the oil of the flue gas is condensed and collected, which reduces the pollution of the atmosphere by the kitchen activities. In addition, the traditional food insulation table and food insulation box have been redesigned to replace traditional steam heating and use capillary heat exchangers. The capillary heat exchanger has the advantages of large heat exchange area, small heat exchange temperature difference, high heat exchange efficiency, and is suitable for passive heating and cooling systems. In the present invention, capillary heat exchangers are laid under the food insulation platform and the partition board of the food insulation box, which increases the heat exchange area, reduces the heat exchange temperature difference, and indirectly reduces the condensation temperature. As the evaporation temperature and condensation temperature rise and fall, the heating efficiency of the system has been significantly improved. .

The invention applies the vapor compression heat pump technology to the heating and cooling supply of the kitchen. Vapor compression heat pump technology can convert low-grade thermal energy in waste heat into higher temperature thermal energy and release it to the required space. At the same time, the heat pump can be used not only as heating and heating equipment, but also as cooling and cooling equipment. Under winter working conditions, the temperature required for food insulation and heating (floor heating) in the canteen kitchen is not much different, most of which require the water temperature to be in the range of 55–65°C; There is not much difference in the temperature required for freshness preservation, and most of them require the water temperature to be within the range of 5-12°C. This invention applies the heat pump technology to the comprehensive thermal management system of the canteen, which can meet different working conditions and different types of cooling and heating requirements at the same time , while reducing the configuration of other equipment in the canteen, it also reduces the initial investment cost and has good economy. It has the following advantages:

1) Vapor compression heat pump technology is adopted, but the working efficiency of the vapor compression heat pump system is low in winter low temperature environment (heating COP is lower than 2). The flue gas waste heat recovery tube-and-tube heat exchanger is used to preheat the air to 25°C through the kitchen exhaust, and then send it to the evaporator for heat exchange, which can significantly increase the heat production of the system and meet the heating demand of the canteen in winter. Central heating system is adopted in winter, which can greatly improve heating efficiency;

2) Capillary heat exchangers are used in food insulation boards and boxes, which greatly reduces the heat transfer temperature difference, reduces heat loss, improves the heat transfer efficiency of insulation boards and boxes, and reduces system energy consumption;

3) In summer working conditions, the central cooling system is adopted to meet the cooling demand of the canteen. The system has high efficiency and prevents the refrigerator in the storage room from dissipating heat to the room;

4) It realizes one machine with multiple functions, avoids the use of too many other cooling and heating equipment, and saves the occupied area. At the same time, the system can run for a long time throughout the year and the investment return period is short.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Figure 2 is a schematic diagram of the front view of the casing heat exchanger;

Fig. 3 is a top view structural schematic diagram of a sleeve-and-tube heat exchanger;

Fig. 4 is the structural representation of the food insulation platform;

Fig. 5 is a structural schematic diagram of the food incubator.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example

A central cooling and heating system for canteens based on vapor compression heat pump technology, its structure is shown in Figure 1, mainly including compressor 1, outdoor heat exchanger 11, indoor condenser 5, canteen heating equipment, canteen cooling equipment , Oil fume purifier 78, casing heat exchanger 84, refrigerated box indoor evaporator 24, air-conditioning indoor evaporator 31, etc.

The inlet and outlet of the compressor 1 are respectively connected with the outdoor heat exchanger 11 and the indoor condenser 5 through the connecting pipe and the refrigerant three-way reversing valve; The three-way reversing valve of the agent is connected with the throttling device (which can be an electronic expansion valve) and the compressor 1, and the other part is connected with the DC fan and the exhaust port through the air connecting pipe; the indoor condenser 5 is provided with two connecting channels, one part The connecting pipe and the refrigerant three-way reversing valve are connected to the compressor 1 and the throttling device, and the other part is connected to the water pump and the stratified hot water storage tank 35 through the connecting pipe; the canteen heating equipment is connected to the stratified hot water storage tank 35 The outlet of the canteen is connected; the canteen cooling equipment is connected with the throttling device; the oil fume purifier 78 is connected with the smoke collection hood and the casing heat exchanger 84 through the flue gas connecting pipe; the casing heat exchanger 84 is provided with two connecting channels One part is connected with the oil fume purifier and the smoke outlet through the flue gas connecting pipe, the other part is connected with the winter air inlet through the air connecting pipe, and the outlet is connected with the outdoor heat exchanger through the air three-way reversing valve and the DC fan; The inlet of the evaporator 24 in the box is connected to the indoor condenser 5 through the refrigerant connecting pipe, throttling device, solenoid valve, and refrigerant three-way reversing valve, and the outlet is connected to the compressor through the refrigerant connecting pipe, the refrigerant three-way reversing valve 1 Unicom; the evaporator 31 in the air-conditioning room is provided with two parts of connecting channels, one part is respectively connected with the throttling device and the compressor 1 through the refrigerant connecting pipe and the refrigerant three-way reversing valve, and the other part is connected with the DC fan, The air-conditioning outlet is connected.

In winter working conditions, the refrigerant is first compressed by the compressor 1, the temperature rises and the pressure increases, and then enters the indoor condenser 5 through the refrigerant connecting pipe 2, the refrigerant three-way reversing valve 3, and the refrigerant connecting pipe 4. The condensed refrigerant passes through the throttling device 7, the temperature and pressure drop, and then passes through the refrigerant connecting pipe 8, the refrigerant three-way reversing valve 9, the refrigerant connecting pipe 10, and enters the outdoor heat exchanger 11 and the preheated air Heat exchange, gasification. The vaporized refrigerant is sucked into the compressor 1 through the refrigerant connecting pipe 12, the refrigerant connecting pipe 13, the refrigerant three-way reversing valve 14, and the refrigerant connecting pipe 15 to complete the heat pump cycle. After being heated by the indoor condenser 5, the heat-carrying medium (water in this embodiment) enters the layered hot water storage tank 35 through the hot water connecting pipe 34 and the stratifier 36, where it is stored in layers according to the temperature gradient. After the hot water is taken out by the floating water fetcher 43, through the hot water connecting pipe 44, it is divided into three pipelines of the canteen heating in winter, the food insulation box and the food insulation board of the canteen. In the heating pipeline of the canteen in winter, the hot water taken out by the floating water fetcher 43 passes through the hot water connecting pipe 44, the hot water connecting pipe 47, the solenoid valve 48, the hot water connecting pipe 49, the hot water connecting pipe 50, the water pump 51, and the hot water connecting pipe. The pipe 52 is fed into the heating equipment 53 (such as floor heating), which is used for heating the dining room and the kitchen to maintain the thermal comfort of the environment. The cooled water can enter the hot water connecting pipe 54, the hot water connecting pipe 55, the check valve 56, the hot water connecting pipe 57, enter the hot water connecting pipe 75, or pass through the hot water connecting pipe 54, the hot water connecting pipe 58 , the temperature regulating valve 59, the hot water connection pipe 60, mixes with the hot water from the hot water connection pipe 49, and regulates the water inlet temperature of the heating equipment 53. The check valve 56 is used to prevent the cooled hot water from entering from other circuits. The temperature regulating valve 59 controls the return flow rate according to the indoor temperature. The pipeline of the food insulation box, the hot water taken out by the floating water fetcher 43 passes through the hot water connecting pipe 44, the hot water connecting pipe 45, the hot water connecting pipe 61, the water pump 62, the hot water connecting pipe 63, the solenoid valve 64, and the connecting pipe 65 Enter the meal insulation box 66. Figure 5 takes a four-layer food incubator as an example. The hot water passes through the hot water distribution pipe 109 and then enters the hot water connection pipe 110 of each layer, the solenoid valve 111, and the hot water connection pipe 112, and finally reaches the bottom of the metal loading plate 113. Some capillary heat pipes 114, after heating and insulating the food on the metal carrier plate 113 and the food in the food incubator 66, the hot water is cooled. The insulation box is wrapped by insulation material (such as foam material) 115 . The cooled water enters the hot water connecting pipe 75 through the hot water connecting pipe 116, the check valve 117, the hot water connecting pipe 118, and the hot water collecting pipe 119 through the hot water connecting pipe 67 and the hot water connecting pipe 74. Check valve 117 is used to prevent from other loops, and the cooled hot water strings into the food insulation box 66. Solenoid valve 111 is used for controlling the opening and closing of each layer, and regulates the temperature in the incubator. The food insulation board pipeline, the hot water taken out by the floating water collector 43 passes through the hot water connecting pipe 44, the hot water connecting pipe 45, the hot water connecting pipe 46, the water pump 68, the hot water connecting pipe 69, the solenoid valve 70, and the connecting pipe 71 Enter the meal warming station 72. In the system, multiple food heat preservation platforms can be connected in parallel. Fig. 4 takes a food heat preservation platform as an example, hot water passes through a manual regulating valve 99, and hot water connection pipes 100 enter some capillary heat pipes 101 laid under the metal table plate 106. A plurality of capillary heat pipes 101 form a capillary heat exchanger, which transfers heat to the food through the metal table plate 106 and the metal food tray 107, so as to realize heating and heat preservation of the food. The cooled water enters the hot water connecting pipe 75 through the hot water connecting pipe 102, the check valve 103, the hot water connecting pipe 73, and the hot water connecting pipe 74. The manual regulating valve is used to manually switch the heat preservation platform and adjust the temperature of the heat preservation platform. The warming platform is supported by table legs 104 . The capillary heat exchanger is surrounded by thermal insulation material 105, so that more heat can be transferred to the food and the loss of heat can be reduced. The metal meal tray 107 is placed on the metal table board 106 for holding food. Electronic meter 108 is installed on the heat preservation platform and is used to display the price of meals. The water at the bottom of the layered heat storage that flows out through the hot water connecting pipe 37 will be mixed with the water from the hot water connecting pipe 75 in the hot water connecting pipe 38, and through the electromagnetic valve 39, the hot water connecting pipe 40, the water pump 41, and the heat The water connection pipe 42 is sent back to the indoor condenser 5 for reheating. The opening and closing of the electromagnetic valve 39 is consistent with the switch of the water pump 41, the opening and closing of the electromagnetic valve 48 is consistent with the switch of the water pump 51, the opening and closing of the electromagnetic valve 64 is consistent with the switch of the water pump 62, and the opening and closing of the electromagnetic valve 70 is consistent with the switch of the water pump 68. Keep equipment safe. When the solenoid valve 39 was closed, the water from the hot water connecting pipe 75 entered the bottom of the stratified hot water storage tank 35 through the hot water connecting pipe 37 . Layered hot water storage tank 35 has the function of storing hot water and expansion tank. The exhaust smoke from the kitchen is sucked by the smoke collecting hood 76, and sent to the oil fume purifier 78 for filtration through the smoke connecting pipe 77. The filtered flue gas passes through the flue gas connecting pipe 79 and enters the sleeve-type heat exchanger 84 to preheat the air sent into the evaporator before being cooled. The cooled flue gas is discharged into the atmosphere through the flue gas connecting pipe 80 (the filter screen in the pipe is optional for further filtering the flue gas), and through the flue gas outlet 81 . The outdoor air is inhaled from the winter air inlet 82, and enters the casing heat exchanger 84 through the air connection pipe 83 (the filter screen in the pipe is optional for preliminary air filtration). The structure of the casing heat exchanger 84 is shown in Figure 2-3, and its main function is to recover the waste heat of the high-temperature flue gas. After the air is preheated in the casing heat exchanger, it enters the outdoor heat exchanger 11 through the air connecting pipe 85, the air three-way reversing valve 86, the air connecting pipe 87, the DC blower 88, and the air connecting pipe 89. The air exchanges heat with the refrigerant in the outdoor heat exchanger 11, and after cooling, passes through the air connecting pipe 90, enters the exhaust port 91, and is discharged into the atmosphere.

In summer working conditions, the refrigerant is first compressed by the compressor 1, the temperature rises and the pressure increases, and then enters the outdoor heat exchange through the refrigerant connecting pipe 2, the refrigerant three-way reversing valve 3, the refrigerant connecting pipe 16, and the refrigerant connecting pipe 12 Device 11. The condensed refrigerant is divided into two pipelines, the fresh-keeping of kitchen ingredients in the canteen and the air-conditioning cooling in summer, through the refrigerant connecting pipe 10, the refrigerant three-way reversing valve 9, and the refrigerant connecting pipe 17. Fresh food branch in the kitchen, the refrigerant passes through the refrigerant connecting pipe 17, the refrigerant connecting pipe 18, the solenoid valve 19, the refrigerant connecting pipe 20, the throttling device (such as an electronic expansion valve) 21, and the refrigeration connecting pipe 22, and enters the refrigerator The indoor evaporator 24 of 23 exchanges heat with the air in the refrigerator, and the refrigerant evaporates and absorbs heat to vaporize. The vaporized refrigerant enters the refrigerant connecting pipe 33 through the refrigerant connecting pipe 25 . Cooling branch circuit of air conditioner in summer, refrigerant passes through refrigerant connecting pipe 17, refrigerant connecting pipe 26, solenoid valve 27, refrigerant connecting pipe 28, throttling device (such as electronic expansion valve) 29, refrigeration connecting pipe 30, and enters the air conditioner The indoor evaporator 31 exchanges heat with the outdoor air brought in through the fresh air outlet 94, the air connecting pipe 95, and the DC fan 96, and the air with reduced temperature is sent through the air connecting pipe 97 to the area that needs to be cooled by the air conditioner outlet 98 , the refrigerant evaporated through the heat exchange of the evaporator 31 in the air-conditioning room absorbs heat and vaporizes, and the vaporized refrigerant enters the refrigerant connecting pipe 33 through the refrigerant connecting pipe 32 . The refrigerant flowing into the refrigerant connecting pipe 33 passes through the refrigerant three-way reversing valve 14, and the refrigerant connecting pipe 15 enters the compressor 1 to meet the cooling demand of the canteen in summer.

The canteen centralized cooling and heating system based on vapor compression heat pump technology can be freely combined with one or more canteen heating and cooling equipment described in the present invention according to actual needs. A central heating system that uses vapor compression heat pump technology and uses the tube-in-tube heat exchanger described in the present invention to recover waste heat from flue gas in winter to provide heat for one or more canteen heating equipment, or at the same time it can be used in summer Centralized cooling and heating systems for canteens, in which one or more types of canteen cooling equipment provide cooling capacity, all belong to the protection scope of the present invention.

After system simulation verification, under the conditions of flue exhaust temperature 30°C (evaporation temperature 25°C) and hot water supply temperature 60°C (condensation temperature 70°C), the heating efficiency of the system is 3.53 (heating power/compressor power ). If a cafeteria of Tongji University undergoes energy-saving renovation, only the function of the meal warmer can save 79% of electricity consumption throughout the year (the annual electricity consumption before the renovation was 58,000 kWh), and the annual operating cost can be saved by 43,000 yuan. , so the present invention possesses broad market prospect.

The above descriptions are only preferred implementation methods of the present invention, and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above implementation methods according to the technical essence of the present invention belong to the protection scope of the present invention.

Claims (8)

1., based on a dining room central cooling heating system for vapor compression heat pump technology, it is characterized in that, this system comprises:

Compressor: entrance and outlet are respectively through tube connector and cold-producing medium three-way diverter valve and outdoor heat exchanger and indoor condenser UNICOM;

Outdoor heat exchanger: be provided with two parts interface channel, a part is through tube connector and cold-producing medium three-way diverter valve and throttling arrangement, compressor UNICOM, and another part is through air tube connector and DC fan and exhaust outlet UNICOM;

Indoor condenser: be provided with two parts interface channel, a part is through tube connector and cold-producing medium three-way diverter valve and compressor, throttling arrangement UNICOM, and another part is through tube connector and water pump, layering heat storage water tank UNICOM;

Dining room heating equipment: with the outlet UNICOM of layering heat storage water tank;

Dining room cooling equipment: with throttling arrangement UNICOM;

Cooking fume remover: through flue gas tube connector and exhaust fume collecting hood and double pipe heat exchanger UNICOM;

Double pipe heat exchanger: be provided with two parts interface channel, a part is through flue gas tube connector and cooking fume remover, exhaust opening UNICOM, the entrance of another part, through air tube connector and winter air entrance UNICOM, exports through air three-way diverter valve and DC fan and outdoor heat exchanger UNICOM;

Refrigerating box indoor evaporator: entrance through connecting refrigerant lines, throttling arrangement, magnetic valve, cold-producing medium three-way diverter valve and indoor condenser UNICOM, outlet via refrigerant tube connector, cold-producing medium three-way diverter valve and compressor UNICOM;

Air-conditioning indoor evaporator: be provided with two parts interface channel, a part through connecting refrigerant lines, cold-producing medium three-way diverter valve respectively with throttling arrangement, compressor UNICOM, another part is through air tube connector and blower fan, air conditioner air outlet UNICOM.

2. a kind of dining room central cooling heating system based on vapor compression heat pump technology according to claim 1, it is characterized in that, the entrance of described throttling arrangement is connected with indoor condenser through tube connector, export through tube connector and cold-producing medium three-way diverter valve respectively at outdoor heat exchanger and dining room cooling equipment UNICOM.

3. a kind of dining room central cooling heating system based on vapor compression heat pump technology according to claim 1, it is characterized in that, described layering heat storage water tank entrance, through hot water tube connector and indoor condenser UNICOM, exports through quantizer, the device for fetching water that swims, magnetic valve, water pump and dining room heating equipment UNICOM.

4. a kind of dining room central cooling heating system based on vapor compression heat pump technology according to claim 1, is characterized in that, described outdoor heat exchanger through air tube connector, air three-way diverter valve and summer air intake UNICOM.

5. a kind of dining room central cooling heating system based on vapor compression heat pump technology according to claim 1, is characterized in that, described DC fan is through air tube connector and air-conditioner fresh air inlet, air conditioner air outlet UNICOM.

6. a kind of dining room central cooling heating system based on vapor compression heat pump technology according to claim 1 or 3, it is characterized in that, described dining room heating equipment comprises thermal insulation carrier for food, meal insulation case or floor heating, and described dining room cooling equipment comprises refrigerating box or refrigeration air-conditioner.

7. a kind of dining room central cooling heating system based on vapor compression heat pump technology according to claim 6, is characterized in that, capillary heat exchanger is laid in the below of described thermal insulation carrier for food table and the below of meal insulation case metal support board.

8. a kind of dining room central cooling heating system based on vapor compression heat pump technology according to claim 1, is characterized in that, described double pipe heat exchanger reclaims the waste heat of high-temperature flue gas.