Pork is going crazy, I want to raise pigs! How to warm the air in the pig farm?With the promotion of air source heat pump products, its application fields have gradually expanded, not only providing people with comfortable hot water, heating, cooling and other needs, but also being well used in the animal husbandry industry. Leomon believes that the application of air source heat pump floor heating to pig farms is one of the potential markets in the future. Next, I will share with you some experiences of air source heat pump heating in pig farms.
Now pig farms are actually all over the country. I believe that there are many ways to heat pig farms. There are coal stoves, fire walls, pits, electric air conditioners, plastic greenhouses, hot fans, infrared rays, biogas, and Electric floor heating, and finally water floor heating. Let's talk about the advantages and disadvantages of these heating methods for different situations.
The first is to use a coal stove to heat the pig farm. Ordinary coal-fired heating is mostly used in cold areas with abundant coal, especially in the north. Its advantages are that the heating speed is relatively fast, the use is relatively convenient, and the coal price is relatively cheap, and it can be installed and used at any time. Its disadvantage is that carbon dioxide and other substances are generated during the combustion process. The carbon dioxide, sulfur monoxide and other substances produced will affect the respiratory tract infections of pigs, and the impact on pigs is very large. It will be prone to respiratory tract infections, coughing and other phenomena, resulting in a very high incidence of pigs. Many pig farm owners are very aware of this shortcoming. In southern pig farm owners, they basically do not use coal to heat the pig farm.
The second is to use a fire wall to heat the pigs. What does the fire wall mean? I believe that everyone should know less about this, and I find it incredible. This method is often used in colder areas in the north. The so-called fire wall is built with bricks near the wall of the pig house to form a fire path. The hot fire path is used to heat the pig farm through the wall and keep it warm. The performance is relatively good, and there are many shortcomings, that is, the labor cost is relatively high. The second shortcoming is that the amount of consumables is very large. Because it is indirect heating, the amount of consumables and coal consumption is very high, and manual labor is required to provide him. Adding firewood, for example, in the middle of the night, someone needs to get up to add firewood to add firewood, which is tantamount to raising a worker, directly leading to an increase in the cost of use.
The third method is to use a pit for heating, which is to design the underside of the pig house as a fire path, which is similar to a fire wall. Using firewood and coal to heat the pit is similar to the way of burning pits in the north, and the cost is relatively high.
The fourth type is air-conditioning and heating. This method is similar to that used in our homes. It is equivalent to using air-conditioning to heat the pigs. In this way, the air plate will be polluted by the pig farm and the failure rate is relatively high. There are basically few people. Only used by individual local bosses, generally not as the main product, only for emergency use.
The fifth type is a hot air blower, which blows the heat of the boiler to the pig house through the blower to heat the pigs. This method is very good, but the use cost is also very high, but it is cheaper than electricity and air conditioning. Many people also use biogas for heating, and then blow the heat into the pig house through fans.
I once saw a pig farm in the county town. They use biogas for heating, and use biogas to boil hot water and circulate the hot water to the pipes to heat the pigs. However, their floor heating pipes are not the commonly used PPR pipes but galvanized pipes, but biogas heating What is the shortcoming of it? It is easy to produce a lot of ammonia, which can cause respiratory infections in pigs, which is not conducive to the healthy growth of pigs.
The sixth is to use infrared lamps or Yuba lamps. Infrared lamps are actually bulbs. This method has a high utilization rate in Fujian, at least 50%-60% of the market share. This heating method has relatively low purchase costs and is very cheap. But there are still many shortcomings, and only partial heating.
Because it is hung on the top of the pig house, the head is very hot, but the ground surface is very cold. It feels like hot and cold, which can easily lead to a high incidence of pigs, causing colds and coughs. Moreover, products like Yuba have relatively high wattage, high power consumption, and are prone to damage. If they are used for a long time in winter, basically, dozens of bulbs have to be replaced every winter, and the service life is not long.
The seventh type is heating cables, which are more common in the market. The pig farm will use cement mortar concrete to make these cables into a piece of precast slab measuring 1 meter by 2 meters, which has been widely used in recent years. What are the disadvantages of this method?
First of all, transportation is more troublesome. It needs to be transported piece by piece. Second, because of the use of electricity, the use cost is also very high. Third, the service life is relatively short, which is about 5 years of service life. Fourth, it is easy to break. Pigs will dig the ground for a while after they grow up, and it is easy to dig out this heating cable.
The Eighth, when talking about the advantages of air source heat pumps, let’s talk about the disadvantages first. The biggest disadvantage of air source heat pumps is that the initial investment cost is relatively high. Many pig farm owners are unwilling to invest so much at the beginning. Presumably, the initial investment will be much more than the previous methods. So how do we turn the disadvantages of air source heat pumps into advantages?
The advantages of air-source heat pumps include power saving. Through the test, we found that the power consumption of the air source heat pump is 70% less than that of the electric product. When it comes to saving 70% of electricity, we will come up with data. For example, for a floor heating of 100 square meters, the power consumption is about 40-50 kilowatt-hours a day in winter, and about 1,000 kilowatt-hours a month, which is 700- Around 800 yuan. However, compared with the cost of electric heating, at least RMB 2,000 is saved a month, and the cost of electric heating is at least RMB 3,000 a month.
In Fujian, China, the pig farm must be heated for at least three or four months in a winter. According to the above algorithm, it can save 2000-3000 yuan a month, so it can save about 10,000 yuan in a winter. In this way, we calculated with the owner of the pig farm to explain the benefits of the air source heat pump, and the initial investment cost can be saved later. Although the initial investment is a bit large, the return on use in the later period is high. Our air energy products have a longer service life than electric heating, which can last from 7 to 10 years.
The second advantage of the air source heat pump is that it generates heat evenly. Because it is laid on the floor heating pipes and laid down in circles, the heat distribution is very uniform, which can improve the comfort of pigs. The more comfortable the pig, the higher the growth rate, and the more willing the farm owner is to invest. The market for pigs is not so good now, and the retail price is 28~35 yuan per catty. The higher the growth rate of pigs, the more profitable pig farm owners can make, so they are still interested in air source heat pump floor heating. They feel that the better they treat the pigs, the more they can make money.
The third benefit of air source heat pump heating for pig farms is intelligent. It does not require human management at all. You only need to adjust the temperature. Unless the equipment fails, otherwise you do not need to consume too much manpower and material resources, which is virtually saved. A labor cost, and the equipment is relatively stable. Unlike light bulbs, the failure rate is relatively high. For example, if the bulb is broken in the middle of the night, pigs may catch a cold and cough if they are not found in time, which increases the incidence of pigs and causes losses.
1. Pig farm zone and heat load selection
Question: What are the specific requirements for temperature in the "birth area", "small pig nursery area", and "medium pig area"? How do they calculate the unit heat load? Each square meter is based on the number of W Calculate, how to select the unit?
A: I believe that everyone is not very clear about the structure of the pig farm. What areas are the pig farms divided into? Let's start with the farrowing area of the sow. When the sow is about to give birth to a piglet, there will be a special farrowing area. Put the sow in the farrowing area and there is a small bed next to it. Put it directly on the small bed. This kind of small bed also needs to be insulated, but if air can be used as the delivery bed area, because the area is too small, it is not suitable for making it.
Because the area of this farrowing area is very small, generally speaking, light bulbs are used for heating, because the sows don’t need to move, they just lie there anyway, so it is not realistic to use air source heat pumps for floor heating with a small area, too. It’s not easy to do when it’s small, and the cost is very high.
What is the piglet nursery area? It points out that the raw piglets are weaned and placed in another area. At this time, the piglets can be fed with feed. These piglet nursery areas are the places where air source heat pump heating is most needed, and they are also the most suitable place for air source heat pumps. Because piglets are weaned, their immunity will decrease and the incidence rate will increase. At this time, a certain amount of warmth is needed.
There are also "middle pig area" and "big pig area". Normal pigs can be separated into "middle pig area" and "large pig area" when they reach 70 or 80 kilograms. At this time, their immunity is already very high. They need to live together with the piglets, and they can be sold longer. In Fujian, China, there is basically no need to heat them separately.
Then we focus on the floor heating design of the piglet conservation area. So how to calculate the heat load of this block? When the temperature is 0℃, the lowest temperature in Fujian is 0℃ under normal conditions. We directly calculate it according to 150W per square meter, for example, an area of 100 square meters. It is the total heating capacity of 15kW, and the unit selection is based on the parameters of the unit based on the total heating capacity. The main engine of the unit 5p or 6p is more suitable.
If the temperature in some areas is from 0°C to minus 10°C, the heating heat load must be calculated relatively speaking. The heating unit heat load should be at least 200W per square meter, and the floor heating of 100 square meters should be 20kW. If the minimum temperature is Between minus 10°C and minus 20°C, the unit heat load must be at least 300-350W per square meter, so a floor heating of 100 square meters requires 30 kilowatts of heating capacity.
Minimum ambient temperature Heat load reference area
0℃ 150w/㎡ China South China, East China, Guangdong, Guangxi, Fujian
-10—0℃ 200w/㎡ China Jiangsu, Henan, Zhejiang, Anhui
-20— -10℃ 300w/㎡ China Xinjiang, Gansu, Heilongjiang
Many materials of our air source heat pump manufacturers’ products will be marked, such as the rated power of the 5p and 6p units and the rated heating capacity, but don’t be "pitted" by the content of these materials. Some data are based on the heating capacity of the ambient temperature of 20℃. If the unit is configured according to this heating capacity, it is not accurate. We must select the unit according to the heating capacity obtained at the dry bulb temperature of 7℃. We must pay attention to this problem. Don't be pitted by the parameters on the air source heat pump manufacturer's data.
2. Difficulties in the selection of different farm structures
Question: In terms of heating design, pig farms will encounter large heights, large spans, large doors and windows, and large heat transfer coefficients of thermal insulation structures, resulting in high heat loads during heating. What problems should be paid attention to when calculating heat loads.
Answer: Many air source heat pump owners are very afraid of heating pig farms, because pig farms have a relatively large space. It is much more difficult to keep the room temperature above 20°C than ordinary residential houses, and the heat preservation performance of pig farms is not good. Some pig farms are directly covered with roll curtain cloth, and asbestos tiles are placed on the roof. The heat preservation performance can be imagined, which increases the difficulty of using air to warm the floor. This kind of scene is very common in pig farms in Fujian, China, and it is very simple to do. If air source heat pumps are used for floor heating, it is not easy to achieve a room temperature of more than 20 degrees.
These two pictures are a case we made. The first picture is what I just said and put down the roll curtain cloth to heat the pig farm. In this way, the heat loss is very fast, so when the host is equipped, The heat of each square meter must be increased, the host must be large, and each square meter must be increased by 10W-20W. For example, if the unit heat load is calculated at 150W, it will be increased to 170W at this time.
In the second picture, the pig farm is made of windows. This insulation effect is much better than that in the first picture. In the second picture, the pig farm owner will also make insulation boards, which will be suspended with baffles. The heat preservation effect is much better. At this time, the heat load calculation can be based on the 150W unit selection at the lowest temperature of 0°C. There is no problem. The floor temperature can reach 20-30°C.
The air source heat pump control system we make is based on the floor temperature. There is no way to control the host by the air temperature, but the floor temperature. We use heated water, for example, to set a 40°C water supply temperature to circulate to the floor heating pipe. At this time, the floor temperature can reach 28°C, 29°C or even 30°C without any problem.
Therefore, many bosses use the ambient temperature as the temperature controlled by the system. This is not feasible. If the ambient temperature is used as the control switch, the heat loss of the system is very large, and the unit is working at full load, which consumes a lot of power. Therefore, we need to understand the characteristics of the pig farm. Only the floor temperature is required to reach 28°C. The requirement for the ambient temperature is not high. It does not matter if it is only a few 10°C, because the pig is lying on the floor and the piglet is comfortable on the floor. Up! So this control system must be paid attention to.
3. both heat preservation and ventilation
Question: Requirements for the building structure of the nursery.
Answer: The requirements of the nursery house must be made according to our requirements. The windows and ceilings must be made of insulation boards. This building structure must be made according to our requirements. Otherwise, the heat loss is too great. The second pig farm I made is for comparison. Large, there are 10,000 pigs in total. We just took their first column to do it now. Normally, the heating area of a column is 100 square meters.
Pig farms are divided into pens. We require that in places where the weather is very cold, between pens and pens, they should be covered with plates to prevent heat from dissipating upward, and they should be opened from time to time for ventilation, otherwise this Too heavy ammonia gas can easily cause respiratory infections in pigs.
Question: How to ensure the heat preservation effect during the end construction, but also pay attention to ventilation, doors and windows, ceilings, etc. What should be paid attention to?
Answer: The problem is to have heat preservation and ventilation. Otherwise, the ammonia gas is too heavy. We have to install an exhaust system on the roof of the pig farm. We will regularly exhaust the ammonia according to the temperature of the pig farm. The owner of this pig farm knows that they also automatically emit ammonia. In order to heat the floor, we must exhaust the air. Like the pig farm in the second picture above, we use a spiral system on the roof to exhaust the air.
4. the uniformity and constant temperature
Question: How can we achieve uniform heat generation during construction at the end?
Answer: The length of the pig farm is no more than 20 meters. The pig farm within 20 meters adopts the linear pipe laying method. If it exceeds 20 meters and is within 40 meters, we adopt another pipe laying method. The host is placed in the middle and the two sides are back. Type of pipe laying.
A project like this is to make a return-shaped pipe laying. The length of the pig farm is more than 20 meters and less than 40 meters. The air source heat pump host is placed in the middle, and the heat is relatively even when running on both sides of the return shape. The lift is not that long. This has the best effect, and it won’t be hot in the front and cold in the back.
Question: How is the supply/return water temperature set, and what methods are used to ensure a constant temperature in different "pig zones"?
Answer: This question has been mentioned just now, it must be calculated based on the floor temperature. We must debug the equipment. For example, when the temperature of the water supply is 40°C, see if the floor temperature reaches 28°C. If it can’t, the temperature will continue to increase. Then the temperature should be adjusted to 45°C and 50°C. Normally it won’t. Above 50°C, the floor temperature can reach 28°C or 29°C.
Some pig farms are partitioned. For example, as long as the left side is open, and the right side is not open, then this needs to be controlled by partition. This is the same as our home floor heating, which is controlled by an electric actuator and an additional temperature control panel. , Which group needs to be opened, but usually, it is most appropriate to divide them into two columns without dividing them so finely. Because some pigs come out of different batches, the required temperature is different. For example, the temperature on the left side only needs to be 28-29°C, but if it comes out there, it may need 30°C. Therefore, only the left and right columns are the most suitable. Up.
Finally, the thickness of the cement mortar backfill should be made as thick as possible to improve the heat storage capacity and make it thicker to prevent back planing of pigs.
Leomon is a professional manufacturer of air source heat pumps. If you have any needs, the pig farm needs geothermal transformation. Please contact us. We will give you professional advice.